Glioma and Alzheimer's Disease

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.

In the current study, we wished to determine the relationship of AD mortality to malignant brain tumor mortality in US states and counties.

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).

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.

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.