There is a significantly decreased risk for a diagnosis of Alzheimer disease (AD) in patients with malignant melanoma (MM), as well as in those with nonmelanoma skin cancer (NMSC), according to the results of a study conducted in a large, single-center, Midwestern US patient population and published in the Journal of the European Academy of Dermatology and Venereology.
The investigators performed a search of electronic medical record data between January 2001 and December 2015 to identify all patients ≥60 and <89 years of age with a clinic follow-up of ≥1 year and no diagnosis of AD, MM, or NMSC at study entry. Data were collected with respect to sex, age, race, and duration of follow-up.
International Classification of Diseases, Ninth Revision, and International Classification of Diseases, Tenth Revision, codes were used to detect MM, NMSC, and incident diagnosis of AD. Crude and adjusted odds ratios (ORs) were obtained with the use of logistic regression analysis.
Data for a total of 82,925 patients between 60 and 88 years of age, with known sex, race, and ≥1 year of in-clinic follow-up, were included for evaluation. Among a total of 1147 patients diagnosed with MM, 5 were subsequently diagnosed with AD. Among 2506 participants diagnosed with basal cell cancer, 5 received a subsequent AD diagnosis; among 967 participants diagnosed with squamous cell carcinoma, only 1 received a subsequent diagnosis of AD.
After adjusting for confounding factors, including age, sex, race, diabetes, cerebrovascular disease, and peripheral vascular disease, a significantly decreased risk for subsequent AD was reported among patients with MM (odds ratio, 0.39; 95% CI, 0.16-0.96; P =.042). Moreover, a significantly decreased risk for subsequent AD was also reported among patients with basal cell cancer (OR, 0.18; 95% CI, 0.08-0.45; P <.0001) and those with squamous cell carcinoma (OR, 0.08; 95% CI, 0.01-0.56; P =.013).
The investigators concluded that an inverse association exists between a diagnosis of AD in patients with MM, as well as in those with NMSC (basal cell cancer and squamous cell carcinoma). Additional examination of these relationships is warranted to help to clarify the complex biologic and psychosocial interactions among AD, MM, and NMSC.
Ibler E, Tran G, Orrell KA, et al. Inverse association for diagnosis of Alzheimer’s disease subsequent to both melanoma and non-melanoma skin cancers in a large, urban, single center, Midwestern U.S. patient population [published online March 24, 2018]. J Eur Acad Dermatol Venereol. doi: 10.1111/jdv.14952