TY - JOUR T1 - Long-term tumour dormancy in a <em>BRCA1</em> heterozygote JF - Journal of Medical Genetics JO - J Med Genet SP - 33 LP - 35 DO - 10.1136/jmedgenet-2021-108269 VL - 60 IS - 1 AU - Setor Amuzu AU - Lili Fu AU - Nadine Demko AU - Barbara Rivera AU - Celine Domecq AU - Leanne de Kock AU - Nancy Hamel AU - Lucy Gilbert AU - Paz Polak AU - Jiannis Ragoussis AU - William D Foulkes Y1 - 2023/01/01 UR - http://jmg.bmj.com/content/60/1/33.abstract N2 - Ovarian high-grade serous carcinoma (HGSC) is thought to mainly arise from the Fallopian tubes from a precursor lesion known as serous tubal intraepithelial carcinoma (STIC).1 2 Germline pathogenic variants (GPVs) in BRCA1/2 are the most important causes of HGSC and risk-reducing salpingo-oophorectomy (RRSO) is offered to BRCA1/2 heterozygotes. We report a BRCA1 heterozygote who developed a pelvic HGSC 15 years post-RRSO, following an occult Fallopian tube HGSC that was missed on initial pathological examination. Exome sequencing of DNA derived from normal and tumour tissues showed that the pelvic tumour is a recurrence from the original Fallopian tube tumour. BRCA1 and BRCA2 GPVs are the strongest known risk factors for HGSC, and for this reason, RRSO is offered to women who are heterozygous for BRCA1/2 GPVs as standard of care, usually between the ages of 35 and 50 years. For women who have undergone RRSO, there persists a small but significant risk for peritoneal cancer.3 A systematic review found that 1.2% of BRCA1/2 patients undergoing RRSO had occult tubal carcinoma at the time of surgery. Moreover, 0.54% of these patients went on to develop peritoneal cancer post-RRSO, of which only 17% (4/24) had STICs at initial diagnosis.4 Incomplete removal of adnexa, lack of standard pathological sectioning protocol and early precursors unidentifiable by routine histological examination potentially explain the lack of detection of early carcinomas at the time of RRSO. Nonetheless, the failure to find a precursor for all recurrences, as well as the often-significantly delayed presentation of the peritoneal cancer after RRSO, highlights some unresolved aspects to the predominant model that most, if not all, pelvic HGSC arise from the Fallopian tube.3 4 Several studies have elucidated identical TP53 mutations in a primary HGSC and a second HGSC arising in the same woman, suggesting a common origin … ER -