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Colorectal Cancer Treatment Options
Available in Canada

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The type (colon and/or rectal), location, stage of your cancer, the biomarkers expressed in your tumour and your general health will determine which colorectal cancer treatment is best for you. Understanding your treatment options is important so that you can participate in making informed decisions together with your doctors.

Planning cancer treatment can take time. It is always recommended to get a second or even third opinion before embarking on any treatment plan. Below are the most common treatment options currently available in Canada for colorectal cancer.

Important terms to know:

First line therapy: the first treatment given for a disease.

Second line therapy: Treatment after first-line therapy has failed, stopped working, or has side effects that are not tolerated.

Third line therapy: treatment that is given when both first-line and second-line therapy don’t work or stop working.

Fight Colorectal Cancer “Guide in the Fight” Digital Book
NCCN Colon Cancer Guide
NCCN Rectal Cancer Guide

Treatment options and healthy lifestyle for early stage colorectal cancer

Treatment options for recurrent or advanced colorectal cancer


There are different approaches to colorectal cancer surgery depending on whether you have colon or rectal cancer. If you have been diagnosed with colon cancer, the first treatment may be surgery to remove the primary tumour. In advanced colon cancer, you may begin your treatment with chemotherapy and/or targeted therapy before surgery.

If you have been diagnosed with rectal cancer, you may be treated with chemotherapy, targeted therapy and/or radiation prior to surgery. You may also decide together with your medical team not to proceed with any surgery and instead, watch-and-wait.


The majority of colorectal cancers begin as a growth on the inner lining of the colon or rectum known as a polyp. Some polyps may develop into cancer over time (usually many years), but not all polyps become cancerous. During a colonoscopy, polyps are removed and sent to pathology for testing to determine the cancer stage. Colorectal cancer in these stages is contained to the original location and has not spread to neighbouring tissues such as the lymph nodes.

When polyps are detected with Stage 0 and some Stage I colon or rectal cancers, local removal of the polyp during a colonoscopy avoids higher-risk abdominal surgery. This is called a polypectomy.

See our Foods that Fight Cancer recommendations to understand how diet can play a role in reducing the recurrence of polyps.

Local excision

Local excision is a surgical procedure that is also done during a colonoscopy. It is generally reserved for early, small stage I rectal cancers which, after testing, do not show a high risk of spreading or coming back (recurrence) During a local excision, the polyp as well as a small amount of surrounding tissues are removed and sent to pathology for further testing.

If the polyp is completely removed during a colonoscopy and is found through testing to have no cancer cells at its margins, no further treatment may be needed. If the polyp:

  • is found to contain a high grade cancer,

  • was removed in many pieces, making it harder to see if cancer cells were present at its margins,

  • or if cancer cells were found at the margins of the polyp, further surgery may be required.

Additional treatment such as chemotherapy, and/or radiation therapy in the case of rectal cancer, usually isn’t required after polypectomy or local excision unless it is discovered that the cancer is more advanced than was believed before surgery. In this case, a combination of chemotherapy, and/or radiation therapy in the case of rectal cancer, may be required.

Transanal resection or transanal endoscopic microsurgery (TEM)

In some stage I rectal cancers, transanal resection or transanal endoscopic microsurgery (TEM) may be performed to remove the cancer. This is a minimally invasive technique that allows the surgeon to remove the cancerous rectal tissue through the anus rather than having to make any incision in the belly (abdomen). Depending on the location of the cancer in the rectum, other surgical techniques may be needed.

Total mesorectal excision (TME)

Total mesorectal excision (TME) is a common procedure used in the treatment of rectal cancer that is confined to the lower two-thirds of the rectum. The mesorectum is a fatty tissue surrounding the rectum that contains blood vessels and lymph nodes. During the surgery, the entire mesorectum is removed, which reduces the risk that the cancer will recur. TME sometimes impairs the function of the rectum and results in the need for a permanent colostomy.

Low anterior resection (LAR)

Low anterior resection (LAR) is a common surgery for treating rectal cancer that is located in the upper part of the rectum. The tumour and a part of the rectal tissue are removed without affecting the anus. Then, the colon is re-attached to the remaining rectum so that after surgery, stool can exit through the anus normally. Sometimes a temporary colostomy is needed.

Abdominoperineal resection (APR)

Abdominoperineal resection (APR) is another common surgery for rectal cancer patients. It is the standard surgical procedure to remove rectal cancer that is located very close to the anus. An incision is made in the abdomen and another in the perineal area. The anus and surrounding tissue, including the sphincter muscle that controls anal function, are removed with the cancer. The cut end of the intestine is reattached to the abdominal wall, forming a permanent colostomy.

Watch-and-wait Strategy

The watch-and-wait strategy for managing rectal cancer aims to spare patients unnecessary surgery to remove the tumour(s), which can have a significant impact on quality of life by disrupting bowel, bladder, and sexual function. In this strategy, doctors treat the patient with intensive radiation and chemotherapy initially instead of surgery to shrink or eliminate the tumour(s). The patient is monitored for five years, being closely watched for any signs that the cancer has come back. If it does, it can be removed by surgery. Evidence from recent studies shows that the approach is associated with excellent long-term outcomes and improved quality of life.


When the cancer has invaded the wall of the colon and surrounding tissues, surgery usually involves removal of the cancerous parts of the colon and the surrounding tissue including the lymph nodes. This surgical procedure is called a colectomy. Once the cancerous parts of the colon are removed, the two resulting ends of the remaining colon are rejoined to allow normal bowel function. This process is called anastomosis.

Surgery to remove part of the colon is called a hemi-colectomy or partial colectomy.

Surgery to remove the whole colon is called a total colectomy.

Your surgeon may perform an open colectomy, where a vertical incision is made down the abdomen to open the abdominal cavity and access the colon. After the removal of cancerous parts, the incision is closed with staples or sutures.

A laparoscopic colectomy or minimally invasive colectomy may also be performed. Several small incisions are made in the abdomen, through which your surgeon passes a tiny video camera and special surgical tools to remove the affected parts of the colon. This technique allows the surgeon to operate from outside the body, reducing healing time and surgical risks such as infection. For stage II-III rectal cancer, most people will get both chemotherapy and radiation therapy (chemoradiation) as their first treatment, or radiation alone. This is usually followed by surgery (see above: TEM, LAR, APR).

Additional chemotherapy is given after surgery, usually for a total of 6 months. Due to the close proximity of organs and the small amount of space in the pelvic area, rectal cancer has a higher rate of local recurrence (recurrence of the tumour at the original site). For this reason, the surgeon needs to be sure that the tumour and surrounding tissues are completely removed.

Sometimes, complete removal of the rectum (proctectomy) is needed.

In some cases, such as after a proctectomy, the ileostomy or colostomy are permanent. Your surgeon will avoid this as much as possible, though it will depend on where the cancer is in your colon or rectum and your overall state of health. Sometimes it is not possible to know before the surgery whether you will need a permanent stoma, as the surgeon will only be able to determine if it is necessary during the operation.

Having a stoma, even temporarily, requires an adaptation period in a person’s life. A stomal therapy nurse will discuss all aspects of living with a stoma and give you the information you need.

