It could also just be bad genes. My grandmother has been a smoker forever, and she's 87 without cancer. Her son, my uncle, has been a chronic alcoholic since he was 20--he's 69 now. He would drink in excess of a couple bottles of soju everyday. Never had any cancer. He recently fell down from being so drunk and suffered a concussion and broken hip. We think he's gonna die soon from that.

Who knows.

What we do know is faulty genetics are responsible for higher incidence of certain cancers. Mutations in the BRCA1 and 2 genes have been linked to earlier and much higher rates of breast and ovarian cancer than the general public. You can get tested for this. Another gene, like HNPCC, have shown to greatly increase your risk of colon cancer.

I, on the other hand, will probably get cancer. I believe in the black swan event.