Evaluation of geographic variation in cancer rates may suggest clues to the roles of environmental or cultural influences. Identification of regions at notably high or low risk may indicate areas where more intensive studies might be particularly fruitful. We have completed preparations for the production of a new atlas of cancer mortality in the United States during 1950-94. We edited data files pertaining to more than 9.5 million whites and 1.1 million blacks who died during 1970-94 and 4.8 million whites who died during 1950-69 from cancer and prepared the corresponding required estimates of person-years at risk. We developed software referred to as the Mortality Rate Generator program to calculate observed and expected counts, age-adjusted rates, and confidence limits by cancer, race, sex, time period, and geographic area. Using special graphics software for Windows on a personal computer, we have generated more than 250 maps at the county or State Economic Area level that will be included in the atlas. Summary tables and figures have been prepared. The analysis of these data and maps has been completed and the accompanying text is finalized. Publication is anticipated in the fall, 1999. The text, maps, and rates will be available on the internet - an example is on our website (http://www.dceg.ims.nci.nih.gov). We are also analyzing changes in the geographic patterns for those cancers with substantial variation by area, race, and/or gender. The geographic patterns of lung cancer mortality have varied across the four race/sex groups and have changed substantially over time, most likely reflecting the prevalence of cigarette smoking in earlier years. Melanoma mortality rates have been increasing and exhibit a strong but diminishing latitudinal gradient. The geographic patterns for breast cancer mortality have remained remarkably static, but are more pronounced for women older than age 50 years than for younger women. With our collaborators in Shanghai, China, we are evaluating variation in cancer incidence by district within the Shanghai urban area. With our collaborators in Beijing, China, we have mounted a pilot study, using data from five provinces, to investigate the feasibility of comparing cancer mortality rates from 1990-92 with rates from 1973-75.