Lomustine and prednisone as a first-line treatment for dogs with multicentric lymphoma: 17 cases (2004-2005)

OBJECTIVE: To assess response rate, median duration of response, adverse effects, and prognostic factors associated with concurrent administration of lomustine and prednisone as a first-line treatment for dogs with multicentric lymphoma. DESIGN: Retrospective case series. ANIMALS: 17 dogs. PROCEDURES: Medical records were reviewed. Information obtained included signalment, physical examination findings, results of diagnostic testing, stage and substage, initial lomustine and prednisone dosages, and total number of lomustine doses administered. RESULTS: Lomustine was administered at a median starting dosage of 67 mg/m(2), PO, every 21 days until 5 doses were given or disease progression was observed. Prednisone was administered at a median starting dosage of 1.8 mg/kg/d (0.82 mg/lb/d), PO, with dosage tapered during the first month of treatment. Six dogs had a complete response, and 3 had a partial response. Mean and median durations of response were 48.8 and 39.5 days, respectively. Median survival time was 111.2 days. In multivariate analyses, female sex and higher total lomustine dose were significantly associated with a longer disease-free inter-val. Neutropenia was the dose-limiting factor, with 4 dogs developing clinically important neutropenia 1 week after administration of a dose of lomustine. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that concurrent treatment with lomustine and prednisone was well tolerated in dogs with multicentric lymphoma, but findings did not support the use of this combination for first-line treatment of affected dogs.