Cancer no, but nicotine is implicated in heart disease and other cardiovascular issues.

Is that because it's a stimulant, or is there some other known mechanism? It seems like most (maybe all) stimulants I've read about are correlated with cardiovascular issues.

I think one theory is that nicotine is a vasoconstrictor. Though whether, in its pure form, it is a particularly significant one, i.e. any worse than caffeine, is really not so clear.

No, //cancer stems from the carcinogens in the burning / heating of tobacco//. Nicotine is not cancerous in itself any more than caffeine.

I'm not a doctor though so while I might sound sure it's based on what I've read on the topic over the many years.

Edit : rightly corrected its not just heating and burning, its tobacco and others in general. But nicotine itself is not cancerous.

Cancer also stems from non-heated tobacco because the plant itself contains carcinogens that are pressed into the skin in the mouth for example, often including lesions and such

Chewing tobacco causes cancer

But not because of the nicotine.