# Health-related quality of life outcomes of surgery for diffuse glioma: A systematic review and pooled analysis

## TL;DR

This study finds that surgery for diffuse gliomas can maintain or improve patients' quality of life, with outcomes worsening over time for some.

## Contribution

The paper provides a pooled analysis showing that HR-QoL outcomes after surgery for diffuse gliomas improve initially but may decline later.

## Key findings

- Pooled odds of unfavorable HR-QoL change were not significant within 3 months but became significant at final follow-up.
- Favorable HR-QoL change incidence was higher than unfavorable after 3 months, driven by EQ-5D and EORTC QLQ-C30.
- Younger patients, high-grade tumors, and lower resection rates were linked to worse outcomes.

## Abstract

Although progress has been made in understanding the effects of adjuvant therapy on health-related quality of life (HR-QoL) in diffuse glioma patients, less is known about the impact of surgical resection. To address this, we conducted a systematic review and pooled quantitative analysis.

PubMed, MEDLINE, and Embase were searched for studies measuring HR-QoL before and after surgery for WHO grade 2-4 adult-type diffuse gliomas. Inclusion was limited to prospective cohort studies and trials on adults with ≥1 month of postoperative follow-up. Metric outcomes were assessed with pooled odds, competing risk analysis, and meta-regression using a random effects model. Bias was assessed using the Newcastle-Ottawa Scale and Cochrane Risk of Bias 2.0 tool.

Twelve studies comprising 1000 patients were included. The pooled odds of an unfavorable versus favorable HR-QoL change compared to baseline was not significantly different from 1 within 3 months of surgery (0.843, 95% CI, 0.339-2.100), but significantly less than 1 at final follow-up (0.481, 95% CI, 0.260-0.888). The cumulative incidence of favorable HR-QoL change was significantly higher than that of unfavorable change, with the incidence curves separating after 3 months (χ2(1) = 95.0, P < .001). This was attributable to EQ-5D and EORTC QLQ-C30 but not SF-36. Studies with younger patients, more high-grade tumors, and lower gross total resection rates showed worse outcomes.

Surgical resection can maintain or improve HR-QoL, but patients at risk of deterioration should be identified early. Future studies must carefully select and interpret HR-QoL instruments, as preference-based and non-preference-based tools may lack comparability.