Trends and Risk Factors of Gastric Cancer in Iran (2005-2010)

Incidence Trends of Gastric Cancer in Southern Iran: Adenocarcinoma and Non-cardia Gastric Cancer Are More Rising Among Younger Ages

BACKGROUND

Gastric Cancer (GC) is still one of the major causes of cancer mortality. Due to health-related transitions, the epidemiology of GC subtypes may change. These changes may have profound effects on clinical approaches as well as on public health management of GC. Iran, as a developing country, has experienced huge demographic and epidemiological transitions during the recent decades. This study aimed to investigate the subtype-specific population-based incidence trends of GC in southern Iran.

METHODS

We used data on GC incidence in southern Iran during 2001-2015. Data preparation and subtype grouping were done based on the ICD-O-3. The trends of Age-Standardized incidence Rate (ASR), truncated ASRs, incidence rate of adenocarcinoma, and cardia GC, and age-gender specific rates were analyzed using joinpoint regression modeling. Annual Percentage Change (APC) and its 95% Confidence Intervals (CIs) were estimated.

RESULTS

Overall APC was estimated as 7.2 for males and 8.7 for females. The estimated APCs for the trends of overall GC, and gastric adenocarcinoma were stable in both genders during 2009-2015. Nonetheless, cardia GC showed increasing trends in both genders. The estimated APCs for the trends of non-cardia GC was also stable.

CONCLUSION

The overall trends of the GC incidence in southern Iran were stable during the past decade. However, significant and different changes have occured in the pattern of GC. Thus, etiological and prognostic studies are needed for the improvement of GC management in Iran.

Mortality Rates and Years of Life Lost Due to Cancer in Iran: Analysis of Data from the National Death Registration System, 2016

Background: Cancer incidence is a major public health concern and one of the leading causes of premature death worldwide. Therefore, this study was conducted to determine the death rate and years of life lost (YLL) due to cancer in Iran. Methods: In this study, death registration system (DRS) data in Iran was used. The Global Health Estimates (GHE-2016) cause categories and ICD-10 codes (C00-C97 and D00-D48) were assigned for deaths due to cancer. The crude, age-standardized mortality rates (ASMR) via world standard population was measured, and also YLL due to cancer were calculated using standard life expectancy. Results: The DRS recorded 53,492 deaths due to cancer (58.82% males and 41.18% females). The cancer mortality rate was 66.92 per 100,000 population (77.7 and 55.87 per 100,000 population in men and women, respectively) and ASMR was 96.4 per 100,000 population (115.7 and 77 per 100,000 population for males and females, respectively). The total YLL due to premature death was 736,564 in males, 580,254 in females, and 1,316,818 in both sexes. Death due to stomach cancer, tracheal, bronchus, and lung, leukemia, brain, and nervous system cancer, and breast cancer comprised the largest YLL category among different cancer sites. Conclusions: Accounting for more than 1,300,000 YLL attributed to cancer, it is a major public health problem in Iran. Therefore, promoting the prevention and control programs and policies are necessary to improve health indicators and since some cancers are preventable, the burden can be reduced by controlling tobacco use, dietary interventions, and promoting physical activity.

Spatiotemporal Analysis of Gastrointestinal Tumor (GI) with Kernel Density Estimation (KDE) Based on Heterogeneous Background

The purpose of this study is to explore hotspots or clusters of gastrointestinal tumors (GI) and their spatiotemporal distribution characteristics and the changes over time in 293 villages and communities in Jianze County, central China, through the kernel density estimation (KDE) method based on the rarely considered heterogeneous background. The main findings were: (1) Heterogeneous background impact: there were substantial differences in the GI case rate among people of different ages and genders in Jianze County. Specifically, the GI case rate was significantly higher in the elderly population over 65 than in the population under 65, and higher in men than in women. (2) GI in Jianze County exhibited spatial specific and aggregated hotspots. The high-value spatial clusters were mainly located in Hujindian Town in the northern county, Wupu Town and Geputan Town in the middle, and Xiaxindian Town in the south. Some villages had persistent hot spots for multiple years. (3) Most GI hotspots in Jianze County were concentrated in areas with both high density of local chemical plants and with water systems in the neighbourhood. We expect that this study provides a scientific basis for exploring unknown risk factors of tumor occurrence from a spatial perspective in the future.

