Dear Doc,
Is there really a breast cancer gene? If my grandmother and mother both had breast cancer, the likelihood of me getting it is high, but does that mean I’m genetically disposed? I’m nearly 50 and have done my regular mammograms, and so far so good.Barbara Simmons
Dear Barbara,
There are genes associated with breast cancer and they are known as BRCA1 and BRCA2. Their mutation is a common cause of hereditary breast cancer. These genes create products that help repair damaged cells that are prone to cancer.
13% of women in the USA population develop breast cancer, whereas 55-72% of women with the variant of these genes develop breast cancer by 70 years.
Of note, variants in these genes are also associated with an increased risk for ovarian cancer. The average woman has a 1.2% chance, whereas those with BRCA1 mutation have a 39-44% chance and 11-17% in those with BRCA2 variant. These variants increase the risk of other cancers, but breast cancer is the predominant presentation.
The correlation between these gene variants and cancer is why physicians ask patients for their family history of cancer. This would lead to earlier screening (testing) for cancer in the individual.
