Differential activity of aspirin, ketoprofen and sulindac as cancer chemopreventive agents in the mouse urinary bladder

In vivo studies were conducted to compare the activity of three non-steroidal anti-inflammatory drugs as inhibitors of urinary bladder carcinogenesis induced in B6D2F₁ (BDF) mice by N-butyl-N-(4-hydroxybutyl)nitrosamine (OHBBN). Mice received continuous dietary exposure to nontoxic doses of aspirin, sulindac or ketoprofen beginning 1 week prior to the first of eight weekly doses of 7.5 mg OHBBN; studies were terminated at 24 weeks after the first carcinogen dose. Both dose levels of sulindac (200 and 400 mg/kg diet) and both dose levels of ketoprofen (40 and 80 mg/kg diet) reduced the incidence of transitional cell carcinoma of the urinary bladder by >70% from that seen in dietary controls. The high dose of sulindac conferred the greatest protection against bladder cancer induction. In contrast, when administered at 400 and 800 mg/kg diet aspirin was inactive as a chemopreventive agent in the OHBBN/BDF bladder cancer model. The significant potency of sulindac and ketoprofen as inhibitors of urinary bladder carcinogenesis, when considered with their history of safe human use, suggests that these agents merit further study as drugs for cancer chemoprevention in this target tissue.