Study Sheds New Light on Reducing Women’s Genetic Cancer Risks
A prospective study involving researchers from Creighton and 10 other U.S. medical centers sheds new light on treatment options for women who are at genetically high risk of developing breast and gynecological cancers.
The research, reported in the Feb. 11 online edition of the Journal of Clinical Oncology, is the first to show that removing a woman's ovaries and fallopian tubes - an often recommended strategy to help prevent these hereditary cancers from occurring - may not be equally effective for BRCA1 and BRCA2 breast cancer-causing gene mutations.
The study showed that this surgery - called risk-reducing salpingo-oophorectomy (RRSO) - proved nearly twice as effective at reducing breast cancer risk in study participants with BRCA2 gene mutations, compared to women with BRCA1 gene mutations. However, the surgery did significantly lower the risk of gynecological (ovarian, fallopian tube, or primary peritoneal) cancers in study participants with the BRCA1 mutation.
"Further studies are needed. However, our findings should help women with these mutations and their doctors select strategies to reduce a patient's chances of developing breast and gynecological cancers," said study co-investigator Henry Lynch, M.D., director of the Creighton University Hereditary Cancer Center and holder of the Charles F. and Mary C. Heider Endowed Chair in Cancer Research. He estimated that the two BRCA mutations are responsible for about one-third of all known hereditary breast cancer cases.
"The bottom line is that lives can be saved. Clearly, these are compelling results, demonstrating that RRSO offers a significant level of protection against breast cancer for women with BRCA2," Lynch said. "Women with BRCA1 also benefit a great deal from this surgery, but our findings suggest they may be wise to consider other treatment options as well, including frequent monitoring and prophylactic mastectomy."
For the study, researchers looked at the incidence of breast and gynecological cancers among 509 women who had BRCA1 or BRCA2 mutations and underwent RRSO surgery and 283 women who had the mutations but no surgery. Participants, all ages 30 and older, were enrolled in the study from November 1994 to November 2005.
After a mean three years of follow-up, RRSO reduced the risk of breast cancer by 72 percent for women with a BRCA2 mutation, compared to 39 percent for those with a BRCA1 mutation. The surgery also reduced the gynecologic cancer risk in the BRCA1 group by 85 percent. Researchers could not determine the level of risk reduction for the BRCA2 group undergoing surgery, because so few gynecological cancers were observed in that group.
About 10 percent of all U.S. women are at genetic risk for developing breast cancer. For more information about hereditary breast cancer and other hereditary cancers, contact the Creighton University Hereditary Cancer Center at 1-800-648-8133 or visit the center's website at http://medicine.creighton.edu/HCI.