A case-control study to evaluate risk factors for gastric cancer was carried out among 292 cases of gastric cancer and 485 controls in a high-risk area of Venezuela. Subjects were interviewed using a structured questionnaire, which elicited information on residential history, socio-economic status, family history of gastric diseases, smoking, drinking and dietary habits. Habitual diet was estimated from a meal-structured food frequency questionnaire on 75 food items. There was a strong inverse association with social class, as measured by education and by indicators of poverty. The results of the dietary analysis suggest that a diet high in starch and low in meat, fish and fresh vegetables increases risk of gastric cancer. A protective effect was observed for frequent consumption of allium vegetables. Inverse associations were found with height, which may reflect nutritional status in childhood, and with refrigerator use in the first two decades of life. Alcohol and tobacco consumption was investigated among males only, since the prevalence of alcohol and tobacco use was very low in females. Alcohol drinkers were at higher risk than non-drinkers and there was a small excess risk for current smokers compared with never smokers. There was some evidence of familial aggregation of gastric cancer. These findings will have important implications in planning preventive strategies for gastric cancer in Venezuela. © Gastric cancer is the second most common cancer in the world. Although gastric cancer rates are decreasing in most populations, the absolute number of cases is increasing due to aging of the population. It has been estimated that there were 700,000 new cases in 1980, 755,000 in 1985 and 1,000,000 in 1990. [1][2][3] In most populations the disease is rapidly fatal. The 5-year survival rate is less than 20% and has improved little in the last few decades. 4 Among males, the cumulative incidence of gastric cancer to age 74 varies from about 1% in the United States to 10% in Japan, with rates being about 50% lower in females. 5 In Venezuela, stomach cancer is the first cause of death from cancer in males and the third in females after cervix and breast. 6 The cumulative mortality to age 74 in 1990 was 1.7% in males and 0.85% in females. The highest rates are found in the Andean region (states of Tachira, Merida, Trujillo and Lara). In Tachira State, cumulative mortality from stomach cancer to age 74 in 1993 was 4.1% in males and 2.2% in females. No previous case-control studies have been conducted to determine the causes of gastric cancer in this high-risk population.Although the etiology of gastric cancer is not well understood, the long-term decline in gastric cancer rates in developed countries suggests an important role of environmental risk factors. 7 In particular, migrant studies suggest that exposures or habits acquired early in life are important. 8 A diet high in salt, carbohydrate and foods rich in nitrate or nitrite and their derivatives has been associated with an increase in risk. Conversely, a de...

This large epidemiologic study shows a strong relationship between the presence of H. pylori DNA in gastric biopsies and the severity of precancerous lesions that is specific to cagA-positive strains. The association between H. pylori and gastric carcinoma may have been previously underestimated due to the poor accuracy of serologic H. pylori markers and lack of discrimination by cagA genotype.

Supplementation with antioxidant micronutrients is not an effective tool for gastric cancer control in this high-risk population. The results of this trial are consistent with previous findings on the lack of effect of nutritional supplementation on precancerous gastric lesions.

Stomach cancer, despite a decline in incidence almost everywhere, remains the second most common cancer worldwide, after lung cancer (Parkin et al., 1993). In Japan, where stomach cancer is a major public health problem, there has been an extensive attempt to reduce mortality by early detection and treatment. The population screening programme aims to examine 30% of the population aged 40 or over each year by photofluorography (Oshima, 1988). The test aims at detecting the disease at an early stage, when cancer is confined to the gastric mucosa and submucosa. The Japanese programmes were introduced as a community service, without any formal randomised trial, so that evaluation of their success has depended upon analyses of time trends in incidence and mortality, comparisons of gastric cancer mortality in screened versus unscreened populations and casecontrol analyses (see reviews by Oshima, 1988;Hisamichi, 1989;Hisamichi et al., 1991). The problem of interpreting the results of non-randomised evaluations has meant that there is still some scepticism concerning the applicability of mass screening for gastric cancer elsewhere (Chamberlain et al., 1986; Miller et al., 1990).In common with other mountainous parts of South and Central America, the state of Tachira in the western part of Venezuela has high rates of gastric cancer -age-standardised mortality rates in 1982-84 were 49.6 per 105 in men and 34.1 in women, compared with 40.8 and 19.0 in men and women, respectively, in Japan in 1987 -88 (Aoki et al., 1992. A screening programme was started in 1980, by means of the established Japanese methodology of six film indirect photofluorography using double contrast. The objective was to examine as large a proportion of the population aged 35 or over as possible at intervals of 1-2 years with the aim of reducing mortality from gastric cancer. Two mobile screening units were used, moving to different localities; they were installed in a locality and subjects were invited for screening by rural nurses, using population lists for health centres close to the screening unit's location.In

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These results confirm that misclassification of histological diagnosis may be a relevant problem in chemoprevention trials of stomach cancer, more so when baseline diagnosis is taken into account in the analysis to estimate progression and regression rates of precancerous lesions. Further, the results suggest that misclassification is limited to early lesions, while diagnostic reliability of severe lesions is quite high.

As Helicobacter pylori (HP) is a Gram-negative bacterium, we investigated the associations between several functional polymorphisms in genes involved in lipopolysaccharide (LPS) signaling and the prevalence of various stages of gastric premalignant lesions in a Venezuelan population. The two NOD2 polymorphisms, del3020insC and Gly908Arg, were too infrequent to study their associations with gastric lesions. The risk of intestinal metaplasia (IM) was significantly increased among subjects with the CD14 T-260 allele compared to those without this allele. A similar, but nonsignificant increase in risk for dysplasia was observed among homozygotes of this allele. There was no association between TLR4 Asp299Gly polymorphism and any type of lesions, except for a slight nonsignificant increase in risk of IM associated with the AA genotype among subjects with a higher histological HP score. These results suggest that genetic polymorphisms in HP LPS signaling may be implicated in the development of intermediate stages of gastric premalignant lesions.

Determinants of plasma pepsinogens (PG) levels were studied in 1365 participants in a chemoprevention trial for gastric pre-cancerous lesions being conducted in Venezuela. Gastric biopsies, plasma samples and information on smoking and dietary habits were obtained at baseline examination. Both PG-I and PG-II levels increased progressively with the level of Helicobacter pylori infection in gastric biopsies, resulting in no clear trend in the I/II ratio. Instead, there was a progressive decrease in the I/II ratio with increasing degrees of infiltration of polynuclear cells and monocytes, atrophy, intestinal metaplasia and the stage of pre-cancerous lesions. The mean I/II ratios for atrophic gastritis or more advanced lesions were less than 4.0. When subjects with the I/II ratio 4 or higher were used as controls, severe reduction in the I/II ratio (< 2.0) was inversely associated with tobacco consumption. This may be due to a pharmacological effect of nicotine. The severe reduction of I/II ratio was also inversely associated with fresh fruit consumption. In addition, a decreased I/II ratio was positively associated with rice/pasta and arepas (tortilla made from corn) consumption and inversely associated with plantain consumption. Possible effects of vitamins and starchy food on the development of atrophic gastritis need to be studied further.