ICARE Newsletter Winter 2017

Ask the Expert

The following question was addressed by Dr. Steven Narod who is a Tier I Canada Research Chair in Breast Cancer and a senior scientist at the Women’s College Research Institute in Toronto, Canada. Dr. Narod is a world-leader in the field of breast and ovarian cancer genetics.

Q. Does salpingo-oophorectomy reduce the risk of breast cancer in those with BRCA mutations

A. Among women in the general population, risk-reducing salpingo-oophorectomy (RRSO) (i.e. removal of the ovaries and fallopian tubes) is recommended to reduce the risk of ovarian and fallopian tube cancer. The removal of the ovaries may reduce the risk of breast cancer as well. In the general population removal of the ovaries before menopause cuts the risk of breast cancer by 30% or more. Similarly, early studies in BRCAcarriers in the United States (US) suggested that removal of the ovaries also cuts their breast cancer risk by half or more, especially when done at an early age. However, a recent Dutch study did not observe a reduced risk of breast cancer after RRSO in BRCA1 carriers.1 The authors of this Dutch study suggest that previous findings may have been due to the design of the studies and how the data was analyzed and casts doubt on the earlier studies. The original US-based study teams subsequently re-analyzed their data but still concluded that RRSO reduced breast cancer risk among BRCA1 and BRCA2 carriers.2

Subsequently, our group led an international study with data from many centers (including ICARE participants) and included almost 4000 BRCA carriers. These women were followed for up to ten years for new cases of breast cancer. The study showed that RRSO reduced the risk of breast cancer risk in BRCA2 carriers, but did not reduce breast cancer risk among BRCA1 carriers.3

Taken together, data suggest there is a benefit of RRSO to lower breast cancer risk among BRCA2 carriers, but not BRCA1 carriers. However, given the strong protective effect of oophorectomy on ovarian cancer risk and on all-cause mortality we recommend an oophorectomy for BRCA1 carriers at age 35 and for BRCA2 carriers at age 40.4

1Heemskerk-Gerritsen BA, et al. J Natl Cancer Inst. 2015 Mar 18. PMID: 25788320.
2Chai X, et al. J Natl Cancer Inst. 2015 Aug 11. PMID: 26264690.
3Kotsopoulos J, et al. J Natl Cancer Inst. 2016 Sep 6. PMID: 27601060.
4Finch AP, et al. J Clin Oncol. 2014 May 20.PMID: 24567435 

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