Robotic-Assisted Surgery

The da Vinci surgical system is a robotic-assisted, minimally-invasive surgical system that may be used to perform a colectomy and/or low anterior proctectomy. Especially for rectal cancer, the use of robotic-assisted surgery allows for a more precise operation of the rectum considering the very tight space in which it is located.

For more information about robot-assisted surgery including which hospitals across Canada offer this surgical option, please visit the robot assisted surgery patient education website links:

Ileostomy and Colostomy

After a colectomy, the surgeon may attach the colon to an opening on the surface of the abdomen called a stoma to allow the colon time to heal after the surgery.

An ileostomy is an opening (stoma) of the small intestine (ileum) to the surface of the belly (abdomen).

A colostomy is an opening (stoma) of the large intestine (colon) to the surface of the belly (abdomen).

In both cases, feces and gas exit the intestine through the opening into a bag or pouch attached externally to the skin. In most circumstances, an ileostomy or a colostomy is only needed for a short time until the colon has healed enough for a second surgery to join its ends back together. This is called a stoma reversal. In the meantime, you will use colostomy or ileostomy bag over the opening of the bowel to collect your stool.

Colorectal Cancer Treatment – Ileostomy and Colostomy Image source: mayoclinic.org


CCC Guide to Understanding Ostomy

For more information on what to eat and drink after ostomy surgery:

Foods that Fight Colorectal Cancer


If your cancer has spread to another organ or part of your body such as the liver, lungs or peritoneum, surgery may still be a treatment option. In this case, a variety of techniques can be used to treat your cancer. To help control the cancer you will likely be offered chemotherapy, possibly in combination with a targeted therapy. These treatments may be used before and/or after surgery to improve the effects of surgery.

There is now a much better prognosis for stage IV colorectal cancer patients. For instance, liver-only metastases have been shown to be successfully managed through surgical resection and adjuvant treatment.

For patients with colorectal cancer, the liver is the dominant site of metastasis. Although many patients’ cancer spreads beyond the liver, some patients have disease that is isolated to the liver. For these patients, regional treatment approaches such as surgical resection may be considered in addition to chemotherapy alone. Your doctor will discuss the best option available to you. It is very important to discuss all your surgical options and goals of your treatment together with your doctor.

Side effects of Surgery

A side effect is any effect other than the primary intended effect of a medicine or treatment. The side effects you experience will depend on what kind of surgery you undergo. People who undergo laparoscopic surgeries that do not require large incisions in the abdomen generally recover quicker. Following surgeries that involve larger incisions, the side effects, your hospital stay, and your recovery time will depend on how your body reacts to the procedure.

Upon leaving the hospital, recovery will likely take a couple of weeks. While you may feel weak at the beginning, with lots of rest and good nutrition you will slowly regain your strength. Talk to your doctor to understand when you can expect to get back to your normal routine.


Following your surgery, you will probably follow a restricted diet. Some patients may need extended periods of healing and may first receive liquid nutrition intravenously through the arm, and then slowly transition to drinking clear liquids. As your intestines recover and regain function, you can slowly return to solid foods.


If your surgery involved a colostomy or ileostomy, you will meet with an ostomy nurse who will show you how to take care of your stoma. The nurse will also teach you how to change the ostomy bag once it has filled with waste.


You may experience temporary pain and tenderness around the surgical sites after surgery, but you will be offered excellent options for pain control.

Nausea, Constipation, Diarrhea

Many patients experience nausea following colorectal cancer surgery, as a side effect of the surgery or because of the pain medication. You may also experience constipation or diarrhea. Be sure to tell your nurse everything that you are experiencing following surgery so that the causes of these conditions can be identified and any tests or adjustments to medications can be made.


Canadian Cancer Society

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Fight Colorectal Cancer

Colorectal Cancer Alliance

American Cancer Society

Cancer Research UK

January 2021


Chemotherapy is a type of cancer treatment that uses powerful drugs to kill cancer cells. It is a systemic treatment, meaning that the drugs enter the bloodstream and affect cells throughout the body. There are many different kinds of chemotherapy drugs that can be prescribed at different stages of treatment, and can be given intravenously (through a vein), orally, or contained to a specific location of the body such as the abdominal cavity. You may receive chemotherapy on an outpatient basis at the hospital, at a doctor’s office, a clinic or at home depending on the type of chemotherapy you receive.


Neoadjuvant chemotherapy

This chemotherapy is given before surgery to help to shrink the target tumour so that it can be removed more easily with fewer complications. Sometimes radiation therapy is given together (chemoradiation) as the two therapies may increase each other’s effectiveness.

The rectum is very closely located to several other organs including the bladder, the uterus in women and the prostate in men. In rectal cancer, the proximity of the rectum to surrounding organs increases the risk of metastasis. As a result, it is important that any cancer cells are treated as quickly as possible.

If you have stage II or III rectal cancer, you may receive neoadjuvant chemotherapy and radiation therapy, as well as adjuvant chemotherapy and radiation therapy after surgery.

Adjuvant chemotherapy

This chemotherapy is given after a colorectal tumour is surgically removed. Cancer cells may still linger in the body, including those that may have spread (metastasized) to the liver or other organs. Adjuvant chemotherapy helps to treat any cancer cells that were left behind after surgery.

In the earlier stages of colorectal cancer, surgery will usually be performed first to remove all or most of a visible tumour. If there is a possibility that the cancer has spread to surrounding tissues such as the lymph nodes, adjuvant chemotherapy may be offered.

Chemotherapy may be given alone or in combination with a targeted therapy. People with stage III and IV and some high-risk stage II colon cancer are generally given adjuvant chemotherapy.

Palliative Chemotherapy

Palliative chemotherapy is a non-curative treatment that aims to prolong survival and improve the quality of life of patients with advanced colorectal cancer that has metastasized to other parts of the body. In advanced stages, it is unlikely that the cancer can be removed by surgery alone. Palliative chemotherapy may help to shrink tumours and reduce symptoms, and in some cases, may shrink the tumours enough to allow for surgery with a possible curative effect.

What to expect before Chemotherapy

Planning a chemotherapy regimen will take into account various factors:

  • Your general health

  • Your age

  • The Stage and location of the cancer

  • Any other medications that you are taking, including vitamins and supplements

  • Any existing health conditions such as diabetes or cardiovascular disease

  • The availability of particular cancer drugs at your cancer centre or hospital

A course of chemotherapy is given in cycles, alternating periods of taking the drug with periods of rest. The rest periods give your body a chance to repair itself and regain strength. A cycle may be daily, weekly, every 2 weeks or monthly. The exact dosage and treatment schedule will depend on the drugs you are given. If you respond well to treatment, you will likely go through several cycles of chemotherapy. On the days you are scheduled to receive chemotherapy, you may receive advice from your medical team about what to eat or drink, since certain substances can have negative interactions with the chemotherapy drugs.


In cancer, a series of mutations causes cells to behave abnormally and divide very rapidly and uncontrollably, resulting in an enlarged mass of cells called a tumour. Chemotherapy drugs work by interfering with specific processes in the cell such as DNA replication and cell division, which eventually causes the cell to die. Since cancer cells divide much more frequently compared to most normal cells, chemotherapy is more likely to affect them.

