Are most cancers associated with exposure to known carcinogens?

Question

Are most cancers associated with exposure to known carcinogens?

Answer 1

No, for most cancers, there is no clear "reason" why they have grown.  There are lots of risk factors (chemicals, being overweight, genetics), but for most people it's not a case of "10 years ago I was exposed to chemical X and now I have cancer".

That's one of the reasons it's hard to find cures for cancer...so far the scientists don't fully understand the reasons some people get cancer, while others with the same lifestyle and exposures do not.

Answer 2

In one sense, yes. Statistically, if you add up the number of cancers due to exposure to ionizing radiation, UV, cigarette smoke, radon, HPV, asbestos, and other known chemical carcinogens, then you probably have a majority of cancers for which the main trigger is known.

That still leaves a lot of cancers, like mine, where there is no hint of a clue as to why the cells went haywire in the first place.

There are probably far more unknown carcinogens than known ones.

Answer 3

Cancer can tie into anything really. Now-a-days you can get cancer from almost anything. Chemicals... dust... smoke... using a pop bottle twice... etc