A prospective study of atrophic gastritis and stomach cancer risk

Early-Onset Gastrointestinal Malignancies: An Investigation into a Rising Concern

There is growing recognition of early-onset gastrointestinal (GI) malignancies in young adults < 50 years of age. While much of the literature has emphasized colorectal cancer, these also include esophageal, gastric, liver, pancreatic, and biliary tract malignancies. Various factors, including lifestyle, hereditary, and environmental elements, have been proposed to explain the rising incidence of GI malignancies in the younger population. This review aims to provide an overview of the recent literature, including global trends and information regarding genetic and environmental risk factors.

Effect of vegetable consumption on risk of gastric cancer: a systematic review and multi-level meta-analysis of prospective studies

Vegetables are known to be beneficial to human health, but the association between vegetable consumption and gastric cancer remains uncertain. To synthesise knowledge about the relationship between vegetable group consumption and gastric cancer risk, update present meta-analyses and estimate associations between vegetable consumption and gastric cancer risk based solely on prospective studies, we perform a PRISMA-compliant three-level meta-analysis. Systematic search identified thirteen prospective studies with fifty-two effect sizes that met all inclusion criteria and no exclusion criteria for our meta-analysis. Pooled risk ratios (RRs) showed a positive association between high vegetable consumption and low gastric cancer risk (pooled RR 0·93, 95% confidence interval 0·90-0·97, P = 0·06). In moderator analyses for indicators of gender, region and quantity of vegetable intake, there was no significant difference between subgroups. However, the effect became significant in populations with lower than the minimum risk exposure level (TMREL) of vegetable consumption (P < 0·05). Higher vegetable intake is associated with a decreased risk of gastric cancer. This effect may be limited to specific populations, such as ones with lower vegetable consumption. Evidence from our study has important public health implications for dietary recommendations.

Epidemiology of Gastric Cancer: Global Trends, Risk Factors and Premalignant Conditions

This review article aims to provide a comprehensive overview of recent epidemiology, pathogenesis, risk factors, and premalignant conditions of gastric cancer. Worldwide, gastric cancer is one of the most common and most fatal cancers. The incidence and mortality remain high in regions such as East Asia and Eastern Europe. Although there is a lower incidence in the United States, it remains a deadly disease. Age, gender, and race are non-modifiable demographic risk factors for developing gastric cancer. There have been several dietary and lifestyle risk factors such as salt preserved foods, N-nitroso compounds containing foods, tobacco smoke, alcohol use, and obesity that have been shown to contribute to the development of gastric cancer. Infections have additionally been shown to have a clear role in the pathogenesis of gastric cancer as Helicobacter pylori eradication has shown a significant reduction in the incidence of gastric cancer as well as other pathogens such as Epstein-Barr virus. There are certain premalignant lesions that increase the risk of developing gastric cancer. These include atrophic gastritis, and intestinal metaplasia amongst others.

White rice consumption and risk of cardiometabolic and cancer outcomes: A systematic review and dose-response meta-analysis of prospective cohort studies

White rice is the food more than half of the world's population depends on. White rice intake can significantly increase the glycemic load of consumers and bring some adverse health effects. However, the quality of evidence implicating white rice in adverse health outcomes remains unclear. To evaluate the association between white rice consumption and the risk of cardiometabolic and cancer outcomes, a systematic review and dose-response meta-analysis of the relevant publications were performed. Twenty-three articles including 28 unique prospective cohorts with 1,527,198 participants proved eligible after a comprehensive search in four databases. For the risk of type 2 diabetes mellitus (T2DM), the pooled RR was 1.18 (16 more per 1000 persons) for comparing the highest with the lowest category of white rice intake, with moderate certainty evidence. Females presented a higher risk (23 more per 1000 persons) in subgroup analysis. And every additional 150 grams of white rice intake per day was associated with a 6% greater risk of T2DM (5 more per 1000 persons) with a linear positive trend. We found no significant associations between white rice intake and risk of cardiovascular diseases (CVD), CVD mortality, cancer, and metabolic syndrome. In conclusion, moderate certainty evidence demonstrated that white rice intake was associated with T2DM risk, with a linear positive trend. However, low to very low certainty of evidence suggested that no substantial associations were found between white rice intake and other cardiometabolic and cancer outcomes. More cohorts are needed to strength the evidence body.

Tumor heterogeneity and carcinoma in resected specimens of gastric low-grade dysplasia: A retrospective single center study

Lesions diagnosed as gastric low-grade dysplasia (LGD) may be pathologically upgraded to early gastric cancer (EGC) or high-grade dysplasia (HGD) after endoscopic resection (ER). In this study, we investigated the risk factors for pathological upgrades after ER and assessed the reason for these upgrades by retrospectively analyzing ER data between January 1999 and December 2019. We enrolled patients with LGD confirmed by forceps biopsy; the patients were classified into pathologically concordant (LGD) and upgraded (HGD and EGC) groups according to the pathology of their resected specimen. To determine the risk factors for upgrade, we compared the endoscopic findings of the concordant and upgraded groups via 1:1 matched case-control design. To find the reasons for discordance, all upgraded cases were pathologically re-evaluated. Among 1,643 cases of LGD, pathological upgrades were observed in 423 (25.7%) resected specimens and EGC was found in 111 (6.7%) lesions. After matching the upgraded and concordant cases, lesion sizes exceeding 1.5 cm (odds ratio (OR): 1.8; 95% CI: 1.1-3.0), mucosal nodularity (OR: 10.8; 95% CI: 5.6-21.0), heterogeneous color (OR: 3.0; 95% CI: 1.7-5.3), presence of erosion (OR: 2.7; 95% CI: 1.8-5.3), and open-type gastric atrophy (OR: 2.9; 95% CI: 1.7-4.9) were noted to be significantly associated with upgraded pathology to EGC. Among the EGC cases, 99 (89.2%) were found to have pre-existing dysplasia. In conclusion, endoscopic evaluations should be performed because of possible pathological upgrades and co-existence of carcinomas in LGDs, especially when they exhibit surface nodularity, erosion, heterogeneous color, and large size.

Dietary Salt Intake and Gastric Cancer Risk: A Systematic Review and Meta-Analysis

The results of prospective cohort studies regarding the role of salt intake and subsequent gastric cancer risk are inconsistent. Thus, we performed a systematic review and meta-analysis to summarize the strength of the association of salt intake with gastric cancer morbidity and mortality. PubMed, EmBase, and Cochrane Library were systematically searched to identify eligible studies published throughout September 2021. The effect estimates with 95% confidence intervals (CIs) for gastric cancer morbidity or mortality in each study were applied to calculate the pooled results; these analyses were performed using the random-effects model. Twenty-six prospective cohort studies involving 4,956,350 individuals were selected; these studies reported 19,301 cases of gastric cancer and 2,871 cases of gastric cancer-associated mortality. High (RR: 1.25; 95%CI: 1.10–1.41; P = 0.001) or moderate (RR: 1.20; 95%CI: 1.04–1.38; P = 0.012) salt intake was associated with a greater risk of gastric cancer. High pickled food intake was associated with an increased gastric cancer risk (RR: 1.28; 95%CI: 1.05–1.57; P = 0.017), while moderate pickled foods intake had no significant effect on gastric cancer risk (RR: 1.10; 95%CI: 0.88–1.37; P = 0.390). Neither high (RR: 1.14; 95%CI: 0.95–1.36; P = 0.161) nor moderate (RR: 1.10; 95%CI: 0.87–1.40; P = 0.436) salted fish intake were associated with gastric cancer risk. A high intake of processed meat was significantly associated with a higher risk of gastric cancer (RR: 1.24; 95%CI: 1.03–1.49; P = 0.023), while moderate processed meat intake had no significant effect on the gastric cancer risk (RR: 1.01; 95%CI: 0.92–1.11; P = 0.844). High (RR: 1.04; 95%CI: 0.90–1.19; P = 0.626) and moderate (RR: 1.02; 95%CI: 0.94–1.11; P = 0.594) miso-soup intake had no effects on the gastric cancer risk. High intakes of salt, pickled food, and processed meat are associated with significantly increased risks of gastric cancer; these increased risks are also seen when participants consumed moderate amounts of salt.