Chemotherapy specifically targets cells that are in the process of dividing into two new cells. As adults, most of our body’s cells do not divide very frequently, and only do so when worn out or damaged cells need to be replaced.

Our body contains various tissues, however, that are made up of cells that divide rapidly as part of their normal functioning. These tissues include:

  • The hair follicle, which is constantly producing hair

  • The bone marrow, which is constantly producing new blood cells

  • The skin and the lining of the digestive system, which are constantly in a process of renewal

Since these tissues are made of frequently dividing cells, chemotherapy may affect them as well. This may result in some of the side effects such as hair loss, diarrhea, and anemia depending on the drugs you receive.


Intravenous chemotherapy

Intravenous chemotherapy drugs are injected into a vein and allow for rapid entry into the body’s circulation. This is the most common method of chemotherapy administration, since most chemo drugs are easily absorbed through the bloodstream. The most common chemotherapy drug for colorectal cancer is 5-fluorouracil (5-FU). It is usually given with a vitamin derivative called folinic acid (leucovorin). Folinic acid enhances the effect of 5-FU against cancer cells. These drugs may be administered by:

  • Direct injection/Bolus: the chemotherapy is injected into a vein lasting from a few minutes to a few hours

  • Continuous Infusion: the chemotherapy is injected through a drip or pump over a few days or for weeks at a time

  • Port: a port-a-cath is a surgically implanted reservoir with a thin silicone tube that attaches to a vein and allows the medication to be given over several days at home rather than as a patient in the hospital. Chemotherapy drugs can be delivered directly into the port rather than a vein, eliminating the need for continue needle sticks.

  • PICC line (peripherally inserted central catheter): a thin, flexible tube is inserted into a vein in the upper arm and guided into a large vein near the heart. A needle is inserted into a port outside the body to give the chemotherapy drugs. A PICC can remain in place for weeks or months and avoids the need for repeated needle sticks.

Image source: cancer.gov Image source: cancer.gov

Intravenous chemotherapy drugs include:

5-fluorouracil (5-FU) and folinic acid (leucovorin)

5-FU is the standard, first-choice chemotherapy drug given in the treatment of colorectal cancer. It is given in combination with folinic acid, a vitamin-derivative, which enhances its effectiveness.

Irinotecan (Camptosar®)

This drug may be given as first-line chemotherapy (the initial treatment given) for advanced colorectal cancer. You may also be given irinotecan in later lines of treatment if your colorectal cancer does not respond to previous chemotherapy. Depending on the treatment you have already received, you may be given irinotecan either on its own or in combination with 5-FU and folinic acid.

Oxaliplatin (Eloxatin®)

Oxaliplatin is given in a similar way to irinotecan. It is a platinum-based chemotherapy drug that is generally given in combination with 5-FU and leucovorin, a treatment known as FOLFOX. It is typically given as first-line treatment for colorectal cancer.

Oral chemotherapy

Oral chemotherapy medications – those that can be swallowed – come in various forms (pills, tablets, capsules, liquid), all of which can be absorbed by the stomach or under the tongue. Oral chemotherapy may be taken at home, making it a simple and more convenient means of treatment compared to intravenous therapies.

Capecitabine (Xeloda®)

Capecitabine is an oral therapy that is transformed into 5-FU in the body. It was developed to mimic the continuous infusion of 5-FU while avoiding complications and the inconvenience of intravenous administration. It has been demonstrated to work as well as daily injections of 5-FU and can be taken from home.

Trifluridine and Tipiracil (Lonsurf®)

Lonsurf is an oral combination tablet that is used for metastatic colorectal cancer that has not responded to previous chemotherapy or targeted therapy.

Combination chemotherapies include:


A chemotherapy regimen that combines FOLlinic acid, Fluorouracil and OXaliplatin. It may be used in first-line treatment of advanced colorectal cancer.


A chemotherapy regimen that combines FOlinic acid, Fluorouracil and IRInotecan. It may be used in first-line treatment of advanced colorectal cancer.


This combination is an intensive combination chemotherapy that includes FOLinic acid, Fluorouracil, OXaliplatin and IRInotecan. FOLFOXIRI may be given as a first-line treatment option among patients who have advanced colorectal cancer.


XELOX, also referred to as CAPOX, is a combination of CApecitabine (XEloda) and OXaliplatin. It may be offered as first-line treatment in patients with advanced colorectal cancer.


This is a combination of capecitabine (XEloda) and IRInotecan typically used in the first-line treatment of advanced colorectal cancer. It is generally used in the treatment of stage IV colorectal cancer and cancer that has not responded to previous treatment.


Chemotherapy may be combined with targeted therapy to enhance its effectiveness against tumours, and to help to shrink tumours so that surgery becomes an option. Currently, the use of targeted therapies is limited to patients with stage IV metastatic colorectal cancer. At this stage, patients who do not benefit from chemotherapy alone may experience an improved response if targeted therapy is added to their treatment regimen.

For patients with advanced colorectal cancer with tumours that cannot be removed by surgery, chemotherapy with the anti-VEGF agent bevacizumab (Avastin®) may be given.

Chemotherapy plus panitumumab (Vectibix®), or chemotherapy with cetuximab (Erbitux®) may also be considered. The use of the EGFR inhibitors panitumumab and cetuximab is preferably given in the first-line setting to patients with left-sided tumours that are wild-type KRAS or wild-type NRAS. Patients with a BRAF V600E mutation or a KRAS/NRAS mutation in their tumours are not good candidates for EGFR inhibitors, which have shown limited effectiveness in these patients.

Patients with unresectable, metastatic tumours may also qualify for immunotherapy. Pembrolizumab (Keytruda®) and nivolumab (Opdivo®) are both PD-1 inhibitors, and can be used in combination with chemotherapy to treat patients with advanced disease who have microsatellite instability-high (MSI-H)/mismatch repair deficient (dMMR) tumours. Nivolumab (Opdivo®) may be given with or without ipilimumab (Yervoy®), depending on the circumstances.


Regional chemotherapy drugs for colorectal cancer are given directly to the liver or the peritoneum (the lining of the abdominal cavity). This type of chemotherapy is used when colorectal cancer has metastasized to other parts of the body such as the liver and lungs.

Colorectal Cancer Treatment – Regional Chemotherapy Drugs

Image source: Sunnybrook Health Sciences Centre

Hepatic arterial infusion (HAI) of chemotherapy agents such as floxuridine (FUDR) is a type of regional chemotherapy that specifically targets liver metastases. The HAI pump is a small, disc-shaped device that is surgically implanted just below the skin of the patient and is connected to the hepatic (main) artery of the liver. Approximately 95% of the chemotherapy that is directed through this pump stays in the liver, sparing the rest of the body from side effects.

For patients with multiple liver metastases that have not responded to first-line chemotherapy, treatment options were previously limited to second-line chemotherapy, which provides a 25% response rate for patients. If second-line treatment does not work, there are even fewer and less effective chemotherapy options. With combined HAI chemotherapy and systemic chemotherapy, response rate among patients is up to 75%.

Hyperthermic intraperitoneal chemotherapy (HIPEC) is a kind of regional chemotherapy that involves the application of chemotherapy drugs into the abdominal cavity after colorectal surgery. This method is reserved for patients who have colorectal cancer that has metastasized to the peritoneum (the inner lining of the abdominal cavity). HIPEC maximizes the amount of chemotherapeutic drugs delivered to these regional tumours, while minimizing side effects by limiting the amount of chemotherapy that circulates throughout the entire body. The chemotherapy solution is also heated to increase the effectiveness of the drugs.