Evaluation of CSTB and DMBT1 expression in saliva of gastric cancer patients and controls

Background

Gastric cancer (GC) is the fifth most common cancer and the third cause of cancer deaths globally, with late diagnosis, low survival rate, and poor prognosis. This case-control study aimed to evaluate the expression of cystatin B (CSTB) and deleted in malignant brain tumor 1 (DMBT1) in the saliva of GC patients with healthy individuals to construct diagnostic algorithms using statistical analysis and machine learning methods.

Methods

Demographic data, clinical characteristics, and food intake habits of the case and control group were gathered through a standard checklist. Unstimulated whole saliva samples were taken from 31 healthy individuals and 31 GC patients. Through ELISA test and statistical analysis, the expression of salivary CSTB and DMBT1 proteins was evaluated. To construct diagnostic algorithms, we used the machine learning method.

Results

The mean salivary expression of CSTB in GC patients was significantly lower (115.55 ± 7.06, p = 0.001), and the mean salivary expression of DMBT1 in GC patients was significantly higher (171.88 ± 39.67, p = 0.002) than the control.

Multiple linear regression analysis demonstrated that GC was significantly correlated with high levels of DMBT1 after controlling the effects of age of participants (R² = 0.20, p < 0.001).

Considering salivary CSTB greater than 119.06 ng/mL as an optimal cut-off value, the sensitivity and specificity of CSTB in the diagnosis of GC were 83.87 and 70.97%, respectively. The area under the ROC curve was calculated as 0.728. The optimal cut-off value of DMBT1 for differentiating GC patients from controls was greater than 146.33 ng/mL (sensitivity = 80.65% and specificity = 64.52%). The area under the ROC curve was up to 0.741.

As a result of the machine learning method, the area under the receiver-operating characteristic curve for the diagnostic ability of CSTB, DMBT1, demographic data, clinical characteristics, and food intake habits was 0.95. The machine learning model’s sensitivity, specificity, and accuracy were 100, 70.8, and 80.5%, respectively.

Conclusion

Salivary levels of DMBT1 and CSTB may be accurate in diagnosing GCs. Machine learning analyses using salivary biomarkers, demographic, clinical, and nutrition habits data simultaneously could provide affordability models with acceptable accuracy for differentiation of GC by a cost-effective and non-invasive method.

Requirements of mobile-based self-management application for patients with gastric cancer: specialists and patients perspective (Preprint)

Background

Objective

Methods

Results

Conclusions

Ten-year data analysis of digestive system malignancies in Babol, North of Iran: 2008-2017

BACKGROUND

Unlike some regions of the world where digestive system cancers are not considered as important health problems, these neoplasms are among the most common malignancies in the northern region of Iran.

METHODS

This observational analytical study was carried out based on data collected by the Cancer Registration Center affiliated to the Vice Chancellery for Health of Babol University of Medical Sciences, North of Iran, during 2008-2017. Crude incidence rate (CR), and age-standardized incidence rate (ASR) have been calculated for different GI cancers, based on the primary involved site; and have been compared in different years, patients' age, gender and place of residence.

RESULTS

Totally, 4332 records were related to digestive system cancers. Mean age of patients was 63.48±14.73 years; men (2743; 63.3%) were more affected than women (1589; 36.7%) (p<0.001). The most incident malignancies of digestive system were from stomach, colorectal and esophagus in men; and colorectal, stomach and esophagus in women, respectively. These three cancers accounted for 3725 (85.98%) of total GI malignancies. The mean age of patients in various types of GI cancers was statistically different (p<0.001). Age- standardized incidence rate showed different values in different years; from 521.40 (95% CI: 462.79-580.00) in year 2016 to 1834.33 (95% CI: 1637.36-2031.29) in year 2008.

CONCLUSION

Gastric, esophageal and colorectal cancers were the most prevalent digestive system malignancies in Babol, North of Iran, and accounted for about 86% of all GI tract cancers. A considerable variation has been found in incident gastrointestinal cancers in different years.

Characteristics of gastric precancerous conditions and Helicobacter pylori infection among dyspeptic patients in north-eastern Iran: is endoscopic biopsy and histopathological assessment necessary?

