Ecological study for refrigerator use, salt, vegetable, and fruit intakes, and gastric cancer

Effect of sodium-reduced potassium-enriched salt substitutes on stomach cancer: the Salt Substitute and Stroke Study (SSaSS)

BACKGROUND

There is an association between increased dietary sodium intake and the risk of stomach cancer. Lowering dietary sodium intake with sodium-reduced potassium-enriched salt substitutes may reduce this risk. To evaluate the effects of sodium-reduced potassium-enriched salt substitutes on the risk of stomach cancer and other types of cancer.

METHODS

The primary analyses of the Salt Substitute and Stroke Study (SSaSS) defined the effects of sodium-reduced potassium-enriched salt substitutes compared to regular salt on the risk of stroke. This post-hoc investigation explored effects on stomach and other cancers. SSaSS was an open-label, cluster randomised controlled trial done in 600 Chinese villages among 20,996 participants. Villages were assigned at random in a 1:1 ratio to receive sodium-reduced potassium-enriched salt substitutes or continue regular salt use. Fatal and hospitalised cancer events were identified through direct face-to-face follow-up and record linkage, with adjudication of fatal, but not non-fatal events.

RESULTS

During a mean follow-up of 4.7 years, there were 1040 cancer events (507 fatal, 533 non-fatal) recorded. There were 212 stomach cancers, 725 other cancers, and 103 cancers with an unknown primary site. There was a trend toward but not a significant effect of randomised treatment on total stomach cancer (rate ratio (RR) 0.77, 95% confidence interval (CI) 0.54 to 1.08). The RR for adjudicated fatal stomach cancer was 0.66 (95% CI 0.44 to 1.00) compared to 0.88 (95% CI 0.56 to 1.37) for unadjudicated non-fatal stomach cancer. There was no detectable effect on total cancer at any site (RR 0.94, 95% CI 0.81 to 1.08), adjudicated fatal cancer at any site (RR 0.85, 95% CI 0.69 to 1.05), or unadjudicated non-fatal cancer at any site (RR 1.04, 95% CI 0.88 to 1.23).

CONCLUSIONS

There was no effect of sodium-reduced potassium-enriched salt substitutes on stomach cancer or other cancer types detected. Trends toward protection against fatal and non-fatal stomach cancer align with the observational epidemiology and warrant further investigation.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov as NCT02092090.

The Association between Peptic Ulcer Disease and Gastric Cancer: Results from the Stomach Cancer Pooling (StoP) Project Consortium

BACKGROUND

Gastric cancer (GC) is the fifth most common type of cancer and the fourth most common cause of cancer-related mortality. Although the risk of GC and peptic ulcer disease (PUD) is known to be increased by H. pylori infection, evidence regarding the direct relationship between PUD and GC across ethnicities is inconclusive. Therefore, we investigated the association between PUD and GC in the Stomach cancer Pooling (StoP) consortium.

METHODS

History of peptic ulcer disease was collected using a structured questionnaire in 11 studies in the StoP consortium, including 4106 GC cases and 6922 controls. The two-stage individual-participant data meta-analysis approach was adopted to generate a priori. Unconditional logistic regression and Firth's penalized maximum likelihood estimator were used to calculate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between gastric ulcer (GU)/duodenal ulcer (DU) and risk of GC.

RESULTS

History of GU and DU was thoroughly reported and used in association analysis, respectively, by 487 cases (12.5%) and 276 controls (4.1%), and 253 cases (7.8%) and 318 controls (6.0%). We found that GU was associated with an increased risk of GC (OR = 3.04, 95% CI: 2.07-4.49). No association between DU and GC risk was observed (OR = 1.03, 95% CI: 0.77-1.39).

CONCLUSIONS

In the pooled analysis of 11 case-control studies in a large consortium (i.e., the Stomach cancer Pooling (StoP) consortium), we found a positive association between GU and risk of GC and no association between DU and GC risk.

The effect of nutrition education for cancer prevention based on health belief model on nutrition knowledge, attitude, and practice of Iranian women

Background

In recent years, nutrition has received an increasingly important role in the etiology of cancer. Thus, public education about dietary factors associated with cancer risk or prevention could be an important intervention for cancer prevention, particularly in low- and middle-income countries where the burden of cancer is increasing rapidly and the access to care is limited. The age-standardized incidence of breast cancer was 35.8 among Iranian women in 2020. We aimed to study the effect of nutrition education on the knowledge, attitude, and practice of Iranian women towards dietary factors related to cancer.

Methods

In this interventional study, 229 women from public health centers were recruited and underwent three 75-min sessions of education based on the Health Belief Model (HBM). Participants were interviewed by trained interviewers using a validated and reproducible nutrition-related cancer prevention knowledge, attitude, and practice questionnaire (NUTCANKAP) questionnaire designed based on the HBM. Nutritional knowledge, attitude, and practice of participants were assessed through this questionnaire. Three 24-h dietary recalls (one weekend and two nonconsecutive weekdays) were also collected before and one month after the intervention.

Results

The mean age of the participants was 45.14 years, and the mean BMI was 27.2 kg/m². After the intervention, the participants had a higher intake of whole grain (p = 0.03) and a lower fat dairy (p = 0.009) and nuts (p = 0.04). However, the intake of high-fat dairy (p = 0.001) decreased after the intervention. We indicated significant differences in knowledge (p < 0.001) and nutritional practice scores (p = 0.01) after education. In addition, after the intervention, there were significant differences in the mean score of the HBM components, except for the perceived self-efficacy.

