Nadir CA-125 Is Prognostic for Recurrence, but Not for Survival in Patients With Ovarian Cancer

Abstract Objective of this study was to evaluate nadir CA-125 in patients with epithelial ovarian cancer. 168 patients, who achieved complete remission (no clinical and radiological signs, CA-125< 35 U/ml) after first line treatment were enrolled in the study. The relation between CA-125 and survival were examined using generalized additive models applied to the Cox proportional hazards model. The median CA-125 concentration after the treatment was 10 U/ml (2.7-35 U/ml). No correlation between CA-125 nadir and overall survival was found (p linear = 0.13; p nonlinear = 0.52). Patients with CA-125 serum concentrations of 11 - 25 U/ml and 26 - 35 U/ml had significantly higher risk of recurrence compared to patients with CA-125 concentration ≤ 10 U/ml with HR = 1.865 (P <0.0024) and HR = 2.17 (P <0.018), respectively. Nadir CA125 was not relevant for risk of recurrence in FIGO I and II (p=0.75 and p=0.99, respectively), neoadjuvant chemotherapy (p=0.49 and p=0.26 respectively) or bevacizumab (p=0.066 and p=0.26). Nadir CA-125 is not related to overall survival. Risk of ovarian cancer relapse increase with CA-125 nadir level. However in patients with early stage disease or those receiving neoadjuvant chemotherapy or bevacizumab may not be associated with recurrence risk.