Introduction

The first-line therapy for dogs with nasal carcinoma has been radiation therapy. Unfortunately, even with the treatment, most dogs with nasal carcinomas experience local progression. However, few studies have evaluated the efficacy of other treatment options for recurrent nasal carcinoma. The aim of this study is to evaluate the efficacy of the treatment with toceranib phosphate in dogs with recurrent nasal carcinoma after radiation therapy. Especially, the survival time and tumor volume were focused on.

Methods

Fifteen dogs with nasal carcinoma treated with radiation therapy were included in this retrospective study. All dogs were administered toceranib phosphate after the recurrence. Thirteen dogs underwent CT examination to confirm recurrence, although two dogs were without CT examination.

Results

Radiation treatments was delivered in a daily protocol of 10×4.4 Gy for 10 dogs, and weekly protocol of 4×8.0 Gy for five dogs. Toceranib phosphate was administered 3 times a week at a dose of 2.3–3.1 mg/kg. Eleven of 13 dogs examined with CT examination after administration of toceranib phosphate experienced clinical benefit (1 complete response, 5 partial response, 5 stable disease), and the clinical signs of all of 2 dogs without CT examination were improved. Overall median survival time (MST) was 506 days. MST for dogs with stage IV was 506 days. Median progression free interval (PFI) after administration of toceranib phosphate was 139 days.

Conclusion

This study indicated that toceranib phosphate improved the clinical signs of the dogs with nasal carcinoma and MST of the dogs with stage IV nasal carcinoma that recurred after radiation therapy, compared with outcomes of them treated with radiation therapy alone in some previous studies.