title: Osteosarcoma of the spine: prognostic variables for local recurrence and overall survival, a multicenter ambispective study.
abstract: OBJECTIVE Primary spinal osteosarcomas are rare and aggressive neoplasms. Poor outcomes can occur, as obtaining marginal margins is technically demanding; further Enneking-appropriate en bloc resection can have significant morbidity. The goal of this study is to identify prognostic variables for local recurrence and mortality in surgically treated patients diagnosed with a primary osteosarcoma of the spine. METHODS A multicenter ambispective database of surgically treated patients with primary spine osteosarcomas was developed by AOSpine Knowledge Forum Tumor. Patient demographic, diagnosis, treatment, perioperative morbidity, local recurrence, and cross-sectional survival data were collected. Tumors were classified in 2 cohorts: Enneking appropriate (EA) and Enneking inappropriate (EI), as defined by pathology margin matching Enneking-recommended surgical margins. Prognostic variables were analyzed in reference to local recurrence and survival. RESULTS Between 1987 and 2012, 58 patients (32 female patients) underwent surgical treatment for primary spinal osteosarcoma. Patients were followed for a mean period of 3.5 ± 3.5 years (range 0.5 days to 14.3 years). The median survival for the entire cohort was 6.7 years postoperative. Twenty-four (41%) patients died, and 17 (30%) patients suffered a local recurrence, 10 (59%) of whom died. Twenty-nine (53%) patients underwent EA resection while 26 (47%) patients underwent EI resection with a postoperative median survival of 6.8 and 3.7 years, respectively (p = 0.048). EI patients had a higher rate of local recurrence than EA patients (p = 0.001). Patient age, previous surgery, biopsy type, tumor size, spine level, and chemotherapy timing did not significantly influence recurrence and survival. CONCLUSIONS Osteosarcoma of the spine presents a significant challenge, and most patients die in spite of aggressive surgery. There is a significant decrease in recurrence and an increase in survival with en bloc resection (EA) when compared with intralesional resection (EI). The effect of adjuvant and neoadjuvant chemotherapeutics, as well as method of biopsy, requires further exploration.
authors.affiliation: Department of Orthopedics, CORE Institute, Phoenix, Arizona; 
authors.forename: Mark B
authors.initials: MB
authors.lastname: Dekutoski
authors.affiliation: Departments of 2 Neurologic Surgery and.
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: Clarke
authors.affiliation: Orthopedics, Mayo Clinic, Rochester, Minnesota;
authors.forename: Peter
authors.initials: P
authors.lastname: Rose
authors.affiliation: Oncologia Ortopedica e Ricostruttiva del Rachide, Istituto Ortopedico Galeazzi, Milan, Italy;
authors.forename: Alessandro
authors.initials: A
authors.lastname: Luzzati
authors.affiliation: Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas;
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Rhines
authors.affiliation: National Center for Spinal Disorders and Buda Health Center, Budapest, Hungary;
authors.forename: Peter P
authors.initials: PP
authors.lastname: Varga
authors.affiliation: Division of Spine, Department of Orthopaedics, University of British Columbia and Vancouver Coastal Health, Vancouver, British Columbia, Canada;
authors.forename: Charles G
authors.initials: CG
authors.lastname: Fisher
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, California;
authors.forename: Dean
authors.initials: D
authors.lastname: Chou
authors.affiliation: Division of Neurosurgery, Department of Surgery, University of Toronto and Toronto Western Hospital, Toronto, Ontario, Canada;
authors.forename: Michael G
authors.initials: MG
authors.lastname: Fehlings
authors.affiliation: Spinal Division, Oxford University Hospitals NHS Trust, Oxford, United Kingdom;
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Reynolds
authors.affiliation: Department of Orthopaedics, Princess Alexandra Hospital, Brisbane, Queensland, Australia;
authors.forename: Richard
authors.initials: R
authors.lastname: Williams
authors.affiliation: Center for Spine Studies and Surgery, Queens Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom;
authors.forename: Nasir A
authors.initials: NA
authors.lastname: Quraishi
authors.affiliation: Research Department, AOSpine International, Davos, Switzerland;
authors.forename: Niccole M
authors.initials: NM
authors.lastname: Germscheid
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland;
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Sciubba
authors.affiliation: Department of Neurosurgery, The Warren Alpert Medical School of Brown University, Providence, Rhode Island; and.
authors.forename: Ziya L
authors.initials: ZL
authors.lastname: Gokaslan
authors.affiliation: Unit of Oncologic and Degenerative Spine Surgery, Rizzoli Institute, Bologna, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Boriani
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000517:prevention & control / Q000601:surgery; D012516:Osteosarcoma / Q000175:diagnosis* / Q000601:surgery*; D011379:Prognosis; D011446:Prospective Studies; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000175:diagnosis* / Q000601:surgery*; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: EA = Enneking appropriate; EI = Enneking inappropriate; en bloc resection; neoadjuvant chemotherapy; oncology; osteosarcoma; primary tumor; spine; surgery; survival; tumor