Effect of the Extent of Resection on Survival Outcome in Glioblastoma: Propensity Score Approach

Objective To evaluate the effectiveness of the extent of resection (EOR) on survival outcome using propensity score-based approaches. Materials and Methods A retrospective cohort study was performed in patients with newly diagnosed glioblastoma. Propensity score matching (PSM) and propensity score regression adjustment were used in the matched and unmatched dataset, respectively. Therefore, the Kaplan-Meier survival curve and Cox's regression analyses were performed to determine the effect of the EOR on survival outcomes. Results One hundred and sixty-eight patients were included for analyzes. The total tumor resection in the unmatched dataset was 22.6% of all cases. Using PSM, incomplete tumor resection had an unfavorable survival outcome when compared with total tumor resection (hazard ratio (HR) 2.92, 95% confidence interval [CI] 1.72-4.94). Additionally, biopsy and partial tumor resection were significantly associated with poor prognosis when compared with total tumor resection using propensity score regression adjustment (HR of biopsy 1.89, 95%CI 1.13-3.16 and HR of partial resection 1.89, 95%CI 1.28-2.80). Conclusions Patients with total tumor resection tend to have a more favorable prognosis than patients with partial tumor resection. The propensity score-based analysis is an alternative approach to evaluate the effect of an intervention that has limitations to perform a randomized controlled trial.