Association of risk of gastric cancer and consumption of tobacco, alcohol and tea in the Chinese population

Dose-response association between cigarette smoking and gastric cancer risk: a systematic review and meta-analysis

This study aims at providing an accurate and up-to-date quantification of the dose-response association between cigarette smoking and gastric cancer (GC) risk, overall and by subsite. We conducted a systematic review and meta-analysis of case-control and cohort studies on the association between cigarette smoking and GC risk published up to January 2023. We estimated pooled relative risks (RR) of GC and its subsites according to smoking status, intensity, duration, and time since quitting. Among 271 eligible articles, 205 original studies were included in this meta-analysis. Compared with never smokers, the pooled RR for GC was 1.53 (95% confidence interval; CI 1.44-1.62; n = 92) for current and 1.30 (95% CI 1.23-1.37; n = 82) for former smokers. The RR for current compared with never smokers was 2.08 (95% CI 1.66-2.61; n = 21) for gastric cardia and 1.48 (95% CI 1.33-1.66; n = 8) for distal stomach cancer. GC risk nonlinearly increased with smoking intensity up to 20 cigarettes/day (RR:1.69; 95% CI 1.55-1.84) and levelled thereafter. GC risk significantly increased linearly with increasing smoking duration (RR: 1.31; 95% CI 1.25-1.37 for 20 years) and significantly decreased linearly with increasing time since quitting (RR: 0.65; 95% CI 0.44-0.95 for 30 years since cessation). The present meta-analysis confirms that cigarette smoking is an independent risk factor for GC, particularly for gastric cardia. GC risk increases with a low number of cigarettes up to 20 cigarettes/day and increases in a dose-dependent manner with smoking duration.

Tea consumption and gastric cancer: a pooled analysis from the Stomach cancer Pooling (StoP) Project consortium

BACKGROUND

Evidence from epidemiological studies on the role of tea drinking in gastric cancer risk remains inconsistent. We aimed to investigate and quantify the relationship between tea consumption and gastric cancer in the Stomach cancer Pooling (StoP) Project consortium.

METHODS

A total of 9438 cases and 20,451 controls from 22 studies worldwide were included. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) of gastric cancer for regular versus non-regular tea drinkers were estimated by one and two-stage modelling analyses, including terms for sex, age and the main recognised risk factors for gastric cancer.

RESULTS

Compared to non-regular drinkers, the estimated adjusted pooled OR for regular tea drinkers was 0.91 (95% CI: 0.85-0.97). When the amount of tea consumed was considered, the OR for consumption of 1-2 cups/day was 1.01 (95% CI: 0.94-1.09) and for >3 cups/day was 0.91 (95% CI: 0.80-1.03). Stronger inverse associations emerged among regular drinkers in China and Japan (OR: 0.67, 95% CI: 0.49-0.91) where green tea is consumed, in subjects with H. pylori infection (OR: 0.68, 95% CI: 0.58-0.80), and for gastric cardia cancer (OR: 0.64, 95% CI: 0.49-0.84).

CONCLUSION

Our results indicate a weak inverse association between tea consumption and gastric cancer.

Upper Gastrointestinal Cancer and Liver Cirrhosis

Simple Summary

There is a higher incidence rate of upper gastrointestinal cancer in those with liver cirrhosis. The contributing factors include gastric ulcers, congestive gastropathy, zinc deficiency, alcohol drinking, tobacco use and gut microbiota. Most of the de novo malignancies that develop after liver transplantation for cirrhotic patients are upper gastrointestinal cancers. The surgical risk of upper gastrointestinal cancers in cirrhotic patients with advanced liver cirrhosis is higher.

