PP-33 Cognitive dysfunction in glioma: meta-analytic evidence linking neurocognitive decline to quality of life

Background Cognitive dysfunction is a prevalent and debilitating complication among patients with glioma, significantly affecting their independence, treatment adherence, and quality of life (QoL). Aim This meta-analysis aimed to quantify the prevalence, degree, and predictors of cognitive decline in glioma patients and evaluate its relationship with overall survival and QoL outcomes. Methods A comprehensive search of PubMed, Embase, and Scopus from inception to September 24, 2025. Studies assessing neurocognitive and QoL outcomes in glioma patients were included. Data were extracted on cognitive scales, neuroimaging correlates, and QoL indices. Pooled estimates were calculated using random-effects models in R, with heterogeneity assessed via I2 and χ2 statistics. Results Eleven eligible studies encompassing 975 patients were analyzed. The pooled cognitive impairment prevalence was 63% (95%CI 56–70%), with glioblastoma patients demonstrating the most severe deficits. The mean MoCA decline over 12 months was −2.7 points (95%CI −3.4- −2.0), while the MMSE decline averaged −1.9 points. Unmethylated MGMT promoter (HR 1.68, 95% CI 1.21–2.33), larger residual tumor volume (HR:1.45, 95%CI 1.05–2.02). Cognitive impairment was associated with a 25% reduction in survival time (0.75, 95% CI 0.70–0.80). Patients receiving Gamma Knife radiosurgery (GKRS) exhibited significantly less cognitive decline compared to those receiving conventional radiotherapy. The mean reduction in MoCA scores following GKRS was −2.9 points, markedly lower than the historically reported decline of approximately −4.5 points associated with standard radiotherapy modalities. Conclusion Cognitive impairment is highly prevalent in glioma patients and independently predicts worse survival and diminished QoL. Both structural and functional neural network disruptions contribute to cognitive decline, highlighting the need for neuroprotective treatment strategies and cognitive monitoring in glioma management. Impact Integrating cognitive and QoL assessments into standard oncologic care may improve patient-centered outcomes and guide therapeutic decisions toward preserving brain function and life quality.