Effect of adjuvant endocrine and adjuvant chemoendocrine therapies on metastasis of androgen-dependent Shionogi carcinoma 115.

Shionogi carcinoma 115 is an androgen-dependent tumor, defined by its failure to grow in either female or castrated male DS mice, and by its ability to grow in intact male DS mice as well as in female or castrated male DS mice given androgen. Since spontaneous lung metastasis was found in about 50% of intact male DS mice on the 40th day after s.c. transplantation of the tumor, we investigated the effect of various therapies on development of metastasis. Therapies were started on the 25th day after transplantation. Castration alone did not reduce the frequency of metastasis, and tumor excision alone reduced the frequency slightly. However, castration following the tumor excision showed an excellent effect. Chemotherapy (cyclophosphamide, 80 mg/kg body weight, three times) with or without tumor excision also showed a beneficial effect, and the combination of the tumor excision, castration, and chemotherapy was the most effective among various therapies examined. These results indicate that the Shionogi carcinoma 115 tumor is a useful model for therapy against metastasis of human hormone-dependent cancers.