Abstract

The extended scope of upper gastrointestinal cancer can include esophageal cancer, gastric cancer and pancreatic cancer. A higher incidence rate of gastric cancer and esophageal cancer in patients with liver cirrhosis has been reported. It is attributable to four possible causes which exist in cirrhotic patients, including a higher prevalence of gastric ulcers and congestive gastropathy, zinc deficiency, alcohol drinking and tobacco use and coexisting gut microbiota. Helicobacter pylori infection enhances the development of gastric cancer. In addition, Helicobacter pylori, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans also contribute to the development of pancreatic cancer in cirrhotic patients. Cirrhotic patients (especially those with alcoholic liver cirrhosis) who undergo liver transplantation have a higher overall risk of developing de novo malignancies. Most de novo malignancies are upper gastrointestinal malignancies. The prognosis is usually poor. Considering the surgical risk of upper gastrointestinal cancer among those with liver cirrhosis, a radical gastrectomy with D1 or D2 lymph node dissection can be undertaken in Child class A patients. D1 lymph node dissection can be performed in Child class B patients. Endoscopic submucosal dissection for gastric cancer or esophageal cancer can be undertaken safely in selected cirrhotic patients. In Child class C patients, a radical gastrectomy is potentially fatal. Pancreatic radical surgery should be avoided in those with liver cirrhosis with Child class B or a MELD score over 15. The current review focuses on the recent reports on some factors in liver cirrhosis that contribute to the development of upper gastrointestinal cancer. Quitting alcohol drinking and tobacco use is important. How to decrease the risk of the development of gastrointestinal cancer in those with liver cirrhosis remains a challenging problem.

Polymorphism of MUC1 Gene in Vietnamese Gastric Cancer Patients: A Multicenter Case-Control Study

Background

A few studies revealed that the polymorphisms of Mucin 1 gene have a role and significance as a susceptible factor contributing to gastric cancer. To better understand the roles of two MUC1 genotype polymorphisms of rs4072037 and rs2070803 in the development of gastric cancer in Vietnamese population, a multicenter, large-sample, case-control study was conducted to investigate the potential association of these single-nucleotide polymorphisms (SNPs) of MUC1 gene with gastric cancer risk and to evaluate the combination factors in relation with these SNPs.

Methods

This case-control study included 302 gastric cancer patients and 304 controls at four national medical hospitals between 2016 and 2018. All participants were interviewed for sociodemographic characteristics, smoking and drinking status, and personal and family history of gastric diseases. Genotyping was done using polymerase chain reaction-restriction fragment length polymorphism analysis. The association of SNPs with gastric cancer was explored using logistic regression models.

Results

AA genotype for rs4072037 was significantly associated with increased gastric cancer. Those with AA genotype had higher gastric cancer risk than had patients with AG (OR: 2.09, 95% CI: 1.48-2.96) and a combination of AG+GG (OR: 1.85, 95% CI: 1.33-2.56). In rs2070803, GG genotype increased gastric cancer risk when compared with AG (OR: 1.97, 95% CI: 1.39-2.80) and AG+AA (OR: 1.71, 95% CI: 1.23-2.39). AG genotypes in both SNPs decreased gastric cancer risk when compared with homogenous genotype, more specifically AA (OR: 0.51, 95% CI: 0.35-0.72) and GG (OR: 0.58, 95% CI: 0.35-0.97). These genotypes in combination with above-60-year-old age, male gender, alcoholism, and personal history of gastric disease were also significantly elevated risk factors for gastric cancer.

Conclusions

rs4072037 and rs2070803 of Mucin 1 genes are two genotypic risk factors for gastric cancer. Those in combination with gender, family history, smoking, and drinking habits significantly increase the risk of gastric cancer.

Green tea (Camellia sinensis) for the prevention of cancer

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (2009, Issue 3).Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea, and drinking habits vary cross-culturally. C sinensis contains polyphenols, one subgroup being catechins. Catechins are powerful antioxidants, and laboratory studies have suggested that these compounds may inhibit cancer cell proliferation. Some experimental and nonexperimental epidemiological studies have suggested that green tea may have cancer-preventative effects.

OBJECTIVES

To assess possible associations between green tea consumption and the risk of cancer incidence and mortality as primary outcomes, and safety data and quality of life as secondary outcomes.