Conclusion

Participation in a nutrition education program positively impacted the knowledge and nutritional practices linked to cancer prevention.

Dietary Intake of Soy Products, Vegetables, and Dairy Products and Gastric Cancer Survival according to Histological Subtype: a Long-term Prospective Cohort Study

PURPOSE

Owing to differences in the general characteristics of gastric cancer (GC) according to histological type, the association of GC risk factors, such as diet, may also differ depending on the histological type. We investigated the associations between individual and combined intake of soy products, vegetables, and dairy products and GC mortality by following up cases of death among Korean GC cases and whether these associations differ according to the histological type.

MATERIALS AND METHODS

A total of 508 GC cases were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephonic surveys. Finally, 300 GC cases classified as intestinal- or diffuse-type GC cases were included. The median follow-up period was 7.1 years.

RESULTS

In the fully adjusted model, a high intake of soy products (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.19-0.96) and the combination of soy products and vegetables (HR, 0.34; 95% CI, 0.12-0.96) or soy products and dairy products (HR, 0.37; 95% CI, 0.14-0.98) decreased the mortality from intestinal-type GC. In particular, patients consuming various potentially protective foods (HR, 0.23; 95% CI, 0.06-0.83) showed a highly significant association with a lower mortality from intestinal-type GC. However, no significant association was found with diffuse-type GC.

CONCLUSIONS

High intake of potentially protective foods, including soy products, vegetables, and dairy products, may help increase survival in intestinal-type GC.

The implications of ripening agents on chemical compositions of plantain (Musa paradisiaca)

Foods frequently eaten supply both micro and macro nutrients to humans which are important in the total assessment of public health status of an individual. The analysis of these foods will provide evidence on their nutritional values, guide to appropriate choice of meal and encourage intake of varieties of food with better qualities during illness while preventing diet-associated disorders. In this study, the proximate and mineral composition of unripe, naturally ripe and the effects of ripening agents on plantain (Musa paradisiaca) commonly consumed in Nigeria were examined. The plantain fruits were analysed for proximate and mineral composition. Proximate composition analysis revealed an increase in moisture content and fat content for all the plantain ripened with ripening agents when compared with the naturally ripened plantain. Furthermore, the mineral composition of the plantain fruits was determined by means of Atomic Absorption Spectrophotometry (AAS). The result showed that plantain is a good source of minerals such as calcium (Ca), potassium (K) and iron (Fe). A relatively high level of K of 1690.55 ± 0.02; 1672.35 ± 0.03 mg kg⁻¹ were found for both unripe and natural ripe plantain while the ripening agents had K values of 1677.45 ± 0.01; 1656.10 ± 0.02; 1589.45 ± 0.01 mg kg⁻¹ for Ethylene glycol, Potassium Dihydrogen Phosphate, Calcium carbide respectively. Also, low level of Fe was obtained in plantain ripened with the different ripening agents.

Vitamin D modulation and microRNAs in gastric cancer: prognostic and therapeutic role

Gastric adenocarcinoma arises after a complex interaction between the host and environmental factors. Tumor location and TNM are the tools that currently guide treatment decisions. Surgery is the only curative treatment, but relapse is common. After relapse or advanced staged disease survival is poor and systemic treatment has modestly improved survival. An association between sun exposure, vitamin D status and gastric cancer (GC) incidence and mortality has been reported. The molecular differences of the histological subtypes and the new molecular classifications account for the great heterogeneity of this disease and are the basis for the discovery of new therapeutic targets. New prognostic and predictive factors are essential and microRNAs (miRNAs) are endogenous small non-coding RNA molecules with a great potential for diagnosis, prognosis and treatment of cancer. There are hundreds of miRNAs with altered expression in tumor gastric tissue when compared to normal gastric tissue. Many of these miRNAs are associated with clinicopathological variables and survival in patients with GC. Furthermore, the expression of some of these miRNAs with prognostic importance in CG is influenced by vitamin D and others are mediators of some of the actions of this vitamin. This review aims to update the evidence on several miRNAs with prognostic value and therapeutic potential in GC, whose expression may be influenced by vitamin D or may regulate vitamin D signaling.

Gastric cancer: epidemiology, biology, and prevention: a mini review

Gastric cancer is one of the most common causes of cancer-related mortality worldwide. The objective of this article is to review the epidemiology and biology of gastric cancer risk. This literature review explores the biological, clinical, and environmental factors that influence the rates of this disease and discuss the different intervention methods that may not only increase the awareness of gastric cancer but also increase screening in efforts to reduce the risk of gastric cancer. Helicobacter pylori infection is the primary risk factor for gastric cancer. Additional risk factors include geographical location, age, sex, smoking, socioeconomic status, dietary intake, and genetics. Primary and secondary prevention strategies such as dietary modifications and screenings are important measures for reducing the risk of gastric cancer. Interventions, such as H. pylori eradication through chemoprevention trials, have shown some potential as a preventative strategy. Although knowledge about gastric cancer risk has greatly increased, future research is warranted on the differentiation of gastric cancer epidemiology by subsite and exploring the interactions between H. pylori infection, genetics, and environmental factors. Better understanding of these relationships can help researchers determine the most effective intervention strategies for reducing the risk of this disease.

