CA-125 cut-off value as a predictor for complete interval debulking surgery after neoadjuvant chemotherapy in patients with advanced ovarian cancer

Objective: In the present study, we evaluated changes in CA-125 cut-off values predictive of complete interval debulking surgery (IDS) after neoadjuvant chemotherapy (NAC) using receiver operating characteristic (ROC) analysis. Methods: This retrospective single-institution study included patients with International Federation of Gynecology and Obstetrics (FIGO) stage III epithelial ovarian cancer and a pre-NAC serum CA-125 level of greater than 40 U/mL who were treated with neoadjuvant platinum-based chemotherapy followed by IDS between 1994 and 2009. Logistic regression analysis was used to evaluate univariate and independent multivariate associations with the effect of clinical, pathological, and CA-125 parameters on complete IDS, and ROC analysis was used to determine potential cut-off values of CA-125 for prediction of the possibility of complete IDS. Results: Seventy-five patients were identified. Complete IDS was achieved in 46 (61.3%) patients and non-complete IDS was observed 29 (38.7%). Median pre-NAC CA-125 level was 639 U/mL (range, 57 to 6,539 U/mL) in the complete IDS group and 1,427 U/mL (range, 45 to 10,989 U/mL) in the non-complete IDS group. Median pre-IDS CA-125 level was 15 U/mL (range, 2 to 60 U/mL) in the complete IDS group and 53 U/mL (range, 5 to 980 U/mL) in the non-complete IDS group (p<0.001). Multivariate analyses performed with complete IDS as the endpoint revealed only pre-IDS CA-125 as an independent predictor. The odds ratio of non-complete IDS was 10.861 when the pre-IDS CA-125 level was greater than 20 U/mL. Conclusion: The present data suggest that in the setting of IDS after platinum-based NAC for advanced ovarian cancer, a pre-IDS CA-125 level less than 20 U/mL is an independent predictor of complete IDS.