The Breast-Cancer Gene

There are multiple factors that can increase a woman’s risk for breast cancer. Obesity, alcohol use, unhealthy diet, hormone therapy, ethnic background (most notably, women of Ashkenazi Jewish descent), and age can all play a role when it comes to breast-cancer risk. Information about a woman’s genetics especially — including family history of breast cancer and other cancers as well — provide huge clues into the likelihood of developing the disease.

There are two genes in particular, called BRCA1 and BRCA2, that have been studied in depth: BRCA1 and BRCA2 are part of a group of genes called tumor suppressors, which means that they help the body fight against the production and spread of cancerous cells.

When one or both of these genes are mutated in some way, it can impede the body’s ability to prevent cancer-cell growth and therefore increase a woman’s risk of breast cancer. BRCA1 and BRCA2 mutations can also lead to an increased risk of uterine and cervical cancers, as well as melanoma and other cancers. In men, it can lead to an increased risk for breast cancer, too, in addition to increased risks for prostate and testicular cancers, among others.

Depending on your family history, your doctor might recommend that you see a genetic counselor to discuss the possibility of genetic testing. If you have two or more first-degree family members (that is, parents, offspring, or siblings) who were diagnosed with breast cancer, testing is likely to be recommended. If you are of Ashkenazi Jewish descent, even one first-degree family member with a breast-cancer diagnosis could be enough reason for you to get tested, as women of this ethnicity have been found to have a higher frequency of a few particular BRCA1 and BRCA2 mutations. All of this can be discussed with your doctor, who can help you understand your risk level and determine whether genetic testing is a smart choice.

Genetic testing for the breast-cancer genes is performed with a simple blood test, and the results can be negative, positive, or unclear. If the result is negative, it means that your risk for developing breast cancer is no higher than that of the general population, but it doesn’t mean that you are guaranteed to never develop breast cancer (or any other type of cancer), and you should continue to get regular checkups and mammograms.

If the result is positive, it doesn’t mean that you are going to develop breast cancer, but it definitely means that your risk is higher than that of the general population. You have several options at this point, including:

• Surveillance. You will need to be diligent about receiving regular mammograms and any other recommended testing.
• Medication. Drugs such as tamoxifen have been shown to help reduce a woman’s risk for developing breast cancer and/or reduce the risk of recurrence.
• Mastectomy. Doctors often recommend this for women who have a serious risk of developing breast cancer. Removing both breasts might be a life-saving option, but it’s certainly a decision that requires a lot of research and examination.

If your test is ambiguous, it means that there is a mutation in your BRCA1 or BRCA2 gene, but not one that has been associated with cancer as of yet. It can be frustrating to undergo the test only to receive an unclear result, but it does happen: It doesn’t mean that your cancer risk is increased, but it also doesn’t mean it is decreased.

Regardless of your result, making healthy choices (eating right, exercising, quitting smoking, and cutting down on alcohol) can help to combat your risk for breast cancer.

In the end, we can’t control who gets cancer, but there certainly are steps we can take to help protect ourselves.