Enhanced cures of spontaneous murine mammary tumors with surgery, combination chemotherapy, and immunotherapy.

Significant numbers of cures of spontaneous mammary adenocarcinoma in CD8F, 9 (BALB/c 9 X DBA/8 Õ) mice have been effected by concomitant administration of three therapeutic modalities: surgery (enucleation) + combination chemotherapy + immunotherapy (nonspe cific immunological adjuvant). The results were obtained following lifetime observation of the animals. Immunotherapy consisted of zymosan (Z), a nonspe cific stimulant of the reticuloendothelial system. When Z treatment was initiated 3 days prior to enucleative sur gery of the spontaneous tumor, it enhanced the thera peutic effect of combination chemotherapy consisting of four simultaneously injected anticancer agents. The first injection of the quadruple combination of streptonigrin (S), thioguanine (T), Endoxan (E) or cyclophosphamide, and mitomycin C (M), or STEM, was given on the day after surgery; thereafter, three additional simultaneous injections of the STEM + Z were given at 14-day in tervals. The combination of surgery + STEM + Z ef fected a 54% local cure rate (i.e., no tumor recurrence) as well as a 24% absolute cure rate (i.e., no tumor re currence as well as no appearance of a new tumor). Surgery alone and surgery + STEM produced local cure rates of 15 and 39% and absolute cure rates of 3 and 11%, respectively. The enhancement of tumor cure rates was attained by the "triple modality" therapeutic approach with negligible