For more information about HIPEC in Canada see the multidisciplinary Mount Sinai Hospital Peritoneal Surface Malignancy Program.

HPIC image Image source: foxchase.org


Chemotherapy is designed to target any rapidly dividing cell in the body. This includes cancer cells, but also means that normal, rapidly dividing cells such as blood cells or cells that line the gastrointestinal tract are also affected. Since chemotherapy drugs affect people in different ways, not all patients will have the same side effects with a given drug. Effective medications are available to reduce many of the side effects, or at least minimize them significantly. Side effects should gradually stop once treatment ends.

The side effects of colorectal cancer chemotherapy may include:


Damage to the cells that line the gastrointestinal tract may cause diarrhea or frequent, loose stools. Although diarrhea is a common side effect of certain drugs, it is often not serious or long-lasting. It can usually be managed with non-prescription anti-diarrheal medication. If you experience diarrhea, drink plenty of fluids to avoid dehydration.

If you experience persistent diarrhea that lasts for days, notify your medical team as it could result in serious loss of body fluid (dehydration) and require admission to the hospital.

Upset stomach and vomiting

Stomach upset or vomiting may occur on the day of and possibly for a few days after you receive chemotherapy. Your doctor may suggest trying anti-nausea drugs or drugs to help soothe an upset stomach. If you experience vomiting, remember to drink plenty of fluids to avoid dehydration and advise your medical team immediately.

Feeling tired (see Anemia)

Feeling tired is a common side effect of chemotherapy. Several factors such as the stress of a cancer diagnosis, recent surgery and anesthesia, lowered red blood cell counts and the effects of the chemotherapy drugs themselves can all contribute to low energy and fatigue.

Mouth sores (mucositis)

Damage to the fast-growing cells lining the mouth may cause mouth sores (mucositis). This is a common side effect and may occur several days after chemotherapy begins. Before beginning chemotherapy, it is recommended that you have a dental checkup and cleaning. When chemotherapy begins, rinse with a mild mouthwash that does not contain alcohol. Mouthwashes may contain some pain relievers as well as an antifungal agent that will help control infections. Talk to your doctor to determine how to best manage any symptoms. Keep your teeth clean using a soft toothbrush and avoid foods that may be irritating to the inside of the mouth or throat, such as acidic or spicy foods.

Hand-foot syndrome

Sometimes chemotherapy can cause dry skin that becomes thick or begins to crack around the palms and soles of the feet. Some patients develop blisters or a rash. This is called hand-foot syndrome. Your medical team can suggest treatments such as lotions or pain medicine to manage your symptoms.

Hair Loss

This side effect is only seen in certain chemotherapy drugs used for colorectal cancer. In some cases, damage to the fast-growing cells in the hair follicle can cause hair loss. Lost hair usually grows back once chemotherapy is over.

Numbness or tingling in the hands and feet (neuropathy)

Numbness or tingling in the fingers and toes is a common side effect with chemotherapy that includes oxaliplatin, which can irritate nerve endings. You may have trouble doing up buttons, for example, or picking up small objects. This is called peripheral neuropathy, and it can occur a few days or a few weeks after treatment.

These side effects usually go away within three weeks of stopping treatment. Remember to always report your side effects to your medical team who will help you find the best way to manage your symptoms. Depending on the severity of your symptoms, your doctors may suggest a reduction in the drug dosage or taking a break from chemotherapy altogether.


Neutrophils are white blood cells that help the body fight infection. A reduction in the number of white blood cells in the blood is called neutropenia.

Almost all patients who receive chemotherapy develop some degree of neutropenia, which puts the body at greater risk of infections. If you experience a fever higher than 38°C or other symptoms of infection, contact a member of your medical team immediately. Since neutropenia is a potentially serious complication of chemotherapy, white blood cell counts are closely monitored during treatment.

On the day you are scheduled to receive your next cycle of chemotherapy, your white blood cell count will be measured to make sure you are able to safely receive the next dose. If your white blood cell count has not recovered to a level that allows chemotherapy to be given, the next cycle of chemotherapy will be delayed until the white blood cell level has recovered.

If you have had serious or longer-lasting neutropenia, your dose during future cycles of chemotherapy may be lowered. Medications such as Neulasta® (pegfilgrastim) or Neupogen® (filgrastim) may be prescribed to you to help to prevent infections during chemotherapy.


Feeling tired more than usual during chemotherapy may be a result of anemia, a common side effect of many chemotherapy regimens. Anemia happens when there is a significant decrease in your red blood cell level. Red blood cells contain hemoglobin, a special protein that carries oxygen throughout the body. A decrease in your red blood cell count can contribute to low energy levels.

Mild or moderate anemia is common with some chemotherapies and treatment is usually not needed. The severity of anemia may increase with certain chemotherapy regimens or with further cycles of treatment. Depending on the circumstances, sometimes a blood transfusion may be required.

Some serious side effects of chemotherapy that may require medical attention:

  • Febrile neutropenia, causing fever and chills

  • Serious vomiting or diarrhea, resulting in dehydration

  • Unexplained bleeding

It is important that you are able to contact a member of your healthcare team, day or night, and know when to seek medical attention if any of these potentially serious side effects occur. If you are ever in doubt, always report to the emergency department of your hospital without delay.

Side effects related to targeted therapies

Like chemotherapy, targeted therapies can also cause side effects. Inform your medical team of any symptoms you may experience during treatment. Most side effects will go away entirely once treatment has ended.

See the Targeted Therapy section for side effects associated with targeted therapies.

For more information on

Managing side effects with good nutrition
What to eat after treatment
Foods that Fight Colorectal Cancer program



  • An excellent resource with detailed chemotherapy drug information

Canadian Cancer Society

Cancer Research UK

Fight Colorectal Cancer

January 2021

Radiation Therapy

Radiation therapy (radiotherapy) is a treatment option for colorectal cancer that uses high-energy x-rays to kill tumour cells. The rays enter the body and disrupt the DNA (genetic material) within the cells, which limits their ability to divide and replicate. Though radiation affects both normal and tumour cells, it is more damaging to cancer cells which divide more rapidly. To shield as much of the surrounding healthy tissue as possible, the radiation oncologist will develop a plan to deliver radiation specifically targeting the tumour area as much as possible.


Radiation therapy is used primarily to treat stage II, III and IV rectal cancer before and after surgery. Often radiation on its own or in combination with chemotherapy (chemoradiation) is used to shrink large tumours before surgery, making it easier to completely remove the tumour. Chemoradiation may also reduce the risk of cancer coming back in the same place, compared to radiotherapy alone. The combination, however, causes more short-term side effects such as diarrhea. For the treatment of colon cancer, radiation therapy is limited to palliative therapy for selected metastatic sites such as bone or brain metastases.

Before surgery

Radiation given before surgery (neoadjuvant radiotherapy) shrinks the tumour to make it easier to remove, and reduces the risk of the cancer coming back after surgery. You may be prescribed short course (such as five days) or long course (such as five treatments a week, for five or six weeks) radiation depending on the size of your tumour.