Fluctuating expression of miR-584 in primary and high-grade gastric cancer

Background

Gastric cancer is the fifth most common cancer worldwide. Along with environmental factors, such as Helicobacter pylori (H. pylori) infection, genetic changes play important roles in gastric tumor formations. miR-584 is a less well-characterized microRNA (miRNA), with apparent activity in human cancers. However, miR-584 expression pattern in gastric cancer development has remained unclear. This study aims to analyze the expression of miR-584 in gastric cancer samples and investigates the associations between this miRNA and H. pylori infection and clinical characteristics.

Methods

The expression level of miR-584 was studied in primary gastric cancers versus healthy control gastric mucosa samples using the RT-qPCR method. The clinical data were analyzed statistically in terms of miR-584 expression. In silico studies were employed to study miR-584 more broadly in order to assess its expression and find new potential target genes.

Results

Both experimental and in silico studies showed up-regulation of miR-584 in patients with gastric cancer. This up-regulation seems to be induced by H. pylori infection since the infected samples showed increased levels of miR-584 expression. Deeper analyses revealed that miR-584 undergoes a dramatic down-regulation in late stages, invasive and lymph node-metastatic gastric tumors. Bioinformatics studies demonstrated that miR-584 has a substantial role in cancer pathways and has the potential to target STAT1 transcripts. Consistent with the inverse correlation between TCGA RNA-seq data of miR-584 and STAT1 transcripts, the qPCR analysis showed a significant negative correlation between these two RNAs in a set of clinical samples.

Conclusion

miR-584 undergoes up-regulation in the stage of primary tumor formation; however, becomes down-regulated upon the progression of gastric cancer. These findings suggest the potential of miR-584 as a diagnostic or prognostic biomarker in gastric cancer.

Nutritional Factors Involved in the Etiology of Gastric Cancer: A Systematic Review

CONTEXT

Since treatment options for GC are limited, the best and most effective way is to try to reduce the incidences and understanding prevention strategies.

OBJECTIVE

The success in prevention strategies depends on understanding etiologic mechanisms. Our goal is to identify the major nutritional risk factors for GC, and we will examine the controversial evidence.

DATA SOURCES

We used Pub Med, Google Scholar, Scopus, Science Direct, Elsevier, Springer, and MEDLINE databases for extracting articles.

DATA EXTRACTION

Human studies published in English from 1997to2018 were included. Two reviewers other than authors initially assessed abstract of 742 papers and 248papers were selected for future assessments. After full review and consideration of the inclusion and exclusion criteria, we used 85 articles.

RESULTS

Dietary salt is a strong independent risk for GC whereas alcohol is most likely a risk only in the presence of heavy alcohol consumption. Red meat and high-fat diet increase the risk of developing GC but fresh fruits, vegetables and certain micronutrients like selenium and vitamin C are protective.

CONCLUSION

Some nutrients such as selenium, vitamin C, folate, iron, and zinc are involved in the etiology of GC. On the other hand; salt, fats, alcohol, red meat, and pepper were reported to be risk factors for GC. Since the GC is a heterogeneous malignancy and multiple factors are involved in its genesis.

Prognostic effect of different etiologies in patients with gastric cardia cancer

There are still many controversies about the characteristics and prognosis of gastric cardia cancer. We aimed to evaluate the clinical characteristics and outcome between cardia and noncardia cancer. Also, we evaluated the clinical outcome according to etiologic factors.We performed a retrospective cohort study of 92 patients with gastric cardia cancer from January 2003 to December 2013. The patients with noncardia cancer were selected as age- and sex-matched control.The frequencies of gastroesophageal reflux disease (GERD) and negative Helicobacter pylori infection without atrophy were significantly higher in gastric cardia cancers, but there was no difference in the frequency of obesity. The frequency of early gastric cancers was 40.0%, which was significantly lower than that of noncardia cancer. The rate of recurrence, disease-free survival, and overall survival duration were significantly lower in gastric cardia cancers (P < .01), even though there was no significant difference in the rate of curative resection (R0). In terms of the etiologic factors, there were no differences of disease prognosis, regardless of the presence of GERD, obesity, and H pylori infection with associated gastritis.Gastric cardia cancer showed distinct clinical characteristics and a negative prognostic impact compared with gastric noncardia cancer.

Time Trends And Age-Period-Cohort Effects On The Incidence Of Gastric Cancer In Changle From 2003 To 2012

Purpose

Although the incidence of gastric cancer in China has declined over the past decades, they were still much higher than the average of global. This aim of this study was to describe the trends and age-period-cohort effects on gastric cancer incidence from 2003 to 2012 in Changle and to explore the potential reason.

Materials and methods

Data on patients with gastric cancer diagnosed between 2003 and 2012 were collected by the population-based Changle cancer registration (n=4111). Age-standardized incidence rates of gastric cancer were calculated and joinpoint regression was used to evaluate the trends of gastric cancer incidence. Time trends in gastric cancer incidence by the period of diagnosis and birth cohort were analyzed by sex. Age-period-cohort analysis was performed to investigate the independent effects of age, period of diagnosis and birth cohort among over 25-year-old residents.

Results

A steady downward trend was observed among men, with the incidence ranging from 96.15 per 100,000 in 2003 to 62.6 per 100,000 in 2012 (APC, −5.1%; 95% CI: −6.9 to −3.2%). A similarly declining trend was observed among women with the incidence ranging from 34.5 per 100,000 to 15.7 per 100,000 (APC, −5.7%; 95% CI: −9.3 to −2.0%). Age-period-cohort model of incidence rate showed increasing age effect and decreasing period of diagnosis effects in both men and women. Birth cohorts exhibited a decreasing trend in the incidence among women who were born after 1935 and men after 1940.

