Etiologic factors of gastric cardiac adenocarcinoma among men in Taiwan

Effect of physical activity on incidence and mortality in patients with gastric cancer: evidence from real-world studies

PURPOSE

Physical activity (PA) has been suggested to reduce the risk of cancer. However, previous studies have been inconsistent regarding the relationship between PA and the risk of developing gastric cancer (GC). The purpose of this study was to evaluate the impact of PA on the incidence and mortality risk of GC through a meta-analysis, as well as investigate potential dose-response relationships.

METHODS

A systematic literature search was conducted in 10 electronic databases and 4 registries. The combined relative risks (RRs) were calculated using a random-effects model with 95% confidence interval (CIs) to assess the effect of PA on the risk of GC. Relevant subgroup analyses and sensitivity analyses were performed.

RESULTS

The results showed that PA correlated with lower incidence of GC (RR: 0.83, 95% CI: 0.77-0.90), decreased risk of GC mortality (RR: 0.76, 95% CI: 0.66-0.89). The results of the subgroup analysis showed that PA was associated with reduced incidence of GC across gender, different regions, study designs, different sites of GC and different types of PA. A linear relationship was found for frequency of PA.

CONCLUSIONS

This meta-analysis found that PA was associated with a reduced risk of GC incidence and mortality. The correlation between PA and GC occurrence was in a dose-response relationship.

Dietary Pattern, Genomic Stability and Relative Cancer Risk in Asian Food Landscape

The incidence of cancer globally is increasing, partly due to lifestyle factors. Despite a better understanding of cancer biology and advancement in cancer management and therapies, current strategies in cancer treatment remain costly and cause socioeconomic burden especially in Asian countries. Hence, instead of putting more efforts in searches for new cancer cures, attention has now shifted to understanding how to mitigate cancer risk by modulating lifestyle factors. It has been established that carcinogenesis is multifactorial, and the important detrimental role of oxidative stress, chronic inflammation, and genomic instability is evident. To date, there is no study linking dietary pattern and genomic stability in cancer risk in the Asian food landscape. Thus, this present review article discusses recent literature on dietary pattern and genomic stability and its relationship with cancer risk in Asia.

The Impact of Whole Grain Intake on Gastrointestinal Tumors: A Focus on Colorectal, Gastric, and Esophageal Cancers

Cereals are one of staple foods in human diet, mainly consumed as refined grains. Nonetheless, epidemiological data indicate that whole grain (WG) intake is inversely related to risk of type 2 diabetes, cardiovascular disease, and several cancer types, as well as to all-cause mortality. Particularly responsive to WG positive action is the gastrointestinal tract, daily exposed to bioactive food components. Herein, we shall provide an up-to-date overview on relationship between WG intake and prevention of gastrointestinal tumors, with a particular focus on colorectal, stomach, and esophagus cancers. Unlike refined counterparts, WG consumption is inversely associated with risk of these gastrointestinal cancers, most consistently with the risk of colorectal tumor. Some WG effects may be mediated by beneficial constituents (such as fiber and polyphenols) that are reduced/lost during milling process. Beside health-promoting action, WGs are still under-consumed in most countries; therefore, World Health Organization and other public/private stakeholders should cooperate to implement WG consumption in the whole population, in order to reach nutritionally effective intakes.

Helicobacter pylori Is Associated With Precancerous and Cancerous Lesions of the Gastric Cardia Mucosa: Results of a Large Population-Based Study in China

