Control of Local Tumor Growth With Combined Fractionated Radiotherapeutic and Chemotherapeutic Regimens

Summary

A treatment concept for the control of alcol tumor growth utilized weekday radiotherapy and weekend chemotherapy. Mice were given sc injections of P815X2 mastocytoma cells on the lower back (day 0) and separated into the following treatment groups: 5-day jweek X-irradiation, adriamycin alone at either 5 mgjkg body wt (days 6 and 13) or 2 mgjkg (days 5, 12, and 19), and combined radiotherapy and chemotherapy. Untreated controls had a mean tumor volume of 2.77 cm3 and a mean survival time of 24 days. Adriamycin alone at 5 mgjkg resulted in an eventual tumor volume of 70% of the control value at death, whereas at 2 mgjkg the tumor volume was 60% of control. After radiotherapy only, tumor size was 52% of control. Irradiation plus either 5 or 2 mg drug per kg body wt resulted in tumor volumes of 23 and 30%, respectively, of control values. Although no treatment regimen prolonged survival, the marked reduction in local tumor growth with combination therapy indicates that it may be a useful concept in future cancer therapy.