After surgery

Radiation can also be given after surgery (adjuvant radiotherapy) to reduce the chances of the cancer returning. The course of radiation can vary from five to six weeks.

Palliative radiotherapy

In advanced colorectal cancer (Stage IV), radiation may be given to help to alleviate or control symptoms, such as bone pain.


External Radiation Therapy

This is the most common type of radiation therapy. A machine outside the body sends a beam of radiation at the cancer cells and the immediate surrounding area to destroy the main tumour and any nearby cancer cells. A team of specialists will work together to determine the exact location at which to aim the radiation, controlling the size and shape of the beam to be as exact as possible in order to minimize damage to healthy cells.

The entire process can take a few hours but the treatment itself lasts a few minutes. This type of radiotherapy is used more frequently with rectal cancer compared to colon cancer, because the rectum does not move as much as the colon making it an easier organ to target. It is used in colon cancer mainly for relief of symptoms associated with advanced cancer. It may also be used to target metastatic tumours that compress other organs causing pain.

Internal Radiation (Implant Radiation or Brachytherapy)

This type of radiation involves the implantation of radioactive sources inside or near the tumour. This type of radiation can deliver a high dose of radiation directly to the cancer while limiting the damage to surrounding healthy tissues and organs. This method is sometimes used in treating people with rectal cancer, particularly those who are unable to undergo surgery. The implant generally remains in place for several days before it is removed, or it may be situated permanently in the tumour area.

Intraoperative Radiation Therapy (IORT)

IORT is a type of external beam radiation that is applied to exposed tumour cells during surgery. This form of radiation allows significantly higher doses (a single dose may be as potent as 10-20 daily radiation treatments) of radiation to be directed to the tumours without damaging nearby healthy tissues. IORT is useful when tumours cannot be completely removed during surgery because they are either attached or located very close to healthy tissue. Specialist techniques: Interventional radiology

Many conditions that once required surgery can be treated less invasively today by interventional radiology. This kind of therapy uses radiology imaging such as X-rays, CT scans or MRI scans to guide the precise application of other therapies including radiotherapy and chemotherapy. These less-invasive techniques limit the size of incisions to the body, and therefore help to reduce risk, pain and recovery times for patients. Interventional radiology can be used to manage metastatic (advanced) disease where tumours have spread to other parts of the body such as the liver and lungs.

Tumour ablation procedures

These minimally-invasive treatments destroy cancerous tissue using extreme temperatures. Ablation may be used to treat tumours (curative) or to alleviate symptoms (palliative). Radiofrequency ablation (RFA) is a technique which uses a thin, needle-like probe to apply high-energy radio waves through the skin directly into metastatic colorectal tumours in the liver or lung. Ultrasound or CT scans help to guide the placement of the probe. The high-energy radio waves produce heat in the tissue. When the temperature rises above 50°C for more than 5 minutes, the tumour cells are destroyed.

Selective Internal Radiation Therapy (SIRT), also known as microspheres, uses millions of radioactive particles (yttrium-90) contained within tiny resin spheres to deliver radiation directly to liver tumours. A catheter is inserted into the hepatic artery (the main artery of the liver) and is guided into the specific branch of the artery that feeds the tumour. The microspheres are infused directly through this artery into the tumour’s blood supply. The microspheres become trapped in the capillaries (small blood vessels) of the tumour and radiation is given selectively to the tumour.


While chemotherapy affects your whole body, radiation therapy only affects the specific area of the body where it is applied. Newer technology has allowed radiation therapy to be more precise, affecting only the target tissues as much as possible. If you are going to receive radiation therapy, talk to your doctor to learn what to expect and what measures can be taken to reduce any discomfort.

Possible short-term side effects of radiation therapy:

  • Fatigue

  • Loss of appetite

  • Nausea

  • Skin irritations at the radiated area, ranging from redness to blistering and peeling

  • Sexual problems in men and women

  • Bladder problems such as having to pee more often, sometimes with burning and discomfort

  • Problems with wound healing if radiation was given before surgery

Be sure to talk to your nurse or doctor right away if you notice any side effects so that steps can be taken to reduce and relieve them. Most side effects should go away gradually after treatment ends. If you receive radiation and chemotherapy together, you may experience more side effects.

Possible long-term side effects of radiation therapy:

Long-term changes to the way your intestine works, such as diarrhea, being woken from sleep to have a bowel movement, have less control over your bowel movements (less warning to get to the toilet in time, or having accidents)

Damage to the bones in your pelvis, leading to a higher risk for fractures (be sure to discuss any pain or stiffness in your pelvis or back with your medical team)

Damage to sperm and eggs, causing possible infertility. Contraception should still be used during treatment and about a year afterward in case there is any chance of pregnancy. It may be possible to preserve sperm or eggs in advance of your treatment to preserve fertility. Speak to your medical team to learn more.

For more information on

Managing side effects with good nutrition
What to eat after treatment
Foods that Fight Colorectal Cancer program


Canadian Cancer Society

Bowel Cancer UK

American Cancer Society


Targeted Therapy


Companion diagnostics are tools or tests that provide information about your body’s specific biology to help your medical team determine if you are likely to benefit from certain therapies. These tools examine your genetic make-up or measure specific biomarkers in your blood or in the tumour that can help to determine whether a particular treatment will be effective for you. The companion diagnostic for each targeted therapy differs based on the biological pathway that a therapy targets. For example, the companion diagnostics for therapies that target the EGFR pathway will look for the presence of KRAS and NRAS genetic mutation before starting therapy to ensure you are a good candidate for the therapy.


Biologic Therapy: Monoclonal Antibodies

Biologic therapies are drugs that are made from living organisms or substances derived from living organisms. Most biologic therapies used to treat colorectal cancer are monoclonal antibodies (MAB). An antibody is a protein that is produced by the immune system in response to a specific substance (antigen) that the body recognizes as foreign. Antigens are proteins that are expressed on the surface of cells including cancer cells, viruses, fungi, and bacteria. The antibody attaches to the antigen in order to flag it for destruction by the body’s immune system.

Colorectal Cancer Treatment – Targeted Therapy

Image source: Cancer research UK

In the laboratory, scientists analyze specific antigens that are found on the surface of cancer cells. Using protein from animals and humans, scientists can create a specific antibody that will attach to the target antigen on the cancer cell. An antibody binds highly specifically to its antigen, like a key fits a lock. That means that this treatment allows for less toxicity to healthy cells and fewer side effects.

Panitumumab (Vectibix®) and cetuximab (Erbitux®) are monoclonal antibodies that target and bind to the epidermal growth factor receptors (EGFR) on the surface of the cell. EGFR is found on the surface of some normal cells and may be overexpressed on cancer cells, stimulating them to grow and divide uncontrollably. By binding to EGFR on the cancer cell, these drugs block the receptor from interacting with its specific partner molecule, or ligand. This prevents activation of cell division and growth, eventually leading to cell death or apoptosis.

Activation of the epidermal growth factor receptor (EGFR) results primarily in activation of RAS/MAPK signaling which results in cell growth and proliferation.

Cetuximab and panitumumab may be indicated for patients with advanced colorectal cancer with wild-type KRAS or NRAS genes.

