Chemotherapy for Colorectal Cancer

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 liver. 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.

Types of 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.

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.

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.

Types of 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.

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.

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

  • 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

Chemotherapy Cycles

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, bi-weekly, 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.

How Chemotherapy Works

In cancer, a series of mutations (changes) 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 related to cell division and proliferation, 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 affects 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.

TRAITEMENTS

How Chemotherapy is Administered

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 continued needle sticks.

PICC

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. An access port outside the body is used to give the chemotherapy drugs. A PICC can remain in place for weeks or months and avoids the need for repeated needle sticks.

Intravenous Chemotherapy Drugs Include:

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.

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 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 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.

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 and Targeted Therapy

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.

Regional Chemotherapy

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.

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 more information on HAI chemotherapy, see the Hepatic Artery Infusion Pump Chemotherapy Program at Sunnybrook Hospital. 

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.

Red Flag – Side Effects Related to Chemotherapy

Red Flag – Side Effects Related to Chemotherapy

  • 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.

Red Flag – Side Effects Related to Chemotherapy

Red Flag – Side Effects Related to Chemotherapy

  • 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 of Chemotherapy

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.

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 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.

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.

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.

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 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.

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.

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.

For More Information On:

External Resources:

Chemocare
Canadian Cancer Society
Cancer Research UK