Mate drinking, alcohol, tobacco, diet, and esophageal cancer in Uruguay.

A case-control study was conducted in Uruguay to investigate the role of mate drinking, alcohol, tobacco, and certain dietary factors in the etiology of esophageal cancer. The study included 261 patients with squamous cell carcinoma of the esophagus and 522 hospital controls matched by sex and age. A strong association with a clear dose-response relationship was observed with the amount of mate drunk daily and duration of the habit. The relative risk for those drinking over 2.5 liters of mate per day was 12.2 (95% confidence interval, 3.8-39.6) after adjusting for the effects of age, area of residence, alcohol, and tobacco. Strong associations were also observed with tobacco smoking and alcohol drinking which appear to act in a multiplicative way. The relative risk for those who smoke and drink heavily compared to that of light smokers and drinkers was 22.6. The risk associated with black tobacco was about three times higher than that associated with blond tobacco. A clear protective effect was found for the consumption of fruits and vegetables but a dose-response relationship was present only for fruits. Finally, an increased risk was also found for those eating barbecued meat daily.

Antibodies to Helicobacter pylori and pepsinogen levels in children from Costa Rica: comparison of two areas with different risks for stomach cancer.

In children and adolescents from two areas of Costa Rica with contrasting gastric cancer risks, two factors suspected to be linked to the natural history of the disease were tested: serum antibodies to Helicobacter pylori and serum pepsinogen levels. One hundred fifty-five subjects from the high-risk area of Turrubares were compared to 127 from the low-risk area of Hojancha. No significant differences were found in the prevalence of IgG or IgA antibodies to Helicobacter pylori between the two regions. The prevalence of IgG was 65.8% in the high-risk area and 72.4 in the low-risk area, and that of IgA was 43% in both areas. The levels of pepsinogen, especially pepsinogen C, were significantly elevated in subjects with H. pylori antibodies in their serum. The mean levels of pepsinogen C in those negative, positive, and strong positive for H. pylori antibodies were 8.7, 14.3, and 21.1 ng/ml. These findings suggest that H. pylori-associated gastritis, predominantly of antral localization, is very prevalent in Costa Rican children and adolescents. Such gastritis might be associated with a high prevalence of intestinal metaplasia and a high gastric cancer risk in the inland, but not the coastal rural populations. H. pylori may therefore be an insufficient cause whose role in gastric carcinogenesis is contingent upon the presence of other factors.

In vivo nitrosoproline formation and other risk factors in Costa Rican children from high- and low-risk areas for gastric cancer.

The hypothesis that intragastric synthesis of N-nitroso compounds (NOC) in early life could play a role in gastric carcinogenesis was tested by applying the N-nitrosoproline (NPRO) test to about 50 children living in high- and low-risk areas for stomach cancer in Costa Rica. The median values of excretion of NPRO and the sum of three nitrosamino acids (micrograms/12 h urine) were 10-20% of those in adults from other geographical high-risk areas for stomach cancer. The urinary NPRO level after proline intake was higher in children from the high-risk area (P < 0.04) and markedly reduced after ingestion of ascorbic acid together with proline (P < 0.05). NPRO levels on the day of proline intake were highly correlated with levels of nitrate excretion (P < 0.001). Mean levels of total NOC in an aqueous (pH 2) extract of cooked beans from the high- and low-risk areas were similar. Acid-catalyzed nitrosation of the extract increased the total NOC concentration up to 1000-fold, but there was no difference between samples from the two areas. About 10% of bean extracts from both areas showed weak direct-acting genotoxicity in Escherichia coli; after acid-catalyzed nitrosation, all samples were genotoxic at similar levels. The diet of children in the low-risk area satisfied recommended levels of intake of energy and most nutrients except riboflavin and retinol equivalents. Diets from the high-risk area were deficient in energy intake and all nutrients except protein and vitamin C.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood transfusion has no effect on colorectal cancer survival. A population-based study.

