Antitumor effects of piroxicam in spontaneous canine invasive urinary bladder cancer, a relevant model of human invasive bladder cancer.

Abstract

Invasive urinary bladder cancer results in >12,000 deaths each year in the US alone. More effective forms of therapy are needed to treat this cancer. Our interest in the antitumor activity of nonsteroidal antiinflammatory drugs (NSAIDs) began when we observed unexpected remission of naturally-occurring cancer in pet dogs who were receiving the NSAID piroxicam for pain relief. These observations led to phase I and II clinical trials of piroxicam in pet dogs with spontaneous cancer.1,2Gastrointestinal toxicity was dose limiting, but remission occurred at lower, less toxic doses.’ Invasive transitional cell carcinoma of the urinary bladder (TCC) was one of the forms of canine cancer that underwent remission with piroxicam therapy.2This finding is of particular interest because naturally-occurring canine TCC is very similar to human invasive urinary bladder cancer in histopathologic characteristics, biological behavior, and response to chemotherapy.3Canine TCC is a heterogenous, chemoresistant solid tumor with <20% of cases responding to single agent chemotherapy.3