A complex mix of factors related to environment, lifestyle, and heredity plays a role in the causation of cancer. For example, 80 percent of all cancers are related to the use of tobacco products, to what we eat and drink, and to our exposure to radiation, asbestos, and some of the other cancer-causing agents. There's not much you can do about your genes, but several other key risk factors are under your control. If you identify them and make the necessary changes in your lifestyle early enough, you can substantially decrease your chances of developing a malignancy. Here are some of the risk factors you can do something about: