Introduction

The objective was to describe the clinical presentation, retroviral status, response to chemotherapy and survival in a population of cats with mediastinal lymphoma.

Methods

Patient characteristics of cats with cytologically confirmed mediastinal lymphoma in a Spanish Referral Center between 2012–2019 were collected, including: retroviral status, staging tests, chemotherapy protocol and response following RECIST criteria assessed 42 days after chemotherapy initiation, adverse effects, median time to progression (MTP) and survival times (MST).

Results

Thirty-six cases were included. Median age was 4,6 years (0.9–13 years); 29 cats were Domestic short hair (80%), 5 Siamese (13.8%), 2 Birmans, and 1 Persian; male to female ratio was 1.1–1.0. Feline leukemia virus positive (FeLV+) cats represented 89% of cases (27/32) with no feline immunodeficiency affected cats. At diagnosis 18 patients had pleural effusion, 31 respiratory clinical signs and 4 gastrointestinal signs. Protocols used included COP (cyclophosphamide, vincristine, prednisolone) (n=15). Madison-Wisconsin 25 weeks including one initial dose of asparaginase (n=18), and LAP (lomustine, asparaginase, prednisolone) (n=3). Overall response rate was 47%, 13 complete responses (36%), 4 partial responses (11%). Median time to progression was 33 days (1–665 days) with a MST of 62 days (1–665 days). Adverse events evaluated were mostly gastrointestinal, being grade I, II (82%), and grade III (18%).

Conclusion

Our population had a high prevalence of FeLV-antigenaemic cats similar to older literature, which could explain our lower overall response rates, MTP and MST when compared to more recent studies, highlighting the notable geographical differences in terms of presentation and response to therapy found in this disease.