ABSTRACT
IV . Single and Combined Therapy of Hepatoma 3924A ............................. 77 A . Cyclophosphamide Alone ................................................ 77 B . Studies with Combinations of Cyclophosphamide and
......................................................... Radiation 78
V1 . Advantages of Alternating Radiotherapy and Chemotherapy ..................... 80
V11 . Alternating Chemotherapy and Radiotherapy in the Treatment of ................................................................... Cancer in Man 82
A . Hodgkin's Disease ........................................................ 82 B . Head and Neck Cancer ................................................... 82 C . Small Cell Carcinoma of the Lung ....................................... 82 D . Plan for Further Clinical Testing of Alternating Chemotherapy
and Radiotherapy in Small Cell Carcinoma of the Lung .................. 83
Cyclophosphamide (CP) has been used extensively in the treatment of cancer.' It is one of the best examples of successful chemical modification of a highly reactive drug to decrease toxicity to the host while maintaining effectiveness toward the t ~ m o r . ~ This low toxicity to normal tissues has made it possible to use doses in the higher region of the dose-response curve for the tumor. Five cancer chemotherapeutic agents have been employed in our studies with the experimental solid tumor 3924A: 5-fluorouracil (5-FU), Adriamycin, melphalan, cisplatin, and CP. Of these, CP is the most effective as a single agent. Even so, no tumors have been cured with CP alone, and decreases in tumor volume to less than 50% of the volume at treatment have only rarely been observed. We summarize here our experience treating the hepatoma 3924A with CP and the use of local X-rays to the tumor as additional therapy to obtain cure.
