Surgical Management of Primary Bone Tumors of the Spine Validation of an Approach to Enhance Cure and Reduce Local Recurrence

Study Design. Multicenter ambispective cohort analysis. Objective. The purpose of this study is to determine whether applying Enneking's principles to surgical management of primary bone tumors of the spine significanti decreases local recurrence and/or mortality. Summary of Background Data. Oncologic management of primary tumors of spine has historically been inconsistent, controversial, and open to individual interpretation. Methods. A multicenter ambispective cohort analysis from 4 tertiary care spine referral centers was done. Patients were analyzed in 2 cohorts, "Enneking Appropriate" (EA), surgical margin as recommended by Enneking, and "Enneking Inappropriate" (EI), surgical margin not recommended by Enneking. Benign tumors were not included in mortality analysis. Results. Two cohorts represented an analytic dataset with 147 patients, 86 male, average age 46 years (range: 10-83). Median follow-up was 4 (2-7) years in the EA and 6 (5.5-15.5) years in the EI. Seventy-one patients suffered at least 1 local recurrence during the study, 57 of 77 in the EI group and 14 of 70 in the EA group. EI surgical approach caused higher risk of first local recurrence (P < 0.0001). There were 48 deaths in total; 29 in the EI group and 19 in the EA. There was a strong correlation between the first local recurrence and mortality with an odds ratio of 4.69, (P < 0.0001). EI surgical approach resulted in a higher risk of mortality with a hazard ratio of 3.10, (P = 0.0485) compared to EA approach. Conclusion. Surgery results in a significant reduction in local recurrence when primary bone tumors of the spine are resected with EA margins. Local recurrence has a high concordance with mortality in resection of these tumors. A significant decrease in mortality occurs when EA surgery is used.