Tumor-associated antigen Ca 125 before and during the treatment of ovarian carcinoma.

Serum concentrations of Ca 125, a tumor-associated antigen of epithelial ovarian cancer, were measured in 29 ovarian cancer patients before cytoreductive surgery and in 112 patients during and after treatment. Ca 125 levels were increased (greater than 30 IU/mL) in 89.8% of patients with clinically demonstrable ovarian tumors and were negative in 92.1% of clinically disease-free patients. Low levels of Ca 125 were associated with early clinical stages or a minimal tumor burden, and predicted a successful response to treatment and a low recurrence rate. High values indicated advanced disease and a poor response to cytotoxic chemotherapy. In 77% of patients the operation was explorative, with a preoperative Ca 125 level higher than 1000 IU/mL, whereas all the patients with values less than 100 IU/mL could be operated radically. Serum levels of Ca 125 were increased in similar frequency in epithelial, sex cord, and germ cell ovarian malignancies. The assay of Ca 125 seems to be a reliable noninvasive method for monitoring the presence and clinical behavior of ovarian cancer. Preoperative values have prognostic significance in predicting operability and response to chemotherapy.