“Test all patients with cancer”: 1 in 8 have inherited mutations

November 2020

Findings from a recent study conducted by the Mayo Clinic found that while about 1 in 8 patients with cancer have an inherited genetic mutation that likely contributed to the development of their cancer, nearly half of these mutations would have been missed under current clinical guidelines.

The study was the largest of its kind, including approximately 3000 patients with a wide range of cancer stages and types. The findings demonstrate that current clinical practice guidelines do not sufficiently prioritize genetic testing, which can shed light on more effective management strategies specific to the individual.

In the study, 2,984 patients with cancer who were receiving treatment for a variety of cancer types were included. All patients were tested for about 84 genes using Next Generating Sequencing (NGS), a type of DNA sequencing technology that rapidly scans the entire human genome for mutations. Patients who tested positive for known cancer mutations were offered genetic counseling, which was also offered to their family members. A significant advantage of genetic testing is that family members are alerted to specific mutations that could lead them to participate in screening to detect early forms of cancer. Based on the results of their genetic testing, patients were offered changes to their treatment for which they may otherwise have not been eligible, including changes to surgical management, immunotherapy, or enrolment in a clinical trial.

Currently, genetic testing is underused in cancer care, often as a result of outdated guidelines that limit testing to a narrow group of high-risk patients, such as those with inherited disorders such as Lynch Syndrome. Cost has also been a limiting factor to wider access, though with the advent of automatic genetic testing technologies such as NGS, the previously high cost of performing genetic testing manually has decreased significantly.

Lead researcher Niloy Samadder, MD, from the Mayo Clinic states that the Mayo Clinic will be changing its clinical practice at all four of its cancer centers, offering every cancer patient genomic evaluation, including genetic testing to screen for any underlying genetic mutations. This information will then be used to help clinicians decide how to design the best surgical and treatment options for that patient and their family.

Take away message:

In the era of precision medicine, genetic testing in cancer care should no longer be restricted to a small subset of high-risk patients. With the advent of automated technologies including Next Generation Sequencing that help to minimize cost barriers, all patients with cancer should undergo genetic testing to identify mutations that could enable them to access more tailored and effective treatments.