A 35-year-old BRCA1 mutation carrier chooses risk-reducing bilateral salpingo-oophorectomy (RRSO) at age 40 and prophylactic mastectomy. Her lifetime breast cancer risk without intervention is approximately 72%. What is the approximate percentage reduction in breast cancer risk achieved by prophylactic mastectomy alone?
- A 50–60%
- B 65–70%
- C 90–95% ✓
- D 100%
Correct answer: C. 90–95%
Explanation
Prophylactic bilateral mastectomy reduces the risk of breast cancer in BRCA1/2 mutation carriers by approximately 90–95%, making it the most effective preventive intervention for breast cancer. It cannot be 100% because small islands of breast tissue may persist along the inframammary fold or axillary tail. RRSO before age 40 additionally confers a significant but lesser reduction in breast cancer risk (approximately 50%) through estrogen deprivation, particularly relevant in BRCA2 carriers.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.