Several studies in Shandong, China investigated environmental and dietary risk factors for gastric cancer and precancerous gastric lesions. A cohort study among 3,400 adult subjects selected at random in Linqu County, Shandong Province, a high-risk area for gastric cancer in China, demonstrated a significantly elevated risk of gastric cancer for subjects with baseline deep intestinal metaplasia (RR=34) and dysplasia (RR=29) compared with subjects with chronic atrophic gastritis. An endoscopic survey conducted in a low-risk area for gastric cancer in Shandong, confirmed the low prevalence of precancerous gastric lesions there and suggested that gastric lesions were strongly associated with Helicobacter pylori (H. pylori) infection. Interestingly, this region is known for its production of garlic, which the inhabitants consume at a rate of 20 grams of garlic per day on average. A subsequent comparison of the high- and low-risk areas in Shandong revealed similar seroprevalence of H. pylori antibodies but higher rates of antibodies for the subtype CagA in the high-risk area. A validation study revealed that an ELISA assay based on Western strains of H. pylori had similar sensitivity and specificity, when applied to the rural Chinese population, to an ELISA assay based on indigenous Chinese strains. A case-control study of squamous-cell esophageal cancer in the U.S. demonstrated increased risk of esophageal cancer among alcoholic beverage drinkers. A standardized proportional mortality ratio (SPMR) study of 8,887 deaths during 1980-1989 among male steel workers in Anshan, China found a significant elevated SPMR of 1.38 for stomach cancer. A nested case-control study of stomach cancer in Anshan, China found a significant elevated stomach cancer risk for those employed for 15 or more years in ore sintering and transportation (OR=3.2), in the fire-resistant brick factory (OR=2.5), in general loading (OR=3.2), as boiler workers and cooks (OR=2.6), and as coke oven workers (OR=5.4). A larger population-based case-control study of gastric cancer in Shanghai suggested that cigarette smoking, and possibly alcohol consumption, may increase the risk of gastric cancer, notably of the distal stomach among men. A study of 3,400 subjects with precancerous gastric lesions in Shandong, China revealed that relative to those with undetectable nitrite, odds of intestinal metaplasia were significantly increased among those with low (OR=1.5) and high nitrite concentrations (OR=4.1). The prevalence of H. pylori varied with gastric pathology; ORs were high for those with chronic atrophic gastritis (CAG), particularly for those with severe CAG (OR=5.9). A linkage study in Sweden revealed that gastric ulcers were associated with an increased risk of gastric cancer, while duodenal ulcers were related to a decreased risk of gastric cancer. The field work for a population-based case-control study of gastric cancer in Poland ended in the fall of 1996, and data preparation and analysis are currently underway. The Shanghai GI-tract study, a case-control study of cancer of the pancreas, suggested that the risk of pancreatic cancer was associated with number of pregnancies, number of live births, and early age at first birth among women and with obesity among both sexes. In a prospective study of 11,000 U.S. men, increased risk of colorectal cancer was seen for beer drinkers, white-collar workers, and those who had an increased consumption of red meat, total fat, animal fat, and animal protein. Ongoing analyses of data from colorectal cancer cases and controls in Japan suggest that frequent consumption of western-style meals, increased consumption of meat, and use of oil-intensive cooking methods are risk factors for colorectal cancer. Regular consumption of beer is a risk factor for women. In another Shanghai GI-tract study, a reduced risk of cancer of the colon, rectum, and pancreas was found among green tea drinkers. This reverse association appeared to be stronger among women than men and more pronounced with increased amounts of green tea consumption.
| You, W C; Ma, J L; Liu, W et al. (2000) Blood type and family cancer history in relation to precancerous gastric lesions. Int J Epidemiol 29:405-7 |
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| You, W C; Zhang, L; Gail, M H et al. (2000) Gastric dysplasia and gastric cancer: Helicobacter pylori, serum vitamin C, and other risk factors. J Natl Cancer Inst 92:1607-12 |
| Brown, L M (2000) Helicobacter pylori: epidemiology and routes of transmission. Epidemiol Rev 22:283-97 |
