Cancer Mortality Maps & Graphs.

Scientists since the time of the ancient Greeks have noted the phenomenon of disease clusters, in which diseases occur in greater-than-expected numbers over a short time in a small area. In the 1850s, pioneering epidemiologist John Snow was one of the first physicians to construct maps solely for the purpose of studying a disease (in his case, cholera). His work was important not only for discovering how cholera is transmitted but also for showing the correlation between geography and disease. Over the past few decades, the use of maps as epidemiologic tools has greatly expanded with the development of computer mapping technologies and the use of the Internet.

In April 2001, the National Cancer Institute (NCI) launched its Cancer Mortality Maps & Graphs Web site, located at http://www.nci.nih.gov/atlasplus/. The site brings online the Atlas of Cancer Mortality in the United States, 1950-94, one of a series of atlases produced by the institute since 1975 showing geographic patterns of disease mortality through color-coded maps. These reference works provide epidemiologists and public health scientists a unique resource for studying disease patterns on both spatial and temporal levels. The new Web site will be updated with additional cancer data as they become available.

Using atlas data, factors contributing to high rates of certain types of cancer have been identified. One example is the finding that elevated death rates from lung cancer in several southeastern U.S. coastal communities were linked to exposure of shipyard workers to asbestos during World War II. Another is that variations in cigarette smoking greatly influence the patterns of certain tobacco-related cancers, such as lung, larynx, esophagus, and oral cavity cancers.

The central core of the site is the atlas itself, accessible through the Atlas of Cancer Mortality in the United States: 1950-94 (Book) link. The atlas provides maps, text, tables, and figures for more than 40 cancers for the time periods 1950-1969 and 1970-1994. Clicking on the Mortality Maps and Rates by Cancer link leads to in-depth overviews of specific types of cancer, including conventional, complementary, and alternative treatment options; clinical trial information; and links to resources and support groups.

Visitors may also choose the Customize Mortality Maps option under each cancer type to create mortality charts and graphs based on any combination of parameters such as cancer type, geographic unit, time period, age group, race, and sex. These charts and graphs can be accessed by the visually impaired through text files that can be converted to speech with a screen reader. Back on the home page, the Customize Mortality Maps and Interactive Mortality Charts and Graphs links provide direct routes to these mapping options.

NCI officials hope this resource will be used not only by researchers and the general public to gain greater insight into patterns of cancer deaths but also by policy makers for allocating resources based on disease rates, availability of health care, and other demographic factors. The Centers for Disease Control and Prevention is using the Web site as a model for an injury mortality Web site it is developing, while several schools, including the Harvard School of Public Health and George Washington University, are using the site as a classroom teaching tool. The NCI plans to expand the site to include noncancer mortality mapping and graphing as well as other variables including environmental, occupational, and economic data.