Cancer is a group of different diseases that have the same feature, the uncontrolled growth and spread of abnormal cells. Each different type of cancer may have its own set of causes. Many factors play a role in the development of cancer. The importance of these factors varies depending on the type of cancer. A person’s risk of developing a particular cancer is influenced by a combination of factors that interact in ways that are not fully understood. Some of the factors include:

• Personal characteristics such as age, sex, and race
• Family history of cancer
• Diet and personal habits such as cigarette smoking and alcohol consumption
• The presence of certain medical conditions
• Exposure to cancer-causing agents in the environment
• Exposure to cancer-causing agents in the workplace

In many cases, these factors may act together or in sequence to cause cancer. 

CONTENT:
Millions of U.S. workers are exposed to substances that have tested as carcinogens in animal studies. However, less than 2% of chemicals manufactured or processed in the U.S. have been tested for carcinogenicity(1).  Based on well-documented associations between occupational exposures and cancer, it has been estimated that 4% to 10% of U.S. cancers (48,000 incident cases annually) are caused by occupational exposures(2).  Key to all occupational exposures is that virtually all such exposures can be prevented (3-5).