Scientists have identified many factors that contribute to the development of cancer. Avoiding these risk factors whenever possible could have a significant effect on your chance of getting cancer. The main risk factors (in alphabetical order) include:
Drinking alcohol has been linked with an increased risk of cancer of the esophagus, oral cavity, pharynx and larynx, breast and liver. The cancer risk from drinking alcohol is especially pronounced if you smoke. If you drink, it’s important to drink moderately. For men, this means no more than two drinks a day. For women, it’s one drink a day.
What we eat makes a difference in our chances of developing a variety of cancers. The content of our meals, as well as the way they are prepared, influences our cancer risk. For example, people who eat a lot of red meat appear to have a slightly higher risk of colon cancer and breast cancer. But the risk appears to be much greater for:
- Meats that are grilled on a barbecue compared with those prepared by baking or boiling
- Processed or cured meats
In some cases, not getting enough of certain foods can increase your risk of getting cancer. Eating a diet rich in fruits, vegetables, whole grains and other plant-based foods is associated with a reduced chance of developing cancer.
There’s evidence that many environmental factors may contribute to cancer development. Examples include:
- Asbestos previously used in insulation materials causes two types of lung cancer. The combination of smoking and significant asbestos exposure raises the risk of lung cancer 90-fold.
- Working with aromatic amines used in some industrial materials is associated with the development of bladder cancer.
- Benzenes in varnish and glue increase the risk of leukemia.
Cancers tend to aggregate within families. Close relatives of someone who has certain types of cancer have a higher risk of getting that particular cancer and possibly others. Most of these cases have a genetic basis. In addition, family members may share exposure to carcinogens in the environment, such as cigarette smoke or environmental pollutants in a particular geographic area. Anyone who has a family history of colon, breast, ovarian and prostate cancer should seek appropriate screening for early detection.
Low levels of physical activity are linked to higher risks of breast and colon cancer. Studies have shown that people who get regular exercise are less likely to develop colon and breast cancer. One theory suggests that exercise protects against colon cancer by stimulating intestinal contractions (peristalsis), which increase the speed at which stools move through the intestine and out of the body. This could reduce exposure of cells in the colon to potential carcinogens in the stools.
Smoking is believed to play a role in approximately 30 percent of all cancer deaths in the United States, and it causes about 80 percent of lung cancer deaths. Other cancers that are strongly associated with smoking are bladder cancer, oral cavity cancers, cancers of the head and neck, esophageal cancer and pancreatic cancer. For example, one-half of all bladder cancer patients are current or former smokers. The only preventive measure is not to smoke. A smoker’s risk of developing cancer decreases after quitting and continues to decrease every year thereafter.
Exposure to the ultraviolet radiation in the sun’s rays is responsible for almost all cases of basal cell carcinoma and squamous cell carcinoma. Sunburns, especially those that occur before the age of 20, are associated with a higher risk of malignant melanoma. The best preventive strategies include staying out of the sun between 10 a.m. and 3 p.m., wearing protective clothing (including a hat that shields the back of your neck) and using a sunscreen with a sun protection factor (SPF) of 30 or higher. Wear ultraviolet light-filtering sunglasses. Do not use tanning booths.
Viruses and Other Infections
A number of cancers have been linked to infectious agents. Examples include HIV, human papillomavirus and hepatitis B and C. Prevention for some of these can be as simple as getting hepatitis vaccinations and practicing safe sex by using a latex condom.