[Relationship between serum CA125 level and second-look findings in ovarian cancers]

Serum CA125 levels were monitored in 30 patients with epithelial ovarian cancer prior to second-look laparotomy. All patients had undergone cytoreductive surgery and multiple courses of chemotherapy and with no clinical and radiologic evidence of tumor. All ten patients who had had negative second-look finding gave normal serum CA125 levels (less than or equal to 35 u/ml). Of the 20 patients who were positive in second-look, 11 had normal CA125 levels, with a false negative rate of 55% including 67% (4/6) patients with microscopic evidence of tumor and 50% (7/14) patients with gross residual tumor. All 9 patients with elevated serum CA125 levels were positive in their second-look. 73% (8/11) patients with residual tumor having greatest diameter less than or equal to 2 cm had normal CA125 with a median value of 13 u/ml. 33% (3/9) patients with tumors having the greatest diameter greater than 2 cm had normal CA125 and the CA125 median value was 114 u/ml. These results show that the size of the residual tumor found in second-look was related to the serum CA125 level. As CA125 level within normal limits gave more false negatives, the necessity of second-look can not be judged by serum CA125 assay though elevated CA125 levels do predict the presence of tumor.