Developing clues to environmental cancer: a stepwise approach with the use of cancer mortality data.

Clues to environmental determinants can often be derived from the patterns of mortality from cancer. This review focuses on the stepwise approach of using cancer mortality maps, supplemented by correlation studies linking mortality rates with demographic and industrial data at the county level, to generate hypotheses to cancer etiology which can then be pursued by analytical epidemiological studies. Advantages and limitations of this approach and its application in the study of lung cancer in the United States are described.