In order to identify processes associated with clinically-proven regression, we analyzed variations of the indices of the antioxidant system in 151 patients with cervical carcinoma (T3N3Mo) who had received remote gamma-therapy or endolymphatic administration of large doses of cytostatic and/or immunomodulating drugs. The study established significant disturbances in the function of the enzymatic and non-enzymatic components of the antioxidant system, the extent of which was determined by therapy effectiveness. A close link was found between regression and the structural and functional condition of cellular membranes of formed elements of the blood. Our investigation identified variations in the basal levels of superoxide dismutase in tumor tissue as well as those in the course of treatment, depending on variations in response.