Risk of Death from Alzheimer's Disease Associated with Brain Tumor, Glioma, and Glioblastoma

Background: No study has compared the risk of Alzheimer's disease (AD) in patients with brain tumors, gliomas, or glioblastomas with the risk in patients with other tumors. Objective: To determine whether, compared with other tumors, brain tumors, gliomas, and glioblastomas increase the risk of AD. Methods: This study identified a case group of 24,441 patients from the Surveillance, Epidemiology, and End Results (SEER) database who were diagnosed with only one primary tumor at age > 20 years in 1975-2019 and died from AD at age > 65 years as case group. The control group comprised 122,205 subjects from the SEER database who died from causes other than AD but otherwise had the same conditions as those in the case group. Results: There was a significantly lower prevalence of glioma (0.074% versus 0.14%, p = 0.007) and glioblastoma (0.0082% versus 0.074%, p = 0.001) in patients who died from AD than in those who died from other causes, while brain tumors were not significantly associated with AD death (p = 0.227). When adjusted for factors including age at death, sex, race, tumor behavior, radiation therapy and tumor-directed surgery, glioblastoma was related to a significantly lower AD risk than other tumors (odds ratio: 0.19, 95% CI: 0.05-0.77). Additionally, patients who were older, female, American Indian/Alaska Native, had a benign tumor, radiation therapy and tumor-directed surgery had a significantly higher risk of dying from AD. Conclusions: Gliomas and glioblastomas were associated with a significantly lower risk of death from AD than other tumors.