Background

Early detection and appropriate treatment of precancerous, mucosal changes could significantly decrease the prevalence of life-threatening gastric cancer. Biopsy of the normal-appearing mucosa to detect Helicobacter pylori and these conditions is not routinely obtained. This study assesses the prevalence and characteristics of H. pylori infection and precancerous conditions in a group of patients suffering from chronic dyspepsia who were subjected to gastric endoscopy and biopsy mapping.

Methods

This cross-sectional study included dyspeptic patients, not previously treated for H. pylori, undergoing esophagogastroduodenoscopy (EGD) with their gastric endoscopic biopsies obtained for examination for evidence of H. pylori infection and precancerous conditions. Demographic and clinical data on the gender, smoking, opium addiction, alcohol consumption, medication with aspirin, corticosteroids and non-steroidal anti-inflammatory drugs (NSAIDs) and family history of cancer were collected by interviewing the patients and evaluating their health records. The cohort examined consisted of 585 patients with a mean (SD) age of 48.0 (14.46) years, 397 (67.9%) of whom were women.

Results

H. pylori infection was identified in 469 patients (80.2%) with the highest prevalence (84.2%) in those aged 40–60 years. Opium addiction correlated with a higher a H. pylori infection rate, while alcohol consumption was associated with a lower rate by Odds Ratio 1.98 (95% CI 1.11–3.52) and 0.49 (95% CI 0.26–0.92), respectively. The prevalence of intestinal metaplasia, gastric atrophy and gastric dysplasia was 15.2, 12.6 and 7.9%, respectively. Increased age, positive H. pylori infection, endoscopic abnormal findings and opium addiction showed a statistically significant association with all precancerous conditions, while NSAID consumption was negatively associated with precancerous conditions. For 121 patients (20.7% of all), the EGD examination revealed normal gastric mucosa, however, for more than half (68/121, 56.2%) of these patients, the histological evaluation showed H. pylori infection, and also signs of atrophic mucosa, intestinal metaplasia and dysplasia in 1.7, 4.1 and 1.7%, respectively.

Conclusion

EGD with gastric biopsy mapping should be performed even in the presence of normal-appearing mucosa, especially in dyspeptic patients older than 40 years with opium addiction in north-eastern Iran. Owing to the high prevalence of precancerous conditions and H. pylori infection among patients with dyspepsia in parts of Iran, large-scale national screening in this country should be beneficial.

Joint Disease Mapping of Breast, Uterine, and Ovarian Cancers in Cities of Isfahan Province from 2005 to 2010 Using Spatial Shared Component Model

BACKGROUND

Breast, uterine, and ovarian cancers are the most prevalent types of cancers among women. The aim of this study was to estimate the relative risk of these cancers and recognizing spatial patterns of their shared and specific risk factors in cities of Isfahan province, one of the most populated provinces of Iran, using spatial shared component model.

METHODS

In this ecological study, the population consisted of all the registered patients having breast, ovarian, and uterine cancers in the cities of Isfahan from 2005 to 2010. In order to simultaneously analyze these diseases and clarify common and specific patterns of disease, spatial Shared component model was applied. Model fitting was done using Bayesian inference in OpenBUGS software.

RESULTS

The highest relative risk of breast cancer was seen in Isfahan (4.96), Shahreza (2.37), Dehaghan (5.01), Lenjan (2.33), and Najafabad (2.68), respectively. For ovarian cancer, Isfahan (4.29), Shahreza (2.51), Dehaghan (5.02), Lenjan (2.06), Najafabad (2.00), and Borkhar (2.39) had the highest relative risk, respectively. However, no significant difference was seen among the cities for uterine cancer (P > 0.05).

CONCLUSIONS

Since ovarian and uterine cancers are the less prevalent disease in comparison with breast cancer, the preciseness of these estimates were improved remarkably over simple mapping models. Based on this model, the estimates were done according to the correlation between the diseases. After recognizing the spatial patterns of the shared and specific risk factors and reviewing of previous studies, regardless of risk factors data, environmental pollution arises as a potential risk factor.