Common side effects of EGFR inhibitors include:

  • Skin rash

  • Tiredness

  • Hypomagnesemia (low magnesium levels in the blood)

  • Nausea

  • Vomiting

  • Diarrhea

  • Dry skin

  • Constipation

The most common side effect of EGFR inhibitors is skin rash. This is a direct effect of the drug on normal skin cells, and can be effectively managed with the appropriate treatment. To help relieve skin rash, it is recommended that you use sunscreen, keep your skin clean and moisturized, avoid direct sun exposure, and avoid using harsh skin products. Talk to your medical team about how to best manage any symptoms you may experience. Depending on the severity and type of rash developed, your doctor may reduce or delay the next dose of EGFR inhibitor. Once the rash has subsided, normal therapy can begin again. Reference side effects brochure


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If you are about to start or have recently started EGFRi therapy, a skin care sample kit is available to you. Please ask your healthcare professional how you can obtain one.

Each kit contains:

  • Soap for sensitive skin
  • Sunscreen
  • Moisturizing body lotion
  • Moisturizing hand cream
  • Facial cleanser
  • Facial moisturizer
  • Lip balm

For patients receiving EGFR therapies, the following video provides tips on managing skin rash:
Skin care tips

Angiogenesis Inhibitors

Angiogenesis is a normal process that the body uses to grow blood vessels to bring oxygen and nutrients to new and dividing cells. Tumour cells produce chemicals which stimulate angiogenesis, enabling them to grow and divide rapidly. Angiogenesis inhibitors block this process, causing blood vessels to shrink away from the tumour and effectively starve it of oxygen and nutrients.

Some angiogenesis inhibitors target the action of the receptor vascular endothelial growth factor (VEGF), which is responsible for activating the signal required for new blood vessel formation. Other angiogenesis inhibitors target molecules that are involved in the blood vessel formation process.

Angiogenesis Image source: longevity.org

Bevacizumab (Avastin®) is a monoclonal antibody that inhibits VEGF, blocking the growth and development of blood vessels. It is typically given in combination with chemotherapy as first-line treatment of advanced colorectal cancer. While chemotherapy attacks the tumour cells directly, bevacizumab blocks the tumour’s blood supply.

Ramucirumab (CYRAMZA™) is another VEGF inhibitor used in combination with chemotherapy in the treatment of metastatic colorectal cancer. It is currently approved by Health Canada but is not reimbursed for colorectal cancer.

Common side effects of angiogenesis inhibitors include:

  • High blood pressure

  • Diarrhea

  • Lowered white blood cell counts

  • Mouth sores

  • Headaches

  • Slow wound healing

  • Loss of appetite

Inform your medical team of any symptoms you may experience during treatment. Most side effects will go away entirely once treatment has ended.


A biosimilar is a biologic medical product that is highly similar to another original medication that is manufactured by a different pharmaceutical company. A biosimilar has no clinically meaningful differences in terms of safety and effectiveness from the original drug. Only small differences in clinically inactive components are allowed in biosimilars.

A Biosimilar is not the same thing as a generic drug. Biosimilar refers to a biologic drug, which is derived from living organisms. Biologic drugs do not come from a specific recipe of ingredients; they are grown from living components of the cell such as proteins. A generic drug refers to a chemically-derived drug, which involves a very specific recipe of active ingredients and inactive ingredients. When a drug patent expires, other manufacturers can create their own recipe using active and inactive ingredients as long as the concentration of active ingredients does not change.

While biosimilars and generics are fundamentally different, both increase patient access to therapies and aim to reduce the cost of medications and treatment.

In Canada, two biosimilars are currently available for the treatment of advanced colorectal cancer. Mvasi® and Zirabev® are both biosimilars of bevacizumab (Avastin®) that are approved for use in combination with 5-FU-based chemotherapy as first-line treatment of patients with metastatic colorectal cancer. Other biosimilars are currently in development.

For more information on biosimilars for colorectal cancer in Canada, please visit the pan-Canadian Oncology Biosimilars Initiative (pCOBI) website.

Other targeted therapies

Regorafenib (Stivarga®) targeted therapy

Regorafenib (Stivarga®) is a type of targeted therapy known as a kinase inhibitor. This drug targets the tyrosine kinase receptor proteins located on the surface of the cell. Regorafenib interferes with several kinase proteins at once – those that are involved in tumour growth and progression as well as blood vessel development (angiogenesis). Regorafenib has been shown to be effective in patients with advanced colorectal cancer with both KRAS mutant and KRAS wild-type tumours.

Common side effects of Regorafenib (Stivarga®) include:

  • Fatigue

  • Loss of appetite

  • Hand-foot-syndrome (redness and irritation of the hands and feet)

  • Diarrhea

  • High blood pressure

  • Weight loss

  • Abdominal pain

Less common but more serious side effects of Regorafenib (Stivarga®) can include:

  • severe bleeding

  • perforations in the stomach or intestines

Encorafenib (Braftovi®) targeted therapy

Encorafenib (Braftovi®) is a targeted therapy directed against the BRAF kinase protein. The BRAF kinase protein is important in both normal and cancer cells. It is part of a chain of molecules that produces a signal directing the cell how to grow and divide. In colorectal cancer, mutations to the BRAF gene can alter the way the BRAF protein works, causing it to drive the uncontrolled growth of cancer cells. Encorafenib targets the BRAF protein and may help to slow down the growth of colorectal cancer. It is usually given in combination with cetuximab. It may sometimes be given in combination with binimetinib.

Binimetinib (Mektovi®) targeted therapy

Binimetinib (Mektovi®) is a targeted therapy that inhibits the MEK 1 and MEK 2 kinase proteins. These two kinases are part of the same chain of molecules involved in cell growth and division as BRAF kinase mentioned above. Binimetinib interferes with the signaling at the MEK 1 and MEK 2 part of the chain, which may help to slow down the growth of cancer.

The results from the BEACON Colorectal Cancer (CRC) trial showed the effectiveness of encorafenib in combination with cetuximab with or without binimetinib among previously treated patients with BRAFV600E-mutant metastatic colorectal cancer. Specifically, the doublet therapy of encorafenib and cetuximab significantly improved overall survival and response rates, and promoted quality of life compared to the standard of care. In the United States, the doublet therapy is currently FDA-approved for use among this subset of CRC patients, and is considered a new standard of care.

Common side effects of encorafenib include:

  • Fatigue

  • Nausea and vomiting

  • Abdominal pain

  • Joint pain

  • Increased serum creatinine

Common side effects of binimetinib include:

  • Fatigue

  • Nausea and vomiting

  • Diarrhea

  • Increased serum creatinine

January 2021


Immunotherapy is a type of biological therapy that uses a person’s own immune system to fight diseases such as cancer. These therapies are designed to stimulate the immune reaction against cancer cells, enabling the body to fight the disease more effectively. Immunotherapy is used in the treatment of colorectal cancer when the tumor can’t be successfully removed by surgery or destroyed by chemotherapy. It may also be a treatment option when cancer recurs or metastasizes (spreads to other areas).