Background: Helicobacter pylori (H. pylori) is widely accepted to be the most important cause of gastric non-cardia adenocarcinoma (GNCA), while its role in the development of gastric cardia adenocarcinoma (GCA) is not well-defined. We aimed to investigate current H. pylori infection in relation to the severity of both precancerous and cancerous lesions of the gastric cardia in an Asian population at high risk of GCA. Methods: A population-based cross-sectional study was conducted in Linzhou County, Henan Province, China. Two thousand three (2,003) randomly selected participants with data on current H. pylori infection, assayed by 13C-urea breath test (13C-UBT), and a sequence of histological diagnoses of the gastric cardia mucosa were analyzed. Results: Of 2,003 subjects, 828 (41.33%) were currently infected with H. pylori. The prevalence of current H. pylori infection increased with increasing severity of histological lesions, from 34.12% in subjects with normal gastric cardia mucosa to 52.17% in subjects with gastric cardia high-grade intraepithelial neoplasia (CHIN)/ gastric cardia adenocarcinoma (GCA) (P for trend <0.001). With H. pylori-negative subjects as the reference category, H. pylori-positive subjects had statistically significant elevated adjusted prevalence odds ratios (PORs) for each of the histological lesions. The PORs (95% CI) were 2.15 (1.74-2.64), 3.46 (2.08-5.75), 2.78 (1.90-4.07), and 3.05 (1.30-7.17) for subjects with carditis, cardia intestinal metaplasia (CIM), cardia low-grade intraepithelial neoplasia (CLIN), and CHIN/GCA), respectively. The associations remained when subjects with abnormal stomach non-cardia mucosa were excluded. Conclusions: This large epidemiologic study demonstrates a positive association between current H. pylori infection and the severity of both precancerous and cancerous lesions of the gastric cardia in an Asian population at high risk of GCA. These findings suggest that H. pylori infection may play a role throughout both early- and late-stage development of GCA.

Milk/dairy products consumption and gastric cancer: an update meta-analysis of epidemiological studies

The relationship between dairy consumption and gastric cancer risk has not been well studied. We therefore performed a update meta-analysis to evaluate the relationship. Published cohort and case-control studies were identified via computer searches and reviewing the reference lists of the key articles. Random effects meta-analysis was used to pool effects from 5 cohort and 29 case-control studies. The odds ratio for the overall association between dairy consumption and gastric cancer was 1.20 (95%confidence interval: 1.04–1.39). The combined risk estimate was similar for population-based case-control studies (odds ratio = 1.27, 95%confidence interval: 1.00–1.61), but was reduced for hospital-based studies (odds ratio = 1.22; 95%confidence interval: 0.95–1.57) and cohort studies (odds ratio = 0.99; 95%confidence interval: 0.77–1.28). There was high heterogeneity in overall analyses. In the population-based subgroup analyses, the odds ratio was 0.96 (95%confidence interval: 0.69–1.34) when considering five studies assessing exposure two or more years before interview, and the association strengthened (odds ratio = 1.91, 95%confidence interval: 1.60–2.28) when dairy consumption was evaluated one year or less prior to interview. In conclusion, we found adverse effect of dairy consumption associated with gastric cancer.

Cancers of the Esophagus and Stomach: Potential Mechanisms Behind the Beneficial Influence of Physical Activity

OBJECTIVE

To compare findings from several recent meta-analyses showing a reduced risk of gastric and esophageal cancers in physically active individuals, to assess the magnitude of this benefit, and to seek information on potential underlying mechanisms.

DATA SOURCES

A comprehensive search of Ovid/Medline from 1996 to February 2016, using the terms physical activity or exercise or training and esophageal or gastric cancer, and supplementing the articles identified by material from references lists and personal files.

MAIN RESULTS

Moderate-to-vigorous physical activity is associated with a 20% to 30% reduction in the risk of gastroesophageal adenocarcinomas, with a significant dose/response relationship. Benefit is greater in women than in men, and greater for noncardia than for cardia or esophageal tumors. Mechanisms could include a reduction of visceral fat (with a lesser production of cancer promoting hormones and reduced gastroesophageal reflux) and/or a lesser likelihood of smoking and excessive alcohol consumption. Physical activity does not protect against Helicobacter pylori infections or gastric ulceration, but mechanisms related to the impact of exercise on immune function, antioxidant mechanisms, and gastroesophageal reflux remain to be explored.

