Evaluation of survival and prognostic factors in cats undergoing surgery for primary non-lymphomatous hepatobiliary tumours

Primary non-lymphomatous hepatobiliary tumours are rare in cats, representing 1.0–2.9% of all feline neoplasms. Limited data exist on outcomes following surgical management. This study aimed to describe outcomes, survival, and prognostic indicators in cats with hepatobiliary tumours undergoing liver lobectomy. A multicentre retrospective study was conducted across four veterinary referral hospitals. Clinical records of 76 cats diagnosed with primary non-lymphomatous hepatobiliary neoplasia between 2003 and 2024 were reviewed. Data collected included signalment, tumour characteristics, histopathology, surgical details, complications, and outcomes. Kaplan–Meier and Cox proportional hazards analyses were used to assess tumour-specific survival (TSS) and associated prognostic factors. Seventy-six cats met inclusion criteria; median age was 12 years. The most common tumour types were biliary cystadenoma (n = 30), hepatocellular carcinoma (n = 19), hepatocellular adenoma (n = 11), and biliary carcinoma (n = 11). The mortality rate was 9%, with 69 cats surviving to discharge. Median TSS for malignant tumours was 673 days; hepatocellular carcinoma and biliary carcinoma had a median survival of 859 and 387 days, respectively. Local recurrence occurred in 5 cats (18%, range 30–840 days), and metastasis in 7 (25%, range 30–435 days). TSS was different among histological subtypes: while for biliary cystadenomas TSS was not reached, for hepatocellular adenoma, HCC and biliary carcinoma TSS was 2916 days, 859 days and 387 days (p < 0.001). Cats with biliary carcinoma had significantly higher bilirubin levels, while cats with biliary cystadenomas had significantly lower ALP and ALT levels compared to other histological subtypes. Incomplete surgical margins or tumour location did not significantly impact survival. Liver lobectomy for feline hepatobiliary tumours is associated with low mortality rate. Although outcomes varied among histological subtypes, favourable survivals were seen even in cats with a diagnosis of hepatocellular or biliary carcinomas. These findings support surgical resection as a viable and potentially curative treatment for selected cats with hepatobiliary neoplasia.