Insights into Risks for Hereditary Breast Cancer
By Lisa Schwartz
GBMC Greater Oncology Today
There are many things that can be passed down from generation to generation. Take hair color or freckles, for example. Certain diseases and genetic mutations, however, can also be passed through family lines. Knowing your family’s medical past can be a history lesson that can one day save your life.
According to genetic counselors in The Harvey Institute for Human Genetics at GBMC, five to 10 percent of all breast cancer cases are hereditary. Mutations in two genes specifically – BRCA1 and BRCA2 – account for about 80 percent of inherited breast cancer cases. Mutations, or alterations, of these genes have been associated with an increased risk of developing breast and ovarian cancers. Individuals with an extensive family history of one or both of these cancers can be referred for genetic testing.
“One purpose of genetic testing for hereditary breast cancer is to figure out the magnitude of the risk for developing the disease,” says Karen Hanson, MS, genetic counselor in The Harvey Institute for Human Genetics. ”What genetic testing does is provide insights into family history and trends so that women can follow a healthy lifestyle, including diet and annual screenings, and make informed health decisions.”
Counselors help educate individuals about the benefits and limitations of genetic testing, advising patients of their risks as well as their future options. Family medical history, early screening and detection methods, as well as management and treatment of cancer, are also discussed at length.
“The majority of the patients we see already have cancer and are worried about others in their family who may develop the disease,” explains Ms. Hanson. “We also see unaffected women who come in for testing because of a strong family history of the disease. Ideally, we like to test an individual who already has cancer for BRCA1 and BRCA2 mutations first to determine if there is a hereditary link.”
Women should be aware that not all hereditary breast cancer patients have a BRCA1 or BRCA2 gene mutation. Yet, there is a strong likelihood of a hereditary syndrome if the disease exists on one or both sides of a family over two or three generations. Most breast cancer, however, is not hereditary.
A three-generational family history is the most helpful tool for determining if a cancer is hereditary. Hereditary risk factors include:
- Early age of diagnosis (before age 50)
- Breast and ovarian cancer in the same individual
- Bilateral breast cancer, multiple tumors in the same breast or tumors in both breasts
- Additional relatives with breast or ovarian cancer
- Ashkenazi Jewish descent