Can cancer be prevented?

Although there is no guaranteed way to prevent cancer, people can reduce their risk (chance) of developing cancer by:

Not using tobacco products Choosing foods with less fat and eating more vegetables, fruits, and whole grains Exercising regularly and maintaining a lean weight Avoiding the harmful rays of the sun, using sunscreen, and wearing clothing that protects the skin Talking with a doctor about the possible benefits of drugs proven to reduce the risk of certain cancers

Although many risk factors can be avoided, some, such as inherited conditions, are unavoidable. Still, it is helpful to be aware of them. It is also important to keep in mind that not everyone with a particular risk factor for cancer actually gets the disease; in fact, most do not. People who have an increased likelihood of developing cancer can help protect themselves by avoiding risk factors whenever possible and by getting regular checkups so that, if cancer develops, it is likely to be found and treated early. Treatment is often more effective when cancer is detected early. Screening exams, such as sigmoidoscopy or the fecal occult blood test, mammography, and the Pap test, can detect precancerous conditions (which can be treated before they turn into cancer) and early-stage cancer.

The NCI is conducting many cancer prevention studies to explore ways to reduce the risk of developing cancer. These studies are evaluating dietary supplements, chemopreventive agents, nutrition, personal behaviors, and other factors that may prevent cancer.

This answer is based on the source infromation from the the National Cancer Institute

There are ways to decrease your risk of developing cancer.  Besides not smoking and protecting against sunlight exposure, you can reduce your risk for cancer by exercising regularly and staying slim.  Also, choose a healthy diet with lots of fruits and vegetables. 

You may want to limit well-done and grilled meats, which could raise the risk for pancreatic cancer.  When meat is cooked at a high temperature, it forms cancer-causing substances.  Marinating meat before cooking and cooking it at lower temperatures (until adequately cooked) can help reduce these substances.

Also, limit alcohol, which is linked to cancers of the mouth, esophagus, and liver.  Health experts suggest no more than two drinks per day for men, and one drink per day for women.

Well, to answer this question, cancer needs to be understood as a class of disease, similar to infections being a class of disease. For example, infections vary widely from a pimple (a skin infection) to AIDS. Similar to infections, cancer varies widely from skin cancer (very curable) to malignant brain tumors (very incurable). Cancer is not one disease but over one hundred different diseases. Therefore, prevention of cancer is directed to the most common types of cancer.

Four types of cancers comprise of half of all new cancer diagnosis in the United States: breast, prostate, colon, and lung cancer.  So if we direct our efforts to prevent these cancers, we can help prevent half of all cancers in the United States .

Breast, prostate and colon cancers are related to life style: being overweight, lack of physical activity, and diet higher in fats and carbohydrates. By changing our habits, we can reduce the risk of these cancers. Breast cancer is also related to alcohol intake, as little as one glass of wine daily.

Lung cancer is related to smoking, if a smoker quits smoking, their risk of lung cancer is reduced by over 70% in after one year of smoking cessation.

Quitting smoking also reduces the risk of oral cavity, pharynx, larynx, esophageal, and bladder cancers. Therefore, quitting smoking will give a person the greatest benefit in terms of cancer prevention.

Cancer prevention can be complex, and depends how you are affected by risk factors. Cancer risk in a nutshell is the likelihood that you will develop a cancer. Many factors play into your personal risk; do you smoke? Do you use a tanning booth? Did your mother have cancer? You can see that some factors are things you can change such as smoking, which we call modifiable risk factors. Some factors you cannot change, such as your family history; these are called unmodifiable risk factors. Some risk factors increase the likelihood of one type of cancer, while others can increase the risk of several types.