Functional Outcomes After Reoperation for Recurrent Glioma: A Systematic Review and Meta-Analysis of Karnofsky Performance Status with Descriptive Health-Related Quality-of-Life Reporting.

Abstract

<h4>Background/objective</h4>Gliomas are the most common primary brain tumors in adults, with recurrence rates varying by tumor grade and initial treatment. Reoperation is a key strategy for managing recurrence; however, its impact on functional status and health-related quality of life (HRQoL) remains insufficiently defined. While HRQoL and neurocognitive outcomes have been described after primary treatment, far less is known following reoperation. This systematic review synthesizes available evidence on postoperative functional outcomes and summarizes HRQoL reporting in the reoperation literature.<h4>Methods</h4>A systematic search of PubMed and Google Scholar retrieved 1336 articles. After removing duplicates (<i>n</i> = 76) and screening full texts (<i>n</i> = 42), 15 studies (total <i>n</i> = 1934; reoperation group <i>n</i> = 947) met the inclusion criteria. Studies were eligible if they employed validated functional or HRQoL instruments (e.g., Karnofsky Performance Status [KPS], FACT-G, SF-36, and EQ-5D-L). Due to limited and heterogeneous HRQoL reporting, only KPS could be aggregated for meta-analysis, and HRQoL measures were descriptively summarized.<h4>Results</h4>Fixed-effect meta-analysis demonstrated a modest decline in postoperative KPS compared with preoperative scores (-3.28, 95% CI: -3.69 to -2.86; <i>p</i> < 0.001), though heterogeneity was high (I² ≈ 97%). The random-effects model, accounting for interstudy variability, showed no significant overall change (+0.16 KPS, 95% CI: -4.04 to +4.35; <i>p</i> = 0.94; I² ≈ 48%). The 95% prediction interval (-14.1 to +14.4) indicated that individual centers may observe either improvement or decline. Sensitivity analyses identified a small outlier study as a major contributor to heterogeneity; its exclusion did not materially alter the results.<h4>Conclusions</h4>Across heterogeneous observational cohorts, reoperation for recurrent glioma was not associated with a consistent decline in functional status as measured by KPS, although substantial variability and uncertainty in outcomes remain. HRQoL reporting remains sparse and inconsistent, underscoring the need for prospective, multicenter studies employing standardized HRQoL instruments to better define quality-of-life trajectories after reoperation.