Descriptive Studies: Evaluation of demographic, temporal, and geographic variation in cancer rates may suggest clues to the roles of environmental or cultural influences; identification of population subgroups or regions at notably high or low risk may indicate areas where more intensive studies might be particularly fruitful. The Atlas of Cancer Mortality in the United States, 1950-94 was published in 1999, and the online version is available at www.nci.nih.gov/atlasplus. Users can create customized maps and have flexibility in choice of cancers, age groups, and sex and race aggregation. We have been analyzing changes in the geographic patterns of mortality for those cancers with substantial variation by area, race, and/or gender. 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. Race- and age-specific breast cancer mortality rates from 1950 through 1999 were calculated for four census regions and 508 state economic areas of the United States. We found that although rates of breast cancer still tend to be highest in the Northeast, intermediate in the West and Midwest, and lowest in the South, the underlying mortality trends suggest somewhat slower recent dissemination of effective breast cancer treatment in the South. We used a spacial scan statistic to further characterize the elevated prostate cancer mortality rates in certain areas of the country, and we identified five clusters of elevated mortality rates among white men and 3 in black men. The patterns observed could not be attributed to selected demographic or socioeconomic characteristics but should provide leads for further study into the risk factors and the medical or reporting practices that may contribute to geographic variation in prostate cancer mortality. With our collaborators in Beijing, China, we mounted a pilot study, using data from five provinces, to investigate the feasibility of comparing cancer mortality rates from the sample survey of 1990-92 with rates from the full survey of 1973-75. Preliminary results suggest that we can proceed, and we recently received data for the full 27 provinces for both time periods. We are editing the data and preparing for our full analysis. In contrast to mortality data, which are limited to specifying the form of cancer, incidence data include information on histologic type of the tumor and in many instances, the subsite of origin. We have used incidence data from the Surveillance, Epidemiology, and End Results (SEER) program to investigate further the demographic patterns to discern subgroups that may be of etiologic significance. We evaluated age-adjusted incidence rates based on data for cases diagnosed in nine SEER registries for oral cavity and pharynx (OCP) cancers by histologic type, anatomical site, race, and sex to identify subgroups that may be etiologically distinct. The data suggest that OCP cancers may be separated into five subgroups: squamous cell carcinoma (SCC) of the lip, SCC of the oral cavity, SCC of the pharynx, adenocarcinoma, and Kaposi?s sarcoma. Squamous cell carcinoma of the esophagus was the main form of esophageal cancer in the past, and rates have been decreasing while remaining higher among blacks than whites. Declines in tobacco use and heavy alcohol ingestion, and increases in consumption of raw fruits and vegetables likely have contributed to decreasing incidence. In contrast, adenocarcinoma of the esophagus has been rising and is more frequent among whites than blacks; obesity, gastroesophageal reflux disease, and possibly reductions in H. pylori prevalence most likely have contributed to the increases. Reductions in smoking, improved diet, and reductions in H. pylori prevalence probably have contributed to the consistent reductions observed for distal gastric cancer. Our analysis of the recent U.S. trends in lung cancer incidence and mortality found convergence of rates among men and women born after 1960, supporting the idea that males and females may be equally susceptible to develop lung cancer from a given amount of cigarette smoking, rather than the hypothesis that women are more susceptible. Breast cancer accounts for one-third of cancer diagnoses and 15% of cancer deaths in U.S. women, making it the most common incident cancer (excluding superficial skin cancers) and the second leading cause of cancer death. Internationally, incidence rates vary threefold, with rates low in Asia, intermediate in South America and Eastern Europe, and high in North America and Western Europe; migrant studies suggest that lifestyle factors largely explain these international differences. We examined crude cumulative probabilities of death from breast cancer and other causes subsequent to a diagnosis of breast cancer by race, stage of disease, age, and tumor size using data from the SEER program. We found that the probability of death from breast cancer declines with age within stage and increases with advancing stage regardless of age. We investigated why incidence rates for malignant tumors of the uterine corpus are lower among blacks than among whites, whereas mortality rates are higher among blacks. We found that less favorable outcomes for usual types of endometrial adenocarcinoma and for rare aggressive tumors contribute equally to the relatively high mortality due to corpus cancer among black women. Our analysis of ovarian cancer incidence rates revealed that white women had significantly higher rates compared with black women of all types of epithelial tumors, whereas black women had higher rates of gonadal stromal tumors. The reported rates for some specific histopathologic tumor types have changed over time, in part reflecting more specific pathologic classification. Our investigation of testicular cancer incidence trends revealed that seminoma incidence continues to increase among white males, although the rates of increase have become less pronounced; nonseminoma rates appear to have plateaued. An investigation the incidence of malignant thymoma revealed the tumor to be quite rare and to occur more frequently among Asian/Pacific Islanders than other racial groups, suggesting a potential role for genetic factors. The incidence of Kaposi?s sarcoma (KS) and non-Hodgkin?s lymphoma (NHL) increased markedly since the onset of the AIDS epidemic in 1981, but HIV infection rates slowed and effective antiretroviral therapies were introduced during the 1990s. We found that KS incidence declined sharply during the mid-1990s, with the declines most evident in San Francisco; NHL rates also decreased, with the most highly AIDS-associated types of NHL declining the most steeply. However, non-AIDS-associated NHL incidence has continued to increase steadily through 1998. The descriptive epidemiology of a number of cancers has been updated in a series of chapters, including cancers of the breast, corpus uteri, biliary tract, and bladder, and non-Hodgkin lymphoma, multiple myeloma, and the leukemias; and cancer incidence and mortality patterns in the United States have been updated. Cancer incidence and mortality rates may be used to assess consistency with hypotheses regarding cancer etiology suggested by other scientific studies. Colorectal cancer incidence rates have been rising rapidly in Shanghai, China, and dietary factors are suspected to play a role in colorectal cancer risk. Our investigation of incidence trends and dietary patterns found significant positive associations between colon cancer rates and per capita consumption of vegetable oil, poultry, fresh eggs, and pork. Because simian virus 40 (SV40) DNA sequences had been detected in some hum
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