Crossroad between Obesity and Gastrointestinal Cancers: A Review of Molecular Mechanisms and Interventions

The burden of gastrointestinal (GI) cancer is increasing worldwide, and in the past decade, cancer had entered the list of chronic debilitating diseases whose risk is substantially increased by hypernutrition. Obesity may increase the risk of cancer by the imbalance of various mechanisms including insulin and insulin-like growth factor1 (IGF-I) signaling, systemic inflammation, immune dysregulation, tumor angiogenesis, adipokines secretion, and intestinal microbiota that usually act interdependently. An increased understanding of the mechanisms underlying obesity-GI cancer link can provide multiple opportunities for cancer prevention. This review discusses various mechanisms involved molecular mechanisms linking obesity with GI cancers including esophagus, stomach, colorectal and hepatocellular. Furthermore, an optional intervention such as diet restriction and exercise is described, which may be preventive or therapeutic in GI cancer.

Correlation of -160C > A and -347GA > G polymorphisms in E-cadherin gene and gastric cancer in north of Iran

BACKGROUND

E-cadherin (CDH1 gene) is a protein involved in cell-cell adhesion. There are reports on the association of -160C > A (rs16260) and -347GA > G (rs5030625) polymorphisms in the 5'-promoter region of the CDH1 gene with tumor development and progression of gastric cancer. This study aimed to examine the potential relationship between these two polymorphisms and gastric cancer in patients from Mazandaran province, Northern Iran.

MATERIALS AND METHODS

A case-control study was conducted to test 97 patients and 95 healthy controls. Genomic DNA was extracted from peripheral blood followed by polymerase chain reaction amplification. Genotyping analysis was carried out using restriction fragment length polymorphism analysis for two potentially functional polymorphisms.

RESULTS

Heterozygous genotype GA/G versus GA/GA of rs5030625 (-347 GA > G) was found to be associated with increased risk of gastric cancer in the people studied (odds ratio = 5.73, 95% confidence interval = 2.11-15.56, P = 0.001). Furthermore, AA or CA genotype in -160C > A polymorphism did not show any increased risk of gastric cancer (P = 0.559).

CONCLUSION

The present study revealed that GA/G genotype of rs5030625 (-347 GA > G) polymorphism is associated with gastric cancer in Northern Iran.

Epidemiologic Study of Gastric Cancer in Iran: A Systematic Review

BACKGROUND

Gastric cancer (GC) is one of the most common cancers in Iran. Knowledge of the epidemiology of the disease is essential in planning for prevention. So this study aimed to investigate the epidemiological aspects of gastric cancer including prevalence, incidence, mortality, and risk factors of Iran.

METHODS

This systematic review study was based on articles published in both English and Persian languages during the years of 1970-2020 in international databases (PubMed, Web of Science, Scopus) and national databases (including SID, Magiran, and IranDoc). Papers related to epidemiological aspects of the disease including mortality, prevalence, incidence, and risk entered the final review.

RESULTS

According to the studies, the minimum and maximum prevalence of gastric cancer in northwestern Iran (Ardabil) is between 0.2 and 100 per 100,000. Also, the death rate per 100,000 people ranged from 10.6 to 15.72 and the ASMR ranged from 4.2 to 32.2%. On the other hand, the incidence of GC was higher in men than in women (74.9 vs 4.6%). The GC risk ratio was 8-times higher in the elderly than in the other age groups (HR=8.0, 2.7-23.5). The incidence of gastric cancer in patients with H. pylori infection was 18-times and that of smokers 2-times higher than other populations. Low level of economic situation and food insecurity increased the odds of GC by 2.42- and 2.57-times, respectively. It should be noted that there was a direct relationship between consumption of processed red meat, dairy products, fruit juice, smoked and salty fish and legumes, strong and hot tea, and consumption of salt and gastric cancer incidence. There was also an inverse relationship between citrus consumption, fresh fruit, garlic, and gastric cancer. In addition, the mRNA genes are the most GC-related genes.

CONCLUSION

Given the high incidence of GC in Iran, changing lifestyle and decreasing consumption of preservatives in food, increasing consumption of fruits and vegetables, and improving the lifestyle can be effective in reducing the incidence of this disease.

