Some inherited genetic mutations increase cancer risk by inhibiting the ability of other genes—cancer-protective ones—to do their jobs. These mutations, dubbed cancer genes, can dramatically raise the risk of first and subsequent cancers. The most common cancers with a genetic component include breast, ovarian, prostate, and colon cancers.
In recent years, doctors have tested people suspected of having cancer genes so they could take steps to avoid future malignancies or detect them at their earliest, most treatable stages. Sharon Osbourne was tested before she opted for a prophylactic double mastectomy.
Andrea Kabourek, the track coach, was young when she was diagnosed with breast cancer. Her grandmother had died of ovarian cancer. Based on those facts, she was tested for a common genetic mutation associated with both cancers, called BRCA1, and was found positive. She plans to have her ovaries removed after age 35, which will drastically reduce her risk.
What you can do: If you developed a cancer at an age considered young for developing it, or if you have a strong family history of certain cancers, talk to a genetic counselor. She can help you decide whether you should have one of the dozens of cancer genetic tests now available and help you interpret the results. The tests help determine what cancers you are at increased risk for, but they can’t determine with certainty whether you’ll develop any cancer.
Physicians also need to know your family history of cancer to monitor you appropriately. “Say you had breast cancer at 40, and your dad had colon cancer. That might be enough of a concern to start your colon cancer screening earlier than the standard guidelines,” says Dr. Wood.