title: Outcome and prognostic factors for osteosarcoma of the maxilla, mandible, or calvarium in dogs: 183 cases (1986-2012).
abstract: OBJECTIVE
  To describe the biological behavior, clinical outcome, and prognostic factors of osteosarcoma of the maxilla, mandible, or calvarium in dogs.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  183 client-owned dogs with osteosarcoma of the maxilla, mandible, or calvarium.
  
  
  METHODS
  Medical records for dogs treated for osteosarcoma of the maxilla, mandible, or calvarium from 1986 through 2012 were reviewed. Dogs with a histopathologic diagnosis of osteosarcoma and treated for a primary tumor arising from these bones of the head were included.
  
  
  RESULTS
  Mean age was 9.3 years, and body weight was 31.8 kg (70.0 lb). Most dogs (124/183 [67.8%]) were purebred, and the most common primary tumor site was the maxilla (80 [43.7%]). Treatments included palliative medical treatment only (11/183 [6.0%]), coarsely fractionated radiation therapy (RT; 12 [6.6%]), fractionated or stereotactic RT (18 [9.8%]), surgery (135 [73.8%]), and both surgery and fractionated RT (7 [3.8%]). Eighty-three (45.4%) dogs received adjuvant chemotherapy. Local recurrence or progression occurred in 80 of 156 (51.3%) dogs, and 60 of 156 (38.5%) dogs developed distant metastases. Median survival time for all dogs was 239 days. Dogs that underwent surgery had a median survival time of 329 days. Histologically tumor-free surgical margins were associated with significantly decreased hazards of progression or recurrence (hazard ratio [HR], 0.4) and death (HR, 0.5). Dogs with osteosarcoma of the calvarium had a significantly greater hazard of local recurrence or progression (HR, 2.0).
  
  
  CONCLUSIONS
  In this study, tumor excision in dogs with histologically tumor-free margins resulted in better local control and longer survival time than did other treatment types.
authors.affiliation: Flint Animal Cancer Center, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Selmic
authors.forename: Mary H
authors.initials: MH
authors.lastname: Lafferty
authors.forename: Debra A
authors.initials: DA
authors.lastname: Kamstock
authors.forename: Alana
authors.initials: A
authors.lastname: Garner
authors.forename: Nicole P
authors.initials: NP
authors.lastname: Ehrhart
authors.forename: Deanna R
authors.initials: DR
authors.lastname: Worley
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Withrow
authors.forename: Susan E
authors.initials: SE
authors.lastname: Lana
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use; D004283:Dog Diseases / Q000628:therapy*; D004285:Dogs; D008339:Mandibular Neoplasms / Q000628:therapy / Q000662:veterinary*; D008441:Maxillary Neoplasms / Q000628:therapy / Q000662:veterinary*; D012516:Osteosarcoma / Q000628:therapy / Q000662:veterinary*; D011878:Radiotherapy / Q000662:veterinary; D012189:Retrospective Studies; D012307:Risk Factors; D012888:Skull Neoplasms / Q000628:therapy / Q000662:veterinary*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents