Risk of gastric cancer by water source: evidence from the Golestan case-control study

Proportion of cancer cases and deaths attributable to potentially modifiable risk factors in Peru

BACKGROUND

Limited evidence exists on the population attributable fraction (PAF) of cancer cases and deaths in Latin America. In Peru several studies have been published regarding the PAF of various risk factors and their associated diseases. The objective of this study was to estimate the fraction of cancer cases and deaths attributable to potentially modifiable risk factors in Peru in 2018, before the COVID-19 pandemic in the population of 15 years old and older.

METHODS

An ecological study was conducted using the prevalence of exposure of the Peruvian population to modifiable risk factors for cancer, the relative risk associated with each factor, and the number of cancer cases and deaths in 2018 as inputs. We used the Parkin formula with a Montecarlo statistical simulation model to calculate the PAF and confidence intervals. The number of new cancer cases and deaths attributed to each risk factor was determined by multiplying the number of cases and deaths in each gender by the PAF of each risk factor.

FINDINGS

In Peru, 38.5% of new cases (34.5% in men and 42% in women) and 43.4% of cancer-related deaths (43.4% in men and 43.4% in women) were attributable to modifiable risk factors. The number of cancers attributable was 25,308 (10,439 in men and 14,869 in women) and the number of deaths attributable to cancer was 14,839 (6,953 in men and 7,886 in women). The predominant modifiable risk factors contributing to the highest number of cases and deaths were HPV infection (4,563 cases, 2,409 deaths), current tobacco use (3,348 cases, 2,180 deaths), and helicobacter pylori infection (2,677 cases, 1,873 deaths). Among the risk factors, oncogenic infections constituted the group with the highest PAF (16.6% for cases, 19.2% for deaths) followed by other unhealthy lifestyle factors (14.2% for cases, 16.7% for deaths), tobacco (7.2% for cases, 7.2% for deaths) and ultraviolet radiation (0.5% for cases, 0.3% for deaths).

CONCLUSIONS

Prior to the COVID-19 pandemic, 38.5% of cancer cases and 43.4% of cancer-related deaths in Peru were linked to modifiable risk factors in the population of 15 years old and older. Most preventable cancer cases and deaths were related to oncogenic infections, primarily caused by HPV and helicobacter pylori, followed by tobacco and obesity.

Joint Effects Between CDKN2B/P15 Methylation and Environmental Factors on the Susceptibility to Gastric Cancer

BACKGROUND

The incidence of gastric cancer has long been at a high level in China, seriously affecting the health of Chinese people.

AIMS

This case‒control study was performed to identify gene methylation biomarkers of gastric cancer susceptibility.

METHODS

A total of 393 gastric cancer cases and 397 controls were included in this study. Gene methylation in peripheral blood leukocytes was detected by a methylation-sensitive high-resolution melting method, and the Helicobacter pylori antibody presence was semi-quantified in serum by ELISA.

RESULTS

Individuals with total methylation of CDKN2B/P15 had a 1.883-fold (95%CI: 1.166-3.040, P = 0.010) risk of gastric cancer compared with unmethylated individuals. Individuals with both CDKN2B/P15 and NEUROG1 methylation had a higher risk of gastric cancer (OR = 2.147, 95% CI: 1.137-4.073, P = 0.019). The interaction between CDKN2B/P15 and NEUROG1 total methylation on gastric cancer risk was affected by the pattern of adjustment. In addition, the joint effects between CDKN2B/P15 total methylation and environmental factors, such as freshwater fish intake (OR = 6.403, 95% CI = 2.970-13.802, P < 0.001), irregular diet (OR = 5.186, 95% CI = 2.559-10.510, P < 0.001), unsanitary water intake (OR = 2.238, 95% CI = 1.144-4.378, P = 0.019), smoking (OR = 2.421, 95% CI = 1.456-4.026, P = 0.001), alcohol consumption(OR = 2.163, 95% CI = 1.309-3.576, P = 0.003), and garlic intake(OR = 0.373, 95% CI = 0.196-0.709, P = 0.003) on GC risk were observed, respectively. However, CDKN2B/P15 and NEUROG1 total methylation were not associated with gastric cancer prognosis.

