"Coffee & Cancer"
One of the reasons it’s so difficult to study the relationship between diet and
cancer is because many dietary behaviors are associated with non-dietary behaviors.
For example, the reason we used to think coffee drinking caused cancer
was because people who drink coffee are more likely to have a
cigarette in the other hand.
When you factor that out, though — for example, by looking at just
nonsmokers who do or don’t drink coffee — we find that,
if anything, coffee consumption may reduce the total cancer incidence.
Not by much, but, "Overall, according to the latest review, an increase in
consumption of one cup of coffee per day was associated with about a 3% reduced
risk of [cancers—especially] bladder cancer, breast [cancer], [mouth,]
colorectal, endometrial, esophageal, [liver,] leukemic, pancreatic,
and prostate cancers."
Coffee beans aren’t really beans, but one is, after all, just soaking
a powdered seed in some water.
So, a reduction in cancer risk not that surprising.