Risk Prediction for Gastric Cancer Using GWAS-Identifie Polymorphisms, Helicobacter pylori Infection and Lifestyle-Related Risk Factors in a Japanese Population

Simple Summary

Gastric cancer remains the major cancer in Japan and worldwide. It is expected that practical intervention strategies for prevention, such as personalized approaches based on genetic risk models, will be developed. Here, we developed and validated a risk prediction model for gastric cancer using genetic, biological, and lifestyle-related risk factors. Results showed that the combination of selected GWAS-identified SNP polymorphisms and other predictors provided high discriminatory accuracy and good calibration in both the derivation and validation studies; however, the contribution of genetic factors to risk prediction was limited. The greatest contributor to risk prediction was ABCD classification (Helicobacter pylori infection-related factor).

Abstract

Background: As part of our efforts to develop practical intervention applications for cancer prevention, we investigated a risk prediction model for gastric cancer based on genetic, biological, and lifestyle-related risk factors. Methods: We conducted two independent age- and sex-matched case–control studies, the first for model derivation (696 cases and 1392 controls) and the second (795 and 795) for external validation. Using the derivation study data, we developed a prediction model by fitting a conditional logistic regression model using the predictors age, ABCD classification defined by H. pylori infection and gastric atrophy, smoking, alcohol consumption, fruit and vegetable intake, and 3 GWAS-identified polymorphisms. Performance was assessed with regard to discrimination (area under the curve (AUC)) and calibration (calibration plots and Hosmer–Lemeshow test). Results: A combination of selected GWAS-identified polymorphisms and the other predictors provided high discriminatory accuracy and good calibration in both the derivation and validation studies, with AUCs of 0.77 (95% confidence intervals: 0.75–0.79) and 0.78 (0.77–0.81), respectively. The calibration plots of both studies stayed close to the ideal calibration line. In the validation study, the environmental model (nongenetic model) was significantly more discriminative than the inclusive model, with an AUC value of 0.80 (0.77–0.82). Conclusion: The contribution of genetic factors to risk prediction was limited, and the ABCD classification (H. pylori infection-related factor) contributes most to risk prediction of gastric cancer.

Serum pepsinogen levels in different regions of China and its influencing factors: a multicenter cross-sectional study

BACKGROUND

The aim of this study is to investigate the difference of serum pepsinogen (PG) baseline levels in different regions of China and its influencing factors.

METHODS

From October 2016 to October 2018, asymptomatic health checkup people who underwent nasal endoscopy in nine health management centers in different regions of China were collected. Lifestyle questionnaires were conducted, and serum PG and gastroscopy were performed. The differences in PG levels in baseline population (OLGA-0 grade) were studied according to geographical subregions of China. SPSS software was used for statistical analysis.

RESULTS

1922 patients were included in the final analysis. Compared with the non-atrophy (OLGA-0) group, PGR levels in atrophy group (OLGA-I to IV) were significantly decreased with the atrophy degree (p < 0.05). A total of 1590 baseline people (OLGA-0) were included in the study, including 254 from South China, 574 from East China, 210 from Southwest China, 332 from Northeast China, and 220 from Central/Northern China. There were significant differences in baseline PGI levels among the five regions (p < 0.05). The PGII levels were also different among the five regions, except for Central/Northern versus Southern China. PGR (PGI/PGII ratio) levels in Southern China were higher than other four regions. Further studies were conducted on the related factors that might affect the baseline PG level, which was affected by nationality, dietary habits, smoking, Helicobacter pylori infection and other related factors.

CONCLUSION

Influenced by many factors, the baseline PG levels are different in different regions of China. In the follow-up studies of PG cut-off value, different PG cut-off value based on region may be more effective in the screening of gastric cancer and precancerous lesions in China.

Pepsinogen Serology and Gastritis OLGA Staging in Mucosal Atrophy Assessment: A Cross-Sectional Study Involving East China Endoscopy Population

The histological gastric stage (OLGA) plays an important role in evaluating gastric atrophy, a symptom which suggests a risk of gastric cancer (GC). However, gastroscopy is an invasive examination, which has limited application in populations undergoing physical examination. Serum pepsinogen (PG) and gastin-17 (G-17) levels are noninvasive indexes which are recommended when screening for GC. We aim to explore the correlation between PG/G-17 and OLGA stage, in order to provide reliable indexes for GC screening. The study included 453 asymptomatic individuals from East China undergoing physical examination, who then underwent endoscopy including collection of biopsy samples. Assays for serum PG, G-17, and Helicobacter pylori (Hp) were performed. Atrophy of gastric mucosa was graded according to OLGA for each individual. 453 participants, average age 52.46 ± 10.30 years, 253 male and 200 female, were included. In the asymptomatic physical examination population, serum PGI, PGII, and PGR levels decreased with increasing OLGA scores. PGI and PGR were inversely correlated with increasing OLGA stage in both Hp-positive and Hp-negative groups. The levels of serum PGI, PGII, and G-17 in the Hp-positive group were higher than those in the Hp-negative group; conversely, the PGR levels were lower. Furthermore, OLGA scores increased with age in the Hp-positive group. In conclusion, there is a significant correlation between OLGA stage and serum PG in populations from East China undergoing physical examination. Serum PG and G-17 combined with Hp test plays an important role in evaluating gastric atrophy.

Pickled Vegetable and Salted Fish Intake and the Risk of Gastric Cancer: Two Prospective Cohort Studies and a Meta-Analysis

An increased risk of gastric cancer for pickled vegetable and salted fish intake has been suggested, yet the lack of a dose-response association warrants a quantitative analysis. We conducted a meta-analysis, combining results from our analysis of two large Korean cohort studies and those from previous prospective cohort studies. We investigated the association of pickled vegetable and salted fish intake with gastric cancer in the Korean Genome Epidemiology Study and the Korean Multi-center Cancer Cohort Study using Cox proportional hazard models. We then searched for observational studies published until November 2019 and conducted both dose-response and categorical meta-analyses. The pooled relative risk (RR) of gastric cancer incidence was 1.15 (95% Confidence Interval (CI), 1.07–1.23) for 40 g/day increment in pickled vegetable intake in a dose-response manner (P for nonlinearity = 0.11). As for salted fish intake, the pooled risk of gastric cancer incidence was 1.17 (95% CI, 0.99–1.38) times higher, comparing the highest to the lowest intake. Our findings supported the evidence that high intake of pickled vegetable and salted fish is associated with elevated risk of gastric cancer incidence.

Metaplasia in the Stomach-Precursor of Gastric Cancer?

Despite a significant decrease in the incidence of gastric cancer in Western countries over the past century, gastric cancer is still one of the leading causes of cancer-related deaths worldwide. Most human gastric cancers develop after long-term Helicobacter pylori infection via the Correa pathway: the progression is from gastritis, atrophy, intestinal metaplasia, dysplasia, to cancer. However, it remains unclear whether metaplasia is a direct precursor of gastric cancer or merely a marker of high cancer risk. Here, we review human studies on the relationship between metaplasia and cancer in the stomach, data from mouse models of metaplasia regarding the mechanism of metaplasia development, and the cellular responses induced by H. pylori infection.

The potential value of serum pepsinogen for the diagnosis of atrophic gastritis among the health check-up populations in China: a diagnostic clinical research

BACKGROUND

The aim of this study is to assess the validity of the measurement of pepsinogen as a screening test for chronic atrophic gastritis (AG) in health check-up populations in China.

METHODS

Patients from consecutive regular health check-up were enrolled from January 2014 to June 2015. Endoscopy, combined with monitoring the Helicobacter pylori (Hp) infections, and measuring the serum pepsinogen (PG) were used to determine the diagnostic accuracy of PG for the screening of atrophic gastritis. Histopathology was assessed by the Operative Link on Gastritis Assessment (OLGA) system. Statistical analysis was performed using SPSS statistical software.

