En Bloc Resection for Primary and Metastatic Tumors of the Spine: A Systematic Review of the Literature

BACKGROUND: The efficacy of en bloc resection for spinal tumors is unknown because most of the current evidence is provided by small, single-institution clinical series or case reports. OBJECTIVE: To combine all previously published reports of en bloc resection for primary and metastatic spinal tumors, to describe the overall pattern of disease-free survival, and to investigate potentially prognostic factors for recurrence. METHODS: A complete MEDLINE search for all articles reporting survival data for en bloc resection of spinal tumors was undertaken; 44 articles met inclusion criteria from which 306 eligible patients were identified. RESULTS: There were 229 cases of primary tumors with a mean follow-up of 65.0 months and 77 cases of solitary metastatic tumors with a mean follow-up of 26.5 months. Median time to recurrence was 113 months for the primary group and 24 months for the metastatic group. Disease-free survival rates at 1, 5, and 10 years were 92.6%, 63.2%, and 43.9%, respectively, for the primary group and 61.8%, 37.5%, and 0%, respectively, for the metastatic group; 5-year disease-free survival rates were 58.4% for chordoma and 62.9% for chondrosarcoma. After adjusting for covariates, age, male sex, metastatic tumors, and osteosarcomas were significantly associated with a tumor recurrence. CONCLUSION: This study provides the largest published series of patients undergoing en bloc resection for spinal tumors. Median time to recurrence reached almost 10 years in patients with primary tumors; however, it was only 2 years in those with isolated metastatic tumors.