Prognostic factors of patients with spinal malignant melanoma after surgical intervention: a case series of 21 patients and literature review.

ABSTRACT

BACKGROUND: Spinal malignant melanoma (SMM) is a rare type of tumor that can cause nerve roots or spinal cord compression. Patients often suffer from fierce pain and paralyzation. And the estimated survival time were less than 6 months. Surgical interventions to remove the tumor and decompress the nearby nerve roots and spinal cord are effective management. Unfortunately, there lack a thorough and persuasive surgical guideline that specifically aims for this disease. It is necessary to obtain some clinical prognostic factors that predict the recurrence rate and overall survival (OS) of patients with SMM who underwent surgical interventions. METHODS: 21 patients with SMM who underwent surgical intervention were retrospectively reviewed. Related patients factors, treatment factors and tumor factors were acquired and subjected into survive analyses using Kaplan-Meier method and the log-rank test. Further Cox proportional hazards model was used to identify independent prognostic factors. Literature regarding surgical interventions on SMM patients were reviewed and summarized as well. RESULTS: Surgical approach total en-bloc spondylectomy (TES/Piecemeal) (p = 0.015, B 0.029, 95%CI 0.002-0.508), preoperative Frankel grade (A-C/D-E) (p = 0.021, B 15.041, 95%CI 1.492-151.669) and tumor metastases (Yes/No) (p = 0.013, B 16.667, 95%CI 1.805-153.897) are independent prognostic factors for recurrence free survival (RFS). Preoperative Frankel grade (A-C/D-E) (p = 0.031, B 10.676, 95%CI 1.241-91.877) is independent prognostic factors for OS. 12 literatures have been reviewed, including 11 case reports and one retrospective study. CONCLUSIONS: Surgical interventions for patients with SMM are beneficial. Surgical approach (TES/piecemeal), tumor origin (primary/metastasis) and preoperative Frankel grade (A-C/D-E) are independent risk factors in predicting RFS. Preoperative Frankel grade (A-C/D-E) is independent prognostic factor in predicting OS.