RESULTS

The total Hp infection rate was 40%. Based on pathology, the 996 participants were divided into three groups: non-atrophic (NAG), mild-moderate atrophic (MAG): stage I and II of the OLGA classification, and severe atrophic (SAG): stage III and IV of the OLGA classification. Compared with NAG and MAG groups, PGR decreased significantly in SAG group (p < 0.05). PGI and PGII levels were significantly elevated in Hp-positive group, while the PGR was markedly decreased (p < 0.01). When MAG and SAG groups were combined and compared with NAG group, the best cutoff value for atrophy diagnosis was PGI ≤50.3 ng/ml; the cutoff value in Hp-negative group was absolutely higher than in Hp-positive group. When NAG and MAG groups were combined and compared with the SAG group, the best cutoff value for diagnosis of severe atrophy was at PGR ≤4.28. The cutoff values in Hp-negative and Hp-positive groups were calculated at PGR ≤6.28 and ≤4.28, respectively.

CONCLUSIONS

Pepsinogens play an important role in the identification of patients with atrophic gastritis and severe AG. Use of different cutoff values of PG for Hp-negative and Hp-positive groups may offer greater efficacy in the diagnosis of AG.

Rice consumption, incidence of chronic diseases and risk of mortality: meta-analysis of cohort studies

OBJECTIVE

Findings from cohort studies investigating the association between rice consumption and risk of chronic diseases or mortality have been inconsistent. We performed a comprehensive systematic review and meta-analysis on all published cohort studies examining white rice consumption in relation to incidence of chronic diseases or risk of mortality.

DESIGN

A systematic literature search of MEDLINE, Embase, Cochrane review, Google Scholar and Scopus databases for relevant cohort studies published until July 2014. For systematic review, we found nineteen studies examining the association between rice intake and risk of chronic diseases (obesity, hypertension, metabolic syndrome, diabetes, CVD and cancers) or mortality. Cohort studies which reported relative risk (RR) or odds ratio for highest v. lowest intake of rice and chronic diseases or mortality were included in the meta-analysis.

RESULTS

In a meta-analysis on seventeen risk estimates for highest v. lowest category of rice intake, provided from twelve studies, we found a trend towards a positive association (RR; 95 % CI) between rice consumption and risk of all chronic diseases (1·11; 0·96, 1·29); however, significant between-study heterogeneity was found (I 2=70·3 %, P<0·001). Stratified analysis by gender showed a significant positive association between rice consumption and risk of chronic diseases in women (1·40; 1·13, 1·73), but not in men (0·95; 0·72, 1·24). Combining ten effect sizes from five studies showed that high consumption of rice was not significantly associated with mortality (0·97; 0·88, 1·06). Subgroup analysis by gender indicated an inverse association between rice consumption and mortality in men (0·87; 0·81, 0·94), but a trend towards a positive association in women (1·08; 0·97, 1·19).

CONCLUSIONS

Although white rice consumption was not found to be associated with individual chronic conditions, we observed a positive association between white rice intake and risk of all overall chronic diseases in women. High rice consumption was related to a modest reduction in risk of mortality in men but not in women. Further studies of these relationships, in different populations, are needed.

Inhibitory Actions of Berberine on Growth and Arylamine N-Acetyltransferase Activity in Strains of Helicobacter Pylori from Peptic Ulcer Patients

N-acetyltransferase(NAT)-catalyzed reactions can result in activation or detoxification of arylamine carcinogens. Studies were conducted to examine the dose effects of berberine on inhibition of growth versus arylamine NAT activities in strains of Helicobacter pylori collected from peptic ulcer patients. An inhibition-of-growth study on H. pylori demonstrated that berberine elicited a dose-dependent growth inhibition in the H. Pylori cultures. The results on the NAT activity was determined using acetyl coenzyme A recycling assay and high pressure liquid chromatography. Cyto-sols or suspensions of H. pylori with or without selected concentrations of berberine cotreatment showed different percentages of 2-aminofluorene and p-aminobenzoic acid acetylation. The data indicated that there was decreased NAT activity associated with increased levels of berberine in the H. pylori cytosols and suspensions. The apparent values of Km and Vmax also decreased after cotreatment of berberine in both examined systems. This report is the first finding of berberine inhibition of arylamine NAT activity in strains of H. pylori.

Helicobacter pylori CagA: From Pathogenic Mechanisms to Its Use as an Anti-Cancer Vaccine

Helicobacter pylori colonizes the gastric mucosa of more than 50% of the human population, causing chronic inflammation, which however is largely asymptomatic. Nevertheless, H. pylori-infected subjects can develop chronic gastritis, peptic ulcer, gastric mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Chronic exposure to the pathogen and its ability to induce epithelial to mesenchymal transition (EMT) through the injection of cytotoxin-associated gene A into gastric epithelial cells may be key triggers of carcinogenesis. By deregulating cell-cell and cell-matrix interactions as well as DNA methylation, histone modifications, expression of micro RNAs, and resistance to apoptosis, EMT can actively contribute to early stages of the cancer formation. Host response to the infection significantly contributes to disease development and the concomitance of particular genotypes of both pathogen and host may turn into the most severe outcomes. T regulatory cells (Treg) have been recently demonstrated to play an important role in H. pylori-related disease development and at the same time the Treg-induced tolerance has been proposed as a possible mechanism that leads to less severe disease. Efficacy of antibiotic therapies of H. pylori infection has significantly dropped. Unfortunately, no vaccine against H. pylori is currently licensed, and protective immunity mechanisms against H. pylori are only partially understood. In spite of promising results obtained in animal models of infection with a number of vaccine candidates, few clinical trials have been conducted so far and with no satisfactory outcomes. However, prophylactic vaccination may be the only means to efficiently prevent H. pylori-associated cancers.

Narrow band imaging versus white light gastroscopy in detecting potentially premalignant gastric lesions: a randomized prospective crossover study

BACKGROUND AND AIMS

Narrow band imaging (NBI) detects mucosal surface details (pit pattern) as well as the microvasculature pattern of mucosa. In premalignant conditions the pattern and regularity of pits and microvasculature are altered. We aimed to assess whether NBI is superior to conventional white light gastroscopy (WLG) in detecting potentially premalignant gastric lesions.

PATIENTS AND METHODS

We conducted a randomized prospective crossover study from January 2009 to July 2009. Patients above 45 years of age with dyspepsia in absence of alarm symptoms underwent gastric mucosal examination using WLG and NBI in the same session by different endoscopists who were blinded to each other's endoscopy findings. Biopsy was taken if required at the end of the second gastroscopy after a third observer reviewed reports of both scopists. The yield of gastric potentially premalignant lesions (atrophic gastritis, intestinal metaplasia, dysplasia, adenomatous polyp) was compared for both procedures.

RESULTS

Two hundred [mean age 52.3 (6.4) years, males-66 %] patients participated in the study. Thirty-two patients were diagnosed to have potentially premalignant lesions using both modalities. No patient had early gastric cancer. WLG detected lesions in 17 patients (atrophic gastritis in 12, atrophic gastritis with intestinal metaplasia in 5) and NBI in 31 patients (atrophic gastritis in 22, atrophic gastritis with intestinal metaplasia in 9). The sensitivity of lesion detection by NBI was significantly higher than WLG (p = 0.001).

CONCLUSIONS

NBI was superior to WLG for detection of atrophic gastritis and intestinal metaplasia.

