Acetylsalicylic acid inhibition of n-butyl-(4-hydroxybutyl)nitrosamine-induced bladder carcinogenesis in rats.

We examined the effect of acetylsalicylic acid (ASA) on n-butyl-(4-hydroxybutyl)nitrosamine (BHBN)-induced bladder carcinogenesis in male Wistar rats. Of 29 rats that received 0.05% BHBN in their drinking water for 9 weeks, 8 developed bladder cancer. Only 1 out of 29 rats that received 0.1% ASA in their diet for 20 weeks, including the period of BHBN consumption, developed a tumor. That difference is statistically significant. Bladder weight was significantly higher in rats given BHBN than in controls and in rats given both BHBN and ASA. We conclude that ASA inhibits BHBN-induced bladder carcinogenesis.