CONCLUSION

CDKN2B/P15 methylation in peripheral blood may be a potential biomarker for evaluating susceptibility to gastric cancer. The joint effects between CDKN2B/P15 methylation and environmental factors may also contribute to gastric cancer susceptibility.

Spatial Cluster Analysis of Stomach Neoplasms in the Center of Iran Based on a Population-Based Study, 2009-2014: Application of the Poisson-Based Probability Model

Background

A better understanding of the spatial pattern of stomach cancer can be helpful in the implementation of preventive strategies. This study is one of the first studies to establish a study unit based on the smallest possible size for cluster analysis. This study includes a novel evaluation of spatial differences in different geographical areas of Arak. The present study seeks to discover the spatial clusters of stomach cancer from 2009 to 2014 in Arak.

Methods

All of the addresses of the stomach cancer cases were geocoded. After that, the number of stomach cancer cases in each census block was calculated to be entered in the SaTScan software. A discrete Poisson-based probability model was used to analyze this cluster.

Results

In Arak, there are 5502 census blocks with a population of about 526,182. The number of identified and registered stomach cancer cases with an acceptable residence address was 392. Totally, 11 stomach cancer clusters were established in the area of Arak, from these; two clusters were detected statistically significant. Relative risks of the first and second clusters were 1.75 (P = 0.01) and 17.60 (P = 0.04) and those are located within the radius of 1.73 and 0.085 km, respectively.

Conclusions

Our results have confirmed that two areas are at a higher risk than others. However, based on the results of this study, community-based interventions in certain geographical areas can be designed to reduce and control the incidence of stomach cancer.

Bile reflux is an independent risk factor for precancerous gastric lesions and gastric cancer: An observational cross-sectional study

OBJECTIVE

To identify whether bile reflux on endoscopy and other related variables are risk factors for precancerous gastric lesions and gastric cancer (GC).

METHODS

A multicenter, cross-sectional and observational study was conducted in five centers in China from June to October 2019, 1162 patients were recruited and divided into the chronic gastritis (CG), the precancerous lesion (low-grade intraepithelial neoplasia and intestinal metaplasia), and GC groups (including high-grade intraepithelial neoplasia). All participants underwent detailed interviews, endoscopy and biopsy, and completed questionnaires. Odds ratio and 95% confidence interval were calculated with multivariate logistic regression models with or without adjustment for Helicobacter pylori infection.

RESULTS

We recruited 668 patients with CG, 411 with precancerous lesions and 83 with GC. By comparing the CG and precancerous lesion groups, independent risk factors for cancerous gastric lesions were the grade of bile reflux, patient's age, dietary habits and family history of GC. Similar results were obtained when comparing the CG and GC groups. In addition, bile reflux was confirmed as an independent risk factor for progression from precancerous lesions to cancer.

CONCLUSIONS

Bile reflux on endoscopy as well as age, dietary habits and a family history of GC were independent risk factors for the development of precancerous gastric lesions and GC.

Downregulation of lncRNA HCP5 has inhibitory effects on gastric cancer cells by regulating DDX21 expression

LncRNA HCP5 has been confirmed to play crucial roles in many types of cancers. However, the role of lncRNA HCP5 in regulating the occurrence and development of gastric cancer (GC) remains unknown. In the current study, we aimed to investigate the precise effects of lncRNA HCP5 on cell proliferation, migration and invasion and molecular mechanisms in gastric cancer. Using RT-qPCR analysis, we found that lncRNA HCP5 was differentially expressed in GC cell lines. CCK-8, wound healing and transwell assay indicated that the proliferation, migration and invasion of gastric cancer cells were inhibited by downregulation of lncRNA HCP5 and lncRNA HCP5 overexpression exhibited the opposite effects in gastric cancer cells. Mechanistically, RNA binding protein immunoprecipitation and dual luciferase reporter assay confirmed the interaction between lncRNA HCP5 and DDX21. The effects of lncRNA HCP5 overexpression the proliferation, migration and invasion of GC cells were partly rescued by DDX21 silencing. Taken together, downregulation of lncRNA HCP5 exerted inhibitory effects on GC cell proliferation, migration and invasion through modulation of DDX21 expression, demonstrating the function of lncRNA HCP5 and DDX21 in GC progression.

