Dietary habits in relation to outcome and therapy-related toxicity in patients with glioblastoma - a retrospective cohort study.
Level 3 - non-randomized controlled study
Retrospective cohort study
PubMed 40690185 · doi:10.1007/s11060-025-05137-3
What was done
In a retrospective cohort study, investigators examined 128 glioblastoma patients treated between January 2010 and December 2019, selected from an initial pool of 1,448 patients. A 35-item food frequency questionnaire was used to compute a dietary score reflecting adherence to a Mediterranean-like diet. The relationships between dietary score (dichotomized by the median), chemotherapy toxicities, and overall survival were evaluated using chi-square tests, binary logistic regression, Kaplan-Meier curves, and multivariable Cox regression.
What was found
Patients with dietary scores above the median had significantly more infections (13.8% vs. 3.2%, p = 0.031) and a trend toward more myelodepression (32.3% vs. 17.5%, p = 0.052). A higher score independently predicted infection risk (OR = 12.33, 95% CI: 1.36–111.98, p = 0.026). Median overall survival was significantly worse in the higher-score group (16.6 vs. 19.4 months, p = 0.004), a finding confirmed on multivariable Cox regression (HR = 1.60, 95% CI: 1.04–2.46, p = 0.034).
Why it matters
Contrary to findings in other oncological settings, higher adherence to a Mediterranean-style diet was associated with worse survival and increased toxicity during glioblastoma chemotherapy. This highlights the need to carefully examine dietary patterns and biological mechanisms specifically within neuro-oncology.
Limits
The cohort was retrospective with heavy attrition (only 128 of 1,448 initial patients analyzed), creating substantial risk of selection and recall bias from the food frequency questionnaire. The effect estimate for infection risk is very imprecise (wide confidence interval), and residual confounding from baseline performance status, steroid use, or molecular subtypes cannot be ruled out from the abstract.
Cited by
- contradicts In a Greek clinical trial of 18 glioblastoma patients receiving standard radiation, those who followed a calorie-restricted Mediterranean diet had significantly improved survival and a higher rate of reaching the three-year mark.