Asparaginase and MOPP Treatment of Dogs with Lymphoma

Background: Dogs with multicentric lymphoma are treated with various cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)‐based chemotherapy protocols with variable success. Objectives: To describe the progression‐free survival (PFS) time and overall survival time (OST) of dogs with T‐cell lymphoma or hypercalcemic lymphoma treated with l‐asparaginase and mechlorethamine, vincristine, prednisone, procarbazine (MOPP). Animals: Fifty dogs with T‐cell lymphoma, hypercalcemic lymphoma, or both treated at 3 referral veterinary hospitals. Methods: Retrospective study. Case were selected based on histologic or cytologic diagnosis of lymphoma; presence of the T‐cell phenotype, presence of hypercalcemia or both; and absence of previous chemotherapy. The T‐cell phenotype was determined by flow cytometry, immunocytochemistry, immunohistochemistry, or polymerase chain reaction of antigen receptor rearrangement. Results: The overall response rate was 98% (78% complete response, 20% partial response). The median PFS for the entire study population was 189 days with 25% PFS at 939 days. The median OST for the entire study population was 270 days with 25% surviving 939 days. Twenty percent of the dogs required hospitalization for treatment related complications. Conclusions and clinical importance: l‐Asp/MOPP chemotherapy might result in longer PFS and OST for dogs with multicentric T‐cell lymphoma, dogs with hypercalcemic lymphoma or both, than achieved with CHOP.