[Experimental studies on the antitumor effect of oral antitumor agents on gynecological malignant tumors]

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.