In this area there are no easy answers. True personal desire and commitment are required for any long term solution. Exercise and cancer is relatively new field of research. It is estimated that about a third of colon cancers may be related to physical inactivity. The exact mechanism is unknown but it is known that people who are active live longer, healthier lives.
Tobacco is felt to be responsible for up to a third of all cancers.
It is the single most commonly recognized cause for cancer. Fortunately, smoking rates for males are now decreasing. Unfortunately, smoking rates for women are still increasing. There are many incentives to stop smoking these include both cost and detriments to health. Recently it has also been shown that smoking causes sexual dysfunction in men.