BRCA1 mutation carriers have the greatest lifetime risk of which ovarian/fallopian tube cancer histotype, and at what approximate lifetime cumulative risk?

• A Mucinous ovarian carcinoma; 15% lifetime risk
• B Clear cell carcinoma; 20% lifetime risk
• C Endometrioid ovarian carcinoma; 10% lifetime risk
• D High-grade serous carcinoma; 40–46% lifetime risk ✓

Explanation

BRCA1 pathogenic variant carriers have an approximately 40–46% lifetime risk of ovarian, fallopian tube, or peritoneal carcinoma, with the predominant histotype being high-grade serous carcinoma (HGSC). Many 'ovarian' HGSCs actually originate in the fimbriated end of the fallopian tube. BRCA2 carriers have a lower risk (~12–20%). Mucinous and clear cell carcinomas are not significantly enriched in BRCA carriers. This data underpins guidelines recommending risk-reducing bilateral salpingo-oophorectomy (RRBSO) by age 35–40 in BRCA1 carriers who have completed childbearing.

Reference: Shaw's Textbook of Gynaecology, 17th ed.

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Written and medically reviewed by the StethoPrep medical team.