Trend of Gastric Cancer Incidence in an Area Located in the Center of Iran: 2009-2014

PURPOSE

There are remarkable differences between the incidence and mortality of gastric cancer in different places of the world. This study, for the first time, estimated the information around the incidence rates and trends of gastric cancer in the central area of Iran, Arak metropolitan.

METHODS

In this study, all cases with gastric cancer in Arak from 2009 to 2014 were included. Direct standardized method was applied to estimate age-standardized incidence rates (ASIRs) by a STATA package, with efficient interval estimation that might be preferable in the case of rare diseases, including cancer data. The obtained standard errors were used to calculate annual percent changes (APCs) by the Joinpoint analysis.

RESULTS

Annual ASIRs of gastric cancer were 23.92 (95% CI 21.62, 26.37) and 9.60 (95% CI 8.20, 11.18) for male and female, respectively. In male, APC of ASIRs was - 5.00% (95% CI - 9.32, - 0.47). In contrast, among female, it was - 2.69% (95% CI - 31.56, 38.34) that was statistically insignificant.

CONCLUSIONS

The ASIRs have significantly decreased trends in males, but not in females. The preventive strategies should be a focus on the declining of the risk factors and the quick early diagnosis of gastric cancer.

Assessment of hydrogeochemical characteristics and quality of groundwater resources in relation to risk of gastric cancer: comparative analysis of high- and low-risk areas in Iran

The chemical quality of groundwater supplies in two high-risk area (HRA) and low-risk area (LRA) for gastric cancer in Iran was assessed through hydrogeochemical analysis and water quality indices. For this aim, Piper and Schoeller diagrams and water quality index (WQI) were applied. In addition, exposure to nitrate via drinking water and its corresponding risk were also assessed using Monte Carlo simulation technique. Data on physicochemical properties of groundwater resources were obtained from Iran Water Resources Management Company. Sampling and analysis of tap water for nitrate concentration were conducted in two cities of Shiraz (as a representative of LRA) and Ardabil (as a representative of HRA). According to Piper diagrams, the dominant hydrogeochemical facies of groundwater supplies in HRA and LRA were Na-HCO₃ (43.75%) and Ca-HCO₃ (41.77%), respectively. The predominant cations in groundwater resources of HRA were found to be Na⁺ (68.06%) and Ca²⁺ (31.94%). For LRA, the typical cations were in decreasing trend: Ca²⁺ (39.64%) > Mg²⁺ (18.35%) > Na⁺ (17.26%). For two areas, HCO₃^-, SO₄^2- and Cl^- were, respectively, the most frequent anions. Two-sample Wilcoxon test showed that there were statistically significant difference between two areas in terms of anions and cations concentrations (p value < 0.05). The mean of total hardness (Ca²⁺ + Mg²⁺) concentration of water supplies in LRA (528.1 mg/L) was higher than HRA (263.1 mg/L), whereas the mean of Na⁺ concentration was found to be lower in LRA (90.6 mg/L) compared with HRA (108.1 mg/L). The sum of nitrate intake and its risk in LRA was higher than HRA. WQI results showed that drinking water quality in HRA and LRA ranged from excellent to poor and most water resources were of a good quality class. Further studies are suggested to investigate the role of drinking water in the etiology of gastric cancer in Iran.