Epidemiology of Gastric Cancer in North Africa and the Middle East from 1990 to 2017

INTRODUCTION

Gastric cancer is the fifth most common cancer worldwide and the third cause of cancer deaths and disability-adjusted life years (DALYs) worldwide. The countries of the Middle East and North Africa are similar in many determinants of health, but there are significant differences in the incidence of gastric cancer in these countries. Therefore, the purpose of this study was to compare the burden of gastric cancer in MENA countries with appropriate policies to reduce the incidence and mortality of gastric cancer in the region.

MATERIALS AND METHODS

GBD database data were used to assess the gastric cancer indices in MENA countries consisted of 21 countries in the Middle East and North Africa in 1900 and 2017. Gastric cancer-related analysis using DALY counts, which is the sum of YLLs (total years lost due to premature death) and YLDs (years lost due to disability), and incidence rates, prevalence rates, death rates, and standardized age rates (ASR) were measured.

RESULTS

The incidence of gastric cancer has decreased in the world and the MENA region from 1990 to 2017, which is higher than the global average in MENA. But death rates in the region have decreased below the global average. The trend of changes in DALY count has increased from 1990 to 2017 in all countries in the region except Turkey. This increase is higher in men than in women and also in Iran. In these countries, the highest percentage of total DALY of gastric cancer is attributable to the risk factors for high sodium and cigarette consumption, in Turkey and the United Arab Emirates, respectively (from 1990 to 2017) Also, the largest decrease is in the UAE and Iraq, respectively.

CONCLUSION

Despite a decrease in the incidence of gastric cancer and, possibly, due to late diagnosis and poor health services, the attenuation of gastric cancer is high in MENA countries. Therefore, it is recommended to reduce the attenuation of screening programs before 50 years old for early detection in addition to prevention programs and to reduce smoking, especially in men.

Survival analysis in gastric cancer: a multi-center study among Iranian patients

BACKGROUND

Gastric cancer (GC) has been considered as the 5th most common type of cancer and the third leading cause of cancer-associated death worldwide. The aim of this historical cohort study was to evaluate the survival predictors for all patients with GC using the Cox proportional hazards, extended Cox, and gamma-frailty models.

METHODS

This historical cohort study was performed according to documents of 1695 individuals having GC referred to three medical centers in Iran from 2001 to 2018. First, most significant prognostic risk factors on survival were selected, Cox proportional hazards, extended Cox, gamma-frailty models were applied to evaluate the effects of the risk factors, and then these models were compared with the Akaike information criterion.

RESULTS

The age of patients, body mass index (BMI), tumor size, type of treatment and grade of the tumor increased the hazard rate (HR) of GC patients in both the Cox and frailty models (P < 0.05). Also, the size of the tumor and BMI were considered as time-varying variables in the extended Cox model. Moreover, the frailty model showed that there is at least an unknown factor, genetic or environmental factors, in the model that is not measured (P < 0.05).

CONCLUSIONS

Some prognostic factors, including age, tumor size, the grade of the tumor, type of treatment and BMI, were regarded as indispensable predictors in patients of GC. Frailty model revealed that there are unknown or latent factors, genetic and environmental factors, resulting in the biased estimates of the regression coefficients.

Relationship between DLEC1 and PBX3 promoter methylation and the risk and prognosis of gastric cancer in peripheral blood leukocytes

PURPOSE

Aberrant DNA methylation could regulate the expression of tumor suppressor gene DLEC1 and oncogene PBX3 and was related to the occurrence and prognosis of gastric cancer (GC). In this study, the associations between DLEC1 and PBX3 promoter methylation in peripheral blood leukocytes (PBLs) and the risk and prognosis of GC were investigated.

METHODS

The methylation status of DLEC1 and PBX3 promoter in PBLs of 368 GC cases and 382 controls was detected by the methylation-sensitive high-resolution melting (MS-HRM) method. Logistic and Cox regression were adopted to analyze the associations of DLEC1 and PBX3 methylation with GC risk and prognosis, respectively. Confounding biases were controlled by propensity score (PS).

