RESUMEN
The serum cancer antigen 125 (CA-125) remains a reliable biomarker in the therapeutic management of epithelial ovarian cancer (EOC). Monitoring the efficacy of cytotoxic chemotherapy (CT) and the early detection of relapse during the follow up of patients in remission represent the two most common clinical situations where the CA-125 has been successfully applied. There are however other scenarios along the course of the disease where the CA-125 can potentially aid in the decision-making process. Preoperative levels of CA-125 can help in selecting a subset of patients where an optimal cytoreduction may not be easily achieved. Perioperative variations in the CA- 125 levels after primary surgery and, more importantly, the nadir value of the CA-125 after primary chemotherapy, are associated with patient outcome. This review focuses on the clinical relevance of dynamic changes in CA-125 levels during the primary treatment of EOC and its potential influence both in the patient management and in the design of clinical trials in the adjuvant setting.