Could be increased environmental toxins, and crap food also.
There are so many supposed risk factors for various cancers, the stress of worrying about all the things, that apparently increase the risk of cancer, will probably give you cancer.
My Mum didn't smoke, didn't drink alcohol, didn't drink coffee, ate a healthy diet, exercised regularly, and yet she still died of cancer. The only thing she did was worry a lot, and stress a great deal over everything.