Women with Breast Cancer Gene Mutations May Need Frequent Screening (dateline September 15, 2004)
Women who carry genetic mutations that put them at higher than average risk of developing breast cancer may need to be screened for the disease more than once a year, according to a new study. Researchers found that women who carry BRCA1 (breast cancer gene 1) or BRCA2 (breast cancer gene 2) mutations were likely to develop breast cancer during the time between their yearly mammogram screenings. The study suggests that more frequent screening and additional tests with ultrasound and/or magnetic resonance imaging (MRI) may be necessary for these women.
BRCA1 and BRCA2 are two tumor suppressor genes that, when functioning normally, help repair damage to DNA (a process that also prevents tumor development). Ten years ago, researchers discovered that women who carry mutations of BRCA1 or BRCA2 are at higher risk of developing both breast and ovarian cancer than women who do not have these genetic mutations. Currently, women with BRCA1 mutations account for 5% of all breast cancer cases. The Mayo Clinic estimates that 20% of women who carry BRCA1 mutations will develop breast cancer by age 40, 51% by age 50, and 87% by age 60.
The American Cancer Societys breast cancer screening guidelines recommend that all women 40 years of age and older receive mammograms once per year, in addition to physical breast exams and monthly breast self-exams. Currently, there are no standard breast cancer screening guidelines for women with BRCA mutations.
To study this issue, Ian K. Komenaka, MD and colleagues from the Columbia-Presbyterian Medical Center in New York reviewed the medical charts of all BRCA mutation carriers who were followed by the genetic counselor at the Columbia-Presbyterian Comprehensive Breast Center between September 1995 and September 2002. Thirteen of these women (ages aged 32 to 59) decided to undergo intensive breast cancer screening.
Among these 13 women, the researchers found that six developed breast cancer in between their annual mammograms. The average time to develop breast cancer was five months after annual screening. In addition, four out of the six women were diagnosed with invasive breast cancer, which had already spread to the nearby axillary (armpit) lymph nodes in three cases.
Based on these findings, Dr. Komenaka and his team recommend that women with BRCA gene mutations undergo breast cancer screening more frequently than once a year. Nearly half of the women diagnosed with breast cancer were found to have dense breast cancer, which can make breast cancers more difficult to detect by mammography. Thus, the researchers recommend the use of additional techniques, such as ultrasound or magnetic resonance imaging (MRI), on these women, in conjunction with mammography.
Genetic testing is available for eligible women to determine whether they carry BRCA gene mutations. Typically, these women with:
Not every woman with a BRCA gene mutation develops breast cancer, but the risk for the disease is significantly higher for these women.