Evaluation of Mitoxantrone with Piroxicam as First Line Therapy for Carcinomas of the Prostate in Dogs

Carcinomas of the prostate in dogs are a heterogeneous group of aggressive cancers that collectively carry a poor prognosis. The aim of this retrospective study was to evaluate the efficacy of using mitoxantrone along with piroxicam for the treatment of carcinomas of the prostate. Survival time, time to treatment failure, subjective and objective responses, prognostic indicators, and toxicity were evaluated. Twenty-five dogs were included in this study. Metastatic disease was diagnosed in 56% of dogs and 72% at the time of death. Seventy-four percent of dogs had a subjective improvement in clinical signs with the majority of dogs responding within 30 days. No objective responses were noted. Median time to treatment failure was 105 days. Median survival time for all dogs was 155 days. Toxicity was minimal with GI toxicity being most common. Results suggest that adding mitoxantrone to piroxicam therapy does not appear to be beneficial in the treatment of carcinomas of the prostate in dogs.