Conclusion

Recent decreases in the incidence of gastric cancer were due to decreased period of diagnosis and cohort effects, which was attributed to the improvements in their lifestyle and habits.

Presentation and Survival of Gastric Cancer Patients at an Urban Academic Safety-Net Hospital

INTRODUCTION

Gastric cancer is decreasing nationally but remains pervasive globally. We evaluated our experience with gastric cancer at a safety-net hospital with a substantial immigrant population.

METHODS

Demographics, pathology, and treatment were analyzed for gastric adenocarcinoma at our institution (2004-2017). Chi-square analyses were performed for dependence of staging on demographics. Survival was evaluated with Kaplan-Meier and Cox regression analyses.

RESULTS

We identified 249 patients (median age 65 years). Patients were predominantly born outside the USA or Canada (74.3%), non-white (70.7%), and federally insured (71.4%), and presented with late-stage disease (52.2%). Hispanic ethnicity, Central American birthplace, Medicaid insurance, and zip code poverty > 20% were associated with late-stage presentation (all p < 0.05). Univariate analyses showed decreased survival for patients with late-stage disease, highest zip code poverty, and age ≥ 65 (all p < 0.05). On multivariate analysis, survival was negatively associated with late-stage presentation (HR 4.45, p < 0.001), age ≥ 65 (1.80, p = 0.018), and H. pylori infection (2.02, p = 0.036).

CONCLUSION

Hispanic ethnicity, Central American birthplace, Medicaid insurance, and increased neighborhood poverty were associated with late-stage presentation of gastric cancer with poor outcomes. Further study of these populations may lead to screening protocols in order to increase earlier detection and improve survival.

Environmental contributions to gastrointestinal and liver cancer in the Asia-Pacific region

In the Asia-Pacific region, gastric, colorectal, and hepatocellular (liver) cancer show substantial regional variation in incidence consistent with the presence of important environmental factors. For gastric cancer, global incidence is concentrated in Asia with substantially higher rates in East Asia than in South-East Asia and Australia. The differences in incidence rates for gastric cancer in the Asia-Pacific region may be due, in part, to differences in the prevalence of Helicobacter pylori infection and the prevalence of H. pylori virulence factors. Smoking is also correlated with gastric cancer risk and is responsible for the highest population attributable fraction among men in East Asia. Colorectal cancer has increased rapidly in incidence to become the third most common digestive cancer in Asia. According to cohort studies in Asia, smoking, alcohol use, obesity, and physical inactivity increase the risk of colorectal cancer. Unlike West Asia, East Asia and Australia have high incidence rates for colorectal cancer that correlates to a high Human Development Index and a high prevalence of alcohol consumption and obesity. Liver cancer is the second most common digestive cancer in Asia. The high incidence of liver cancer in East Asia and South-East Asia is concordant with the high prevalence of hepatitis B virus and hepatitis C virus infection. Other important risk factors include alcohol use, smoking, and diabetes. The identification of the earlier and other environmental factors (currently under investigation) is central to the development and implementation of effective cancer control programs for the region.

Cancer mortality trends in an industrial district of Shanghai, China, from 1974 to 2014, and projections to 2029

We aimed to characterize the trends and projections of cancer mortalities in Yangpu, an industry restructuring district of Shanghai, China. With high-quality data from the death registration system, the authors analyzed the trends in cancer mortalities during 1974-2014 and their relationship with pollution control and socioeconomic improvements. Cancer burden was projected into 2029. During 1974-2014, cancer death accounted for 28.80% of all-cause death. The 5 leading causes of cancer death were cancers of the lung & bronchus, stomach, liver, colon & rectum, and esophagus. Age-standardized mortality of all cancers was higher in men than in women (153.1/105vs. 88.8/105, p<0.001) and increased from 1974 to 1991 and decreased thereafter. The mortalities of cancers of the larynx, bladder, liver, nasopharynx, lung & bronchus, esophagus, lip oral & pharynx, stomach, kidney, and lymphoma were significantly higher in men than in women. Age-standardized mortalities of cancers of the esophagus, stomach, leukemia, female nasopharynx, female bladder, liver, and bone decreased especially after the 1990s, those of the colon & rectum, kidney, prostate, pancreas, breast, gallbladder, and ovary increased significantly. Lung cancer, breast cancer, colorectal cancer, and pancreas cancer in women and lung cancer, colorectal cancer, prostate cancer, and stomach cancer in men will be the leading causes of cancer death in 2025-2029. Cancer-caused life loss kept increasing since 2000. Conclusively, cancers associated with pollutions and infection decreased, especially after the 1990s, while those related to metabolic syndrome increased. These trends are related to closedown of polluted industries in the 1980s and lifestyle changes.