SEARCH METHODS

We searched eligible studies up to January 2019 in CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and reference lists of previous reviews and included studies.

SELECTION CRITERIA

We included all epidemiological studies, experimental (i.e. randomised controlled trials (RCTs)) and nonexperimental (non-randomised studies, i.e. observational studies with both cohort and case-control design) that investigated the association of green tea consumption with cancer risk or quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. We summarised the results according to diagnosis of cancer type.

MAIN RESULTS

In this review update, we included in total 142 completed studies (11 experimental and 131 nonexperimental) and two ongoing studies. This is an additional 10 experimental and 85 nonexperimental studies from those included in the previous version of the review. Eleven experimental studies allocated a total of 1795 participants to either green tea extract or placebo, all demonstrating an overall high methodological quality based on 'Risk of bias' assessment. For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence). The summary RR for gynaecological cancer was 1.50 (95% CI 0.41 to 5.48; 2 studies, 1157 participants; low-certainty evidence). No evidence of effect of non-melanoma skin cancer emerged (summary RR 1.00, 95% CI 0.06 to 15.92; 1 study, 1075 participants; low-certainty evidence). In addition, adverse effects of green tea extract intake were reported, including gastrointestinal disorders, elevation of liver enzymes, and, more rarely, insomnia, raised blood pressure and skin/subcutaneous reactions. Consumption of green tea extracts induced a slight improvement in quality of life, compared with placebo, based on three experimental studies. In nonexperimental studies, we included over 1,100,000 participants from 46 cohort studies and 85 case-control studies, which were on average of intermediate to high methodological quality based on Newcastle-Ottawa Scale 'Risk of bias' assessment. When comparing the highest intake of green tea with the lowest, we found a lower overall cancer incidence (summary RR 0.83, 95% CI 0.65 to 1.07), based on three studies, involving 52,479 participants (low-certainty evidence). Conversely, we found no association between green tea consumption and cancer-related mortality (summary RR 0.99, 95% CI 0.91 to 1.07), based on eight studies and 504,366 participants (low-certainty evidence). For most of the site-specific cancers we observed a decreased RR in the highest category of green tea consumption compared with the lowest one. After stratifying the analysis according to study design, we found strongly conflicting results for some cancer sites: oesophageal, prostate and urinary tract cancer, and leukaemia showed an increased RR in cohort studies and a decreased RR or no difference in case-control studies.

AUTHORS' CONCLUSIONS

Overall, findings from experimental and nonexperimental epidemiological studies yielded inconsistent results, thus providing limited evidence for the beneficial effect of green tea consumption on the overall risk of cancer or on specific cancer sites. Some evidence of a beneficial effect of green tea at some cancer sites emerged from the RCTs and from case-control studies, but their methodological limitations, such as the low number and size of the studies, and the inconsistencies with the results of cohort studies, limit the interpretability of the RR estimates. The studies also indicated the occurrence of several side effects associated with high intakes of green tea. In addition, the majority of included studies were carried out in Asian populations characterised by a high intake of green tea, thus limiting the generalisability of the findings to other populations. Well conducted and adequately powered RCTs would be needed to draw conclusions on the possible beneficial effects of green tea consumption on cancer risk.

Risk factors associated with gastric cancer in Mexico: education, breakfast and chili

BACKGROUND AND AIM

the aim of the study was to use a validated questionnaire to identify factors associated with the development of gastric cancer (GC) in the Mexican population.

METHODS

the study included cases and controls that were paired by sex and ± 10 years of age at diagnosis. In relation to cases, 46 patients with a confirmed histopathological diagnosis of adenocarcinoma-type GC, as reported in the hospital records, were selected, and 46 blood bank donors from the same hospital were included as controls. The previously validated Questionnaire to Find Factors Associated with Gastric Cancer (QUFA-GC©) was used to collect data. Odds ratio (OR) and 95% confidence interval (IC) were estimated via univariate analysis (paired OR). Multivariate analysis was performed by logistic regression. A decision tree was constructed using the J48 algorithm.