The effect of serum carotenoids on atrophic gastritis among the inhabitants of a rural area in Hokkaido, Japan

A total of 206 residents (76 males and 130 females) of a rural area of Hokkaido, Japan, attending a health check in August, 1997, were studied to assess the relationship between serum carotenoids and atrophic gastritis (AG). Of the participants, 91 had AG as indicated by their serum levels of pepsinogen I and pepsinogen II. Logistic regression analysis, after adjusting for gender and age, revealed that the odds ratios for serum carotenoid levels were lower for subjects with high serum levels of α-carotene (odds ratio, 0.41; 95% C.I., 0.19-0.88) and β-carotene (odds ratio, 0.41; 95% C.I., 0.18-0.91) than for those with low serum carotenoid levels. In addition, the odds ratios of subjects with high serum levels of β-cryptoxanthin (odds ratio, 0.60; 95% C.I., 0.28-1.31), provitamin A (odds ratio, 0.38; 95% C.I., 0.17-0.85), and retinol (odds ratio, 0.67; 95% C.I., 0.31-1.48) were found to be lower than the odds ratios for those with low serum levels. Odds ratios for subjects with high serum zeaxanthin/lutein levels were higher than odds ratios for those with low serum levels. These results suggest that frequent intake of foods ric, in carotenoids with provitamin A activity may reduce the risk of AG.

Habitual salt intake and risk of gastric cancer: a meta-analysis of prospective studies

BACKGROUND & AIMS

Systematic reviews of case-control studies evaluating the relationship between dietary salt intake and gastric cancer showed a positive association, however a quantitative analysis of longitudinal cohort studies is lacking. Therefore, we carried out a meta-analysis to assess the association between habitual salt intake and risk of gastric cancer in prospective studies.

METHODS

We performed a systematic search of published articles (1966-2010). Criteria for inclusion were: original articles, prospective adult population studies, assessment of salt intake as baseline exposure and of gastric cancer as outcome, follow-up of at least 4 years, indication of number of participants exposed and events across different salt intake categories.

RESULTS

Seven studies (10 cohorts) met the inclusion criteria (268 718 participants, 1474 events, follow-up 6-15 years). In the pooled analysis, "high" and "moderately high" vs "low" salt intake were both associated with increased risk of gastric cancer (RR = 1.68 [95% C.I. 1.17-2.41], p = 0.005 and respectively 1.41 [1.03-1.93], p = 0.032), with no evidence of publication bias. The association was stronger in the Japanese population and higher consumption of selected salt-rich foods was also associated with greater risk. Meta-regression analyses did not detect specific sources of heterogeneity.

CONCLUSIONS

Dietary salt intake was directly associated with risk of gastric cancer in prospective population studies, with progressively increasing risk across consumption levels.

The Role of CDX2 in Intestinal Metaplasia Evaluated Using Immunohistochemistry

Background/Aims

Intestinal metaplasia (IM) has been regarded as a premalignant condition. This study evaluated the role of the transforming factor CDX2 according to the severity and type of IM.

Methods

This analysis was performed on 383 subjects with IM in the antrum and/or body, with diagnoses that were categorized as controls, dysplasias, and gastric cancers. The IM grades were classified into four groups as negative, mild, moderate or severe using the updated Sydney scoring system. The IM subtypes were categorized as type I, type II, and type III using high iron diamine and alcian blue (pH 2.5) staining. The CDX2 expression in the IM foci was evaluated using immunohistochemistry in specimens from the antrum and/or body.

Results

CDX2 expression increased according to IM severity (p=0.001) but was not associated with the IM subtype (p=0.881) in the antrum specimens. Similarly, CDX2 expression increased according to the IM grade (p=0.001) but was not associated with the IM subtype (p=0.755) in the body specimens. CDX2 expression was also increased according to baseline disease in the antrum, especially dysplastic and GC group (p=0.003), but not in the body (p=0.582). However, status of Helicobacter pylori infection was not associated with CDX2 expression in the antrum (p=0.692) and body (p=0.271).

Conclusions

These results show that CDX2 expression is associated with the IM grade regardless of the IM subtype and that it was more frequent in the dysplasia group. These results suggest that CDX2 expression might play an important role in the progression of IM in various environments that can affect neoplastic change.

Prevalence of gastric cancer versus colorectal cancer in Asians with a positive fecal occult blood test

AIM

Prior studies have reported conflicting results on the yield of esophagogastroduodenoscopy (EGD) in patients with a positive fecal occult blood test (FOBT). Our aim was to compare the yield between EGD and colonoscopy performed in a racially diverse population with a positive FOBT.

METHODS

A retrospective, cross-sectional study of FOBT positive patients who underwent EGD and colonoscopy from January 1, 1999 to November 1, 2008. Endoscopic lesions deemed responsible for GI bleeding were identified.

RESULTS

Two hundred and eighty-seven patients met entry criteria, among which, 63% were Asian and 81% were immigrants to the U.S. Forty-four patients had EGD findings deemed responsible for a positive FOBT, the most common being esophagitis (25.0%) and gastric ulceration (15.9%). Forty-two patients had colonoscopic findings likely responsible for a positive FOBT with the most frequent lesion being colonic polyps ≥9 mm in diameter (76.2%). Prevalence of lower and upper GI tract lesions responsible for positive FOBT was similar (14.6% vs. 15.3%, p = 0.2). There was no association between a patient reporting upper GI symptoms, or the presence of anemia and the detection of upper GI tract lesions on endoscopy. Gastric adenocarcinoma (n = 3) was as prevalent as colorectal adenocarcinoma (n = 4). All three patients with gastric adenocarcinomas were Asian (prevalence 1.6%).

CONCLUSIONS

In our racially diverse population evaluated for a positive FOBT, gastric adenocarcinoma was as prevalent as colorectal adenocarcinoma; however, gastric adenocarcinoma was limited to Asian patients. EGD and colonoscopy should be considered in the evaluation of patient populations similar to ours, particularly Asian immigrants.

Fermented and non-fermented soy food consumption and gastric cancer in Japanese and Korean populations: a meta-analysis of observational studies

Soy food is known to contribute greatly to a reduction in the risk of gastric cancer (GC). However, both Japanese and Korean populations have high incidence rates of GC despite the consumption of a wide variety of soy foods. One primary reason is that they consume fermented rather than non-fermented soy foods. In order to assess the varying effects of fermented and non-fermented soy intake on GC risk in these populations, we conducted a meta-analysis of published reports. Twenty studies assessing the effect of the consumption of fermented soy food on GC risk were included, and 17 studies assessing the effect of the consumption of non-fermented soy food on GC risk were included. We found that a high intake of fermented soy foods was significantly associated with an increased risk of GC (odds ratio [OR] = 1.22, 95% confidence interval [CI] = 1.02-1.44, I(2) = 71.48), whereas an increased intake of non-fermented soy foods was significantly associated with a decreased risk of GC (overall summary OR = 0.64, 95% CI = 0.54-0.77, I(2) = 64.27). These findings show that a high level of consumption of non-fermented soy foods, rather than fermented soy foods, is important in reducing GC risk.

Non-organ-specific preventive effect of long-term administration of Korean red ginseng extract on incidence of human cancers

Previously, two case-control studies and a cohort study strongly suggested that Panax ginseng C.A. Meyer exerted non-organ-specific preventive effects against cancer. The purpose of the present study was to evaluate the effects of red ginseng extract on the incidence of human primary cancer. We conducted a randomized, double-blinded, placebo-controlled trial on 643 chronic atrophic gastritis patients in four hospitals in Zhejiang Province, China. Red ginseng extract powder (1 g) was administered orally to each patient per week for 3 years and followed up for 8 years. The development of various cancers in the red ginseng subjects was compared to that of a placebo group. The red ginseng extract powder was specified in terms of its components. Twenty-four cancers of various organs were diagnosed from these subjects during the 11 years: eight lung cancers, six stomach cancers, two liver cancers, two colorectal cancers, and one cancer each of the nasopharynx, esophagus, pancreas, urinary bladder, prostate, and gallbladder. The red ginseng group, which included both genders, demonstrated a relative cancer risk of 0.54 (95% confidence interval, 0.23-1.28; P = .13) compared to the placebo group, which was not statistically significant. Among the 24 cancer patients, 21 were male. The male red ginseng group showed a relative cancer risk of 0.35 (95% confidence interval, 0.13-0.96; P = .03) compared to the male placebo group, which was highly significant statistically. In the present clinical trial on chronic atrophic gastritis patients, administration of red ginseng extract powder for 3 years exerted significant preventive effects on the incidence of non-organ-specific human cancers in males.

