ASSOCIATION BETWEEN ALZHEIMER DISEASE AND CANCER: A POSTMORTEM CROSS‐SECTIONAL STUDY IN BRAZIL

Abstract

AbstractBackgroundA biological mechanism in cancer promotion may have a protective role against AD1. Although disparities between the clinical and the anatomopathological postmortem diagnoses related to the etiology of dementia and cancer were described2, most previous studies were based only on the clinical diagnoses for both diseases. Therefore, we aimed to investigate the association between AD and cancer in a large autopsy study from a racially diverse sample.MethodThis cross‐sectional study analyzed data with postmortem brain tissue from participants over 55 years of age from the Biobank for Aging Studies. Data from the full‐body autopsy reports and a Functional Clinical Questionnaire (FCQ) applied to an informant were used to determine the presence of cancer. The association between AD and cancer was investigated using logistic and linear models adjusted for sociodemographic and clinical variables and APOE allele 4.Result689 subjects were included (mean age 74.2 ± 10.8 years old, 47.5% women, 68% White) (Table 1). 18% of the sample had cancer. The frequencies of cancer types and neuropathological post‐mortem diagnoses are shown in Figure 1. Cancer was not associated with AD (OR = 0.56, 95% CI = 0.21;1.39), or CERAD neuritic plaque score [ b = 0.057, 95% CI = ‐0.31; 0.41], but was associated with lower Braak neurofibrillary tangle staging (b = ‐0.49, 95% CI = ‐0.98; ‐0.03] (Table 2).ConclusionIn a large autopsy study, we found an association between cancer and Braak neurofibrillary tangle staging, which is in accordance with previous research suggesting a protective role of cancer in AD risk3.1. Ospina‐Romero M, Glymour MM, Hayes‐Larson E, Mayeda ER, Graff RE, Brenowitz WD, Ackley SF, Witte JS, Kobayashi LC. Association Between Alzheimer Disease and Cancer With Evaluation of Study Biases: A Systematic Review and Metaanalysis. JAMA Netw Open. 2020 Nov 2;3(11):e2025515.2. Landefeld CS, Chren MM, Myers A, et al. Diagnostic yield of the autopsy in a university hospital and a community hospital. The New England Journal of Medicine. 1988 May;318(19):1249‐1254.3. Nakamura M, Kaneko S, Dickson DW, Kusaka H. Aberrant Accumulation of BRCA1 in Alzheimer Disease and Other Tauopathies. J Neuropathol Exp Neurol. 2020 Jan 1;79(1):22‐33.