The surgical removal of ovaries or breasts significantly improves the longevity of women who are most at risk for breast and ovarian cancer, according to a study published Tuesday in the Journal of the American Medical Association (JAMA).
Researchers observed nearly 2,500 carriers of the BRCA1 and BRCA2 gene mutations in the United States, England, Holland and Austria. Forty percent of the women chose to have their ovaries and fallopian tubes removed as a precaution against cancer. Their reward? They were 89% less likely to develop ovarian cancer and 61% less likely to develop breast cancer over three years than their counterparts who did not have prophylactic surgery. Among the 250 study participants who underwent preventive mastectomies, none developed breast cancer during the study follow-up. Additionally, a patient’s surgical choice affected overall mortality rates, both cancer related and not: only 3 percent of surgery participants died at the time of the study follow-up versus 10 percent of those who avoided the surgery.
The study, which is the largest of its kind to date, confirms what many doctors have already known — that pre-emptive breast or ovary removal can dramatically reduce a high-risk woman’s odds of developing cancer. Most doctors currently recommend breast removal for all women who are diagnosed with a BRCA mutation; they also recommend ovary removal once women are finished having children.
Women who carry the BRCA1 or BRCA2 gene mutations have a 56% to 84% lifetime risk of developing breast cancer — five times the risk of non-carriers. Women with the BRCA1 mutation have a 36% to 63% lifetime risk of ovarian cancer — 10 times that of other women. BRCA2 confers a 10% to 27% risk of ovarian cancer. About 5% to 10% of breast cancer cases are attributable to genetic mutation rather than environmental factors. Although BRCA mutations may appear in any woman, they are slightly more common among Ashkenazi Jews.
The new study was observational — rather than a randomized, controlled trial, which is the gold standard of studies — so other factors, like diet and exercise, stress levels and increased cancer screening may have contributed to the results. For example, women who had their ovaries removed could be more cautious about their health in general, compared with women who chose not to have the prophylactic surgery. Another statistic from the study might corroborate this: women who did not undergo the surgery were more likely to die from any cause, cancer or not.
Further, ovary removal is serious surgery that forever alters hormone levels. It means a loss of estrogen and progesterone and causes early menopause, possibly accelerated osteoporosis, and potential heart problems. Women who elect to have the surgery will not be able to become pregnant, an additional consideration. However, patients must weigh the drawbacks against the benefits: significant reduction in cancer and death risk.
For both women and physicians who fear breast or ovarian cancer as an inevitability, the new evidence for a life-saving solution comes as a comfort. Dr. Virginia Kaklamani of Northwestern University’s Feinberg School of Medicine, who wrote an editorial accompanying the study in JAMA, says the findings help validate the usefulness of genetic testing for patients. “I can tell them, ‘If we know you test positive, there are things to do that will help you live longer,'” she told the AP.