According to Dr. Lynn Dyess, a surgeon with USA Physicians Group and professor of surgery at the University of South Alabama College of Medicine, one in eight women will get breast cancer in their lifetime. Primary risks of breast cancer, she said, include family history, early menarche (starting menstrual cycles early in life), late menopause, having never been pregnant, or having your first full-term pregnancy after the age of 30.
Dr. Dyess said not everyone needs the BRCA gene test, a blood test that uses DNA analysis to identify mutations in either one of the two breast cancer susceptibility genes – BRCA1 and BRCA2.
“Many people walk in the office and are concerned because of the number of breast cancers being identified, and they request testing,” Dr. Dyess said. “But, they have no risk factors. The test is expensive and shouldn’t be performed without the appropriate indications.”
The BRCA gene test is offered only to people who are likely to have an inherited mutation, based on personal or family history, or who have specific types of breast cancer.
Dr. Dyess said only a small percentage of women with breast cancer actually have the BRCA gene mutation. Inherited BRCA gene mutations are responsible for about 5 percent of breast cancers and about 10 to 15 percent of ovarian cancers.
Women who do have inherited mutations in these genes face a much higher risk of developing breast cancer and ovarian cancer compared with the general population. “Rates vary, but literature would suggest that 60 to 85 percent of women with positive genes will get breast cancer in their lifetime, and about 50 percent with positive genes will develop ovarian cancer,” Dr. Dyess said.
If there is sufficient evidence that the patient may meet criteria for genetic testing, the first step is for the patient to meet with a genetic counselor to determine if the test is appropriate and to discuss risks and benefits of genetic testing. Dr. Dyess said there are trained counselors at the USA Mitchell Cancer Institute that assess and counsel women, as well as obtain the specimen for testing.
After having a BRCA gene test performed, you learn whether you carry an inherited BRCA gene mutation and receive an estimate of your personal risk of breast cancer and ovarian cancer.
“If I identify a patient who tests positive for the gene mutation, I would recommend follow-up counseling regarding the results,” Dr. Dyess said. “Women have an option about what to do or not to do if the test is positive, and it is important that a complete discussion of options be presented to the patient. These options include surgery, medications for prevention, and scheduled screenings for early detection.”
If a patient tests positive for the gene mutation and ultimately decides to undergo a double mastectomy, Dr. Dyess said literature suggests that the procedure would reduce the risk of developing breast cancer by up to 90 percent.
Again, Dr. Dyess said the implications of the test should strongly be considered before consenting to gene testing. “As most women who develop breast cancer do not have the gene, a negative test doesn’t necessarily mean the patient will not get breast cancer,” she said. “It should not give a false sense of security that they will not get breast cancer.”
Dr. Dyess said tools are available to determine if a patient is at increased risk for developing invasive breast cancer. The modified Gail model is a commonly used tool developed by the U.S. National Cancer Institute that asks simple questions about your age, number of breast biopsies, menarche, and pregnancy. The Gail tool can be found here - http://www.cancer.gov/bcrisktool.
Most importantly, Dr. Dyess said early detection is key. To learn more about early detection and risk factors of breast cancer, visit http://www.usahealthsystem.com/breast-cancer-2012.
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