RESULTS

an association was found by univariate analysis between GC risk and a lack of formal education, having smoked for ≥ 10 years, eating rapidly, consuming very hot food and drinks, a non-suitable breakfast within two hours of waking, pickled food and capsaicin. In contrast, a protective association against GC was found with taking recreational exercise and consuming fresh fruit and vegetables. No association was found between the development of GC and having an income that reflected poverty, using a refrigerator, perception of the omission of breakfast and time period of alcoholism. In the final multivariate analysis model, having no formal education (OR = 17.47, 95% CI = 5.17-76.69), consuming a non-suitable breakfast within two hours of waking (OR = 8.99, 95% CI = 2.85-35.50) and the consumption of capsaicin ˃ 29.9 mg capsaicin per day (OR = 3.77, 95% CI = 1.21-13.11) were factors associated with GC.

CONCLUSIONS

an association was found by multivariate analysis between the presence of GC and education, type of breakfast and the consumption of capsaicin. These variables are susceptible to intervention and can be identified via the QUFA-GC

Knockdown of long noncoding RNA GHET1 inhibits cell‑cycle progression and invasion of gastric cancer cells

GHET1 is an oncogenic long noncoding RNA (lncRNA) that promotes the proliferation and invasion of many malignant cell types. However, the function and underlying mechanisms of lncRNA GHET1 in gastric cancer are not fully understood. In this study, the expression of GHET1 was investigated in gastric cancer and it was determined whether GHET1 may potentially be used as a biomarker for the disease. The gastric cancer cell lines MGC‑803 and AGS were transfected with GHET1‑directed small interfering RNA (siRNA) and the changes in phenotype and cell‑cycle‑related molecules were assessed. The downregulation of GHET1 induced G0/G1‑phase arrest in gastric cancer cells and inhibited their proliferation, migration, and invasion. DNA synthesis and the expression of proliferating cell nuclear antigen (PCNA) decreased, which was consistent with the results of the CCK‑8 assay. The levels of specific cell‑cycle regulators were determined and the expression and activities of positive cell‑cycle regulators (cyclin D, CDK4, CDK6, cyclin E, CDK2) were reduced, whereas those of a negative regulator (P21) were increased in GHET1‑knockdown cells. Taken together, the present findings show that the downregulation of GHET1 not only inhibits the migration and invasion of gastric cancer cells, but also inhibits their proliferation, at least in part by upregulating P21 expression and downregulating cyclin and CDK expression to inhibit the G0/G1 to S phase transition. The present findings may provide a potential therapeutic target for gastric cancer.

Alcohol intake and gastric cancer: Meta-analyses of published data versus individual participant data pooled analyses (StoP Project)

BACKGROUND

Individual participant data pooled analyses allow access to non-published data and statistical reanalyses based on more homogeneous criteria than meta-analyses based on systematic reviews. We quantified the impact of publication-related biases and heterogeneity in data analysis and presentation in summary estimates of the association between alcohol drinking and gastric cancer.

METHODS

We compared estimates obtained from conventional meta-analyses, using only data available in published reports from studies that take part in the Stomach Cancer Pooling (StoP) Project, with individual participant data pooled analyses including the same studies.

RESULTS

A total of 22 studies from the StoP Project assessed the relation between alcohol intake and gastric cancer, 19 had specific data for levels of consumption and 18 according to cancer location; published reports addressing these associations were available from 18, 5 and 5 studies, respectively. The summary odds ratios [OR, (95%CI)] estimate obtained with published data for drinkers vs. non-drinkers was 10% higher than the one obtained with individual StoP data [18 vs. 22 studies: 1.21 (1.07-1.36) vs. 1.10 (0.99-1.23)] and more heterogeneous (I²: 63.6% vs 54.4%). In general, published data yielded less precise summary estimates (standard errors up to 2.6 times higher). Funnel plot analysis suggested publication bias.