Management of gastric cancer in Indian population

Adenocarcinoma stands the most common malignancies in the gastric carcinomas and holds a significant mortality and morbidity rates annually, due to the early vague symptoms among the population and hence the delayed presentation at advanced stages of cancer. In India the screening programs for gastric cancer has been a setback due to various logistics reasons and the data available from reporting is also not content. Our study is a review article featuring the management of gastric cancer in the Indian population. The lifestyle of India population is varied right from its southern region to its northern counterparts, which is due to its diversified culture within the country. Studies have concluded that the northern population tends to have a higher incidence comparatively and the various risk factors associated with the disease has been discussed. Management of the gastric cancer in India remains the same compared to the outside world, though the availability of endoscopic ultrasound and other technical advancements remain sparse in the field of diagnostics and staging of the disease. D2 gastrectomy remains the mainstay of surgery among the Indian population though significant number of patients are deemed inoperable on table. Neo adjuvant Chemotherapy, Radiotherapy and Targeted therapy is yet to be efficiently used across the country according to our study as there is lack of data in our registries. The incidence is decreasing in developing nations and more proximal cancers are reported. However, in India the major population-based cancer registries report an incidence decline only in Mumbai and Chennai. A shift from distal to proximal as the site of disease has not been reported from India. The contribution of the Indian scientific fraternity to the world medical literature for gastric cancer is sparse and it is clear that a lot more is to be done; the possible reason may be a busy clinical schedule or lack of initiatives. There is an urgent need for research in various aspects of gastric cancer from India including epidemiological and therapeutic areas.

Waterpipe Tobacco Smoking and Gastric Cancer Risk among Vietnamese Men

BACKGROUND

The association of waterpipe tobacco (WPT) smoking with gastric cancer (GC) risk was suggested.

METHODS

A hospital-based case-control study was conducted to examine the association of WPT with GC risk among Vietnamese men, in Hanoi city, during the period of 2003-2011. Newly-diagnosed GC cases (n = 454) and control patients (n = 628) were matched by age (+/- 5 years) and the year of hospitalization. Information on smoking and alcohol drinking habits and diet including salty food intake and fruits/vegetables consumption were obtained by the interview. Maximum likelihood estimates of odds ratios (ORs) and corresponding 95% confidence intervals (Cis) were obtained using conditional logistic regression models.

RESULTS

The group with the highest consumption of citrus fruits showed a significantly low GC risk (OR = 0.6, 95%CI = 0.4-0.8, P for trend = 0.002). However, there was no association of raw vegetable consumption with GC risk. Referring to never smokers, GC risk was significantly higher in current WPT smokers (OR = 1.8, 95%CI = 1.3-2.4), and it was more evident in exclusively WPT smokers (OR = 2.7, 95%CI = 1.2-6.5). GC risk tended to be higher with daily frequency and longer duration of WPT smoking but these trends were not statistically significant (P for trend: 0.144 and 0.154, respectively). GC risk of those who started smoking WPT before the age of 25 was also significantly high (OR = 3.7, 95%CI = 1.2-11.3). Neither cigarette smoking nor alcohol drinking was related to GC risk.

CONCLUSION

The present findings revealed that WPT smoking was positively associated with GC risk in Vietnamese men.

Etiology and Prevention of Gastric Cancer

BACKGROUND

Gastric cancer is a heterogeneous malignant disease associated with environmental and genetic predisposing factors. While gastric cancer incidence and mortality fell greatly globally over the past decades, it remains the fourth cause of cancer-related death worldwide. Thus, prevention of gastric cancer is still a major strategy for improvement of gastric cancer prognosis.

SUMMARY

Helicobacter pylori infection has been demonstrated to be a major risk factor for the development of gastric cancer. Unhealthy diet and lifestyle, including high-salt food, smoking and drinking, are able to induce genotypic and phenotypic transformation of gastric epithelial cells. Gene mutations (such as E-cadherin) in stomach epithelial cells are major genetic causes for gastric cancer. The eradication of H. pylori has been demonstrated to be an effective approach for primary prevention of gastric cancer. Increased intake of a diet rich in vegetables and fresh fruits as well as smoking cessation have been shown to reduce the incidence of gastric cancer. The secondary prevention strategy is to screen premalignant gastric lesions by endoscopy. Biomarker tests are also reliable methods to identify gastric precancerous lesions. Endoscopy screening is still the gold standard for diagnosis of gastric cancer.

KEY MESSAGE

H. pylori infection, a diet rich in salted and/or smoked food and red meat, as well as gene mutations are major risk factors for the development of gastric cancer.

PRACTICAL IMPLICATIONS

The eradication of H. pylori is a major primary preventive strategy of gastric cancer. A healthy lifestyle, including increased intake of a diet rich in fruit and vegetables, reduced intake of salted and smoked food and red meat, a reduction of alcohol intake as well as smoking cessation will be effective approaches for the prevention of gastric cancer.

The Effects of Dinner-to-Bed Time and Post-Dinner Walk on Gastric Cancer Across Different Age Groups: A Multicenter Case-Control Study in Southeast China

Gastric cancer (GC) remains a major killer throughout the world. Despite the dramatic decrease in GC over the last century, its etiology has not yet been well characterized. This study investigated the possible independent and combined effects of the dinner-to-bed time and post-dinner walk on the risk for GC across different age groups. A population-based, case-control study was conducted in southeast China, including 452 patients with GC and 465 age-, race-, and gender-matched controls. A self-designed questionnaire was used to collect information on demographic characteristics, dinner-to-bed time, post-dinner walk, and other behavioral factors. Conditional logistic regression models were used to estimate the effects of the dinner-to-bed time and post-dinner walk as well as their joint effect on the risk for GC across different age groups. Individuals with dinner-to-bed time <3 hours were more prone to have GC (P < 0.001), and the shorter the dinner-to-bed time was, the higher was the risk for GC (Ptrend < 0.001). Post-dinner nonwalk was associated with a 2.9-fold increased risk for GC compared with post-dinner walk (adjusted odds ratio [AOR] = 2.942, 95% confidence intervals [95% CIs] = 2.072-4.179). The interaction effect of dinner-to-bed time and post-dinner walk on GC risk was detected (AOR = 1.862, 95% CIs = 1.584-3.885, synergy index [SI] = 2.654, 95% CIs = 2.27-3.912). Participants with dinner-to-bed time <3 hours who did not walk after dinner were 7.4 times likely to suffer from GC (AOR = 7.401, 95% CIs = 4.523-13.16) than those with dinner-to-bed time ≥4 hours who took such walk. The risk of GC due to dinner-to-bed time <3 hours, post-dinner nonwalk and their interaction was positively correlated with age. The strongest risk was observed among people ≥70 years old, but the effects were not significant for people ≤55 years old. Dinner-to-bed time <3 hours and post-dinner nonwalk are independent risk factors for GC; the synergistic interaction between the 2 factors was positively related to age, which might significantly increase the risk for GC among people >55 years old.

