Prediction of the presence of ovarian cancer at surgery by an immunochemical panel: CA 125 and copper-to-zinc ratio.

Preoperative levels of the trace elements copper and zinc, in addition to the level of the known marker CA 125, were studied in sera of 32 patients undergoing exploratory laparotomy for suspicion of ovarian cancer and in sera of 49 patients with the diagnosis of ovarian cancer prior to second-look operation. Most patients (63/81) had stage III or IV disease. CA 125 levels greater than 35 U/ml, copper levels greater than 1.5 mg/liter, and zinc levels less than 0.9 mg/liter were considered pathologic. An immunochemical panel composed of CA 125 serum level and ratio of copper to zinc (Cu/Zn) (normal less than 1.65) was found to be most sensitive (98%) in predicting the existence of ovarian cancer before laparotomy, and its overall predictability was 89%. In 14 of 14 patients (100%) who had complete primary surgery for ovarian cancer, the panel was correct in predicting no tumor at second-look operation. In 13 of 14 patients (93%) who had incomplete primary surgery but had no clinical evidence of disease prior to second-look operation, the panel was correct in predicting ovarian cancer. In these two groups of patients, second-look operation could have been replaced by the results of the immunochemical panel.