CONCLUSION

Meta-analyses of the association between alcohol drinking and gastric cancer tended to overestimate the magnitude of the effects, possibly due to publication bias. Additionally, individual participant data pooled analyses yielded more precise estimates for different levels of exposure or cancer subtypes.

Clinicopathological features and prognosis in elderly gastric cancer patients: a retrospective cohort study

Background

Little is known about the clinicopathological features and prognosis in elderly gastric cancer (GC) patients aged 65–79 years. The aim of this study was to evaluate clinicopathological features and prognosis in elderly GC patients.

Patients and methods

From May 2008 to December 2014, a total of 5,282 GC patients were enrolled in our present study. Patients were divided into elderly and middle-aged groups. The clinicopathological features and clinical outcomes were analyzed.

Results

The proportion of dysphagia was significantly higher in elderly patients than that in middle-aged patients (P=0.002), whereas the proportion of abdominal pain and heartburn was significantly lower in elderly patients than that in middle-aged patients (P<0.001 vs P=0.038, respectively). The proportion of patients with carbohydrate antigen (CA) 19-9 was significantly higher in elderly patients than that in middle-aged patients (P=0.009). There was no significant difference in clinicopathological features between elderly and middle-aged patients with D2 gastrectomy (all P>0.05). Age, tumor size, histological type, tumor depth, lymph node metastasis, carcinoembryonic antigen, alpha fetoprotein, CA19-9, and CA125 were independent risk factors for the prognosis of GC patients in univariate and multivariate analyses. Overall survival in elderly patients was significantly reduced compared with middle-aged patients (P=0.001), especially in patients with tumor size >5 cm (P=0.002), poorly differentiated tumor (P<0.000), stage III tumor (P=0.002), or normal levels of carcinoembryonic antigen (P=0.009), alpha fetoprotein (P=0.002), CA19-9 (P=0.002), and CA125 (P=0.004).

Conclusion

The clinicopathological features of elderly patients were different to those of middle-aged patients. The prognosis for elderly GC patients was significantly worse than for middle-aged patients.

Alcohol drinking and gastric cancer risk: a meta-analysis of observational studies

BACKGROUND

Many studies investigated the association between alcohol drinking and gastric cancer risk, but the results were controversial. We performed a meta-analysis of observational studies to explore the association.

MATERIALS AND METHODS

We searched PubMed to identify the relevant studies that reported the association between alcohol drinking and gastric cancer risk up to December 31, 2016. We pooled relative risks (RRs) in random effects model and performed dose-response analysis to quantify the association. Cochran Q test and I2 analyses were used to evaluate the heterogeneity. Meta-regression, subgroup, sensitivity and publication bias analyses were also performed.

RESULTS

75 studies were included in our study. The pooled RR of high vs low total alcohol drinking was 1.25 (95% CI, 1.15-1.37, P < 0.001), and a nonlinear association was further observed. Subgroup analysis showed that alcohol drinking significantly associated with the risk of gastric noncardia cancer (RR, 1.19; 95% CI, 1.01-1.40, P = 0.033), but not with the risk of gastric cardia cancer (RR, 1.16; 95% CI, 0.98-1.39, P = 0.087). Notably, the pooled RRs of high vs low analyses were 1.13 (95% CI, 1.03-1.24, P = 0.012) for beer drinking, 1.22 (95% CI, 1.06-1.40, P = 0.005) for liquor drinking, and 0.99 (95% CI, 0.84-1.16, P = 0.857) for wine drinking.

CONCLUSIONS

Our meta-analysis found a nonlinear association between alcohol drinking and gastric cancer risk, and heavy drinking level was strongly related to gastric cancer risk. Beer and liquor had significant positive associations with gastric cancer risk, while wine drinking would not increase gastric cancer risk. These results need to be verified in future research.

