Predictors of outcome in dogs with subcutaneous or intramuscular hemangiosarcoma

Objective—To identify prognostic factors in a large group of dogs with subcutaneous or intramuscular hemangiosarcoma (HSA) or both. Design—Multi-institutional retrospective cohort study. Animals—71 dogs with subcutaneous or intramuscular HSA. Procedures—Medical records of affected dogs were reviewed. The following factors were evaluated for an association with outcome: dog age and sex, clinical signs, anemia, thrombocytopenia, neutrophilia, tumor stage at diagnosis, achievement of complete excision, intramuscular involvement, presence of gross disease, tumor recurrence, and treatment. Results—Of the 71 cases identified, 16 (29%) had intramuscular tumor involvement. For all dogs, median time to tumor progression and overall survival time (OST) were 116 and 172 days, respectively; 25% survived to 1 year. Univariate analysis identified presence of clinical signs or metastasis at diagnosis, dog age, tumor size, use of any surgery, and presence of gross disease as predictors of time to tumor progression and OS...