Preoperative grading scale to predict survival in patients undergoing resection of malignant primary osseous spinal neoplasms

Abstract Background context Large population-based studies of malignant primary osseous spinal neoplasms are lacking and are necessary to have sufficient statistical power to determine if various patient-related factors are in fact significant indicators of prognosis. Purpose Using a 30-year US national cancer registry (Surveillance, Epidemiology, and End Results [SEER]), we introduce a preoperative grading scale that is associated with survival in patients undergoing surgical resection for malignant primary osseous spinal neoplasms. Study design Large-scale retrospective study. Patient sample SEER registry. Outcome measure Survival. Methods The SEER registry (1973–2003) was queried to identify adult patients undergoing surgical resection of histologically confirmed primary spinal chordoma, chondrosarcoma, or osteosarcoma via International Classification of Disease for Oncology, Third Edition coding. Variables independently associated with survival were determined via Cox proportional hazards regression analysis for all tumor types. A grading scale comprising these independent survival predictors was then developed and applied to each histology-specific tumor cohort. Results Three hundred forty-two patients who underwent surgical resection of a malignant primary osseous spinal neoplasm (114 chordoma, 156 chondrosarcoma, and 72 osteosarcoma) were identified. Overall median survival after surgical resection was histology specific (osteosarcoma: 22 months; chordoma: 100 months; and chondrosarcoma: 160 months). Increasing age (years) and increasing tumor invasion (confined to periosteum; invasion through periosteum into adjacent tissues; and distal site metastasis) were the only variables independently associated with decreased survival (p