Molecular Basis of Alcohol-Related Gastric and Colon Cancer

Many meta-analysis, large cohort studies, and experimental studies suggest that chronic alcohol consumption increases the risk of gastric and colon cancer. Ethanol is metabolized by alcohol dehydrogenases (ADH), catalase or cytochrome P450 2E1 (CYP2E1) to acetaldehyde, which is then further oxidized to acetate by aldehyde dehydrogenase (ALDH). Acetaldehyde has been classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen to humans. The acetaldehyde level in the stomach and colon is locally influenced by gastric colonization by Helicobacter pylori or colonic microbes, as well as polymorphisms in the genes encoding tissue alcohol metabolizing enzymes, especially ALDH2. Alcohol stimulates the uptake of carcinogens and their metabolism and also changes the composition of enteric microbes in a way to enhance the aldehyde level. Alcohol also undergoes chemical coupling to membrane phospholipids and disrupts organization of tight junctions, leading to nuclear translocation of β-catenin and ZONAB, which may contributes to regulation of genes involved in proliferation, invasion and metastasis. Alcohol also generates reactive oxygen species (ROS) by suppressing the expression of antioxidant and cytoprotective enzymes and inducing expression of CYP2E1 which contribute to the metabolic activation of chemical carcinogens. Besides exerting genotoxic effects by directly damaging DNA, ROS can activates signaling molecules involved in inflammation, metastasis and angiogenesis. In addition, alcohol consumption induces folate deficiency, which may result in aberrant DNA methylation profiles, thereby influencing cancer-related gene expression.

Recent advances in proximal gastric carcinoma

The American Joint Committee on Cancer (AJCC) staging scheme requires staging proximal gastric carcinoma (PGC) as esophageal adenocarcinoma (EAC), which has been shown to be controversial by recent research results. To update the current research findings on PGC, we systematically reviewed and analyzed the scientific evidence on key arguments related to PGC. The data of high-quality research articles showed that PGC arised in the cardiac mucosa in the proximal stomach within 3 cm below the gastroesophageal junction. Its incidence is rising in East Asian countries, but decreasing in the West, and plateaued at a low level in the United States. PGC is a slowly progressive cancer with unknown independent risk factors and the mechanisms of pathogenesis. This carcinoma exhibits a wide histopathological spectrum and heterogeneous post-resection patient survival characteristics, and cannot be adequately staged for prognotic stratification by the current AJCC staging classification. The results on PGC genomics reveal unique genetic profiles, especially in East Asian populations. In conclusion, mounting evidence defies a simple placement of PGC in a single category of EAC for disease classification; further investigations on the mechanisms of PGC pathogenesis are urgently needed.

Individualized Chemotherapy for Metastatic Gastric Cancer: Retrospective Data from a University Hospital in Brazil

BACKGROUND

Despite the decreased incidence, gastric cancer is still a frequent cause of cancer related death. The 1st line 2 or 3 drugs regimen is still a debatable issue. HER2 targeted therapy has emerged as the standard of care, but it is unavailable in the Brazilian Public Health System. The end-point of this trial was overall survival (OS) in patients with metastatic gastric cancer treated in a public university hospital in Brazil. The secondary end-points were efficacy and safety of regimens with 2 (F+P) or 3 (EOX) drugs to develop an institutional guideline to facilitate optimal treatments.

MATERIALS AND METHODS

In this retrospective study, 1st line regimens were evaluated for OS and PFS stratified by age and ECOG using Cox regression.

RESULTS

47 patients were treated over the last 3 years. In 1st line, 29 were treated with F+P (mean 59.3 years, 34.5% ECOG 2 and a mean of 5.69 cycles) and 16 with EOX (mean 47 years, 18.8% ECOG 2 and a mean of 5.44 cycles). The median OS was 13.8 months (95%CI 10.7-16.9). Response was evaluated in 40 cases and was 64.3% for EOX and 37.5% for F+P (p=0.25). The median PFS was 9.5 months for EOX and 5.6 months for F+P (HR 0.85, 95%CI 0.41-1.74). However, among patients with ECOG 2 mPFS was 3.70 vs 5.40 months, respectively (p=0.86). Regimens showed similar manageable adverse events. A total of 34 patients suffered progression and 14 received 2nd line therapy. Diffuse histology (HR 1.89, 95%CI 1.22-2.88), achieving 2nd line (HR: 0.25, 95%CI 0.11-0.58) and treatment response (HR 0.23, 95%CI 0.12-0.47) were OS prognostic factors.

