Two inherited gene variations — BRCA1 and BRCA2 — have been strongly linked to early-onset breast and ovarian cancers. It is the BRCA1 mutation that led actress / activist Angelina Jolie, at age 37, to undergo a much-publicized preventive double mastectomy in 2013. Jolie’s mother, actress Marcheline Bertrand, died of breast cancer at the age of 56. Bertrand’s mother was 45 when ovarian cancer took her life. Bertrand’s sister died in 2013, after battling breast cancer for nine years.
Data from the National Cancer Institute attributes as much as 15% of all ovarian cancers to the BRCA gene mutations. The institute estimates 39% of women with the BRCA1 mutation and 11% to 17% of those who inherit the BRCA2 mutation will be diagnosed with ovarian cancer by the time they turn 70 years old.
“Heredity is not destiny,” says Dr. Timothy R. Rebbeck, of the Abramson Cancer Center, a branch of the University of Pennsylvania Perelman School of Medicine. There are specific measures a woman can take that significantly reduce the odds of developing a BRCA-related cancer. Jolie’s mastectomy is certainly effective but there are less extreme measures that help, too, such as breastfeeding.
Reddeck led a team of researchers through analysis of 44 high-quality studies on the BRCA gene mutation and its effect on cancer. His study identified various measures that can be taken to minimize the negative impact of this gene variant:
- Women with the BRCA1 variant who breastfeed their children are less likely to develop ovarian cancer than women with BRCA1 who do not breastfeed.
- Tubal ligation lowers the risk, also.
- Women with the BRCA1 variant who have their first live birth before age 25 are more likely to develop breast cancer than when the first live birth occurs between ages 25 and 29. The cancer risk drops even further when first live birth occurs after 30.
- Breastfeeding and / or tubal ligation have no effect on the risk of breast cancer development.
- Women with either BRCA1 or BRCA2 who have used birth control pills are significantly less likely to get ovarian cancer than women with either gene variant who never use birth control pills.
- Cigarette smokers with BRCA2 are more likely to develop breast cancer than women with the mutation who do not smoke.
Dr. Susan Domcheck, a co-author of the Reddeck study, says “Patients deserve better cancer-risk reduction options than surgically removing their healthy breasts and ovaries.” Domcheck, affiliated with the University of Pennsylvania Basser Research Center for BRCA, considers it “imperative that we continue examining and building upon past research in this area so that we can provide BRCA mutation carriers with options at every age and at every stage of their lives.”
Reddeck encourages “women with BRCA mutations (to) take proactive steps that may reduce their risk of being diagnosed with ovarian cancer.” There is a growing body of evidence that breastfeeding every child for six months or longer produces life-long health benefits for both a mother and her child.
Source: Rebbeck, Timothy R, et al. “Modifiers of Cancer Risk in BRCA2 and BRCA2 Mutation Carriers: Systematic Review and Meta-Analysis.” JNCI / Journal of the National Cancer Institute. Oxford University Press. May 14, 2014