April 2008
Researchers have examined the impact of surgical removal of the ovaries on BRCA1 and BRCA2 mutation carriers separately for the first time.
Background
Women with BRCA1 or BRCA2 mutations have an increased risk of breast and ovarian cancer.
The surgical removal of the ovaries, known as risk-reducing salpingo- oophorectomy (RRSO), is well established as a risk reduction strategy for women with either BRCA1 or BRCA2 mutations. RRSO has been found to reduce the risk of epithelial ovarian cancer by at least 90 per cent and may also halve the risk of breast cancer. However, previous studies evaluating the benefit of this strategy have only examined BRCA1 and BRCA2 mutation carriers together or have limited their analysis to BRCA1 mutation carriers alone.
Research findings
Researchers compared the incidence of breast and gynaecological cancers between a group of 509 women who carried a BRCA1 or BRCA2 mutation who had undergone RRSO, and a group of 283 women with these mutations who did not have the surgery. For the purpose of this study the researchers define gynaecological cancers as ovarian, fallopian tube or primary peritoneal cancer.
The researchers found:
- RRSO was associated with a 72 per cent breast cancer risk reduction in women with BRCA2 mutations.
- A 39 per cent breast cancer risk reduction was noted in women with BRCA1 mutations. However, it did not reach statistical significance.
- The surgery reduced the risk of gynaecological cancer by 85 per cent in women with a BRCA1 mutation.
- The researchers noted a protective effect in women with a BRCA2 mutation, but were not able to estimate the level of risk reduction due to the low incidence of gynaecological cancers among women with this mutation.
- RRSO appeared to reduce the risk of oestrogen-receptor positive breast cancer by 78 per cent in women with either a BRCA1 or BRCA2 mutation, but had no effect on the development of oestrogen-receptor negative breast cancers.
The researchers concluded the protective effect of RRSO against breast and gynaecological cancers may differ between carriers of BRCA1 and BRCA2 mutations.
National Breast and Ovarian Cancer Centre comment
This study confirms the benefit of RRSO in reducing breast and gynaecological cancer risk in women with BRCA1 or BRCA2 mutations. However, it indicates that approaches to RRSO may need to be tailored based on the magnitude of the potential benefits according to BRCA status.
Just as treatment for women with breast and ovarian cancer is becoming more tailored, these findings indicate prevention strategies will continue to become more targeted according to the characteristics of the individual.
Source
- Risk-Reducing Salpingo Oophorectomy for the Prevention of BRCA1 and BRCA2 Associated Breast and Gynaecologic Cancer: A Multicenter, Prospective Study. Journal of Clinical Oncology 26(8) Online 11 February 2008. 1-7.