Prevalence of and factors associated with Helicobacter pylori infection in preschoolers in Havana, Cuba: A population-based study

INTRODUCTION

Helicobacter pylori (H. pylori) infection is usually acquired in childhood. In Cuba, its study in pediatric ages is a little explored field.

AIM

To identify the prevalence of the infection and its associated risk factors in 3-year-old children in Havana.

MATERIALS AND METHODS

An analytic, cross-sectional, epidemiologic analysis was conducted on 1,274 children belonging to the cohort of participants in the Natural History of Wheezing in Cuba study (HINASIC for its Spanish acronym) that were 3 years of age and provided a stool sample. H. pylori infection was identified by determining the H. pylori antigen (Ag) in stool, utilizing the commercial Spinreact kit, from Spain. The data were collected through a questionnaire applied by the researchers that included sociodemographic, environmental, and lifestyle variables, as well as infection from other parasites. Prevalence and the prevalence ratio with a 95% confidence interval were calculated and the dichotomous logistic regression analysis was employed.

RESULTS

The prevalence of positive H. pylori Ag was 5%. Sleeping together was the risk factor found (PR:1.27; 95% CI: 1.03-1.50). Protective factors were drinking water from water delivery trucks (PR: 0.16; 95% CI: 0.04-0.72) and living in a nuclear family unit (PR: 0.94; 95% CI: 0.85-0.99).

CONCLUSIONS

The prevalence of H. pylori infection in early childhood places Havana in an intermediate position at the international level. To control the infection, causal studies should be conducted and opportune interventions implemented.

Water hardness zoning of Isfahan Province, Iran, and its relationship with cardiovascular mortality, 2013-2015

BACKGROUND

Cardiovascular disease (CVD) is one of the common diseases and today, it is considered as not only an important cause of mortality but also a significant aspect of health geography. The evidence presented in the literature indicates that hard water may reduce the cases of sudden death caused by CVDs because drinking water contains significant amounts of calcium and magnesium, which play a crucial role in the electrical activity of heart. Hence, the present study aimed at investigating the relationship between water hardness and CVD mortality rate in Isfahan, Iran.

METHODS

In this ecological study, the available data regarding the cardiovascular mortality rate and water hardness have been used. Preparation of zoning map has been conducted using the Geographic Information System (GIS) software considering Inverse Distance Weighting (IDW) interpolation models. Moreover, statistical analysis has been conducted using SPSS software.

RESULTS

A reverse relationship was observed between cardiovascular mortality rate and water hardness. However, the observed relationship was not statistically significant (2013: r = -0.066, 2014: r = -0.155, 2015: r = -0.051, P > 0.050).

CONCLUSION

The results of mapping with GIS and statistical analysis with SPSS both indicated a non-significant inverse relationship between the water hardness and CVDs. However, lack of a significant relationship highlights the necessity of conducting similar studies involving larger sample sizes and wider areas of investigation to present a definitive and generalizable result.

Lack of in-home piped water and reported consumption of sugar-sweetened beverages among adults in rural Alaska

OBJECTIVE

To assess whether a community water service is associated with the frequency of sugar-sweetened beverages (SSB) consumption, obesity, or perceived health status in rural Alaska.

DESIGN

We examined the cross-sectional associations between community water access and frequency of SSB consumption, body mass index categories, and perceived health status using data from the 2013 and 2015 Alaska Behavioral Risk Factor Surveillance System (BRFSS). Participants were categorized by zip code to 'in-home piped water service' or 'no in-home piped water service' based on water utility data. We evaluated the univariable and multivariable (adjusting for age, household income and education) associations between water service and outcomes using log-linear survey-weighted generalized linear models.

SETTING

Rural Alaska, USA.

SUBJECTS

Eight hundred and eighty-seven adults, aged 25 years and older.

RESULTS

In unadjusted models, participants without in-home water reported consuming SSB more often than participants with in-home water (1·46, 95 % CI: 1·06, 2·00). After adjustment for potential confounders, the effect decreased but remained borderline significant (1·29, 95 % CI: 1·00, 1·67). Obesity was not significantly associated with water service but self-reported poor health was higher in those communities without in-home water (1·63, 95 % CI: 1·05, 2·54).

