Assessment of anemia as an independent predictor of response to chemotherapy and survival in dogs with lymphoma: 96 cases (1993-2006)

OBJECTIVE: To determine whether the presence of anemia (Hct < or = 37%) at the time of diagnosis of lymphoma is a negative prognostic indicator for response to treatment and survival time in dogs that are undergoing chemotherapy. DESIGN: Retrospective case series. Animals-96 dogs with lymphoma that were receiving chemotherapy. Procedures-Information regarding signalment, initial hematologic data, chemotherapy protocol, clinical response, and date of death was retrospectively collected from medical records of dogs with lymphoma. Univariate, multivariate, and survival analyses were performed to determine the effect of anemia on initial response to chemotherapy and on survival time. RESULTS: Overall, dogs without anemia (n = 56) were 4 times as likely as dogs with anemia (40) to have a complete response following chemotherapy. Anemic dogs had a significantly shorter median survival time (139 days), compared with survival time of nonanemic dogs (315 days). Subset analysis of dogs with multicentric lymphoma (matched for clinical stage and chemotherapy protocol) revealed that the dogs with anemia (n = 24) had a significantly shorter median survival time (101 days), compared with survival time of dogs without anemia (24; 284 days). Other variables were not associated with survival time. CONCLUSIONS AND CLINICAL RELEVANCE: These findings suggested that anemia is a negative prognostic factor for dogs with lymphoma that are undergoing chemotherapy. Further investigation will be necessary to determine the impact of resolution of anemia on clinical outcome in dogs with lymphoma.