145. VALIDATION OF THE ENNEKING ONCOLOGIC CLASSIFICATION IN THE MANAGEMENT OF PRIMARY TUMOURS OF THE SPINE: A COHORT STUDY

Abstract

Purpose: Oncologic management of primary bone tumors of the spine is inconsistent, controversial and open to individual interpretation. Tumor margin violation intraoperatively increases local recurrence and mortality. The purpose of this study is to determine whether applying Enneking’s principles to the surgical management of primary bone tumors of the spine significantly decreases local recurrence and/or mortality.

Method: A prospective and retrospective multicenter Cohort Study: Inclusion of patients undergoing en bloc or intralesional resection of primary tumors of the spine at four separate quaternary care centers, between January 1994 and January 2008. Patients were staged, using the Enneking system, prior to surgery and baseline demographic and surgical variables were recorded. Outcomes measured were disease local recurrence, or death. The results were statistically analyzed for significance.

Results: One hundred-fifty patients with primary tumors of the spine were recruited. Average age was 47.0 (range 8 to 83). Sixty-two patients were identified to have local recurrence. A statistically significant decrease in local recurrence (p=0.0001) was observed in favor of en bloc resection. In patients with local recurrence there was a significant increased risk of mortality, (p< 0.0001). There was a trend to decreased mortality in the en bloc resection group, not statistically significant (p=0.64).

Conclusion: Wide resection of primary tumors of spine with reconstruction is the standard of care. Application of Enneking’s principles to the spine when managing primary bone tumors significantly reduces local recurrence of the disease process, without an adverse outcome on mortality, and with acceptable HRQOL. Further cohort studies based on stringent data collection prospectively will provide a basis for more detailed study of individual tumor types.