Weaknesses and Pitfalls of Using Mice and Rats in Cancer Chemoprevention Studies

Many studies, using different chemical agents, have shown excellent cancer prevention efficacy in mice and rats. However, equivalent tests of cancer prevention in humans require decades of intake of the agents while the rodents' short lifespans cannot give us information of the long-term safety. Therefore, animals with a much longer lifespan should be used to bridge the lifespan gap between the rodents and humans. There are many transgenic mouse models of carcinogenesis available, in which DNA promoters are used to activate transgenes. One promoter may activate the transgene in multiple cell types while different promoters are activated at different ages of the mice. These spatial and temporal aspects of transgenes are often neglected and may be pitfalls or weaknesses in chemoprevention studies. The variation in the copy number of the transgene may widen data variation and requires use of more animals. Models of chemically-induced carcinogenesis do not have these transgene-related defects, but chemical carcinogens usually damage metabolic organs or tissues, thus affecting the metabolism of the chemopreventive agents. Moreover, many genetically edited and some chemically-induced carcinogenesis models produce tumors that exhibit cancerous histology but are not cancers because the tumor cells are still mortal, inducer-dependent, and unable to metastasize, and thus should be used with caution in chemoprevention studies. Lastly, since mice prefer an ambient temperature of 30-32°C, it should be debated whether future mouse studies should be performed at this temperature, but not at 21-23°C that cold-stresses the animals.

Age, period, and cohort effects on gastric cancer mortality

BACKGROUND

The incidence of gastric cancer varies both within and among populations and can change rapidly without a corresponding decline in Helicobacter pylori prevalence. Here, we describe the changes in gastric cancer mortality in Japan in relation to age-period-cohort effects as well as the decline in H. pylori prevalence.

METHODS

We used data from Japanese for men and women aged 30-94 for birth years 1875-1970 (calendar time 1950-2000) to observe the age, period and cohort effects on gastric cancer mortality rates. Additionally, we used Poisson regression to simultaneously adjust for concurrent age, period and cohort effects as well as for declining H. pylori prevalence in the Japanese population.

RESULTS

There was an approximate 60 % decline in gastric cancer mortality between 1965 and 1995. Detailed age, period and cohort analyses and Poisson regression analysis showed these factors interact in complex ways, analyses focused on one or two of these effects, such as birth cohort without considering concurrent age and period would obscure important interactions that affected different age groups at different times to produce this composite effect.

CONCLUSION

The underlying complexity in population-disease dynamics requires population-specific descriptions of trends using multiple methods to provide an in-depth analysis while simultaneously allowing for necessary statistical adjustments as well as identification of interactions. More thorough descriptions of the population-specific general trends in relation to changes in the population structure (age-period-cohort) enable better prevention and health care policy planning, and further, the descriptions enable hypothesis generation regarding causes of population-specific disease patterns.

Proteinase activated-receptors-associated signaling in the control of gastric cancer

Gastric cancer (GC) is the fourth most common cancer in the world and the second cause of cancer-related death. Gastric carcinogenesis is a multifactorial process, in which environmental and genetic factors interact to activate multiple intracellular signals thus leading to uncontrolled growth and survival of GC cells. One such a pathway is regulated by proteinase activated-receptors (PARs), seven transmembrane-spanning domain G protein-coupled receptors, which comprise four receptors (i.e., PAR-1, PAR-2, PAR-3, and PAR-4) activated by various proteases. Both PAR-1 and PAR-2 are over-expressed on GC cells and their activation triggers and/or amplifies intracellular pathways, which sustain gastric carcinogenesis. There is also evidence that expression of either PAR-1 or PAR-2 correlates with depth of wall invasion and metastatic dissemination and inversely with the overall survival of patients. Consistently, data emerging from experimental models of GC suggest that both these receptors can be important targets for therapeutic interventions in GC patients. In contrast, PAR-4 levels are down-regulated in GC and correlate inversely with the aggressiveness of GC, thus suggesting a negative role of this receptor in the control of GC. In this article we review the available data on the expression and role of PARs in GC and discuss whether manipulation of PAR-driven signals may be useful for interfering with GC cell behavior.

Review article: the epidemiology and prevention of gastric cancer

BACKGROUND

Gastric cancer can be divided into cardia and noncardia gastric adenocarcinoma (NCGA). Non cardia gastric cancer is a disease that has declined in global incidence but has remained as an extremely lethal cancer.

AIM

To review recent advances in epidemiology and strategies in prevention of non cardia gastric cancer.

