The effect of four dose levels of piroxicam administered during different stages of colon tumor development was studied in male F344 rats to obtain a data base on the efficacy of piroxicam as an inhibitor of colon carcinogenesis. Piroxicam was added at levels of 25, 50, 75, and 150 ppm to the NIH-07 open-formula diet and fed to male F344 rats starting 1, 13, and 23 wk after the carcinogen admin...
