Glioma and Alzheimer's Disease

Background: Cancer mortality and Alzheimer's disease (AD) mortality increase with age, but some studies have shown an inverse relationship of the two diseases, that is, older persons with cancer have a reduced risk of AD and vice versa. However, other analyses suggest that AD and brain tumor might be positively correlated. Objective: In the current study, we wished to determine the relationship of AD mortality to malignant brain tumor mortality in US states and counties. Methods: Data and maps of malignant brain tumor mortality and Alzheimer's disease mortality (1999-2016) are from the CDC Wonder tool (https://wonder.cdc.gov/cmf-icd10.html) . Data on malignant brain tumor types and their frequencies are from the Surveillance, Epidemiology, and End Results Program (SEER, https://seer.cancer.gov ). Data on the genetics of lower grade glioma are from the TCGA Lower Grade Glioma (LGG) dataset in TCGA (The Cancer Genome Atlas). Results: SEER data indicate that astrocytomas make up 58.2% of malignant brain tumors in patients 65 and older; glioblastoma and anaplastic astrocytoma make up 41.6%. We found a significant positive correlation between AD mortality rate and malignant brain tumor mortality rate 1999-2016 in persons age 65 and older in A) 1,101 US counties, p < 0.001 and B) 50 US states, p < 0.001. Conclusion: Adult malignant brain tumors may share some environmental risks with AD. Malignant brain tumors and AD also have some genes in common: TREM2, SPI1, CD33, and INPP5D. The interaction of environment and genetics is complex and overlaps in malignant brain tumors and AD.