Predictive value of CA 125 antigen levels in second-look procedures for ovarian cancer.

Serum CA 125 levels were evaluated in 44 patients undergoing 56 second-look or subsequent laparoscopies (43) and laparotomies (13) for ovarian cancer. In each patient studied, a previous CA 125 level had been greater than or equal to 35 U/ml. Clinical or radiologic evidence of tumor was absent in all patients at the time of surgical evaluation. CA 125 levels were less than 35 U/ml in 36 cases (64%); 14 patients were free of tumor, while 22 were found to have tumor at surgery. CA 125 levels were greater than or equal to 35 U/ml in 20 cases; 18 had tumor at surgery, one has had recurrence of tumor, and the other remains clinically free of tumor at 3 months. A CA 125 level less than 35 U/ml was not predictive of the presence of intraperitoneal tumor; however, when tumor was present in this group of patients, the largest tumor mass did not exceed 1 cm. In contrast, a CA 125 level greater than or equal to 35 U/ml was a strong predictor of the presence of intraperitoneal tumor or future recurrence. These data suggest that second-look procedures may not be required in the select group of patients with CA 125 levels greater than or equal to 35 U/ml.