Clinical characterisation and long‐term survival of paediatric and juvenile lymphoma in cats: 33 cases (2008‐2022)

Abstract

ObjectivesThe aims of this study were to describe the clinical presentation, tumour characteristics, responses to chemotherapy protocols and toxicity in a cohort of cats with lymphoma up to 18 months of age. In addition, the probability of long‐term (>2 years) survival was explored.Materials and MethodsThe medical records of client‐owned cats aged up to 18 months diagnosed with lymphoma between 2008 and 2022 at five UK‐based veterinary referral hospitals were reviewed.ResultsThirty‐three cats were included. The most common anatomical forms were mediastinal (42%), disseminated disease (30%) and renal (15%), with all cats having intermediate to large cell lymphoma. Three out of 29 cats tested were positive for FeLV but none for FIV. Twenty‐six cats were treated with multi‐agent chemotherapy protocols with complete and partial responses seen in 46% and 50% of cats, respectively. For this group, median progression‐free survival was 133 days (95% confidence interval [Cl] 67 to 199) and median survival time was 268 days (95% Cl 106 to 430). Complete response to chemotherapy was associated with a longer progression‐free survival. Seven cats were considered long‐term survivors (>2 years). Chemotherapy was generally well tolerated with none of the long‐term survivors suffering from chronic sequelae from cytotoxic treatment.Clinical SignificancePaediatric and juvenile cats with lymphoma showed a high response rate to multi‐agent chemotherapy protocols with rare significant toxicities. The presence of long‐term survivors may suggest a more favourable outcome in a subset of patients.