Can Optimal Primary Cytoreduction Be Predicted in Advanced-Stage Epithelial Ovarian Cancer?

Abstract

Forty patients (median age, 59.5 years) with stage III ovarian cancer underwent primary cytoreductive surgery at Cambridge Cancer Centre. Their median preoperative serum CA-125 levels were 467 U/mL (range, 19-10,000 U/mL). Only 2 women did not have an elevated serum CA-125 level. After surgery, the residual tumor was 1 cm or less in 22 patients (55%) and considered optimally cytoreduced. Residual disease was 1 to 2 cm in 4 patients and larger than 2 cm in 14 (35%). These patients had suboptimal cytoreduction. They had significantly higher preoperative serum CA-125 levels than those who had optimal cytoreduction (P = 0.021). The data were used to generate a receiver-operating characteristic (ROC) curve. The highest point of both sensitivity and specificity for prediction of optimal cytoreduction was achieved at a serum CA-125 threshold level of 500 U/mL (sensitivity 0.72, 95% confidence interval [CI] = 0.47-0.90; specificity 0.73, 95% CI = 0.50-0.89). In this study, 16 of the 21 patients (76%) who had optimal cytoreduction and 5 of the 18 (24%) who had suboptimal cytoreduction had serum CA-125 levels of less than 500 U/mL. Therefore, a serum CA-125 level of less than 500 U/mL had a positive predictive value of 68% and negative predictive value of 76% for optimal tumor cytoreduction.