Comment by sniperjoe360

As an oncologist, the cause is unknown. But it's not so simple to point fingers at one cause. For example someone who is a heavy smoker (ie. a pack a day) gets cancer at a rate of 25% in their lifetime should they live to age 80. It's a delicate interplay between genetics, development, and environment. We should identify all modifiable risk factors and change our behavior to reduce exposure to them.