Chronic atrophic antral gastritis and risk of metaplasia and dysplasia in an area with low prevalence of Helicobacter pylori

INTRODUCTION

The Northeastern region of Peninsular Malaysia is an area with exceptionally low prevalence for Helicobacter pylori infection. The risk of intestinal metaplasia and dysplasia in patients with chronic atrophic gastritis (CAG) and its association with Helicobacter pylori is unknown in this region.

METHODS

This was a cross-sectional study on gastric biopsies from 234 consecutive patients (mean age 53.5 [14.8] years) who underwent upper gastrointestinal endoscopy between January 2006 and December 2006.

RESULTS

There were 137 (59%) men and 185 (79%) Malay patients. Among 234 biopsies, CAG was found in 99 and non-atrophic gastritis in 135. Intestinal metaplasia and dysplasia were detected in 8 and 6 atrophic gastritis biopsies, respectively, and in 10 and 3 of non-atrophic gastritis biopsies, respectively. H. pylori were detected in 16 (9 Malays, 7 non- Malays) biopsies (p=0.024); intestinal metaplasia was detected in 4 biopsies (p=0.3) and dysplasia in 5 biopsies (p=0.3). Of the 218 biopsies negative for H. pylori, intestinal metaplasia was found in 14 and dysplasia in 4. The risk of intestinal metaplasia as well as dysplasia was associated with presence of H. pylori infection (p=0.029 and p<0.001 respectively).

CONCLUSION

Even in a setting of low prevalence of H. pylori, intestinal metaplasia and dysplasia were significantly associated with H. pylori infection. The frequency of intestinal metaplasia and dysplasia was similar different between biopsies with atrophic gastritis and non-atrophic gastritis.

Fresh and pickled vegetable consumption and gastric cancer in Japanese and Korean populations: a meta-analysis of observational studies

It is widely known that vegetable consumption contributes to reducing the risk of gastric cancer (GC). However, the incidence rates of GC remain high in both Japanese and Korean populations, even though they have a high consumption of total vegetables. This may be due to the fact that Japanese and Koreans mainly consume processed vegetables, such as cooked, salted, or pickled vegetables, rather than fresh vegetables. To determine whether the intakes of fresh and pickled vegetables have different effects on the risk of GC in Japanese and Korean populations, we carried out a meta-analysis of published epidemiological reports. Eight studies on the consumption of fresh vegetables and 14 studies on the consumption of pickled vegetables related to GC risk were included in this meta-analysis. Four studies exploring differences in GC risk in men and women were considered separately. We observed that a high intake of fresh vegetables was significantly associated with a decreased risk of GC (overall summary OR = 0.62, 95% CI = 0.46-0.85) but that a high intake of pickled vegetables was significantly associated with an increased risk of GC (overall summary OR = 1.28, 95% CI = 1.06-1.53). The results of this meta-analysis provide evidence that a high intake of pickled vegetables may increase GC risk and suggest that a high consumption of fresh vegetables, rather than a large total amount of vegetables including pickled vegetables, is important to reduce GC risk.

Helicobacter pylori infection and gastropathy: A comparison between Indonesian and Japanese patients

AIM: To compare the effects of Helicobacter pylori (H pylori) infection on gastropathy between Indonesian and Japanese patients.

METHODS: Biopsy specimens were obtained during upper gastrointestinal endoscopy from 167 subjects (125 Indonesians and 42 Japanese) with uninvestigated symptoms of dyspepsia. The specimens were analyzed for the presence of H pylori using urease analysis, histopathology, and cell culture. The grade and activity of gastritis was assessed using the updated Sydney system.

RESULTS: The percentages of Indonesian and Japanese patients who were H pylori-positive at the antrum or body of the stomach were similar (68% and 59.5%, respectively; P = 0.316). Of those who were H pylori-positive, more Japanese patients than Indonesian patients had high levels of polymorphonuclear cells (P = 0.001), mononuclear cells (P = 0.013), glandular atrophy (P = 0.000), and intestinal metaplasia (P = 0.011) in both the antrum and body of the stomach.

CONCLUSION: The grade of gastritis and prevalence of mucosal atrophy and intestinal metaplasia were higher in Japanese patients. The difference between Indonesian and Japanese patients was significant.

Increased formation of gastric N(2)-ethylidene-2'-deoxyguanosine DNA adducts in aldehyde dehydrogenase-2 knockout mice treated with ethanol

We analyzed an acetaldehyde-derived DNA adduct, N(2)-ethylidene-2'-deoxyguanosine (N(2)-Eti-dG) in stomach DNA of aldehyde dehydrogenase (Aldh)-2-knockout mice that were fed with alcohol to determine effects of alcohol consumption and Aldh2 genotype on the level of DNA damage in stomach. Aldh2-active(+/+), heterozygote(+/-) and knockout(-/-) mice were fed 20% ethanol for 5 weeks, then the level of N(2)-Eti-dG in stomach was determined by liquid chromatography tandem mass spectrometry. The average N(2)-Eti-dG level in DNA from untreated mice was not significantly different among Aldh2 genotypes (2.0-3.1 adducts/10(7) bases), however, the average N(2)-Eti-dG level in DNA from ethanol-treated mice was 4.8+/-2.6 adducts/10(7) bases in Aldh2+/+ mice, 7.9+/-1.1 adducts/10(7) bases in Aldh2+/- mice, and 48.6+/-12.0 adducts/10(7) bases in Aldh2-/- mice, respectively. Our data clearly showed that alcohol drinking caused DNA damage in stomach, which was Aldh2 genotype-dependent in this experimental animal model. This result suggests that heavy-alcohol drinking and Aldh2 deficiency might be risk factors of stomach cancer.

Smoking and gastric cancer: systematic review and meta-analysis of cohort studies

OBJECTIVE

We conducted a systematic review of studies addressing the relation between cigarette smoking and gastric cancer to estimate the magnitude of the association for different levels of exposure and cancer locations.

METHODS

Published cohort, case-cohort, and nested case-control studies were identified through PubMed, Scopus, and Web of Science searches, from inception to July 2007. Relative risk (RR) estimates referring to the comparison of two categories of exposure (e.g., current smokers vs. never smokers) were combined using a random effects model. Generalized least squares regression was used for trend estimation. Heterogeneity was quantified using the I (2) statistic.

RESULTS

Forty-two articles were considered for the systematic review. Comparing current smokers with never smokers: the summary RR estimates were 1.62 in males (95% CI: 1.50-1.75; I (2) = 46.0%; 18 studies) and 1.20 in females (95% CI: 1.01-1.43; I (2) = 49.8%; nine studies); the RR increased from 1.3 for the lowest consumptions to 1.7 for the smoking of approximately 30 cigarettes per day in the trend estimation analysis; smoking was significantly associated with both cardia (RR = 1.87; 95% CI: 1.31-2.67; I (2) = 73.2%; nine studies) and non-cardia (RR = 1.60; 95% CI: 1.41-1.80; I (2) = 18.9%; nine studies) cancers.

CONCLUSION

Our study provides solid evidence to classify smoking as the most important behavioral risk factor for gastric cancer.

Review article: Helicobacter pylori eradication for the prevention of gastric cancer

BACKGROUND

Gastric cancer is the fourth most common cancer and second leading cause of cancer-related death worldwide. A clear association between Helicobacter pylori infection and gastric cancer was established years ago. H. pylori eradication may be an effective approach to decrease morbidity and mortality of gastric cancer.

AIM

To discuss current evidence of H. pylori eradication for prevention of gastric cancer.