This study was conducted to evaluate the impact on survival of perioperative blood transfusion in a series of 698 colorectal cancer patients undergoing radical surgery. Patients were identified, and follow-up was carried out by the local population-based cancer registry. Data on blood transfusion was obtained by record linkage with the files of the blood banks operating in the area covered by the registry. Prognostic factors were age, Dukes stage and topography of the primary tumour. Relative risk (RR) for Dukes B patients was 1.53 [95% confidence interval (CI) 0.94-2.50] and for Dukes C, 3.57 (95% CI 2.22-5.75) when compared with Dukes A patients. For the left colon, RR was 0.96 (0.61-1.52) and for the rectum 1.87 (1.22-2.86) when compared with the right colon. When adjusting for these factors and excluding operative mortality, RR for transfused patients was 1.16 (95% CI 0.87-1.55). It is concluded that blood transfusion does not adversely affect survival in colorectal cancer patients.

Pre-cancerous lesions of the oesophagus in Argentina: prevalence and association with tobacco and alcohol.

The prevalence of pre-cancerous lesions of the oesophagus and their association with alcohol and tobacco were examined in an endoscopic survey carried out in La Plata, Argentina. The study included 406 subjects over 15 years of age attending several gastroenterology clinics because of various gastrointestinal symptoms. Among males, the prevalence rates of chronic oesophagitis, epithelial atrophy and dysplasia were 42%, 3.8% and 2.4% respectively, and in females these prevalences were 36%, 2.5% and 0.0%. The presence of these pre-cancerous lesions was significantly associated with alcohol drinking and tobacco smoking.

Exposure to N-nitrosamines and other risk factors for gastric cancer in Costa Rican children.

The hypothesis that endogenous chemical nitrosation in the normal stomach in early life could play a crucial role in inducing chronic atrophic gastritis/intestinal metaplasia in later life was tested by applying the N-nitrosoproline (NPRO) test to 12-h urine samples from about 50 children (aged 8-14 years) living in high- and low-risk areas for stomach cancer. The median values of NPRO and the sum of four nitrosamino acids analysed were 0.28-0.84 micrograms/12 h and 0.75-1.75 micrograms/12 h, respectively. The NPRO level after proline intake was significantly higher in children from a high-risk area than in those from a low-risk area (p less than 0.04), and markedly reduced after ingestion of ascorbic acid and proline (p less than 0.05). Urinary nitrate level was lower than that of adults. NPRO levels on the day of proline intake, however, correlated well with nitrate levels (p less than 0.001), indicating that children in a high-risk area in Costa Rica have high endogenous nitrosation potential. Blood samples were also collected from about 300 children (aged 7-20 years) and analysed for antibodies against Campylobacter pylori, a suspected gastritis-causing bacteria. About 71% of children in both high- and low-risk areas for stomach cancer had antibodies. In addition, raw and cooked beans, which are consumed very frequently in Costa Rica, were collected from families in both areas and analysed for levels of nitrite/nitrate, total N-nitroso compounds and genotoxicity in the SOS chromotest.(ABSTRACT TRUNCATED AT 250 WORDS)

Intestinal metaplasia types and the risk of gastric cancer: a cohort study in Slovenia.

Between 1967 and 1976, 1,525 Slovenian patients with a histological diagnosis of intestinal metaplasia (IM) were classified according to subtype of IM based on morphology and mucin staining; 518 cases were diagnosed with type I, 197 with type II and 275 with type III, but in 291 the diagnosis of IM was not confirmed. Patients who had developed cancer or died up to 1986 were identified by record linkage at the Slovenia Cancer Registry and the Central Population Registry in Slovenia. A total of 34 incident cases of gastric cancer occurring at least 6 months after the diagnosis of IM were identified. The standardised incidence ratio (SIR) for stomach cancer was 2.23 in the whole cohort. It was highest for IM type III, followed by type II and IM-unconfirmed, but not increased for type I. The relative risk (RR) of developing gastric cancer based on Cox's proportional hazards model was 2.14 for type II and 4.58 for type III, compared with type I. The RR was especially increased for a subgroup of type III secreting sulphomucins in their goblet cells in comparison with types I-II negative to sulphomucins. Our results confirm that subtyping of IM is useful for identifying individuals at high risk for gastric cancer.