Modalities of chemotherapy and endocrine therapy for growth inhibition of androgen-stimulated mouse carcinoma (Shionogi carcinoma 115).

Effects of chemotherapy and endocrine therapy applied individually or in combination on growth of an androgen-stimulated mouse tumor, Shionogi carcinoma 115 (SC 115), were examined. In the present study cyclophosphamide and castration were used as chemo- and endocrine therapy, respectively, and simultaneous combination of these two treatments was found to be the most effective in inhibiting tumor growth. When comparing the effect of castration alone with that of injection of cyclophosphamide alone, the former retarded the tumor growth more efficiently, but relapse occurred in both instances. Injection of cyclophosphamide to the relapsed tumor after castration caused a marked effect when compared with the effect of the drug on the untreated or the chemotherapy-relapsed tumors. Castration caused a retardation of growth in the chemotherapy-relapsed tumor, but the survival period was shorter than that observed in the mice that received castration followed by injection of cyclophosphamide. From these results, it was concluded that castration followed by chemotherapy was the preferred order among sequential treatments for the SC 115; however, the optimal treatment was produced by simultaneous combination of chemotherapy plus castration.