Retrospective evaluation of doxorubicin-piroxicam combination for the treatment of transitional cell carcinoma in dogs

Objectives: To determine whether doxorubicin-piroxicam combination is safe and has activity against transitional cell carcinoma in dogs. Methods: Data was collected retrospectively from 34 dogs from two institutions over a 6-year period. Signalment, clinical presentation, treatment specifics, adverse events, response, progression-free survival and overall survival time were evaluated. Results: Dogs received doxorubicin every 3 weeks and daily piroxicam; 17 dogs (50%) had surgery. Clinical presentations were those typically reported for transitional cell carcinoma. Mean number of doses administered was 3·5. Of the 23 dogs with measurable disease, 14 (60·5%) had stable disease, 7 (30·5%) had progressive disease and 2 (9%) a partial response. Adverse events were generally manageable, and gastrointestinal in origin; one dog died of treatment-related complications. Overall median progression-free survival and overall survival were 103 and 168 days, respectively. Cytoreductive surgery did not result in prolongation of progression-free survival, but significantly prolonged overall survival. All dogs but one died as a result of disease progression. Clinical Significance: Doxorubicin-piroxicam combination therapy is well-tolerated in dogs with transitional cell carcinoma although progression-free survival, overall survival and biological response rates appear modest. Combination with surgery appears to offer a survival advantage; however, this may reflect tumour location and volume. Prospective studies are necessary to compare activity of combination doxorubicin-piroxicam to currently applied therapies.