CONCLUSIONS

Not having access to in-home piped water could affect behaviours surrounding SSB consumption and general perception of health in rural Alaska.

Individual and Combined Effects of Environmental Risk Factors for Esophageal Cancer Based on Results From the Golestan Cohort Study

BACKGROUND & AIMS

Northeast Iran has one of the highest reported rates of esophageal squamous cell carcinoma (ESCC) worldwide. Decades of investigations in this region have identified some local habits and environmental exposures that increase risk. We analyzed data from the Golestan Cohort Study to determine the individual and combined effects of the major environmental risk factors of ESCC.

METHODS

We performed a population-based cohort of 50,045 individuals, 40 to 75 years old, from urban and rural areas across Northeast Iran. Detailed data on demographics, diet, lifestyle, socioeconomic status, temperature of drinking beverages, and different exposures were collected using validated methods, questionnaires, and physical examinations, from 2004 through 2008. Participants were followed from the date of enrollment to the date of first diagnosis of esophageal cancer, date of death from other causes, or date of last follow-up, through December 31, 2017. Proportional hazards regression models were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for the association between different exposures and ESCC.

RESULTS

During an average 10 years of follow-up, 317 participants developed ESCC. Opium smoking (HR 1.85; 95% CI 1.18-2.90), drinking hot tea (≥60°C) (HR 1.60; 95% CI 1.15-2.22), low intake of fruits (HR 1.48; 95% CI 1.07-2.05) and vegetables (HR 1.62; 95% CI 1.03-2.56), excessive tooth loss (HR 1.66; 95% CI 1.04-2.64), drinking unpiped water (HR 2.04; 95% CI 1.09-3.81), and exposure to indoor air pollution (HR 1.57; 95% CI 1.08-2.29) were significantly associated with increased risk of ESCC, in a dose-dependent manner. Combined exposure to these risk factors was associated with a stepwise increase in the risk of developing ESCC, reaching a more than 7-fold increase in risk in the highest category. Approximately 75% of the ESCC cases in this region can be attributed to a combination of the identified exposures.

CONCLUSIONS

Analysis of data from the Golestan Cohort Study in Iran identified multiple risk factors for ESCC in this population. Our findings support the hypothesis that the high rates of ESCC are due to a combination of factors, including thermal injury (from hot tea), exposure to polycyclic aromatic hydrocarbons (from opium and indoor air pollution), and nutrient-deficient diets. We also associated ESCC risk with exposure to unpiped water and tooth loss.

Environmental etiology of gastric cancer in Iran: a systematic review focusing on drinking water, soil, food, radiation, and geographical conditions

The aim of this systematic review study was to investigate the causal relationship between environmental factors and gastric cancer (GC) in Iran. In a narrow definition, the environment includes water, soil, air, and food. This definition was the main criterion for the inclusion of articles in this study. In addition, exposure to radiation and geographical conditions were considered as less investigated environmental factors in the literatures. International (PubMed, Web of Science, ScienceDirect, Scopus, and Cochran) and national (Scientific Information Database) databases were searched for articles on GC and environmental risk factors in Iran. Twenty-six articles were found to meet the inclusion criteria after title, abstract, and full text review. Risk factors identified for GC include consumption of red meat; high fat, fried, and salted meat; smoked, salted, and fried foods; some dairy products; roasted and fried seeds; strong and hot tea; and un-piped and unchlorinated drinking water, as well as exposure to radiation, loess sediment, soft and grassy soil, soil containing low concentration of molybdenum, and proximity to volcanos. Fresh fruits and vegetable, fresh fish, and honey consumption were recognized as protective agents. Given the risk factors identified, strategies to prevent GC would be educating people to choose a healthy diet and to cook and store food properly, providing access to safe drinking water, taking into account topographical and geographical conditions in choosing a right location to build residential areas, and regulating the use of radiation-emitting devices.