CONCLUSIONS

Patients treated in our hospital had outcomes compatible with the literature. The regimen choice should be related to patient features. Second line treatment should be considered.

Enhanced expression of long non-coding RNA NEAT1 is associated with the progression of gastric adenocarcinomas

BACKGROUND

Long non-coding RNAs (lncRNAs) are emerging as new players in the cancer. The aim of this study was to examine the abnormalities of NEAT1 (nuclear paraspeckle assembly transcript 1, also known as MENε/β) in gastric adenocarcinomas (GACs).

METHODS

One hundred thirty-one GAC tissues and matched adjacent normal tissues (ANTs) were collected from patients who undergone surgery. Differences in of NEAT1 expression were examined via quantitative reverse transcriptase PCR (qRT-PCR). WST-1 assay and transwell assay were carried out in vitro to investigate the proliferation and migration of GAC cells with alteration in NEAT1 long non-coding RNA (lncRNA) expression.

RESULTS

The expression levels of lncRNA NEAT1 were significantly elevated in GAC tissues (P<0.001) compared with ANTs. There was also a statistical difference in NEAT1 expression between early and advanced GACs (P=0.0111). GACs with lymph node metastasis (LNM) expressed higher levels of NEAT1 lncRNA compared with those without LNM (P=0.004). In the in vitro experiments, the proliferation but not migration of GAC cells was attenuated after NEAT1 knockdown by RNA interference.

CONCLUSIONS

Expression of NEAT1 lncRNA was enhanced in GACs; and NEAT1 may influence GAC progression by promoting tumor growth.

Treatment outcomes and survival study of gastric cancer patients: a retrospective analysis in an endemic region

PURPOSE

To present information about prognostic factors of gastric cancer patients treated in our Erzurum center including age, gender, tumour location, pathological grade, stage and the effect of treatment on survival.

MATERIALS AND METHODS

This retrospective study was performed on patients who applied to our clinic and diagnosed as gastric cancer. Age and gender of the patients, primary location, histopathological characteristics, TNM stage of the gastric cancers (GCs), treatment applied, oncological treatment modalities and survival outcomes were studied. A univariate analysis of potential prognostic factors was performed with the log-rank test for categorical factors and parameters with a p value < 0.05 at the univariate step were included in the multivariate regression.

RESULTS

A total of 228 patients with a confirmed diagnosis of gastric cancer were included in the study with a male/female ratio of 1.47. Median follow-up period was estimated as 22.3 (range, 3 to 96) months. When diagnosis of the patients at admission was analysed, stage III patients were most frequently encountered (n=147; 64.5%). One hundred and twenty-six (55.3%) underwent surgical treatment, while 117 (51.3%) were given adjuvant chemotherapy. Median overall survival time was 18.0 (± 1.19) months. Mean overall survival rates for 1, 2, 3 and 5 years were 68 ± 0.031%, 36 ± 0.033%, 24 ± 0.031% and 15.5 ± 0.036%, respectively. Univariate variables found to be significant for median OS in the multivariate analysis were evaluated with Cox regression analysis. A significant difference was found among TNM stage groups, location of the tumour and postoperative adjuvant treatment receivers (p values were 0.011, 0.025 and 0.001, respectively).

CONCLUSIONS

This study revealed that it is possible to achieve long-term survival of gastric cancer with early diagnosis. Besides, in locally advanced GC patients, curative resection followed by adjuvant concomitant chemoradiotherapy based on the McDonald regimen was an independent prognostic factor for survival.

