Background/Objective: The risk of stroke in patients with glioma is increased after cranial radiation therapy, with hyperlipidemia further increasing this risk. We report on the stroke rate and associated risk factors in patients with glioma and hyperlipidemia after cranial radiation. Design: This is a subgroup of a retrospective cohort study, from a single tertiary academic brain tumor center, of patients with brain gliomas and hyperlipidemia diagnosed between 2004-2021 who received brain radiation therapy during their treatment. Hyperlipidemia diagnosis was extracted from chart review. Chi-square test was used to calculate odds ratios and logistic regression was used to evaluate independent predictors for all-cause and ischemic stroke adjusting for demographic factors, vascular risk factors, and statin use. Results: Among a cohort of 297 patients with glioma and hyperlipidemia who received cranial radiation, 65 patients (21.9%) were diagnosed with stroke with media time to stroke of 653 days with 76.9% of all strokes being ischemic. Individuals with stroke were 41.5% women with mean age at diagnosis of tumor of 58.6 years. Median dose of cranial radiation was 5940 cGy (Range 1800-6000). Presence of other vascular risk factors such as hypertension, obesity, and smoking were similar between those with stroke vs. those without. In a univariable logistic regression model radiation necrosis (OR 6.36, 95% CI 1.48-27.37, P=0.001) and Black race (OR 2.73, 95% CI 1.11-6.72, P=0.03) were found to be associated with increased odds of all-cause stroke, while statin use (OR 0.24, 95% CI 0.13-0.42, P<0.001) was associated with lower odds of stroke. Multivariable logistic regression for all cause stroke found radiation necrosis (OR 5.88, 95% CI 1.15-30.02, P=0.03) to be an independent predictor of stroke, while statin use (OR 0.23, 95% CI 0.12-0.42, P<0.001) was found to be protective in regard to diagnosis of stroke. Multivariable regression modeling for ischemic stroke found statin use (OR 0.35, 95% CI 0.17-0.71, P=0.004) to be protective. Discussion: In a cohort of 297 patients with glioma and hyperlipidemia, about a quarter were diagnosed with stroke after cranial radiation with a median of 653 days. Logistic regression models found statin use was protective of a diagnosis of all-cause and ischemic stroke. Further study is warranted to assess prospectively the effect of statins on stroke risk reduction in patients with hyperlipidemia undergoing radiation therapy.
Ryan et al. (Thu,) studied this question.