Immunotherapies act on the body’s immune system, intervening in the communication between a specialized type of immune cell, the T cell, and the target tumour cells. PD-1 is one protein that is expressed on the surface of cells. It plays a role in controlling the immune system’s response so that it does not attack our own cells. PD-1 is involved in preventing autoimmune diseases, but it can also prevent the immune system from effectively attacking cancer cells.

An important approach in immunotherapy has been to target PD-1. PD-1 is a receptor that acts as a “lock” that can only be opened or activated when it comes in contact with the right “key”, or ligand, known as PD-L1. PD-1/PD-L1 activation causes a decrease in immune activity. By blocking this interaction with PD-1/PD-L1 inhibitors, the brake on the immune system is lifted and the T cells are able to attack cancer cells more effectively. Examples of PD-1 inhibitors include:

  • Pembrolizumab (Keytruda ®), given through intravenous infusion

  • Nivolumab (Opdivo®), given through intravenous infusion

Ipilimumab (Yervoy®) is another drug given intravenously that boosts the immune response by targeting another protein called CTLA-4. CTLA-4 is another protein found on T cells that helps keep the body’s immune responses in check. Ipilimumab is typically used in combination with nivolumab.


In the treatment of colorectal cancer, immunotherapy has so far been shown to be effective in a small subset of patients. Tumours that express the biomarkers microsatellite instability (MSI-H) and mismatch-repair deficiency (dMMR) are more difficult to treat with standard chemotherapy. MSI-H and dMMR are genetic changes that prevent the tumour cells from repairing damage in their DNA. As a result, MSI/dMMR tumours often develop many mutations, which makes them less responsive to standard treatment.

About 5% of advanced colorectal cancer patients have MSI-H/dMMR tumours, and recent advances in immunotherapy strategies have found that pembrolizumab (Keytruda®) is an effective, viable treatment option for this subset of patients.

Pembrolizumab (Keytruda ®)

The KEYNOTE-177 trial showed that pembrolizumab significantly extended progression-free survival (the amount of time from the beginning of treatment to when the cancer progresses or worsens) when it was used as initial treatment for patients with MSI-H or dMMR advanced colorectal cancer compared to standard of care chemotherapy. Pembrolizumab also caused far fewer side effects. Pembrolizumab is currently approved by Health Canada, though it is still not reimbursed by provincial health care plans for colorectal cancer. Some drugs may be accessible through compassionate access or expanded access programs.

Nivolumab (Opdivo®) and Ipilimumab (Yervoy®)

Nivolumab and ipilimumab are immunotherapy drugs given in combination for the treatment of MSI-H/dMMR advanced colorectal cancer that did not respond to previous chemotherapy.

The CheckMate 142 trial found that the combination of nivolumab plus low-dose ipilimumab in the first-line treatment of patients with metastatic colorectal tumours that are MSI-H/dMMR produced very positive outcomes in patients, and caused far fewer side effects compared to chemotherapy.

Nivolumab and ipilimumab are currently approved by Health Canada for the treatment of advanced colorectal cancer, though it is still not covered by provincial health care plans. However, if immunotherapy could be right for you, talk to your medical team as some drugs may be accessible through compassionate access or expanded access programs.

Side effects of Immunotherapy


  • Feeling tired

  • Itching

  • Rash

  • Constipation

  • Pain in muscles, bones or joints, and abdomen

  • Diarrhea

  • Nausea

  • Shortness of breath

  • Cough

  • Fever

  • Decreased appetite

Common side effects of nivolumab include:

  • Feeling tired

  • Lymphocytopenia (low white blood cells)

  • Low sodium

  • Shortness of breath

  • Musculoskeletal pain

  • Decreased appetite

  • Cough

  • Diarrhea

  • Itching

  • Rash

  • Nausea/vomiting

Common side effects of ipilimumab include:

  • Feeling tired

  • Diarrhea

  • Nausea

  • Itching

  • Rash

  • Vomiting

  • Headache

  • Weight loss

  • Fever

  • Decreased appetite

  • Difficulty falling or staying asleep

Remember that not all patients will experience all of the side effects mentioned above. If you do experience any side effects, be sure to talk to your medical team to learn about options to help manage and prevent the worsening of side effects. Most side effects will go away entirely once treatment has ended.

Some side effects can be cumulative and may become more severe with time or when given in combination with other drugs. Speak to physician to find out how to best manage your side effects.

See our brochure for more information on immunotherapy

CCC Immunotherapy Program

January 2021

Clinical Trials

What are Clinical Trials?

Clinical trials are research studies performed in people that evaluate new ways of preventing, detecting, treating or managing cancer or other diseases. Through clinical trials, doctors can determine whether new treatments such as drugs, procedures, or medical devices are safe and effective, and whether or not they work better than current treatments. Knowing more about clinical trials can help you make an informed decision about whether or not you will take part in one as part of your colorectal cancer treatment.

Clinical Trials Fact Sheet

Patient & Caregiver Guide to Cancer Clinical Trials

It Starts with Me – N2 Canada

Patient-Friendly Language for Cancer Clinical Trials – a Glossary U.S. Food and Drug Administration

This glossary addresses key words and phrases that patients with cancer have identified as particularly difficult to understand when discussing potential participation in a clinical trial or reading an informed consent document.


Clinical trial sponsors

The person or organization that tests a drug in a clinical trial is called a sponsor. Sponsors of clinical trials are usually drug companies or researchers from a hospital, university or research organization. Before conducting a trial, the sponsor submits a clinical trial application to Health Canada for review.

Clinical trial investigators

The people who carry out the clinical trials are called investigators. In Canada, investigators are usually physicians. Researchers, nurses, or other health professionals may also be involved in a clinical trial.

Podcast - What are Clinical Trials? – Cancer.Net

Clinical trial control groups

In clinical trials, participants are typically randomly assigned to the treatment group (or groups) or the control group. The control group receives the standard treatment that they would have received for their disease if they were not participating in the trial. People in the other group or groups receive the new treatment or procedure that is being tested. In general, placebos or “dummy” treatments are not used as the control in cancer clinical trials, since it would be unethical to not offer someone a real treatment for their disease.

Randomization of clinical trials to minimize bias

Clinical trials are randomized to minimize any bias that could change the trial outcomes. For example, doctors may subconsciously put all the participants who are sicker into one particular treatment group. The participants in this group then might not do as well on that treatment compared to people in another treatment group because they were sicker to begin with. This would generate results that would show that one treatment was not as good as another when in fact, it isn’t true.


Blind clinical trials

A blind trial is one in which the participants do not know which treatment they are getting. Sometimes, we may feel better simply by knowing we have taken a specific treatment. Blind trials avoid this type of patient bias.

Double blind clinical trials

A double blind trial is one in which both the researchers and the patients do not know which treatments are given to which patients. This avoids patient and experimenter bias.

Types of Clinical Trials

Pilot studies and feasibility studies

These are small studies that may be done before a larger trial takes place.

Feasibility studies see if it is possible to do the main study, examining pre-trial factors such as whether patients and doctors would be willing to participate, or how long it might take to collect and analyze results. Findings from a feasibility study do not answer the main research question.

Pilot studies are smaller versions of the main study. They can help to test out the different parts of the study to see how well they work together. The findings from the pilot study can help to answer the main research question.

Prevention trials

This type of trial looks at whether a particular treatment can help to prevent cancer. These trials can be directed toward the general population or toward people who have a higher than normal risk of developing a certain cancer such as those that have a family history of the disease.