RESULTS

Compared with negative methylation (Nm), DLEC1-positive methylation (Pm) was associated with increased GC risk in PS (OR 2.083, 95% CI 1.220-3.558, P = 0.007), but PBX3 Pm was not associated with GC risk. In the elderly group (≥ 60 years), DLEC1 Pm was associated with increased GC risk (OR 2.951, 95% CI 1.426-6.104, P = 0.004). The combined effects between DLEC1 methylation and consumption of dairy products, fried food intake and Helicobacter pylori (H. pylori) infection on GC risk were discovered (ORc 3.461, 95% CI 1.847-6.486, P < 0.001, ORc 3.246, 95% CI 1.708-6.170, P < 0.001 and ORc 2.964, 95% CI 1.690-5.197, P < 0.001, respectively). Furthermore, DLEC1 and PBX3 methylation were not associated with GC prognosis.

CONCLUSION

DLEC1 methylation in PBLs and the combined effects of gene-environment can influence GC risk.

Long non-coding RNAs as the critical factors during tumor progressions among Iranian population: an overview

BACKGROUND

Cancer is associated with various genetic and environmental risk factors. Beside the mutations or aberrant expression of protein-coding genes, the genetic deregulation of non-coding RNAs has also an important role during tumor progression and metastasis. Long non-coding RNAs (lncRNAs) are a class of ncRNAs larger than 200 nucleotides that may function as tumor-suppressor or oncogene.

MAIN BODY

There is a raising trend of cancer incidence among Iranian population during the last decades. Therefore, it is required to prepare a general population specific panel of genetic markers for the early detection of cancer in this population. The tissue-specific expression characteristics and high stability in body fluids highlight the lncRNAs as efficient diagnostic and prognostic noninvasive biomarkers in cancer. In present review we summarized all of the lncRNAs which have been reported until now in different tumors among Iranian patients.

CONCLUSIONS

This review paves the way of introducing a population based noninvasive diagnostic panel of lncRNAs for the early detection of tumor cells among Iranian population.

Time Series Analysis of Monthly Suicide Rates in West of Iran, 2006-2013

INTRODUCTION

Iran's western provinces have higher suicide rate compared to the other provinces of the country. Although suicide rates fluctuate over time, suitable statistical models can describe their underlying stochastic dynamics.

METHODS

This study was conducted to explore the fluctuations of the monthly suicide rates in the most populated western province of Iran using exponential smoothing state space model to compute the forecasts. For this reason, the monthly frequencies of completed suicides were converted to rates per 100,000 and a state-space approach was identified and fitted to the monthly suicide rates. Diagnostic checks were performed to determine the adequacy of the fitted model.

RESULTS

A significant seasonal variation was detected in completed suicide with a peak in August. Diagnostic checks and the time series graph of the observed monthly suicide rates against predicted values from the fitted model showed that in the study period (from March 2006 to September 2013), the observed and predicted values were in agreement. Thus, the model was used to obtain the short-term forecasts of the monthly suicide rates.

CONCLUSIONS

In this study, we had no significant trend but seasonal variations in the suicide rates that were identified. However, additional data from other parts of the country with longer duration are needed to visualize the reliable trend of suicide and identify seasonality of suicide across the country.

Bivariate Spatio-Temporal Shared Component Modeling: Mapping of Relative Death Risk due to Colorectal and Stomach Cancers in Iran Provinces

BACKGROUND

Gastrointestinal cancers make for nearly half fatal cancers with colorectal and stomach cancers' being listed among the ten most common in Iran. This research aims to determine the spatial pattern and temporal trend of death risk due to colorectal and stomach cancers among provinces of Iran and estimate the effect of shared and specific components as surrogates of risk factors for the aforementioned cancers on changes of death due to the cancers over time and place.

METHODS

In this ecological study, the data regarding death causes in colorectal and stomach cancers during 2006-2011 were obtained from the death registration system of the Iranian Ministry of Health. The estimation of relative risk (RR) of death due to the target cancers was performed applying Bayesian spatiotemporal shared component (SC) model in OpenBUGS software.

RESULTS

North-Western provinces ranked first regarding stomach cancer RR of death (RR >1.75). Furthermore, some North-Western and central provinces had the highest RR of death due to colorectal cancer (RR >1.5). The SC surrogating the risk factor shared between both cancers had the most effect in Northern, North-Western and western provinces, and the least effect in Southern and South-Eastern ones.

CONCLUSIONS

North and North-West of Iran found to be the high-risk area for death due to both stomach and colorectal cancers and South-East and South provinces shown to have the lowest RR. The obtained results can be illuminating to health resource allocation to the health policymakers.