Mutagenicity Assessment of Drinking Water in Combination with Flavored Black Tea Bags: a Cross Sectional Study in Tehran

Diseases related to water impurities may present as major public health burdens. The present study aimed to assess the mutagenicity of drinking water from different zones of Tehran, and evaluate possible health risks through making tea with tea bags, by Ames mutagenicity test using TA 100, TA 98 and YG1029 strains. For this purpose, 450 water samples were collected over the period of July to December 2014 from 5 different zones of Tehran. Except for one sample, no mutagenic potential was detected during these two seasons and the MI scores were almost normal (≤ 1-1.6) in TA 100, TA 98 and YG1029 strains. Although no mutagenic effects were considered in TA 98 and TA 100 in the test samples of our three evaluated tea bag brands, one sample from a local company showed mutagenic effects in the YG1029 strain (MI=1.7-1.9 and 2) after prolonged (10-15 min.) steeping. Despite the mild mutagenic effect discovered for one of the brand, this cross sectional study showed relative safety of water samples and black tea bags in Tehran. According to the sensitivity of YG1029 to the mutagenic potential of water and black tea, even without metabolic activation by s9 fraction, this metabolizer strain could be considered as sensitive and applicable to food samples for quantitative analysis of mutagens.

Challenges of deciphering gastric cancer heterogeneity

Gastric cancer is in decline in most developed countries; however, it still accounts for a notable fraction of global mortality and morbidity related to cancer. High-throughput methods are rapidly changing our view and understanding of the molecular basis of gastric carcinogenesis. Today, it is widely accepted that the molecular complexity and heterogeneity, both inter- and intra-tumour, of gastric adenocarcinomas present significant obstacles in elucidating specific biomarkers for early detection of the disease. Although genome-wide sequencing and gene expression studies have revealed the intricate nature of the molecular changes that occur in tumour landscapes, the collected data and results are complex and sometimes contradictory. Several aberrant molecules have already been tested in clinical trials, although their diagnostic and prognostic utilities have not been confirmed thus far. The gold standard for the detection of sporadic gastric cancer is still the gastric endoscopy, which is considered invasive. In addition, genome-wide association studies have confirmed that genetic variations are important contributors to increased cancer risk and could participate in the initiation of malignant transformation. This hypothesis could in part explain the late onset of sporadic gastric cancers. The elaborate interplay of polymorphic low penetrance genes and lifestyle and environmental risk factors requires additional research to decipher their relative impacts on tumorigenesis. The purpose of this article is to present details of the molecular heterogeneity of sporadic gastric cancers at the DNA, RNA, and proteome levels and to discuss issues relevant to the translation of basic research data to clinically valuable tools. The focus of this work is the identification of relevant molecular changes that could be detected non-invasively.

Molecular Links between Alcohol and Tobacco Induced DNA Damage, Gene Polymorphisms and Patho-physiological Consequences: A Systematic Review of Hepatic Carcinogenesis

Chronic alcohol and tobacco abuse plays a crucial role in the development of different liver associated disorders. Intake promotes the generation of reactive oxygen species within hepatic cells exposing their DNA to continuous oxidative stress which finally leads to DNA damage. However in response to such damage an entangled protective repair machinery comprising different repair proteins like ATM, ATR, H2AX, MRN complex becomes activated. Under abnormal conditions the excessive reactive oxygen species generation results in genetic predisposition of various genes (as ADH, ALDH, CYP2E1, GSTT1, GSTP1 and GSTM1) involved in xenobiotic metabolic pathways, associated with susceptibility to different liver related diseases such as fibrosis, cirrhosis and hepatocellular carcinoma. There is increasing evidence that the inflammatory process is inherently associated with many different cancer types, including hepatocellular carcinomas. The generated reactive oxygen species can also activate or repress epigenetic elements such as chromatin remodeling, non-coding RNAs (micro-RNAs), DNA (de) methylation and histone modification that affect gene expression, hence leading to various disorders. The present review provides comprehensive knowledge of different molecular mechanisms involved in gene polymorphism and their possible association with alcohol and tobacco consumption. The article also showcases the necessity of identifying novel diagnostic biomarkers for early cancer risk assessment among alcohol and tobacco users.