Some Skin Cancers Tied to Lower Odds of Alzheimer's
A weak immune response might allow skin cancer but protect brain from inflammation, expert suggests
Town thinks the study suggests a fascinating and important concept: skin cancer may be a biomarker for resistance to Alzheimer's disease. That means, for example, that it may be possible that drugs that dampen the inflammatory response, such as a TNF-alpha inhibitor, could potentially be used to help prevent Alzheimer's disease.
TNF-alpha inhibitors block TNF-alpha, a protein that is present in larger quantities in people who have certain inflammatory conditions, such as rheumatoid arthritis, Crohn's disease and psoriasis. TNF-alpha inhibitors include adalimumab (Humira), etanercept (Enbrel) and infliximab (Remicade).
The latest research involved 1,102 people in New York City, whose average age was 79 when they enrolled in the study. None of the participants had dementia at the beginning of the study. Every year, a team tested them for memory, concentration, language, planning abilities and other factors. During the average four-year follow-up, they were asked annually whether they had developed non-melanoma skin cancer.
At the start of the study, 109 people reported that they had been diagnosed with skin cancer in the past. During the study, 32 people developed skin cancer and 126 people developed dementia, 100 of those with Alzheimer's. Of the 141 people with skin cancer, only two developed Alzheimer's disease, compared to 98 of the 961 people without skin cancer.
Alzheimer's is the most common form of dementia, defined by declines in memory and other thinking abilities.
"For a long time, we didn't even know inflammation was important, a key factor in the evolution of Alzheimer's disease," said Town. "Now [this paper suggests that] we can start to think more broadly; maybe it's inflammation in the blood or the skin that might be important factors."
Although the study found an association between certain non-melanoma skin cancers and lower risk of Alzheimer's, it did not prove a cause-and-effect relationship.