Evaluation of Factors Associated with Survival in Dogs with Lymphoma Treated with Prednisone. The Canine Lymphoma Steroid Only (CALYPSO) Open-Label Prospective Clinical Trial: 69 Cases (2016–2017)
Introduction
Intermediate-to-high grade lymphomas in dogs are biologically aggressive and typically fatal within weeks if not treated. Despite inclusion of prednisone in multiagent chemotherapy protocols and frequent use of single-agent prednisone when chemotherapy is declined, only small studies with variable dosing and follow-up have evaluated benefits of corticosteroids alone. The objective of this study was to assess survival time of dogs with lymphoma treated only with a standardized steroid protocol. Factors potentially associated with prognosis also were examined.
Methods
Dogs with naïve peripheral nodal lymphoma were recruited from 15 institutions. Diagnosis was confirmed by cytology and immunophenotype established via immunocytochemistry. Dogs received prednisone at 40 mg/m2/d PO for 7 days then 20 mg/m2/d thereafter. Quality-of-life (QOL) on a scale of 0–100 was assessed by dog-owners.
Results
Sixty-nine dogs with large-cell lymphoma met all inclusion criteria (53 B-cell, 16 T-cell). Median age and body weight were 8 years and 28.8 kg, respectively. Thirty-eight dogs were classified as substage-a, 31 as substage-b. Overall median survival was 50 days (95% CI, 39–62). Baseline QOL was correlated with survival (r=0.38; P=0.001). Median survival time for 18 dogs with QOL <50 was 27 days (95% CI, 7–51) compared to 68 days (95% CI, 55–83) for 48 dogs with QOL >/=50 (P=0.0088). Substage, phenotype, and duration of signs before diagnosis were not significant.
Conclusion
Dogs with peripheral nodal lymphoma treated with single-agent prednisone experience short-term survival. Baseline client-assessed QOL might be predictive of survival. Results of this study provide clinicians with meaningful considerations to discuss with owners at time of treatment decision.