Prevention

Cancer can be caused by a variety of different factors and may develop over a number of years. Some risk factors can be controlled. Choosing the right health behaviors and preventing exposure to certain environmental risk factors can help prevent the development of cancer. For this reason, it is important to follow national trends data to monitor the reduction of these risk factors. This section focuses on national trends data from two major groups of risk factors: Behavioral and Environmental.

Behavioral Factors
Scientists estimate that as many as 50–75 percent of cancer deaths in the United States are caused by human behaviors such as smoking, physical inactivity, and poor dietary choices. The first part of the Prevention section describes trends in the following behaviors that can help to prevent cancer.

Tobacco Use
Smoking causes about 30 percent of all U.S. deaths from cancer. Avoiding tobacco use is the single most important step Americans can take to reduce the cancer burden in this country.

• Not using cigarettes or other tobacco products:
  • Age at smoking initiation
  • Youth smoking
  • Adult smoking
  • Quitting smoking
  • Health Professional Advice to Quit Smoking

Diet
Maintaining a healthy weight and eating a moderate-fat diet and enough fruits and vegetables while limiting consumption of red meat and avoiding too much alcohol is also an important step in reducing cancer risk.

• Eating fruits and vegetables
• Limiting red meat consumption
• Eating a moderate-fat diet
• Not drinking too much alcohol

Physical Activity
Obesity and physical inactivity cause about 25–30 percent of several of the major cancers in the U.S., including colon, breast, endometrial, kidney, and esophageal cancers. Obesity is estimated to cause 14 percent of cancer deaths in men and 20 percent of cancer deaths in women.

• Maintaining or reaching a healthy weight
• Being physically active

Sun Protection
The number of new cases of melanoma skin cancer has increased between 1975 and 2004, with an estimated number of 60,000 new cases in 2007.

• Protecting skin from sunlight

Environmental Factors
Certain chemicals, biological agents, toxins, etc. are associated with cancer development. In this section, national trends data associated with environmental exposures and their relationship to cancer are reported.

Secondhand Smoke

• Secondhand tobacco smoke (also known as environmental tobacco smoke)

Chemical Exposures

• Pesticides
• Dioxins

The environmental measures highlighted in this report were chosen based on the availability of national trends data and their inclusion in the Healthy People 2010 Report. Because national trends data were unavailable for other environmental exposures that cause cancer, they were excluded from this report.

*Note: Updated data on pesticides and dioxins will be provided in late 2008. The updated data on these environmental factors is based on the release of the Centers for Disease Control’s Fourth National Report on Human Exposure to Environmental Chemicals, expected to be published in summer 2008. For more information, please see: http://www.cdc.gov/exposurereport/results_reporting_process.htm.

Page last reviewed: December 6, 2007