METHODS

A rapid literature search strategy was developed for all English language literature published before March 2013. The search was conducted using the electronic databases PubMed and EMBASE. The search strategy included the keywords 'stomach neoplasms', 'gastric cancer', 'epidemiology', 'risk factor', 'early detection of cancer', 'mass screening', 'cancer burden', 'prevention' and 'cost-effectiveness'. The search strategy was adjusted according to different requirements for each database. The specific search was also performed in cancer-related websites for country-specific information. The search was limited to past 10 years.

RESULTS

Gastric cancer is the fifth most common cancer but the third leading cause of cancer death. The case fatality rate is 75%. Screening by radiological or endoscopic methods has limited success in prevention of gastric cancer. Helicobacter pylori has been identified as a carcinogen, accounting for 60-70% of gastric cancer globally and eradication is a potential preventive measure. A meta-analysis in 2009 demonstrated that individuals treated with H. pylori eradication therapy can reduce gastric cancer risk. The extended Shandong Intervention trial that lasted 14.3 years showed that H. pylori eradication therapy significantly reduced gastric cancer incidence by 39%. Consensus groups from Asia, Europe and Japan have recommended H. pylori eradication as primary prevention in high-risk areas. Following eradication therapy, endoscopic surveillance of pre-malignant lesions using enhanced imaging appears to be another promising preventive strategy.

CONCLUSIONS

Gastric cancer remains a major diagnostic and therapeutic challenge. There is emerging evidence that H. pylori eradication in high gastric cancer regions can lead to a decline in the incidence of this highly lethal disease.

History of Helicobacter pylori, duodenal ulcer, gastric ulcer and gastric cancer

Helicobacter pylori (H. pylori) infection underlies gastric ulcer disease, gastric cancer and duodenal ulcer disease. The disease expression reflects the pattern and extent of gastritis/gastric atrophy (i.e., duodenal ulcer with non-atrophic and gastric ulcer and gastric cancer with atrophic gastritis). Gastric and duodenal ulcers and gastric cancer have been known for thousands of years. Ulcers are generally non-fatal and until the 20^th century were difficult to diagnose. However, the presence and pattern of gastritis in past civilizations can be deduced based on the diseases present. It has been suggested that gastric ulcer and duodenal ulcer both arose or became more frequent in Europe in the 19^th century. Here, we show that gastric cancer and gastric ulcer were present throughout the 17^th to 19^th centuries consistent with atrophic gastritis being the predominant pattern, as it proved to be when it could be examined directly in the late 19^th century. The environment before the 20^th century favored acquisition of H. pylori infection and atrophic gastritis (e.g., poor sanitation and standards of living, seasonal diets poor in fresh fruits and vegetables, especially in winter, vitamin deficiencies, and frequent febrile infections in childhood). The latter part of the 19^th century saw improvements in standards of living, sanitation, and diets with a corresponding decrease in rate of development of atrophic gastritis allowing duodenal ulcers to become more prominent. In the early 20^th century physician’s believed they could diagnose ulcers clinically and that the diagnosis required hospitalization for “surgical disease” or for “Sippy” diets. We show that while H. pylori remained common and virulent in Europe and the United States, environmental changes resulted in changes of the pattern of gastritis producing a change in the manifestations of H. pylori infections and subsequently to a rapid decline in transmission and a rapid decline in all H. pylori-related diseases.

Helicobacter pylori and the molecular pathogenesis of intestinal-type gastric carcinoma

Gastric carcinoma is an inflammation-related cancer caused by long-term infection with the human bacterial pathogen, Helicobacter pylori. The pattern of acute-on-chronic inflammation causes progressive mucosal damage which may result in atrophy with metaplastic epithelia and eventually gastric cancer. Recently, it has been recognized that H. pylori can also cause genetic instability such as double-stranded DNA breaks and can produce gene activation and silencing via epigenetic pathways. As genetic instability is the hallmark of cancer, we highlight recent progress in understanding the gastric carcinogenesis in relation to H. pylori-related inflammation, H. pylori-induced double-stranded DNA breakage and aberrant gene expression as well as the mechanisms and role of H. pylori-associated epigenetic change in gene expression.

Study of risk factors for gastric cancer by populational databases analysis

AIM: To study the association between the incidence of gastric cancer and populational exposure to risk/protective factors through an analysis of international databases.

METHODS: Open-access global databases concerning the incidence of gastric cancer and its risk/protective factors were identified through an extensive search on the Web. As its distribution was neither normal nor symmetric, the cancer incidence of each country was categorized according to ranges of percentile distribution. The association of each risk/protective factor with exposure was measured between the extreme ranges of the incidence of gastric cancer (under the 25^th percentile and above the 75^th percentile) by the use of the Mann-Whitney test, considering a significance level of 0.05.

RESULTS: A variable amount of data omission was observed among all of the factors under study. A weak or nonexistent correlation between the incidence of gastric cancer and the study variables was shown by a visual analysis of scatterplot dispersion. In contrast, an analysis of categorized incidence revealed that the countries with the highest human development index (HDI) values had the highest rates of obesity in males and the highest consumption of alcohol, tobacco, fruits, vegetables and meat, which were associated with higher incidences of gastric cancer. There was no significant difference for the risk factors of obesity in females and fish consumption.

CONCLUSION: Higher HDI values, coupled with a higher prevalence of male obesity and a higher per capita consumption of alcohol, tobacco, fruits, vegetables and meat, are associated with a higher incidence of gastric cancer based on an analysis of populational global data.

