Combination chemotherapy with 1-methyl-1-nitrosourea (MNU) and cyclophosphamide in solid tumors.

Twenty-four patients with far advanced malignant tumors, resistent to established chemotherapy,, were treated with the combination of MNU and Cyclophosphamide. The drugs were administered in six-day cycles sequentially. MNU in doses of 4 mg/kg body weight and Cyclophosphamide in doses of 8 mg/kg body weight were given. Results of treatment showed response (greater than 50% tumor regression) in 10 (42%) of the 24 treated patients. Seven remissions were complete and three partial. Patients with Hodgkin's disease, malignant melanoma and breast cancer responded to this combination chemotherapy. Objective remissions were obtained also in five of thirteen patients with primary or metastatic brain tumors and in five of nine patients with pulmonary metastases. Nausea and vomiting were the main toxic effects, especially after injections of MNU. Myelosuppression was noted in about 50% of treated patients. Since this combination of cytostatics showed significant antitumor activity, further investigations are necessary on a larger number of patients and in other types of malignant tumors.