Joining FORCES is the FORCE newsletter with news, views and supportive information for individuals concerned about hereditary breast and ovarian cancer.
by Drea Thew
A strong family history of breast or ovarian cancer is a well-known hallmark for possible BRCA family mutations. When women from such families develop breast cancer before age 50, they may be appropriately identified by their health care team as candidates for genetic counseling and testing. The guidelines are less clear, however, for women who develop early-onset breast cancer but have no close relatives with breast or ovarian cancer.
Researcher and FORCE Health Care Advisory Board member Dr. Jeffrey Weitzel conducted a study which was recently published in the Journal of the American Medical Association. Dr. Weitzel found that having few women on each side of the family who reached an older age to express the trait can be an important predictor of whether a young breast cancer patient carries a BRCA mutation, even in the absence of any known family history of cancer. His research may help the medical community better determine which young women with breast cancer should consider genetic testing.
The 306 study participants were patients referred for hereditary cancer risk assessment at the City of Hope Cancer Screening and Prevention Program Network in California. All were diagnosed with breast cancer before age 50; only patients with no family history of breast or ovarian cancer in first-degree (parents or siblings) or second-degree (grandparents, aunts) relatives were included. Participants were divided into two equal groups based on their family history: A “limited” group included women with one or no first- or second-degree female relatives on either parent’s side who lived past age 45, and women with no information about their biological relatives. All other participants were considered to have “adequate” family structure.
When tested for BRCA mutations, 29 participants (9%) were found to have deleterious BRCA1 or BRCA2 mutations. Women in the limited family group were almost three times as likely to have a deleterious mutation than women with an adequate family structure. Specifically, a limited family structure on the father’s side was predictive of having a mutation. Three statistical models (Couch, Myriad and BRCAPRO) commonly used to predict the likelihood of BRCA mutations proved to be poor predictors of which women with limited female relatives had a mutation.
Having few female relatives past age 45 does not in and of itself increase risk of BRCA mutations, but it can allow a BRCA mutation to “hide” in the family tree until someone is diagnosed seemingly “out of nowhere.” Geneticists and genetic counselors specializing in hereditary cancer risk take this into account when counseling women with early-onset breast cancer about BRCA testing. Unfortunately, armed with just one or two generations of family history, oncologists, primary care physicians, and other providers without specific genetics training may fail to refer women with early breast cancer and a limited family structure for genetic counseling. This oversight may be falsely reassuring and leave many women with early-onset breast cancer in the dark about their own future cancer risks, as well as the risk of cancer in other family members. Hopefully, Dr. Weitzel’s study will allow health professionals to accurately assess which of their patients with early-onset breast cancer should be referred to a genetics expert.
…consult first with a genetics expert to review your family medical history, discuss all your options, and determine which test, if any, is appropriate for you. If you are tested, a genetics expert can properly interpret your test results, explain the implications of those results, and describe your overall risk for hereditary cancer. The National Society of Genetic Counselors offers a lookup tool for finding a genetic expert by state and specialty. The National Cancer Institute provides a lookup tool for healthcare providers offering genetic counseling and testing that includes information on providers’ certification.
The Young Survival Coalition (YSC) is a national nonprofit organization devoted to action, advocacy and awareness concerning young women and breast cancer. Their website includes comprehensive information about early-onset breast cancer and maintains a busy message board where visitors can share issues with other young women and find support.
Collaborating with Living Beyond Breast Cancer, YSC hosts the only national conference for young women with breast cancer. Visit the YSC conference website for more information.
Weitzel JN, Lagos VI, Cullinane CA, Gambol PJ, et al. Limited family structure and BRCA gene mutation status in single cases of breast cancer. Journal of the American Medical Association, 2007; 23: 2587-2595.