Comparative assessment of essential and heavy metals in fruits from different geographical origins

The aim of this investigation was to estimate and compare essential and heavy metals contents in 98 commercially available fresh fruits from different geographic regions using multivariate techniques. The concentrations of 12 elements (calcium, magnesium, potassium, sodium, phophorus, cobalt (Co), manganese, iron, chromium (Cr), nickel (Ni), zinc and copper) were determined using flame atomic absorption spectrometry with deuterium-background correction. Phosphorus was determined in the form of phosphomolybdate by a spectrophotometric method. Reliability of the procedure was checked by analysis of the certified reference materials tea (NCS DC 73351), cabbage (IAEA-359) and spinach leaves (NIST-1570). Recoveries of the elements analysed varied between 85.5 and 103%, and precisions for the reference materials were 0.13-6.08%. Based on recommended dietary allowance and adequate intake estimated for essential elements, it was concluded that accessory fruits such as pineapples, raspberries and strawberries supply organism with the highest amounts of bioelements. Although accessory fruits were also found to be the greatest source of Ni among all the analysed fruits, in all the fruits Ni was more abundant than Cr and Co. Significant correlation coefficients (p < 0.001, p < 0.01 and p < 0.05) were found between concentrations of some metals in fresh fruits. Application of ANOVA Kruskal-Wallis test and multivariate techniques such as factor analysis and cluster analysis enabled us to differentiate particular botanical families and types of fruits.

Ecologic correlations of selected food groups with disease incidence and mortality in Switzerland

BACKGROUND

There is little information regarding the impact of diet on disease incidence and mortality in Switzerland. We assessed ecologic correlations between food availability and disease.

METHODS

In this ecologic study for the period 1970-2009, food availability was measured using the food balance sheets of the Food and Agriculture Organization of the United Nations. Standardized mortality rates (SMRs) were obtained from the Swiss Federal Office of Statistics. Cancer incidence data were obtained from the World Health Organization Health For All database and the Vaud Cancer Registry. Associations between food availability and mortality/incidence were assessed at lags 0, 5, 10, and 15 years by multivariate regression adjusted for total caloric intake.

RESULTS

Alcoholic beverages and fruit availability were positively associated, and fish availability was inversely associated, with SMRs for cardiovascular diseases. Animal products, meat, and animal fats were positively associated with the SMR for ischemic heart disease only. For cancer, the results of analysis using SMRs and incidence rates were contradictory. Alcoholic beverages and fruits were positively associated with SMRs for all cancer but inversely associated with all-cancer incidence rates. Similar findings were obtained for all other foods except vegetables, which were weakly inversely associated with SMRs and incidence rates. Use of a 15-year lag reversed the associations with animal and vegetal products, weakened the association with alcohol and fruits, and strengthened the association with fish.

CONCLUSIONS

Ecologic associations between food availability and disease vary considerably on the basis of whether mortality or incidence rates are used in the analysis. Great care is thus necessary when interpreting our results.

Gastric cancer epidemiology and risk factors

Gastric cancer is a prevalent yet heterogeneous disease. From diet and lifestyle to genetics and ethnicity, our appreciation of the complexity of gastric cancer has evolved. This review will discuss the epidemiology of gastric cancer focusing on trends across various risk categories. We realize that gastric cancer is not merely a single disease, but rather individual diseases within a single organ-a distinction that will aid our understanding of disease heterogeneity and its significance.

Carcinoma of the stomach: A review of epidemiology, pathogenesis, molecular genetics and chemoprevention

Carcinoma of the stomach is still the second most common cause of cancer death worldwide, although the incidence and mortality have fallen dramatically over the last 50 years in many regions. The incidence of gastric cancer varies in different parts of the world and among various ethnic groups. Despite advances in diagnosis and treatment, the 5-year survival rate of stomach cancer is only 20 per cent. Stomach cancer can be classified into intestinal and diffuse types based on epidemiological and clinicopathological features. The etiology of gastric cancer is multifactorial and includes both dietary and nondietary factors. The major diet-related risk factors implicated in stomach cancer development include high content of nitrates and high salt intake. Accumulating evidence has implicated the role of Helicobacter pylori (H. pylori) infection in the pathogenesis of gastric cancer. The development of gastric cancer is a complex, multistep process involving multiple genetic and epigenetic alterations of oncogenes, tumor suppressor genes, DNA repair genes, cell cycle regulators, and signaling molecules. A plausible program for gastric cancer prevention involves intake of a balanced diet containing fruits and vegetables, improved sanitation and hygiene, screening and treatment of H. pylori infection, and follow-up of precancerous lesions. The fact that diet plays an important role in the etiology of gastric cancer offers scope for nutritional chemoprevention. Animal models have been extensively used to analyze the stepwise evolution of gastric carcinogenesis and to test dietary chemopreventive agents. Development of multitargeted preventive and therapeutic strategies for gastric cancer is a major challenge for the future.

Gastric cancer epidemiology in Korea

Gastric cancer has been the most commonly diagnosed cancer in Korea although the age-standardized mortality and incidence has decreased gradually during last two decades. Helicobacter pylori infection and cigarette smoking are well-established risk factors, and the role of dietary factors, such as salted foods, fresh vegetables and fruits, soy foods, and processed or grilled meats on gastric carcinogenesis has been suggested. In this review, we review national and international gastric cancer statistics, studies on environmental risk factors conducted in the Korean population, and gastric cancer screening activities.