In order to evaluate the antitumor effect of oral
antitumor agents on gynecological malignant
tumors, experimental studies were carried out using nude mice which had received implants of human
endometrial carcinoma. The agents used for the study were
tegafur (T) and UFT, and their effects on inhibiting
tumor growth, and on preventing
tumors from implanting or recurring were investigated in mice in continuous long-term administrations. The results were as follows: As to the inhibitory effect on the
tumor growth, while both T and UFT had no inhibitory effect on large to medium
tumors, both were mildly effective on small
tumors having a diameter of 2-3 mm (Inhibition Rate (IR): T-60.0%, UFT-71.0%), however, the no effect great enough to reduce the
tumor size was recognized with either agent. The implantation rates of
tumor under the administration of T and UFT were 80.0% and 70.0% respectively, indicating no significant differences from the control (90.0%) and either agent, however, UFT was judged to have the effect of preventing
tumors from implanting to a certain extent. The recurrence rates for
tumor under the administration of T and UFT were 30.0% (6/20) in both cases, which was significantly lower than the control (70.0%) (p less than 0.05). Both agents were evaluated as useful for preventing
tumors from recurring. These findings, indicated that while the maintenance
therapy of an oral
antitumor agent has no effect on macroscopic
tumors, a fairly good effect is expected on microscopic
tumors, especially on the prevention of
tumor recurrence.