CONCLUSIONS

Regular, moderate-to-vigorous physical activity is associated with a clinically significant reduction in the risk of gastroesophageal adenocarcinomas, but mechanisms are as yet unclear, and a causal relationship remains to be proven.

Physical Activity and Gastric Cancer Risk: A Systematic Review and Meta-Analysis

OBJECTIVE

Physical activity represents a well-established way to prolong the life span; yet, it remains an unfulfilled goal for a great part of the population. In parallel, the burden of gastric cancer is considerable throughout the globe. In that context, the present meta-analysis aims to shed light on the association between physical activity and gastric cancer risk.

DATA SOURCES

Eligible observational studies were sought in PubMed up to June 01, 2015. In addition, a snowball procedure was conducted and contact with authors was implemented. Separate analyses were performed by type of physical activity (total; occupational; recreational), study design, published/provided data, anatomical site, and study location, along with stratification by gender.

MAIN RESULTS

Ten cohort studies (7551 incident cases in a total cohort size of 1 541 208 subjects) and 12 case-control studies (5803 cases and 73 629 controls) were eligible. "Any" type of physical activity was associated with lower risk of gastric cancer [pooled relative risk (RR) = 0.81; 95% CI: 0.73 to 0.89], which was reproducible in men (pooled RR = 0.87; 95% CI: 0.77-0.99). The protective effect was significant in the subgroup analyses of published data, noncardia cancer (pooled RR = 0.62; 95% CI: 0.52-0.75), and studies stemming from Asia (pooled RR = 0.82; 95% CI: 0.74-0.90).

CONCLUSIONS

This meta-analysis suggests a protective effect of physical activity regarding gastric cancer risk, especially in Asian populations.

Dairy product consumption and gastric cancer risk: A meta-analysis

AIM: To investigate whether dairy product consumption is a risk factor for gastric cancer.

METHODS: We searched the PubMed and Web of Science databases for English-language studies on dairy product consumption and gastric cancer risk that were published between October 1980 and September 2013. One author independently extracted data and assessed study quality. Based on the heterogeneity results, we used either the fixed effects model or the random effects model to compute the summary relative risks and 95% confidence intervals (CIs). We also analyzed subgroups according to the study design, geographic region, sex, and whether there were adjustments for confounders (smoking and drinking) with respect to the sources of heterogeneity.

RESULTS: We found 39 studies that were potentially eligible for inclusion in this meta-analysis, including 10 cohort studies and 29 case-control studies. The summary relative risk for gastric cancer, comparing the highest and lowest dairy product consumption categories, was 1.06 (95%CI: 0.95-1.18). Specific analyses for milk, butter, and margarine yielded similar results, but the results for cheese and yogurt were different. There was significant heterogeneity for all studies (Q = 112.61; P = 0.000; I² = 67.1%). No publication bias was observed (Egger’s test: P = 0.135; Begg’s test: P = 0.365). There was a nonsignificant association between dairy product consumption and gastric cancer risk in the subgroup analysis for the study design, sex, geographic region, and whether there were adjustments for confounders (smoking and drinking).

CONCLUSION: In our meta-analysis, dairy product consumption was associated with a nonsignificantly increased risk of gastric cancer. However, this result should be verified using large, well-designed prospective studies.

Infection and esophageal cancer

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on infection and cancer, and includes commentaries on the influence of bacterial infections on mucin expression and cancer risk; the role of esophageal bacterial biota in the incidence of esophageal disease; the association between human papilloma virus (HPV) and esophageal squamous cell carcinoma; the role of HPV in esophageal adenocarcinoma; the role of Helicobacter pylori in cardiac carcinoma; and the role of Epstein-Barr virus infection in esophageal cancer.

Physical activity and risks of esophageal and gastric cancers: a meta-analysis

BACKGROUND

The incidence of esophageal and gastric cancer has been increasing rapidly worldwide in recent years, although the reason for this increase is unclear. Here, a statistical synthesis of studies that evaluated the association between physical activity, a well-known protecting factor against death and other chronic diseases, and the risk of esophageal and gastric cancer was performed.

