Abstract
Introduction
Primary spinal chondrosarcomas are rare. Best available evidence consists of small case series, making it difficult to determine optimal management and risk factors for local recurrence and mortality. The application of the Enneking classification in the treatment of primary bone tumors in the appendicular skeleton has led to a longer life expectancy, yet the application of the Enneking system in the treatment of primary bone tumors in the spine has not been widely accepted. Therefore, the aim of this multicenter cohort study was to determine prognostic variables, including application of the Enneking classification, for local recurrence and mortality following surgical intervention for spinal chondrosarcomas.
Patients and Methods
AOSpine knowledge forum tumor developed a multicenter ambispective database of surgically treated patients with spinal chondrosarcoma. Patient data pertaining to demographics, diagnosis, treatment, cross-sectional survival, and local recurrence were collected. Tumors were classified according to the Enneking classification. Patients were analyzed in the following two different cohorts; Enneking appropriate (EA) and Enneking inappropriate (EI). EA was defined by the final pathology margin matching the Enneking recommended surgical margin and EI by not matching.
Results
Between 1987 and 2011, 112 patients (mean age at surgery = 47 ± 16 years) underwent surgical treatment for a primary spinal chondrosarcoma. EA surgery was performed in 61 (58%) patients. Overall, 15 patients (25%) suffered a local recurrence in the EA group and 21 (48%) in the EI group. EI approach significantly increased the risk for local recurrence (p = 0.009). Overall, 38 (34%) patients died during the study period (mean follow-up = 3.6 ± 3.2 years); factors associated with increased overall survival were absence of adjuvant therapy (p = 0.002), low-grade tumors (p = 0.051), and involvement of one or two vertebral levels (p = 0.038). Enneking appropriateness and surgical margin was not significantly associated with survival. Local recurrence was strongly related to mortality, with an odds ratio of 7.4.
Conclusion
This is the largest multicenter cohort of spinal chondrosarcomas. EI surgical management correlated with increased rates of local recurrence. This robust correlation strongly mandates to surgeons perform an EA resection with disease-free margins for spinal chondrosarcomas.