Examining the Link Between Breast Cancer and Genetics
Do inherited genetic mutations affect your likelihood of developing breast cancer? Local experts weigh in on the DNA-cancer link.
The reality of breast cancer hit Tracy Elliman early. She was 10 when she lost her grandmother to the disease. While her grandmother was dying, her mother was diagnosed with Stage 3 breast cancer. Seven years later, her mother developed a new cancer in the other breast.
“We never thought of the connection,” says Elliman, 41, of Kennett Square, Pa. “We just thought it was a terrible coincidence.”
But the discovery of the breast cancer genes raised their suspicions. They wanted to know if the mutations resided in their DNA. It was 2004 and by that time, Elliman was married and the mother of two young children. The testing confirmed their fears: both were carriers of the BRCA 1 mutation.
Women without a BRCA mutation or a strong family history of breast cancer have a 13 percent lifetime risk of developing breast cancer compared to a 60 percent risk for women with the harmful genes. The mutations also increase the risk for developing ovarian cancer.
Elliman enrolled in two clinical trials designed to screen her for both cancers. But living with the fear of developing breast cancer was taking its toll and when funding for one of the programs was cut, she opted for prophylactic surgery. Her ovaries and tubes were removed in 2008. The following year she underwent a bilateral mastectomy and reconstruction.
The surgery reduced her risk of developing a breast cancer by about 90 percent.
Elliman found the decision empowering. “I had done my homework and felt I was in the right place,” she says. “I knew I was doing the right thing.”
Fewer than 10 percent of all breast cancers are thought to be due to this inherited genetic mutation. Researchers estimate that one in every 300 to 500 people carries a BRCA mutation.
“It’s a fairly small group of extremely high-risk people who are carrying the mutation,” says Dr. Diana Dickson-Witmer, surgeon and medical director of the Breast Center at the Helen F. Graham Center at Christiana Care Health System.
A BRCA genetic mutation is more likely to run in a family if: many women in the family have had breast and/or ovarian cancers, particularly before age 50; there are instances of bilateral breast cancers; a male relative has had breast cancer or early onset prostate cancer; a history of gastrointestinal cancers; or the family is of Eastern European Jewish descent.
But even if you don’t fall into any of these categories, you’re not out of the woods. Women without a strong family history of breast and other cancers can still be at a high risk for developing breast cancer.
“When you have a striking family history and you test negative (for either BRCA mutation), then it most likely means a different gene that we haven’t discovered yet or we’re unable to test for yet,” says Zohra Ali Khan-Catts, director of Cancer Genetic Counseling at Christiana Care Health System.
Dickson-Witmer stresses the need for women to educate themselves about their risk for breast cancer when considering surgical options to prevent the disease.
“There’s no question if your risk of developing a breast cancer is upwards of 60 percent, that if you reduce that by 90 percent, then it’s worth sacrificing your breasts,” she says. “But in groups of women who are at moderate risk, it is not worth the risk of surgical trauma or sometimes years of chest-wall discomfort that can be the true price of having both breasts removed.”
For more about the Delaware Breast Cancer coalition, click here.