CARBOGEN AND NICOTINAMIDE IN THE TREATMENT OF BLADDER-CANCER WITH RACIAL RADIOTHERAPY

Carbogen and nicotinamide have been evaluated in a phase II study as h ypoxia-modifying agents during radical radiotherapy for bladder cancer using a standard daily 20-fraction schedule. Three groups of patients have received (a) nicotinamide alone, given orally in a dose of 80 mg kg(-1) daily with 52.5 Gy in 20 fractions over 4 weeks, (b) carbogen alone, with 50 Gy in 20 fractions over 4 weeks, and (c) carbogen and n icotinamide, with 50-52.5 Gy in 20 fractions over 4 weeks. Ten patient s were treated in each group. All patients completed carbogen and radi otherapy as prescribed, but only 45% completed daily nicotinamide over the 4-week treatment period. The end points of this study were acute bowel and bladder morbidity and local control at cystoscopy 6 months a fter treatment. An expected level of acute bower and bladder morbidity was seen that reverted to normal in most patients by 12 weeks with no difference between the three treatment groups. Complete response rate s at 6 months were seven out of ten (100%) in the nicotinamide alone g roup, nine out of ten (90%) in the carbogen alone group and seven out of ten (70%) in the carbogen and nicotinamide group. It is concluded t hat carbogen and nicotinamide may improve the results of daily fractio nated radiotherapy in bladder cancer and that further evaluation is re quired.