Associations Between Malignant Tumors and Alzheimer's Disease: A Cross-Sectional Study

Although there is potential overlap in the pathological and physiological mechanisms underlying malignant tumors and Alzheimer's disease (AD), a significant gap remains in the epidemiological evidence supporting their association. We used data from the National Health and Nutrition Examination Survey (NHANES) to elucidate the epidemiological relationship between malignant tumors and AD.

We analyzed data from NHANES from 2013 to March 2020, prior to the COVID-19 pandemic, including 9274 participants aged ≥ 20 years. Multivariate logistic regression was used to explore the link among malignant tumors, tumor types, and AD risk. Sensitivity analyses were performed to evaluate the robustness of the association with neurofilament light chain levels, composite cognitive function scores, and different analytic populations. Additionally, subgroup analyses were performed to explore the association between malignancy and AD risk in specific subpopulations.

Among the 9274 participants included in the study, 1432 were identified as having malignant tumors. There was a significant association between malignant tumors and AD [adjusted odds ratio (aOR): 1.55; 95% confidence interval (CI): 1.27-1.89; p < 0.001]. The risk of AD was higher in patients with colorectal and prostate cancer compared to those with other malignancies. Sensitivity analysis of neurofilament light chain levels suggested that malignant tumors may contribute to the development of mild cognitive impairment (aOR: 1.52; 95% CI: 1.01-2.27; p = 0.044). Subgroup analysis revealed that AD risk following a malignant tumor diagnosis was higher in people < 65 years old and those with medium-high incomes.

Malignant tumors may be significantly associated with increased AD risk, particularly in patients with colorectal and prostate cancer. Moreover, individuals < 65 years old and those with middle-high income had increased risk of developing AD following a malignancy. These findings underscore the significance of early AD detection and prevention in patients with a history of malignant tumors.