Influence of misonidazole on the incidence of radiation-induced intestinal tumours in mice

C57BL mice were given local irradiation to 2 cm2 of the lower abdomen in the dose range 16-24 Gy. There were some early deaths, but mice dying between 50-240 days predominantly developed invasive adenocarcinomas of the intestine. When the radiosensitizer misonidazole was given in a single dose shortly before irradiation the proportion of mice developing tumours was higher, but the difference was not statistically significant. However, there was a significant increase in the incidence of multiple tumours, largely attributable to tumours arising in the rectum. (author)