A 48-year-old woman with a history of epithelial ovarian cancer (stage IIIC) completed platinum-based chemotherapy 6 months ago. CA-125 was elevated at diagnosis (850 U/mL) and normalized to 18 U/mL after chemotherapy. At follow-up, CA-125 is now 65 U/mL (normal <35). Imaging is normal. What is the most appropriate next step?

Explanation

## CA-125 Elevation in Ovarian Cancer Surveillance **Key Point:** A single elevated CA-125 in a previously normalized case is not diagnostic of recurrence. Confirmation with repeat measurement and imaging correlation is mandatory before escalating treatment. **Clinical Pearl:** CA-125 can be transiently elevated due to benign causes (menstruation, infection, inflammation). A rising trend (2 consecutive elevations >35 U/mL, 2 weeks apart) warrants imaging investigation. **High-Yield Management Algorithm:** 1. **Single elevation with normal imaging** → Repeat CA-125 in 2 weeks 2. **Confirmed rise (2 consecutive elevations)** → CT abdomen/pelvis ± PET-CT 3. **Imaging-negative, CA-125 rising** → Consider diagnostic laparoscopy or treat based on clinical judgment 4. **Imaging-positive** → Initiate appropriate salvage therapy **NCCN Guideline:** CA-125 elevation alone does not mandate treatment initiation; imaging must be performed and clinical correlation essential.