title: Adjuvant carboplatin and gemcitabine combination chemotherapy postamputation in canine appendicular osteosarcoma.
abstract: BACKGROUND
  Appendicular osteosarcoma (OSA), the most common bone tumor in dogs, is typically treated by amputation and adjuvant chemotherapy. Despite numerous efforts, the median survival time (MST) for dogs receiving a platinum compound, doxorubicin, or a combination of these remains at 8-12 months. Evidence from studies in mice suggests that gemcitabine has activity against OSA in vivo. Our preliminary work demonstrated that the addition of low-dosage (10 mM) gemcitabine to carboplatin resulted in synergistic inhibition of OSA cell viability in vitro.
  
  
  OBJECTIVE
  The purpose of the following study was to determine whether the addition of low-dosage (2 mg/kg) gemcitabine to carboplatin chemotherapy in dogs with OSA after amputation would improve MST over carboplatin monotherapy.
  
  
  METHODS
  Fifty dogs with histologically confirmed appendicular OSA.
  
  
  METHODS
  Dogs were treated prospectively with amputation and up to 4 dosages of carboplatin and gemcitabine in combination every 3 weeks.
  
  
  RESULTS
  The chemotherapeutic regimen was well tolerated with only 5 episodes of grade 3 or 4 hematologic toxicity. The median disease-free interval (DFI) was 203 days and the MST was 279 for all dogs in this study. The 1- and 2-year survival rates were 29.5 and 11.3%, respectively. Dogs with proximal humeral OSA had a shorter median DFI (P = .04) compared with dogs with OSA in other locations.
  
  
  CONCLUSIONS
  These results are comparable to those reported for carboplatin monotherapy indicating that the addition of gemcitabine to carboplatin in dogs with appendicular OSA does not appear to improve outcome.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA.
authors.forename: M
authors.initials: M
authors.lastname: McMahon
authors.forename: T
authors.initials: T
authors.lastname: Mathie
authors.forename: N
authors.initials: N
authors.lastname: Stingle
authors.forename: E
authors.initials: E
authors.lastname: Romansik
authors.forename: D
authors.initials: D
authors.lastname: Vail
authors.forename: C
authors.initials: C
authors.lastname: London
mesh_terms: D000671:Amputation, Surgical / Q000662:veterinary; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000188:drug therapy / Q000601:surgery / Q000662:veterinary*; D016190:Carboplatin / Q000008:administration & dosage*; D017024:Chemotherapy, Adjuvant; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004283:Dog Diseases / Q000188:drug therapy* / Q000601:surgery; D004285:Dogs; D012516:Osteosarcoma / Q000188:drug therapy / Q000601:surgery / Q000662:veterinary*; D016019:Survival Analysis; D016896:Treatment Outcome; D000093542:Gemcitabine
chemical_list: D003841:Deoxycytidine; D016190:Carboplatin; D000093542:Gemcitabine