Objective—To evaluate the antitumor activity and toxic effects of a conservative dose of cisplatin administered in combination with piroxicam to dogs with transitional cell carcinoma (TCC) of the urinary bladder.
Animals—14 client-owned dogs with histologically confirmed TCC of the urinary bladder.
Procedures—Each dog was treated with cisplatin (50 mg/m2, IV, q 21 d [reduced to 40 mg/m2, IV, q 21 d because of toxic effects]) and piroxicam (0.3 mg/kg [0.14 mg/lb], PO, q 24 h). A CBC, serum biochemical analyses, and urinalysis were performed prior to each cisplatin treatment. Tumor staging (determined from thoracic and abdominal radiographic and urinary bladder ultrasonographic findings) was performed before treatment and at 6-week intervals during treatment.
Results—5 dogs received only 1 dose of cisplatin because of the rapid progression of disease (n = 2) or toxic effects (3). With regard to the neoplastic disease among the other 9 dogs, 1 had partial remission, 5 had stable disease, and 3 had progressive disease after 6 weeks of treatment. Median progression-free interval was 78 days (range, 20 to 112 days). Median survival time was 307 days (range, 29 to 929 days). Moderate to severe renal toxicosis and moderate to severe gastrointestinal toxicosis developed in 5 and 8 dogs, respectively.
Conclusions and Clinical Relevance—Because of minimal efficacy and associated renal and gastrointestinal toxicosis, administration of cisplatin (40 to 50 mg/m2) with piroxicam cannot be recommended for treatment of dogs with TCC of the urinary bladder.