prophylactic mastectomy in patients with BRCA mutations
Last reviewed 06/2022
A study enrolled 28 women with:
- a family history of breast cancer
- mutations in the BRCA genes which are known or suspected to cause breast cancer
The women are estimated to have had a 56-85% lifetime risk of developing breast cancer.
Women were given bilateral prophylactic mastectomies.
During the 15 year follow-up the researchers estimated that they would have expected to see 10.7 cases of breast cancer. In the trial none of the patients developed breast cancer.
This represents a relative risk reduction of 90% (95% confidence interval 50-100%) (1).
Risk-reducing mastectomy for women with no personal history of breast cancer (2)
- bilateral risk-reducing mastectomy is appropriate only for a small proportion
of women who are from high-risk families and should be managed by a multidisciplinary
team
- bilateral mastectomy should be raised as a risk-reducing strategy option with all women at high risk
- women considering bilateral risk-reducing mastectomy should have genetic counselling in a specialist cancer genetic clinic before a decision is made
- discuss the risks and benefits of risk reducing mastectomy with women
with a known or suspected BRCA1, BRCA2, or TP53 mutation
- offer women who have BRCA1, BRCA2 or TP53 mutations but who decide against risk-reducing mastectomy, surveillance according to their level of risk
- pre-operative counselling about psychosocial and sexual consequences of bilateral risk-reducing mastectomy should be undertaken
- the possibility of breast cancer being diagnosed histologically following a riskreducing mastectomy should be discussed pre-operatively
- all women considering bilateral risk-reducing mastectomy should be able to discuss their breast reconstruction options (immediate and delayed) with a member of a surgical team with specialist oncoplastic or breast reconstructive skills
- a surgical team with specialist oncoplastic/breast reconstructive skills should carry out risk-reducing mastectomy and/or reconstruction
- women considering bilateral risk-reducing mastectomy should be offered access to support groups and/or women who have undergone the procedure
Breast cancer risk category
| Near population risk | Moderate risk | High Risk * | |
| Lifetime risk from age 20 | Less than 17% | Greater than 17% but less than 30% | 30% or greater |
| Risk between ages 40 and 50 | Less than 3% | 3-8% | Greater than 8% |
*This group includes known BRCA1, BRCA2 and TP53 mutations and rare conditions that carry an increased risk of breast cancer such as Peutz-Jegher syndrome (STK11), Cowden (PTEN) and familial diffuse gastric cancer (E-Cadherin)
Reference:
- Hartmann, L. American Association of Cancer Research meeting April 2, 2000.
- NICE (June 2013). Familial breast cancer - Classification and care of people at risk of familial breast cancer and management of breast cancer and related risks in people with a family history of breast cancer