Abstract
Objective: Tumor-associated edema has been implicated as a marker of aggressive tumor biology in gliomas, yet most existing evidence is derived from preoperative imaging and glioblastoma-focused cohorts. The prognostic significance of postoperative edema in non-glioblastoma diffuse gliomas remains insufficiently characterized.
Material and Methods: This retrospective cohort study included patients with histologically confirmed non-glioblastoma diffuse gliomas who underwent surgical intervention at a single tertiary center between October 2010 and January 2024. Postoperative edema was assessed using routine magnetic resonance imaging and classified as present or absent. Overall survival (OS) was defined as the time from diagnosis to death from any cause or to last follow-up. Survival analyses were performed using Kaplan-Meier methods and Cox proportional hazards regression models. Multivariable models were constructed using clinically relevant covariates selected a priori, with sensitivity analyses incorporating performance status and comorbidity burden.
Results: A total of 79 patients were included. Postoperative edema was present in 34 patients (54.8%). Median OS was significantly shorter in patients with postoperative edema compared with those without edema (69 vs. 108 months; log-rank p=0.007). In multivariable Cox regression analysis, postoperative edema was independently associated with worse OS (hazard ratio: 2.86; 95% confidence interval: 1.41-5.88; p=0.004), after adjustment for tumor grade, tumor location, surgical procedure, and adjuvant treatment. Tumor grade and non-supratentorial location were also independently associated with poorer survival. The association between postoperative edema and OS remained significant in sensitivity analyses that included Eastern Cooperative Oncology Group performance status and the Charlson Comorbidity Index.
Conclusion: Postoperative edema is a independently associated with OS in patients with non-glioblastoma diffuse glioma. These findings suggest that routine assessment of postoperative edema may provide clinically meaningful prognostic information beyond established clinicopathological factors and may support its potential role in postoperative risk stratification.