Feasibility and oncologic outcome of en resection with intentional tumor transgression in primary spinal sarcoma: The Korean Society of Spinal Tumors multicenter study (KSST 2024-02)

Abstract

Introduction: Primary spinal sarcoma is rare and technically challenging, particularly when attempting en bloc resection with negative margins. Intentional tumor transgression may be used when Enneking-appropriate en bloc resection is not feasible, but its oncologic implications remain unclear. This study evaluated the feasibility and outcomes of en bloc resection with intentional tumor transgression compared with other resection strategies.

Methods: This multicenter retrospective study included patients who underwent surgery for primary spinal sarcoma across five tertiary hospitals from 2000 to 2022. Patients were grouped by resection method: (A) en bloc resection with negative margins, (B) en bloc resection with intentional tumor transgression, (C) piecemeal resection, and (D) subtotal resection. Tumor extent was assessed using a modified Weinstein-Boriani-Biagini classification. The primary outcome was overall survival; secondary outcomes included local recurrence, distant metastasis, and perioperative complications.

Results: The study included 119 patients (mean age 46.0 ± 19.8 years). Oncological outcomes (overall survival, local recurrence, and distant metastasis) demonstrated significant trends in survival analysis across groups A to D. Although Group B had more extensive disease (>3 quadrants, canal encroachment, multi-level involvement), its overall survival, local recurrence, and distant metastasis did not differ significantly from Group A (hazard ratio [HR] 0.54, p = 0.467; HR 0.46, p = 0.307; HR 0.46, p = 0.237, respectively). Complication rates were comparable between groups A and B.

Conclusion: En bloc resection with intentional tumor transgression offers oncologic outcomes comparable to margin-negative en bloc resection in selected patients with more extensive tumors. This technique may be a viable alternative when Enneking-appropriate en bloc resection is not feasible.

Keywords: Complication; Distant metastasis; Local recurrence; Margin; Resection; Spinal sarcoma; Survival.

Graphical abstract

Fig. 1

Illustrative case of en bloc resection with intentional tumor transgression in a 74-year-old man with T3 osteosarcoma. A) Preoperative MRI showing pathologic fracture and involvement of the entire vertebral body and both pedicles. B) Surgical specimen viewed from the top and side showing intentional tumor transgression at both pedicles. C) Postoperative 8-year follow-up images demonstrating stable construct and no recurrence.

Fig. 2

Tumor extent assessment using modified WBB classification, dividing 12 zones into four quadrants as shown in different colors.

Fig. 3

Comparison of oncologic outcomes between resection methods: (A) overall survival, (B) local recurrence, (C) distant metastasis.

Fig. 4

Illustrative case of en bloc resection with negative surgical margins in a 63-year-old woman with T7 osteosarcoma. A) Preoperative MRI and CT images showing an extensive extraosseous mass encasing the descending aorta. B) A surgical specimen including a vertebral body and a segment of descending aorta after en bloc resection with aorta replacement surgery using a synthetic graft. C) Surgical field showing a synthetic aortic graft and spinal column reconstruction after tumor removal. D) Postoperative X-ray shows stable construct at 4 years after surgery. The patient experienced lower extremity paraparesis immediately after surgery, possibly due to spinal cord infarction during aortic replacement. Patient's motor weakness gradually improved, and she was able to walk independently with a walking aid at postoperative 4 years.