Breast Cancer Genes Affect Men, Too
Researchers Say Men Unaware That BRCA Mutations Raise Their Risk of Cancer
Dec. 14, 2007 (San Antonio) -- Men whose mothers, sisters, or daughters test positive for the inherited gene mutation known as BRCA are at increased risk of developing breast and prostate cancer, but nearly half are unaware of that risk, a new study suggests.
Like women, men can harbor mutations in the BRCA1 and BRCA2 genes, says Mary B. Daly, MD, PhD, senior vice president for population science at Fox Chase Cancer Center in Philadelphia.
In women the inherited gene mutations account for just 5% to 10% of all breast cancers diagnosed in the U.S. BRCA1 and BRCA2 mutations are the most common ones linked to hereditary breast cancer and ovarian cancer, but the lifetime risk of developing breast cancer is between three times and seven times higher for carriers than noncarriers, according to the National Cancer Institute.
A man who carries the BRCA2 mutation faces a 7% risk of developing breast cancer in his lifetime, she says. In contrast, the chance that the average American man will develop breast cancer is less than 1 in 1,000.
The BRCA1 mutation doubles a man's risk of developing prostate cancer, giving him a 33% chance of developing the disease in his lifetime, she says.
Both BRCA1 and BRCA2 may also raise a man's risk of pancreas cancer and melanoma, Daly says.
Despite these risks, "men think it's all a female issue," she tells WebMD. "They don't even understand they can inherit the gene and pass it on to their offspring."
Men Unaware of Breast Cancer Risks
Daly and her colleagues interviewed 24 men, each with a first-degree female relative who tested positive for a BRCA1 or BRCA2 mutation. All the women said they told their relatives the results of their genetic test, but only 18 of the men remembered receiving them.
Forty percent of the men who remembered receiving results did not know that the test results increased their own risk of cancer, Daly says.
She reported the results here at the San Antonio Breast Cancer Symposium.
Fourteen of 24 men expressed concern about the meaning of the test results, but "most were worried not for themselves but for their daughter or other relative," Daly says.