Background: Advanced hepatocellular carcinoma (HCC) in dogs has limited systemic treatment options once tyrosine kinase inhibitors (TKIs) fail. Capecitabine is a fluoropyrimidine prodrug with reported activity in human HCC and tolerability in dogs with carcinomas; however, its role as salvage therapy in canine advanced HCC remains unclear.
Objective: To evaluate clinical outcomes and adverse events of capecitabine administered as salvage therapy in dogs with advanced HCC
Animals: Seven client-owned dogs with advanced HCC
Methods: This retrospective case series included dogs with advanced HCC treated with capecitabine as second- or third-line therapy after TKI treatment. Tumor-specific survival (TSS) was calculated from capecitabine initiation to tumor-related death. Adverse events (AE) were graded according to VCOG-CTCAE v2.0.
Results: Capecitabine was given as second-line therapy in 3 dogs and third-line therapy in 4 dogs, at a median dosage of 590 mg/m² [467–790]. Median TSS was 146 days [11–416]. AEs were observed in 6 of 7 dogs. Neurologic adverse events occurred in 3 dogs and gastrointestinal events in 4 dogs. Grade ≥3 toxicities occurred in 3 dogs. One dog experienced grade 3 gastrointestinal/systemic toxicity requiring hospitalization, and one experienced a grade 5 fatal neurologic adverse event.
Conclusions and Clinical Importance: In this cohort of dogs with advanced HCC treated after TKI failure, capecitabine was associated with measurable tumor-specific survival but demonstrated a variable safety profile, including potentially fatal neurologic toxicity. These findings suggest that capecitabine may represent a salvage treatment option in selected dogs, provided that appropriate patient selection and close monitoring are implemented.
