Retrospective analysis of axial skeleton osteosarcoma in 22 large-breed dogs

Medical records of 22 large-breed dogs (>15 kg) with osteosarcoma (OSA) of the axial skeleton were reviewed to determine prevalence of metastasis and survival associated with this neoplasm. All Jogs were treated with more tha n 1 mode of therapy including palliative radiation (n = 12). definitive rad iation (n = 8). surgery (n = 7). chemotherapy (n = 12). or some combination of these therapies. Metastasis was documented in 10 of 22 dogs (46%), and the median survival for all dogs was 137 days. Primary cause of death was l ocal tumor recurrence (54%). Breed (retriever versus purebred versus mixed- breed survival was 100. 182. and 264 days, respectively) and radiation ther apy protocol (survival in dogs treated with palliative radiation therapy ve rsus those treated with definitive radiation therapy was 79 and 265 days, r espectively) were significantly related to survival (P <.05) Prevalence of metastasis and median survival for large-breed dogs with axial skeleton OSA seems to be similar to that reported for large-breed dogs with appendicula r skeleton OSA. Definitive radiation therapy may have a role in the treatme nt of axial skeleton osteosarcoma.