CA 125 in monitoring clinical course in ovarian cancer patients. A prospective clinical study.

CA 125 concentration was estimated using an immunoenzymatic test (Abbott) in sera of 130 women treated for ovarian cancer, before the treatment was started and during chemotherapy. Serum half-life of CA 125 was estimated in several of the patients after three months of chemotherapy. CA 125 serum level was found to be associated with the clinical course. Before the treatment was started, CA 125 levels showed no prognostic value as to survival but absence of a decrease in CA 125 levels after 2 to 3 months of chemotherapy was unfavourable to survival and required that alteration in treatment scheme be considered. Estimation of CA 125 half-life time after three months of treatment provided a useful prognostic index. Monitoring with the use of CA 125 levels facilitated adequate decision as to the time of performing second-look surgery. In patients with CR, who showed normal CA 125 levels at earlier stages of treatment, monitoring with the use of the marker was useless, since no elevation of CA 125 level was observed during relapse.