[abracadaniel]

It seems that many (maybe most) cancers are kicked off by inflammation, or otherwise stressed tissues, after the conditions are just right (genetics, carcinogen, or otherwise damaged dna). Cells that are damaged enough to spread as cancer can avoid getting replicated for years or even never without a trigger. So, it could be that we aren't more exposed to carcinogens, but more frequently encounter the conditions that make the damaged cells start spreading. So, vitamin-D and Omega-3 could indeed help in that regard, and some other cause of chronic inflammation could be responsible for the upward trend.