Aside from BRCA testing, several other genetic tests are useful for determining whether you have a high risk of developing certain cancers. As with BRCA, tests for these particular genetic cancers should be considered only in those with strong family histories.
- Melanoma. If this deadly skin cancer runs in your family, you should ask your doctor about getting tested for inherited melanoma. The test looks for mutations in genes called CDKN2A and CDK4. Those who test positive should visit a dermatologist every six months, says Kaklamani, for skin checks to detect moles and other growths before they turn cancerous. And they should take seriously the oft-repeated advice to cover up and use sunscreen.
- Colon cancer. You may be at increased risk if close relatives developed colon cancer before age 60 or had colon cancer as well as endometrial cancer. Tests screen for gene mutations that cause hereditary forms of colon cancer such as familial adenomatous polyposis and Lynch syndrome. Those who have these gene mutations can get a yearly colonoscopy to remove polyps before they become cancerous, says Kaklamani. Those with dozens or hundreds of polyps, though, may want to consider surgery to remove all or part of their colon, which has been shown to cut cancer risks.
- Thyroid cancer. Hereditary thyroid cancer is more deadly than traditional thyroid cancer. Genetic testing looks for mutations in the RET gene, and removing the gland—a thyroidectomy—may be the best way to prevent cancer. Taking thyroid hormone pills would then be necessary.
While more genetic tests for cancer will surely crop up in the next few years, inherited gene mutations account for a small portion of cancer cases; most cancers are caused by a combination of lifestyle and environmental factors and how they interact with your genes. A negative test for a cancer-causing gene can bring some relief, but it doesn't completely eliminate your risk of getting that cancer.