Transplantable human tumors in experimental chemotherapy. The effects of Cytoxan on H.S. No. 1 and H.Ep No. 3 in the rat.

Cytoxan, a cyclic phosphamide ester of nitrogen mustard, was tested for tumor-inhibiting activity in the transplantable human tumor-rat host experimental chemotherapy systems with the use of the sarcoma II.S. #1 and the epidermoid carcinoma II.Ep. #:3. The compound inhibited the growth of both tumors when the initial dose was given s hours after tumor transplantation, by the intraperitoneal or oral route of administration. Cytoxan was found to have limited ability to suppress growth of established human tumors.