AFAIK Alzheimer’s is a single disease, whereas cancer is kind of a catch-all category for a huuuuge set of different disorders caused and treated by different things.
Alzheimer's is currently categorized as a single disease. But I suspect the result will turn out to be similar to Ulcers which were initially thought to be the result of acid diets, and predisposed conditions, but turns out there are many types, and the most common type is bacterial.
I think we'll find there are many types of Alzheimer's, some Amyloid based, others viral, or dietary, etc.
