Arizona Oncology - The US Oncology Network

Benefits of Cancer Genetic Testing

12/22/2015

By Mike Janicek, MD, Arizona Oncology

Genetic testing is a wonderful tool for physicians and patients.  5-10%, and in some cases up to 25% of certain cancers are due to an inherited genetic cause, or mutation, which is identifiable with genetic testing.  Not only can this provide information that could impact treatment decisions if a person has cancer, but it allows physicians to screen appropriately for any other cancers a patient may be at increased risk for.  It is also useful for relatives who can then be tested for the familial mutation.  Genetic testing provides the ability to not just help one person, but all of their blood relatives across the whole family tree.

Genetic testing also has some practical value for treating, not just preventing, cancers. First, patients who have a BRCA mutation actually have a relatively better chance of survival for breast and ovarian cancer.  Second, new drugs like PARP inhibitors specifically target the BRCA mutation to exploit a weakness in the cancer. One of them has recently been FDA-approved in the treatment of ovarian cancer.

The genetic testing is complex, as there are now dozens of other genes that can be tested, beyond the BRCA genes.  It is not just a simple matter of positive or negative results. There may be unusual “variants of uncertain clinical significance” that require the expertise of a genetic counselor to decipher.

Genetic testing should be considered when there is a strong family history of cancer or with rare cancers such as ovarian cancer or male breast cancer.  There are many facets to a genetic risk assessment that are useful to the physician, the patient fighting cancer, and family members who might potentially benefit from this life-saving information. To learn more about the benefits of genetic testing for cancer prevention and determining treatment options, call our Cancer Genetic Risk Assessment team at 480.223.9828.