RESULTS

Recent studies have shown that the association between H. pylori and gastric cancer has probably been underestimated. This may have resulted from negative H. pylori status in subjects after loss of colonisation in the presence of atrophic gastritis and intestinal metaplasia, prior to development of gastric cancer. The recognition of the central role of H. pylori in carcinogenesis has increased expectations of gastric cancer prevention by H. pylori eradication. A primary preventive effect of eradication in subjects with H. pylori-induced gastritis has been demonstrated. However, a secondary preventive effect in patients with pre-malignant gastric lesions is still controversial, especially in patients with intestinal metaplasia and dysplasia.

CONCLUSIONS

At this moment, H. pylori eradication seems indicated at the earliest stage of gastric carcinogenesis. This treatment policy requires confirmation; results of ongoing randomised controlled trials are therefore eagerly awaited.

Tobacco smoking and gastric cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population

BACKGROUND

We evaluated the association between tobacco smoking and gastric cancer risk among the Japanese population based on a systematic review of epidemiologic evidence.

METHODS

Original data were collected by searches of MEDLINE using PubMed, complemented with manual searches. Evaluation of associations was based on the strength of evidence and the magnitude of association, together with biological plausibility, as evaluated previously by the International Agency for Research on Cancer.

RESULTS

Ten cohort studies and 16 case-control studies were identified. In men, most studies reported moderate or strong positive associations between smoking and gastric cancer. In women, the positive association was weaker than in men. Of eight studies (three cohort studies and five case-case control studies), two cohort and three case control studies reported a weakly to strongly increased risk of gastric cancer. The summary relative risk for current smokers was estimated to be 1.56 (95% confidence intervals 1.36-1.80), 1.79 (1.51-2.12), 1.22 (1.07-1.38) for the total population, men and women, respectively.

CONCLUSION

We conclude that there is convincing evidence that tobacco smoking moderately increases the risk of gastric cancer among the Japanese population.

Highly salted food and mountain herbs elevate the risk for stomach cancer death in a rural area of Japan

BACKGROUND

Although many case-control and experimental studies have shown that highly salted foods are risk factors for stomach cancer, only a few cohort studies have supported the relationship.

METHODS

In a cohort study conducted in a rural area of Japan, 8035 residents aged over 30 years (approx. 55% were female) filled out a questionnaire. Seventy-six of them died from stomach cancer during an 11-year follow-up period. In the questionnaire, intake frequencies of 29 food items, smoking and drinking habits were investigated. Tsukemono (pickled vegetables) and tsukudani (foods deep boiled in soy sauce) are highly salted foods in the area. Frequency of each food item intake was classified into three levels, and age- and sex-adjusted risks were calculated using proportional hazard models.

RESULTS

In the final model obtained by backward elimination, frequent intake of tsukemono and tsukudani and that of mountain herbs remained as significant risk factors. Compared with the least frequent intake, risk (95% confidence interval) of the most frequent intake was 5.4 (1.8-16.3) for highly salted foods (P for trend < 0.01) and 3.7 (1.4-9.6) for mountain herbs (P for trend = 0.04).

CONCLUSION

Highly salted foods and mountain herbs were important risk factors for death from stomach cancer.

Lifestyle factors, radiation and gastric cancer in atomic-bomb survivors (Japan)

OBJECTIVE

To examine the association between the incidence of gastric cancer and lifestyle factors such as cigarette smoking, alcohol drinking, and diet as well as atomic bomb radiation exposure.

METHODS

Longitudinal study including 38,576 atomic-bomb survivors in Hiroshima and Nagasaki, Japan, followed-up between 1980 and 1999. Individual radiation dose was estimated according to the Dosimetry System 1986 (DS86). Lifestyle determinants were based on the responses to a mail survey sent at baseline. 1270 incident carcinomas of gastric cancer were identified during the 485,575 person-years of follow-up. Poisson regression was used to estimate incidence rate ratios.

RESULTS

Ionizing radiation exposure, male gender, age, and smoking were significantly associated with an increased risk of stomach cancer. No association was suggested between the frequency of consumption of fruit, vegetables, green tea, and soy products and gastric cancer.

CONCLUSIONS

In this Japanese population, although radiation and smoking were strong determinants of stomach cancer, no supportive evidence could be shown for the effect of dietary factors.

Fruit and vegetables consumption and gastric cancer: a systematic review and meta-analysis of cohort studies

Fruit and vegetable intake is widely recognized as protective for gastric cancer occurrence but prospective research challenged this belief. To evaluate the influence of design options in such results we did a meta-analysis of relevant published cohort studies identified from inception to 2004 in PubMed, EMBASE, and LILACS. Random-effects meta-analysis, stratification, and meta-regression were used to pool effects and to analyze the association with type of outcome event and length of follow-up independent of other study characteristics. An inverse association was observed between fruit intake and gastric cancer incidence (relative risk, RR = 0.82; 95% confidence interval, CI = 0.73-0.93) and stronger for follow-up periods of > or = 10 yr (RR = 0.66; 95% CI = 0.52-0.83) but not when the study outcome was death (RR = 1.08; 95% CI = 0.86-1.35). For vegetables, the RR was 0.88 (95% CI = 0.69-1.13) using all incidence studies and 0.71 (95% CI = 0.53-0.94) when considering only those with the longer follow-up. The association observed between vegetable intake and gastric cancer mortality was 1.05 (95% CI = 0.89-1.25). Other study characteristics assessed added no significant contribution to explain heterogeneity. This meta-analysis showed that design options might play a key role in the observed magnitude or the direction of the association between fruit and vegetable intake and gastric cancer.

Detection and treatment of early cancer in high-risk populations

In this paper we describe how to more efficiently detect and treat early gastric cancer (EGC) in high-risk populations. For detection, we first assess the value of known risk factors from the viewpoint of availability for cancer screening. Serum pepsinogen appears to be the most useful and realistic of the factors examined, although its adequacy needs to be assessed in high-risk populations other than those in Japan. Helicobacter pylori infection is known to be a universal risk factor (or gastric carcinogen), and several interventional studies have recently shown positive results. However, H. pylori infection can be eradicated from at-risk populations, thereby decreasing its availability for cancer screening. Smokers are thought to be at risk epidemiologically, but the efficacy of screening in this population has yet to be elucidated, and further studies are warranted. Gender and aging can be risk factors in Japanese populations; male gender and old age are predominant in the intestinal type of carcinoma which is dominant in Japan, although this is not the case in the West. As for early diagnosis of cancer, only endoscopy can be commonly used for the detection of gastritis-like EGC, seen as a faint mucosal irregularity or discoloration. To make early diagnosis more accurate, it is indispensable to carry out detailed endoscopy together with careful scrutiny of the mucosa using dye-spraying techniques. The remarkable progress of early diagnosis in Japan prompted the endoscopic treatment for less invasive EGCs. The first success was with endoscopic mucosal resection (EMR). Although convenient, its therapeutic efficacy is inadequate, particularly for larger lesions. Endoscopic submucosal dissection (ESD) has no limitation on resection size and is expected to replace surgery, although it needs a high level of skill and there are several technical problems to be solved.

Long-term follow-up in atrophic body gastritis patients: atrophy and intestinal metaplasia are persistent lesions irrespective of Helicobacter pylori infection

BACKGROUND

Long-term outcome of atrophic body gastritis has not yet been defined.

AIM

To investigate at long-term follow-up the behaviour of atrophy and intestinal metaplasia and the occurrence of neoplastic lesions in atrophic body gastritis patients.

METHODS

Overall 106 atrophic body gastritis patients with > or = 4-year follow-up were studied; 38 were Helicobacter pylori-positive at histology + serology and cured of infection (group A), 36 were positive at serology and not treated (group B) and 32 were H. pylori-negative (group C). Patients underwent gastroscopy with antral (n = 3) and body (n = 3) biopsies for histology according to the Sydney System.

