Evaluation of toceranib for treatment of apocrine gland anal sac adenocarcinoma in dogs.

Caitlin M Heaton,Arthur F A Fernandes,Paulo C Jark,Xuan Pan

doi:10.1111/jvim.15706

Abstract

BackgroundThere is no widely accepted standard medical treatment for apocrine gland anal sac adenocarcinoma (AGASACA) in dogs. Targeted agents such as toceranib may be effective in treatment of AGASACA, but the number of clinical reports investigating its efficacy is limited.Hypothesis/AimTo evaluate the efficacy of toceranib treatment of AGASACA in dogs, and to assess prognostic factors in the study population. Our hypothesis was that toceranib would provide a clinical benefit in the treatment of dogs with AGASACA.AnimalsThirty‐six client‐owned dogs with either a cytologic or histologic diagnosis of AGASACA that were treated with toceranib alone or in combination with surgery, nonconcurrent chemotherapy or both.MethodsRetrospective study.ResultThe median progression‐free survival (PFS) and overall survival time (OST) for the study population was 313 days and 827 days, respectively. A clinical benefit from toceranib treatment was observed in 69% of dogs, with 20.7% of dogs experiencing partial response and 48.3% of dogs experiencing stable disease. Dogs that responded to toceranib treatment had significantly prolonged PFS and OST. Hypercalcemia was a negative prognostic factor for clinical outcomes.ConclusionsToceranib is effective in the treatment of AGASACA in dogs. Prospective, controlled clinical trials are needed to determine the efficacy of toceranib in comparison to other treatment protocols for dogs with AGASACA.

Highlights

Apocrine gland anal sac adenocarcinoma (AGASACA) is a malignant tumor that arises from the epithelium of the anal sac
Most dogs treated in the macroscopic disease setting (69%) experienced clinical benefit from treatment (20.7%, partial response (PR); 48.3%, stable disease (SD)) and clinical benefit was positively associated with overall survival time (OST) and progression-free survival (PFS)
A clinical benefit from toceranib treatment was observed in the majority of dogs in our study (69%)

Summary

| INTRODUCTION

Occurs before distant metastasis to sites such as the lungs, liver, and spleen.[3] Polyuria and polydipsia may be present as a consequence of paraneoplastic hypercalcemia, which is reported in approximately 25% to 50% of cases.[3,5,6] Despite its high propensity to metastasize, this tumor tends to have an overall indolent disease course with median survival times of 1-2 years with single or multimodal therapeutic modalities, including surgery,[6,7] chemotherapy,[8,9] and radiation.[5] numerous chemotherapeutic agents (carboplatin,[8] actinomycin D,9 mioxantrone,[5] and melphalan6) have been investigated, the definitive role of adjuvant chemotherapy in the treatment of AGASACA remains unclear Alternative treatment options such as targeted therapy require further assessment to define therapeutic benefit.

| RESULTS

Findings

| DISCUSSION

| CONCLUSIONS