METHODS

Potentially suitable studies were identified using Medline and Embase. The reference lists of all included articles and those of several recent reviews were searched manually. Studies were included if they (1) were published as case-control or cohort studies evaluating the association between physical activity and risk of esophageal or gastric cancer; and (2) reported point estimates (i.e., risk ratios, odds ratios) and measures of variability (i.e., 95% confidence intervals [CIs]) for physical activity and risk of esophageal or gastric cancer.

RESULTS

Fifteen studies were identified (7 cohorts, 8 case-controls; 984 esophageal and 7,087 gastric cancers). Collectively, they indicated that the risk of gastric cancer was 13% lower among the most physically active people than among the least active people (RR = 0.87, 95% confidence interval [CI] = 0.78 to 0.97) and that of esophageal cancer was 27% lower (RR = 0.73, 95% CI = 0.56 to 0.97).

CONCLUSIONS

Pooled results from observational studies support a protective effect of physical activity against both esophageal and gastric cancer.

Tobacco smoking and esophageal and gastric cardia adenocarcinoma: a meta-analysis

BACKGROUND

Smoking has been related to esophageal and gastric cardia adenocarcinoma, but the magnitude of the association is uncertain.

METHODS

We conducted a meta-analysis of 33 studies published up to January 2010. We derived summary estimates using random-effects models.

RESULTS

Compared with never-smokers, the pooled relative risk (RR) was 1.76 (95% confidence interval = 1.54-2.01) for ever-smokers, 2.32 (1.96-2.75) for current smokers, and 1.62 (1.40-1.87) for ex-smokers. There was no important difference between esophageal (RR = 1.85 for ever- vs. never-smokers) and gastric cardia (RR = 1.76) adenocarcinoma. We found a direct association with dose (RR = 2.48 [2.14-2.86] for ≥ 20 cigarettes/d) and duration (RR = 2.32 [1.92-2.82] for ≥ 40 years) of cigarette consumption.

CONCLUSIONS

This meta-analysis estimates the excess of esophageal and gastric cardia adenocarcinoma risk for smokers. This risk was similar for the 2 cancer sites.

Barrett's esophagus, esophageal and esophagogastric junction adenocarcinomas: the role of diet

Identification of modifiable risk factors is an attractive approach to primary prevention of esophageal adenocarcinoma (EAC) and esophagogastric junction adenocarcinoma (EGJAC). We conducted a review of the literature to investigate the association between specific dietary components and the risk of Barrett’s esophagus (BE), EAC and EGJAC, supposing diet might be a risk factor for these tumors. Consumption of meat and high-fat meals has been found positively associated with EAC and EGJAC. An inverse association with increased intake of fruit, vegetables and antioxidants has been reported but this association was not consistent across all studies reviewed. Few studies have examined the association between diet and BE. Additional research is needed to confirm the aforementioned association and clarify the mechanisms by which dietary components affect the risk of developing EAC and EGJAC. Future studies could advance our knowledge by emphasizing prospective designs to reduce recall bias, by using validated dietary intake questionnaires and biological measures and by considering important confounders such as gastro-esophageal reflux disease (GERD) symptoms, tobacco and alcohol use, biometrics, physical activity, and socioeconomic factors.

Gastric cardia adenocarcinoma in Taiwanese men: Positive associations due to selection bias

The factors associated with an increase in gastric cardia adenocarcinoma are poorly understood. Environmental factors such as Helicobacter pylori (H. pylori) infection and diet have been hypothesized to play a role in the recently increased risk of this disease, but additional studies are needed. In conducting studies to establish the relationship between potential risk factors and gastric cardia adenocarcinoma, it is necessary to carefully consider the role of bias. In a recently published study, the reported associations between H. pylori as well as post-meal physical exertion and gastric cardia adenocarcinoma may have been greatly influenced by selection bias.