RESULTS

At 6.7-year follow-up body atrophy and intestinal metaplasia remained unchanged in all 106 patients irrespective of H. pylori status. Antral atrophy was significantly increased at follow-up only in group C, whereas antral intestinal metaplasia was unchanged in all three groups. During follow-up eight (8%) patients developed neoplastic lesions (one adenocarcinoma, one adenoma with low-grade dysplasia and six low-grade dysplasia without endoscopic lesions). Antral atrophic gastritis was present at baseline in all but one (88%) of the eight patients with neoplastic lesions, but only in 15 (15%) of the 98 patients without (P < 0.0001, RR = 26.7).

CONCLUSIONS

Atrophy and intestinal metaplasia persist at 6.7-year follow-up and atrophic body gastritis patients with panatrophic gastritis are at increased risk of developing neoplastic lesions.

Alcohol consumption and the risk of cancer in Japanese men: the Miyagi cohort study

The objective of this study was to investigate the association between alcohol consumption and the risk of total cancer, and to estimate the proportion of total cancer attributable to drinking habit in Japanese men. From June through August 1990, a total of 21 201 Japanese men completed a self-administered questionnaire on various health habits, including alcohol consumption. During 153 389 person-years of follow-up through December 1997, we identified a total of 882 cases of cancer. We used Cox proportional hazards regression to estimate the relative risk of total cancer according to categories of alcohol consumption. The risk for total cancer was significantly higher in ex-drinkers than never-drinkers. There was a dose-response relationship between the amount of alcohol consumed and the risk of total cancer among current drinkers: multivariate RRs in reference to never-drinkers (95% confidence intervals (CI)) were 1.1 (0.8-1.3), 1.3 (1.0-1.7), and 1.3 (1.1-1.7) in current drinkers who consumed less than 22.8 g, 22.8-45.5 g, 45.6 g or more alcohol per day, respectively (P for trend <0.001). Estimated 17.9% (95% CI 3.1-30.5) of total cancer risk was attributable to drinking habit. In our findings, approximately 20% of the total cancer cases in Japanese men may be prevented by alcohol control.

Cigarette smoking and mortality due to stomach cancer: findings from the JACC Study

BACKGROUND

Several epidemiologic studies reported the positive association between cigarette smoking and stomach cancer. The prevalence of smoking in men remains high in Japan compared to other developed countries. It is therefore of great importance to determine the impact of cigarette smoking on stomach cancer among the Japanese population. The Japan Collaborative Cohort Study (JACC Study) provided an opportunity to examine the association between smoking and the risk of mortality due to stomach cancer.

METHOD

A baseline survey was conducted throughout Japan from 1988 through 1990 among 110,792 inhabitants of 45 areas. Data retrieved for 98,062 participants (43,482 male and 54,580 female) who provided sufficient information about their smoking habits, without any history of caner at the baseline. Of total 970,251 person-years, 757deaths due to stomach caner were identified.

RESULTS

Current smokers were at a higher risk of death due to stomach cancer than non-smokers (Hazard ratio=1.36; 95% confidence interval [CI]: 1.07, 1.73). The risk of stomach cancer for men who smoked 15 or more cigarettes per day was approximately 1.4-fold greater than that of non-smokers, and those who smoked 35 or more cigarettes per day had an approximately 1.7-fold higher risk of stomach cancer, although the dose-response trend among men was unclear (p for trend=0.063). No associations between smoking and stomach cancer were detected among women.

CONCLUSION

The present results, together with previous findings, strongly support a hypothesis that cigarette smoking increases the risk of stomach cancer in Japanese men.

Prospective study of three major dietary patterns and risk of gastric cancer in Japan

Dietary pattern analysis is an alternative and complementary approach to identify the relationship between diet and the risk of chronic disease. This study was aimed at investigating the associations between dietary patterns and the risk of gastric cancer in Japan. Using baseline data from a prospective study of 20,300 men and 21,812 women, we conducted factor analysis and identified 3 major dietary patterns, healthy, traditional and Western, and calculated the factor scores of each pattern for individuals. During 10 years of follow-up, 400 cases of gastric cancer were identified. We found an inverse association between the healthy pattern and gastric cancer risk in women [rate ratio for highest quartile (RR) = 0.56; 95% CI = 0.32-0.96; p for trend = 0.03], but not in men. In contrast, the traditional pattern was significantly associated with the increased risk of gastric cancer in both genders (for men, RR = 2.88, 95% CI = 1.76-4.72; for women, RR = 2.40, 95% CI = 1.32-4.35). The Western pattern was not associated with risk. These associations persisted in histologic subtypes. Our findings support the idea that the healthy pattern decreased the risk of gastric cancer among females, while the traditional pattern increased the risk in both genders.

Epidemiologic evidence of the protective effect of fruit and vegetables on cancer risk

BACKGROUND

Diets rich in fruit and vegetables have been recommended for preventing cancer. The evidence supporting this recommendation is based on observational studies, although results of several prospective studies have cast some doubts on whether fruit and vegetables are associated with cancer risk reduction.

OBJECTIVE

We sought to summarize evidence from case-control and prospective studies on fruit and vegetable intake and cancer risk with a meta-analytic approach.

DESIGN

Published case-control and cohort studies that reported on total vegetable and fruit intake and risk of cancer of several sites were included. Relative risks were estimated by using linear logistic regression models.

RESULTS

Case-control studies overall support a significant reduction in the risks of cancers of the esophagus, lung, stomach, and colorectum associated with both fruit and vegetables; breast cancer is associated with vegetables but not with fruit; and bladder cancer is associated with fruit but not with vegetables. The overall relative risk estimates from cohort studies suggest a protective effect of both fruit and vegetables for most cancer sites considered, but the risk reduction is significant only for cancers of the lung and bladder and only for fruit.

CONCLUSIONS

Prospective studies provide weaker evidence than do case-control studies of the association of fruit and vegetable consumption with reduced cancer risk. The discrepancies may be related to recall and selection biases in case-control studies. In contrast, the association may have been underestimated in prospective studies because of the combined effects of imprecise dietary measurements and limited variability of dietary intakes within each cohort.

Food/nutrient intake and risk of atrophic gastritis among the Helicobacter pylori-infected population of northeastern Japan

Although Helicobacter pylori (H. pylori ) infection is considered a key risk factor for atrophic gastritis, along with other environmental factors, it is still unclear which factor is involved in the development of atrophic gastritis among H. pylori-infected subjects. In the present cross-sectional study, therefore, we analyzed various dietary factors in relation to the presence of atrophic gastritis among H. pylori-infected subjects who participated in a health check-up program in a town in northeastern Japan. One thousand and seventy-one subjects (362 males and 709 females) who provided both self-administered validated food frequency questionnaires and blood samples were the basis for the study, and all of them were serologically positive for H. pylori immunoglobulin G (IgG) antibody. Among them, 663 (223 males and 440 females) were diagnosed as having atrophic gastritis on the basis of serum pepsinogen levels. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated based on tertile categories of subjects without atrophic gastritis, using logistic regression analysis. Among females, high consumptions of rice (OR = 1.6, 95% CI: 1.1-2.3), cod roe (OR = 1.5, 95% CI: 1.0-2.2) and cuttlefish (OR = 1.5, 95% CI: 1.0-2.3) were associated with a moderately increased risk of atrophic gastritis after adjustment for age (P for trend = 0.02 for these items). Among males, high consumptions of rice and miso soup showed a tendency toward an increased risk (P for trend = 0.12 and 0.13, respectively). Vegetables and fruits showed no association among either males or females. From these results, it is suggested that the dietary habits of consumers of traditional Japanese foods may play a role in the development of atrophic gastritis after H. pylori infection.

