Cancer arises when cells are unable to repair DNA damage and experience abnormal cell growth and division. The process known as metastasisDictionary of Environmental Health occurs when cancer cells travel to other parts of the body via the bloodstream and replace normal tissue. According to the American Cancer Society, this chronic disease is the second leading cause of death in the U.S. with half of all men and one-third of all women developing some form of cancer during their lifetimes.

Although cancer is responsible for 23% of all deaths in the U.S., millions of Americans have recovered from the disease. People may reduce their chances of getting cancer by employing prevention methods such as having regular screenings and living a healthy lifestyle.

The NIEHS is committed to understanding the connection between genetics and environmental exposures with regard to cancer. In addition to several Division of Intramural Research (DIR) groups studying the molecular mechanisms behind the disease, the NIEHS funds cancer research at other institutions.