Evaluation of piroxicam for the treatment of oral squamous cell carcinoma in dogs

Objective-To evaluate the use of piroxicam for the treatment of oral squamous cell carcinoma in dogs. Design-Prospective case series. Animals-17 dogs with measurable oral squamous cell carcinoma. Procedure-Dogs were treated with piroxicam at a dosage of 0.3 mg/kg (0.14 mg/lb) of body weight, PO, every 24 hours until progressive disease or unacceptable signs of toxicosis developed or the dog died. Results-One dog had a complete remission (maxiilary tumor), and 2 dogs had partial remissions (lingual tumor and tonsillar tumor). An additional 5 dogs had stable disease, including 1 with a maxillary tumor, 2 with mandibular tumors, and 2 with tonsiliar tumors. Variables associated with tumor response were not identified. Median and mean times to failure for the 3 dogs that had a remission were 180 and 223 days, respectively Median and mean times to failure for the 5 dogs with stable disease were 102 and 223 days, respectively. Time to failure was positively associated with tumor response and negatively associated with tumor size. One dog had mild adverse gastrointestinal tract effects that resolved with the addition of misoprostol to the treatment regimen. Conclusions and Clinical Relevance-Results suggest that piroxicam may be useful in the treatment of dogs with oral squamous cell carcinoma; response rate was similar to that reported for other cytotoxic treatments. Larger-scale studies are warranted to determine what role piroxicam may have, alone or in combination with other treatments, for the treatment of dogs with oral squamous cell carcinoma.