Tumor promoter role of miR‑647 in gastric cancer via repression of TP73

It has previously been demonstrated that miRNA (miR)‑647 exhibits an important role in various cancers, and is aberrantly expressed in gastric cancer (GC). However, the exact role of miR‑647 in GC still remains unclear. The present study aimed to investigate the functional significance of miR‑647 and its target gene in GC. TargetScan and Miranda databases were used to predict the putative targets, and the prediction was validated by Dual‑luciferase Reporter Assays. To investigate whether miR‑647 affects GC cell behavior, a stable miR‑647‑overexpression/low‑expression cell line was generated by transfection with miR‑647 mimic/inhibitor. MTT, Flow Cytometry and Transwell invasion assays were performed to investigate the proliferation, cell apoptosis, migration and invasion properties of MGC‑803 cells. Additionally, reverse transcription‑quantitative polymerase chain reaction and western blot analysis were performed to detect the mRNA and protein expression levels of the apoptosis‑associated genes. The results suggested that tumor protein P73 (TP73) is a target gene of miR‑647. TP73 was markedly decreased following miR‑647 overexpression and significantly increased following miR‑647 inhibition. Following overexpression of miR‑647, the proliferation, migration and invasion of MGC‑803 cells were significantly increased, whereas the percentage of apoptotic cells decreased. Conversely, the proliferation, migration and invasion of MGC‑803 cells were significantly declined, and the percentage of apoptotic cells increased following miR‑647 inhibition. In addition, the B cell lymphoma (Bcl)‑2 Associated X, Apoptosis Regulator/Bcl‑2 ratio was markedly decreased when miR‑647 was overexpressed by miRNA mimics, and significantly increased when miR‑647 expression was inhibited via an miRNA inhibitor. Overall, miR‑647 functions as a tumor promoter in GC by repressing TP73.

Epidemiology of Helicobacter pylori infection

This review of recent publications related to the epidemiology of Helicobacter pylori highlights the origin of the infection, its changing prevalence, transmission, and outcome. A number of studies have addressed the ancestor roots of the bacteria, and the first genomewide analysis of bacterial strains suggests that its coexistence with humans is more ancient than previously thought. As opposed to the generally declining prevalence of H. pylori (including China and Japan), in Sweden, the prevalence of atrophic gastritis in the young population has risen. The prevalence of the infection remains high in the indigenous populations of the Arctic regions, and reinfection rates are high. A high prevalence is permanently found in the Siberian regions of Russia as well. Several studies, some of which used multiplex serology, addressed prevalence of and risks associated with various H. pylori serotypes, thereby enabling more precise risk assessment. Transmission of H. pylori was discussed, specifically fecal-oral transmission and the use of well-water and other unpurified water. Finally, the long-term course of H. pylori infection was considered, with an estimated 89% of noncardia gastric cancer cases being attributable to the infection.

Hydroxyflavanone inhibits gastric carcinoma MGC-803 cell proliferation

Gastric carcinoma (GC) is the most common primary malignancy of the digestive tract, with increasing incidence in many countries. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to assess inhibition of HepG2 cell proliferation by 2'-hydroxyflavanone. The STAT3 pathway was performed. 2'-hydroxyflavanone reduced inhibitory effects on MGC-803 cell proliferation. 2'-hydroxyflavanone exhibited the highest inhibition rate. Treatment of MGC-803 cells with 400, 200, and 100 μg/ml 2'-hydroxyflavanone resulted in 88.9±0.7%, 81.2±0.5%, 68.4±0.5% decrease in cell viability, respectively, indicating an IC50 of 9.3 μg/ml. The 100 μg/ml 2'-hydroxyflavanone can significantly inhibit the STAT3 pathway activation. 2'-hydroxyflavanone inhibits MGC-803 cell proliferation by inhibiting STAT3 pathway activation. This extract is therefore a potential drug candidate for treatment of liver cancer.