Women with the inherited mutations of the BRCA1 or BRCA2 genes who had preventive (prophylactic) breast removal (mastectomy) or the removal of the fallopian tubes and ovaries (salpingo-oophorectomy) were found to have a significantly lower risk of developing ovarian and breast cancers, says a study published in JAMA (Journal of the American Medical Association), September 1st issue.

The authors wrote that females who carry the inherited mutations of the BRCA1 or BRCA2 genes have a considerably higher chance of developing breast or ovarian cancer – there is a 56% lifetime risk of breast cancer and 84% lifetime risk of ovarian cancer.

The authors added:

Women who are mutation carriers have cancer risk-management options that include risk-reducing salpingo-oophorectomy, risk-reducing mastectomy, annual cancer screening, and chemoprevention.

Susan M. Domchek, M.D., of the University of Pennsylvania School of Medicine, Philadelphia, and team carried out a study involving 2,482 women who had the BRCA 1 and BRCA 2 mutations to find out what their cancer risk reduction was following a prophylactic salpingo-oophorectomy and mastectomy, incorporating mutation type (BRCA1 vs. BRCA2), and cancer history (prior history of breast cancer vs. none). The women’s gene mutations were determined between 1974 and 2008.

The study was performed at 22 clinical and research genetics centers in North America and Europe. The participants were monitored through to the end of 2009.

Breast Cancer Risk: The investigators found that:

  • None of the women with the mutated genes who had a prophylactic mastectomy developed cancer during the 3-year follow-up period.
  • 7% of the women with the mutated genes who did not have a prophylactic mastectomy developed cancer during the 3-year follow-up period.

Ovarian Cancer Risk: The investigators found that:

  • Risk-reducing salpingo-oophorectomy was associated with a decreased risk of ovarian cancer, with no ovarian cancer events seen during the 6 years of prospective follow-up in BRCA2 mutation carriers without prior breast cancer who underwent the procedure.
  • Three percent of women without salpingo-oophorectomy over a similar follow-up period were diagnosed with ovarian cancer.

The researchers found no cases of ovarian cancer among women with the BRCA 1 mutation after salpingo-oophorectomy, which was also linked to a lower risk of breast cancer in BRCA1 and BRCA2 mutation carriers without prior diagnosis of breast cancer.

The authors wrote:

Compared with women who did not undergo risk-reducing salpingo-oophorectomy, undergoing salpingo-oophorectomy was associated with lower all-cause mortality (10 percent vs. 3 percent), breast cancer-specific mortality (6 percent vs. 2 percent), and ovarian cancer-specific mortality (3 percent vs. 0.4 percent).

“Association of Risk-Reducing Surgery in BRCA1 or BRCA2 Mutation Carriers With Cancer Risk and Mortality”
Susan M. Domchek, MD; Tara M. Friebel, MPH; Christian F. Singer, MD, MPH; D. Gareth Evans, MD; Henry T. Lynch, MD; Claudine Isaacs, MD; Judy E. Garber, MD, MPH; Susan L. Neuhausen, PhD; Ellen Matloff, MS; Rosalind Eeles, PhD; Gabriella Pichert, MD; Laura Van t’veer, PhD; Nadine Tung, MD; Jeffrey N. Weitzel, MD; Fergus J. Couch, PhD; Wendy S. Rubinstein, MD, PhD; Patricia A. Ganz, MD; Mary B. Daly, MD, PhD; Olufunmilayo I. Olopade, MD; Gail Tomlinson, MD, PhD; Joellen Schildkraut, PhD; Joanne L. Blum, MD, PhD; Timothy R. Rebbeck, PhD
JAMA. 2010;304(9):967-975. doi:10.1001/jama.2010.1237

Written by Christian Nordqvist