Meta-Analysis of Overall Survival in Intramedullary Spinal Gliomas: Comparing Gross Total Resection to Subtotal Resection and Biopsy

Background and ObjectivesIntramedullary spinal cord tumors (IMSCTs) are rare, and the extent of surgical resection may influence overall survival (OS). Gross total resection (GTR) may offer superior outcomes compared to subtotal resection (STR) or biopsy. Our study seeks to quantify the benefits of resection extent on OS in patients with spinal gliomas (SGs). MethodsA systematic review was conducted using the following databases: Scopus, Embase, and PubMed. Studies reporting OS in patients who underwent GTR, STR, or biopsy for low- or high-grade SG. We used a random-effects model to calculate pooled hazard ratios (HRs) and 95% confidence intervals (CIs); this was performed separately for low-grade (WHO grade I-II) and high-grade (III-IV) SGs. Subgroup analysis was performed for radiotherapy. I2 statistic and Cochrans Q tests evaluated study heterogeneity, Eggers and funnel plot asymmetry tests assessed publication bias, and Risk Of Bias In Non-randomized Studies of Exposure (ROBINS-E) evaluated individual study bias. ResultsIn a pooled analysis of 5 studies, GTR was not associated with improvement in OS compared to STR or biopsy in high grade SGs (HR=0.48, 95% CI: 0.19 -1.26). However, low-grade SGs revealed significant benefit in overall survival with GTR (HR=0.27, 95% CI: 0.15-0.46). Patients treated with radiotherapy were associated with worse outcomes following GTR in low-grade SGs (HR=1.48, 95% CI: 1.30-1.69) but no survival differences in high-grade SGs (HR=1.21, 95% CI: 0.52-2.83). ROBINS-E determined only 1 study with high risk of bias. ConclusionGTR for intramedullary spinal gliomas may not confer a significant benefit in overall survival for high-grade lesions but may provide benefit in lower grades. Radiotherapy confers a worse survival in lower-grade tumors, potentially due to their infiltrative nature. Future studies should stratify outcomes based on tumor biology, as well as follow functional outcomes overtime.