Factors associated with the extent of resection of glioblastoma

Abstract

Background: The extent of resection (EOR) has been reported to be the leading factor associated with the prognosis of patients with glioblastoma (GBM). The purpose of this study was to identify the factors related to EOR and to determine the confounding effects of EOR for survival in patients with GBM. Methods: The study was a retrospective cohort review of the electronic medical records of newly diagnosed patients with GBM. Binary logistic regression analyzed the factors associated with total resection. Furthermore, stratification and multivariable analysis were used to fit the prognostic models according to the anatomical factors to control confounding effects. Results: One hundred and seventy-three patients were newly diagnosed with GBM. The EOR in this study was composed of total resection (22.0%), partial resection (63.0%), and biopsy (15.0%). The EOR was dichotomized into total resection and non-total resection subgroups. In univariate analysis, the factors associated with complete resection were single GBM [odds ratio (OR), 4.71; 95% CI, 1.06-20.76] and tumor volume <30 mL (OR, 3.06; 95% CI, 1.44-6.48). Therefore, the factors associated with complete resection were single GBM (OR, 6.81; 95% CI, 1.47-31.38) and tumor volume <30 mL (OR, 3.79; 95% CI, 1.72-8.34) in the multivariable analysis. Conclusions: Not all GBMs are amenable to complete surgical resection, and multiple lesions and tumor volume of ≥30 mL are the potential limiting factors. Before evaluating the association between the EOR and survival time, the EOR should be controlled from confounders by stratification, multivariable analysis, or propensity scores.