Early diagnosis of peritoneal carcinoma based on a subtle rise in serum CA125 level within the normal range in a BRCA2 mutation carrier with serous tubal intraepithelial carcinoma discovered after risk-reducing salpingo-oophorectomy: A case report an

OBJECTIVES: To illustrate the potential benefit of surveillance strategies for early primary peritoneal cancer (PPC) detection in BRCA2 mutation carriers with serous tubal intraepithelial carcinoma (STIC) identified at risk-reducing salpingo-oophorectomy (RRSO). CASE REPORT: A 74-year-old BRCA2 mutation carrier underwent at 71 years of old, with incidental STIC. She was monitored with CA125 and imaging. At 34 months postoperatively, a subtle but progressive CA125 increase, still within normal limits, led to further evaluation. Imaging and laparoscopy confirmed PPC. She received optimal cytoreductive surgery, chemotherapy, and maintenance olaparib, remaining disease-free at 20 months. Additionally, a literature review revealed a moderate negative correlation between age at RRSO and the interval from RRSO to PPC diagnosis (r = -0.481), although this was not statistically significant (p = 0.082). CONCLUSION: This case underscores the utility of combining CA125 and imaging for early PPC detection in STIC-positive BRCA2 carriers, particularly in older patients. Olaparib may also offer therapeutic benefit.