There are many environmental influences that correlate with cancer, but nothing is absolute. The body creates tumors regularly, but usually keeps them in control. Carcinogens increase the likelihood of cancer, but the lack of carcinogens does not eradicate the possibility of cancer. Sad to say, luck plays a large role in possibly 2/3 of all cancers.
“Two Thirds Of Cancer Cases Caused By Bad Luck” – Sydney Morning Herald
Pretending Not To Panic 