Screening trials

Screening trials involve testing people for early signs of cancer before they show any symptoms. These trials may be directed toward the general population, or toward a group of people with a higher than normal risk of developing cancer. Screening trials may look at the effectiveness of a new screening test compared to standard tests.

Treatment trials

Treatment trials are done in stages or phases (see section: “Phase of clinical trials” below). For trials that compare two or more treatments, the participants are randomly assigned to a particular treatment group. Randomized trials enable the researchers to get the most reliable information about how well a new treatment works.

A multi-arm treatment trial involves several different treatment groups (arms) at once, as well as the standard treatment group (the control group).

Cancer Clinical Trials: What you need to know – Northwell Health

Webinar: Cancer Clinical Trials

Roche Canada: Understanding Clinical Trials in Canada

Phases of clinical trials

Phases of clinical trials

Image source: ideastream.org

Clinical trials which examine the effectiveness of a particular treatment are generally done in four phases. Each phase has a different focus and helps the researchers to answer specific questions. In some clinical trials, phases may be combined.

Phases of Cancer Clinical Trials: An Introduction - Cancer.Net

Phase 1: these trials test an experimental drug on a small group of people for the first time. The purpose is to:

  • Look at the drug’s safety

  • Find out the safe dosage range

  • See if there are any side effects

Phase 2: the drug is given to a larger group of people (usually 100 or more) to:

  • Gather data on how well the drug works to treat a disease or condition

  • Check the drug’s safety on a wider range of people

  • Figure out the best dose

Phase 3: the drug is given to even larger groups of people (usually 1000 or more) to:

  • Make sure it is still effective

  • Monitor side effects

  • Compare it to commonly used treatments

  • Collect information about the drug that will allow it to be used safely on the market

Phase 4: these trials take place after the drug is approved and is on the market. Information is gathered on things like the best way to use a drug and the long-term benefits and risks.

Possible benefits of participating in a clinical trial

If you have a disease such as colorectal cancer, there could be personal benefits such as:

getting early access to a new treatment with positive results the treatment may cure or control your condition or improve your quality of life you may get more expert health care from the research teams that are involved in the study

Furthermore, participating in a clinical trial can help others by moving medical research forward.

Why should I consider a cancer clinical trials? - Genentech

Possible risks of participating in a clinical trial

Since clinical trials often compare a new drug to an approved drug or combination of drugs that are part of the current standard of care, you may not always receive a new treatment. Even if you do get a new drug, it may not help you. It may be less effective than the standard therapy. As with any treatment, there is also the risk of serious short- or long-term side effects.

Reducing your risk

Before you participate in a clinical trial, it is very important that you understand what is involved and give your informed consent. Talk to your doctor to best understand the risks and benefits so you can make an informed choice about participating.

Patient Safety in Clinical trials

Clinical Trials and Safety – cancer.net

Video Library – PRE-ACT (Cancer.Net)

Finding the right clinical trial

Talk to your medical team to find out if participating in a clinical trial could be right for you. You can also access the clinical trial websites and databases below to help you learn more and find trials specific to your needs and location.

Finding a Clinical Trial (Cancer.Net):

Canadian Clinical Trials Resources

It Starts With Me

www.itstartswithme.ca is the central resource created by N2 Canada to help potential participants, families, caregivers, and the general public to understand basics about clinical trials and clinical research.

Download the N2 Canada It Starts With Me Brochure on Clinical Trials


Canadian Cancer Clinical Trials Network (3CTN) Clinical Trials Navigator

3CTN’s Clinical Trials Navigator can help patients with cancer search and connect to clinical trials they may be eligible for. The patient begins by filling out a Consent Form, or their physician may fill out a Referral Form. The patient is connected with the Clinical Trials Navigator, which will help them search for all eligible trials.

Contact the Clinical Trials Navigator at clinicaltrialsnavigator@wrh.on.ca;

P: (519) 253- 3191 ext. 58583

F: (519) 253- 8102

Canadian Cancer Trials Database

This Canadian database enables you to filter your clinical trial search by cancer type, province, city/town, as well as by drug, age, and other specifics of your disease. The site also provides an option to sign up for trial alerts, which will notify you by e-mail when a new trial for a selected type of cancer or locations becomes available.

Health Canada’s Clinical Trials Database

Provides a listing of specific information relating to phase I, II and III clinical trials in patients. You can contact Health Canada support staff directly by email or telephone for assistance.

Canadian Cancer Trials Group (CCTG)

CCTG is a cooperative oncology group that designs and administers clinical trials in cancer therapy, supportive care and prevention across Canada.

Provincial Clinical Trials Databases

British Columbia:

BC Cancer


Prince Edward Island:

PEI Cancer Treatment Centre

US and International Clinical Trials Resources

National Cancer Institute

In-depth educational information and videos about participating in clinical trials. You can fill out the NCI clinical trial search form to find a trial or contact NCI for help by phone, email or online chat. NCI-supported trials are offered at sites across the US and Canada.

Clinicaltrials.gov Database

An American database of privately and publicly funded clinical trials from around the world.

World Health Organization Clinical Trial Search

The World Health Organization Clinical Trials Search Portal enables the public to access a central database of registered clinical trials from all over the world.

CureiTT app

The CureiTT app is designed to help you to identify and participate in clinical trials. The app is a web and mobile-friendly platform that connects you to clinical trials in your geographical area that match your disease profile.

Available for download on Google Play and the Apple App Store.

American Cancer Society

Educational information, videos and resources about clinical trials. Cancer Research UK https://www.cancerresearchuk.org/about-cancer/find-a-clinical-trial Educational information, resources and search engine for cancer-related clinical trials.


in-depth clinical trials information and resources, including the PRE-ACT! series of short educational videos about clinical trials.

Clinical Trials: Colorectal Cancer-Specific

Fight Colorectal Cancer

General information about clinical trials with downloadable educational materials.

Fight Colorectal Cancer Clinical Trial Matching Service

By filling out a short questionnaire, you can identify clinical trials specific to your diagnosis, stage and treatment history from the full national database of colorectal cancer treatment trials. You can also call 866-278-0392 to speak to a Clinical Trial Navigator at EmergingMed for direct assistance.


Offers a free and confidential service that allows patients to curate a personalized list of clinical trials.

Smart Patients

Lets you search and browse colorectal cancer clinical trials. The Smart Patients Colorectal Cancer Community is available for patients and their families affected by colorectal cancer to learn from each other.

CCC and Clinical Trials in Canada


In the fall of 2020, in collaboration with Colorectal Cancer Canada, Q-CROC has established and coordinated a community of practice in colorectal cancer. This entity includes a group of physicians who work and interact together at quarterly meetings to learn from one another, sharing challenges, experiences and good practices in their professional clinical research practice.

The objectives of this community of practice are to optimize the recruitment and referral of clinical trial participants between centres, to facilitate the flow of information related to current and future clinical trials, and to increase the visibility of the community with study sponsors. This group of physicians also has a desire to improve access to clinical trials in targeted therapy.

For more information about CCC’s involvement in clinical trials in Canada, visit our page on a Patient-Centered Approach to Clinical Trials (PACT).

Last updated: July 2021


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