consumption among persons with the ADH 31-1 genotype. These studies have been classified as Category I and II studies.
African Americans and Chinese Americans suffer from higher rates of esophageal cancer than whites. NCI-supported scientists are studying tumors that occur in excess among African Americans in a series of case-control studies. In addition, studies are in progress to collect DNA from samples of populations at high and low risk for esophageal cancer in Shanghai, China. In Linxian, China, NCI researchers are studying the impact of a nutritional intervention on late-stage progression of esophageal cancer among individuals in a high-risk population. These studies have been classified as Category I studies.
Asian Americans, African Americans, and farmers all suffer from higher rates of stomach cancers than other Americans. NCI is studying the effect of a nutritional intervention on the progression of precancerous gastric lesions among subjects in Shandong, China. A screening program in China is also sponsored by NCI to evaluate the role of diet on precancerous lesions of the stomach. Similarly, DCEG staff are evaluating the risk posed by agricultural hazards such as pesticides, fertilizers, and dust on stomach cancers in a case-control study in Nebraska. In addition, DCEG staff, working with the U.S. Environmental Protection Agency and NIEHS, are evaluating stomach cancer and agricultural exposures among African-American and white farmers in North Carolina and Iowa in the Agricultural Health Study. To encourage further research in this area, NCI, along with NIDDKD, NIAID, the NIH Office of Research on Minority Health, and the American Digestive Health Foundation, recently issued an RFA on Helicobacter pylori and its relationship to digestive diseases and cancer, with an emphasis on research related to minority populations. This research has been classified as Category I research by NCI.
NCI supports several studies that are investigating a range of risk factors associated with colorectal cancer. In a case-control study being conducted in China and the United States, researchers found that Chinese-American men and white men have colorectal cancer rates seven times higher than those of men in China. High-fat diets and low levels of physical activity were among the identified risk factors. In addition, a new multicenter study is assessing the independent and combined effects of dietary factors, physical activity, body size, reproductive factors, and family history on the risk of colon cancer among African Americans and whites. Finally, staff of the Cancer Prevention Studies Branch of NCI are collaborating with VA to collect blood and tissue specimens from patients