Vegetables, fruit and risk of gastric cancer in Japan: a 10-year follow-up of the JPHC Study Cohort I

The association between vegetables and fruit consumption and gastric cancer risk was investigated in a population-based prospective study in 4 public health center areas in Japan. Dietary and other exposure data were obtained in 1990 from a cohort of 19,304 men and 20,689 women with a self-administered questionnaire. After 10 years of follow-up, a total of 404 cases of gastric cancer were documented among them. After adjustment for age, gender, areas and other potential confounding factors and after exclusion of the cases diagnosed in first and second follow-up years, the relative risk associated with intake 1 or more days per week compared to less than 1 day per week was 0.64 (95% CI 0.45-0.92) for yellow vegetable, 0.48 (95% CI 0.25-0.89) for white vegetable and 0.70 (95% CI 0.49-1.00) for fruit. Relative risks associated with quintile of total vegetable consumption were 1.00, 0.86, 0.75, 0.90 and 0.75 (p for trend = 0.17). In the differentiated type of gastric cancer, the association became clearer: 1.00, 0.96, 0.78, 0.88 and 0.53 (p for trend = 0.03). This prospective study suggests that vegetable and fruit intake, even in low amounts, is associated with a lower risk of gastric cancer. Although no striking differences in the association were seen between cardia and noncardia cancer, an inverse association was higher in differentiated rather than in undifferentiated types of gastric cancer.

Cigarette smoking, alcohol consumption and subsequent gastric cancer risk by subsite and histologic type

The effect of cigarette smoking or alcohol consumption on the risk of gastric cancer has not been clarified. We investigated this relationship, considering the anatomic subsite and histologic type of gastric cancer. A total of 19,657 men (aged 40-59 years at baseline), who responded to the baseline questionnaire and reported no serious illness at that time, were followed for 10 years, from January 1990 to December 1999. Gastric cancer was confirmed histologically in 293 men. Smoking was associated with an increased risk of the differentiated type of distal gastric cancer; compared to the group who never smoked, the adjusted rate ratios (RRs) of gastric cancer for past and current smokers were 2.0 (95% CI 1.1-3.7) and 2.1 (95% CI 1.2-3.6), respectively. No association was observed between cigarette smoking and risk of the undifferentiated type of distal gastric cancer except for a suggestive association with cardia cancer. For alcohol consumption, elevated risk was suggested only for cardia cancer of all histologic types, though the relationship failed to reach significance. Among those who drank alcohol at least once per week, RRs for ethanol intake of 2.7-161.0, 162.0-322.0 and 322.5+ g/week compared to those who drank 0-3 times/month were 2.5 (95% CI 0.7-9.5), 3.3 (0.9-11.6) and 3.0 (0.8-11.1), respectively (p(trend) = 0.66). In conclusion, our results confirm that smoking is related to gastric cancer of the differentiated type. Further studies with more cases are needed to detect a positive association between cigarette smoking or alcohol consumption and cardia cancer.

Diagnosis of chronic atrophic gastritis by morphometric image analysis. A new method to overcome the confounding effect of the inflammatory infiltrate

The risk of gastric cancer increases with the severity of gastric mucosal atrophy. Atrophy is a 'loss of properly specialized glands'. These glands may be substituted by metaplastic cells and by interstitial fibrosis, or displaced by an inflammatory infiltrate. Agreement among pathologists for the diagnosis of atrophy is poor (kappacoefficient < 0.4), probably because inflammatory infiltrate can confound the identification of gland loss. The aim of this study was to evaluate interstitial fibrosis by image analysis, and thereby overcoming the confounding effect of the inflammatory infiltrate. Gastric biopsies of 40 controls (20 children and 20 adults) and 111 patients with chronic atrophic gastritis were examined. Patients underwent another biopsy a year later. Gastric sections were examined by conventional histology (updated Sydney system) and image analysis to detect collagen and non-collagen fibres. There were no significant intra- or inter-operator differences in the evaluation by image analysis of fibre content in either controls or patients. In both controls and patients, the mean percentage of collagen fibres was lower in the gastric body (9%) than in the antrum (10%). In the antrum it was 14%, 17% and 20% in patients with mild, moderate and severe atrophy, respectively. A year later, histology showed that the grade of atrophy had decreased in 42%, probably due to the regression of inflammation, and increased in 10% of cases, but interstitial fibrosis (expressed as collagen fibre content) was practically unchanged. The use of image analysis of gastric biopsies appears to be a reliable method with which to measure interstitial fibrosis, even in the presence of an inflammatory infiltrate. This study highlights the difference between 'real gastric atrophy', where glands are replaced by collagen fibres, and 'apparent gastric atrophy', where glands are displaced by an inflammatory infiltrate.

Loss of E-cadherin expression in gastric intestinal metaplasia and later stage p53 altered expression in gastric carcinogenesis

Gastric cancers are commonly subdivided into intestinal and diffuse subtypes on a morphologic basis, supported by corollary evidence of differences at the pathogenetic and molecular levels. Chronic atrophic gastritis with intestinal metaplasia is a common precursor lesion for the intestinal type of carcinoma. To identify early molecular changes, in this study we have examined 13 surgical specimens both for the expression of E-cadherin, p53 and beta-catenin by immunohistochemistry and for methylation of the CDH1 promoter (E-cadherin) by bisulfite genomic sequencing of laser capture microdissected samples. Each specimen examined contained areas of normal (nonmetaplastic) gastric mucosa, as well as areas of intestinal metaplasia and/or carcinoma. Reduced or absent E-cadherin and partial to complete methylation of one to multiple CpG sites examined in the CDH1 promoter were observed in all of the metaplasia samples. Thus, the methylation status of the CDH1 promoter and expression of E-cadherin together provide strong evidence that loss of E-cadherin is an early event in intestinal type gastric carcinogenesis. In contrast, expression of p53, assumed to be mutant p53, was generally not detected (except for isolated cells) until the carcinoma stage in tissues from these patients. These results suggest that mutation of p53 is a late event in intestinal type gastric cancer. The level of beta-catenin expression did not appear to change between normal, metaplastic and carcinoma cells of intestinal type, and no nuclear staining was visible in any of the tissues. These results suggest that the Wnt signaling pathway is not upregulated in this type of cancer.

Inhibitory actions of luteolin on the growth and arylamine N-acetyltransferase activity in strains of Helicobacter pylori from ulcer patients

Helicobacter pylori is now recognized as an important cause of type B gastritis, which is strongly associated with gastric and duodenal ulcer disease. H. pylori may be a causative factor in patients with gastric cancer. The growth inhibition and N-acetylation of 2-Aminofluorene (AF) or P-aminobenzoic acid (PABA) by arylamine N-acetyltransferase (NAT) in H. pylori were inhibited by luteolin, a component in herbal medicine. The growth inhibition was based on the changes of optical density (OD) by using a spectrophotometer. The N-acetylation of AF or PABA by NAT from H. pylori were assayed by the amounts of acetylated and non-acetylated AF or PABA in cytosols and intact bacteria of H. pylori by using HPLC. An inhibition of growth on H. pylori demonstrated that luteolin elicited a dose-dependent growth inhibition in the H. pylori cultures. Cytosols and suspensions of H. pylori with or without specific concentrations of luteolin co-treatment showed different percentages of AF or PABA acetylation. The data indicated that there was decreased NAT activity associated with increased levels of luteolin in H. pylori cytosols and suspensions. Using standard steady-state kinetic analysis, it was demonstrated that luteolin was a possible uncompetitive inhibitor to NAT enzyme in H. pylori. This report is the first demonstration to show that luteolin can inhibit H. pylori growth and NAT activity.

Effects of polyunsaturated fatty acids on atrophic gastritis in a Japanese population

In the present study, 92 people were found to have atrophic gastritis (AG) according to depressed serum levels of pepsinogen I and pepsinogen II in a screening involving 208 Japanese people, participating in a group health check. Serum levels of n-3 polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), were higher in AG than in non-AG individuals, while those of gamma-linolenic acid (GLA) were significantly lower in AG individuals. The odds ratios for high serum DHA and GLA levels in AG subjects were 2.20 (95% C.I.: 1.10-4.39) and 0.34 (95% C.I.: 0.17-0.68), respectively. The above results suggested that GLA plays a role in reducing the incidence of AG, whereas DHA may increase a risk of AG.