Cancer is the second leading cause of death in the United States today and causes more than half a million deaths each year. Yet, after decades of steady increases in cancer death rates, the 1990s saw the beginning of a downward trend. Furthermore, cancer survival rates have increased in large part because of earlier detection of cancer as a result of screening programs and advancements in chemotherapy. These positive trends, however, tell only part of the story since the incidence of some cancers is still on the rise.

Both environmental and genetic factors are known to be involved in the development of cancer. For example, environmental factors such as exposure to chemicals and sunlight have long been known to be linked to the development of some types of cancer. Research suggests that other factors (e.g., diet, lifestyle, economic status, and infections) may also contribute to the development of certain forms of cancer.

Not everyone exposed to a particular cancer-causing chemical will develop cancer. Complex interactions that require additional research are involved in individual susceptibilities to cancer. A focus of genetic research on cancer has traditionally looked at single dominant genes, but recent research is beginning to address the role of multiple modifier genes and their interactions with multiple environmental factors, that is, the research paradigm of "gene-environment interactions."

In June 2000, the Institute of Medicine Roundtable on Environmental Health Sciences, Research, and Medicine held the first of a series of workshops aimed at examining the role of the environment in health. This workshop, entitled Rebuilding the Unity of Health and the Environment: A New Vision of Environmental Health for the 21st Century, considered environmental health broadly, to encompass health effects of the social, built, and the natural environments.

At the next workshop, the Roundtable will work from this broader perspective of environmental health to better define and understand the contribution of the environment in the development of cancer. The two-day workshop, entitled Cancer and the Environment: Gene-Environment Interactions, will be held at the National Academy of Sciences on Wednesday, May 16 and Thursday, May 17.

Registration is free.

Those who cannot attend the symposium are invited to participate by listening to a live audio Webcast of the event and submitting questions using an e-mail form. Both the Webcast link and the form will become available at the time of the event at http://national-academies.org.