Burden of gastrointestinal cancer in Asia; an overview

The cancers in the digestive system including gastric cancer, colorectal cancer, liver cancer, esophageal cancer and pancreatic cancer are one of the most common cancers in Asia. The burden of GI cancer is increasing in Asia because of aging, growth of the population and the risk factors including smoking, obesity, changing lifestyle and high prevalence of H pylori, HBV and HCV. In most Asian countries, cancer control programs or early detection and treatment services are limited despite this increase. There are many people in the developing countries inside Asia who have no health insurance and many of them are too poor to go for screening tests, early detection or medical treatments. Therefore, it is important for the health organizations and governments in each country to recognize these groups and reduce the incidence and mortality of gastrointestinal cancers, using simple and economic screening test, vaccination and changing risk factors such as smoking, diet and lifestyle by education programs

Recurrence and five -year survival in Colorectal Cancer patients after surgery

Background: Colorectal cancer [CRC] is a common malignancyworldwide and its outcome is most closely related to the extent of disease at presentation. Early diagnosis of an asymptomatic recurrence increases the likelihood of a complete surgical resection

Objectives: The aim of this study was to evaluate the incidence of colorectal cancer recurrence and survival rate within 5 years, after surgery

Patients and Methods: During the 9-year period since 21[st] Mar, 2004 to 20th Mar, 2013, patients whose primary colorectal cancer were resected in Taleghani hospital, Tehran, Iran were selected in a historical cohort. The necessary data such as demographic, age, gender, family history of CRC, site and size of tumor, stage of tumor, operation details, histological results, treatment method, histopathologic, etc. were collected. Then the recurrence and survival of colorectal cancer within 5 years after operation and their risk factors were evaluated. P value less than 0.05 were considered significant. All analysis was done using SPSS software

Results: A total of 107 patients underwent resection for colorectal cancer during the study period, with mean age of 53.50 +/- 12.68 years [range 24 - 76 years], survival rate of 73.8% [rectum 70.0% and colon 75.9%], and mean survival time of 142.17 +/- 21.60 month. The recurrence rate of CRC patients, during five years after surgery was 5.7%. Regional lymph nodes, Distance metastasis and Adjuvant therapy were significant prognosis factors of survival after surgery

Conclusions: The rate of recurrence in Iranian patients was low, which could be due to improvement of exactness and expertise of surgeons or better adjuvant therapy. The significant association between survival and adjuvant therapy clarifies this finding. Early diagnosis and primary detection could increase the rate of survival

Polymorphism of SMAD 7 gene [rs2337104] and risk of colorectal cancer in an Iranian population: a case-control study

The purpose of this study was to evaluate the influence of intronic polymorphism of the SMAD7 [Mothers Against Decantaplegic Homolog 7] gene [rs2337104] on the risk of colorectal cancer [CRC] and clinicopathological features in an Iranian population. SMAD7 has been identified as an antagonist of transforming growth factor beta [TGF-b]-mediating fibrosis, carcinogenesis, and inflammation. Regarding to the recent genome-wide scan, a risk locus for colorectal cancer at 18q21 has been found, which maps to the SMAD7 gene. This case-control study was performed on 109 CRC patients and 109 healthy controls recruited in Taleghani Hospital. The genotyping of all samples were done by TaqMan assay via an ABI 7500 Real Time PCR System [Applied Biosystems] with DNA from peripheral blood. The association of this polymorphism with the risk of CRC and clinico pathological features was investigated. Our results indicated that there were no significant association between genotypic and allelic frequencies of SMAD7 polymorphism [rs2337104] and CRC risk in our population. Although the T allele is the most frequent one in this population and its frequency was 86.7% in patients compared with 91.7% in controls [OR=1.705, 95% CI= 0.916-3.172]. Also, the SMAD7 genotypes were not associated with any clinicopathological characteristics in CRC patients [P>0.05]. For the first time, this study results revealed that this SMAD7 polymorphism couldn't be a potential risk factor for CRC or a prognostic biomarker for prediction of clinicopathological features in an Iranian population. A large-scale case-control study is needed to validate our results

Application of semi-parametric single-index two-part regression and parametric two-part regression in estimation of the cost of functional gastrointestinal disorders

For the purpose of cost modeling, the semi-parametric single-index two-part model was utilized in the paper. Furthermore, as functional gastrointestinal diseases which are well-known as common causes of illness among the society people in terms of both the number of patients and prevalence in a specific time interval, this research estimated the average cost of functional gastrointestinal diseases. Health care policy-makers seek for real and accurate estimations of society's future medical costs. However, data dealt with in hygienic studies have characteristics which make their analysis complicated; distribution of cost data is highly skewed since many patients pay great costs. In addition, medical costs of many persons are zero in a specific time interval. Indeed, medical costs data are often right skewed, including remarkable number of zeros, and may be distributed non-homogeneously. In modeling these costs by the semi-parametric single-index two-part model, parameters were determined by method of least squares; a result of this method was compared with the results yielded from two-part parametric model. Average costs of functional gastrointestinal diseases and their standard deviation in semi-parametric and parametric methods were yielded as $72.69 +/- 108.96 [R[2]=0.38] and $75.93 +/- 122.29 [R[2]=0.33] respectively. Based on R[2] index, the semi-parametric model is recognized as the best model. Totally, the two-part parametric regression model is a simple and available model which can be easily interpreted; on the other hand, though the single-index two-part semi-parametric model cannot be easily interpreted, it has considerable flexibility. The study goals can be indeed used as me main factor for choosmg one of these two models

Study of association between interleukin 20 polymorphism [Rs1518108] and chronic hepatitis C infection

Chronic hepatitis C is a major concern for global health as it causes liver problems, cirrhosis and liver cancer. Immune factors have a determinant role in susceptibility to chronic infection or clearance of infection in body. As a defensive agent, cytokines are important factors of immune system, since they can activate immune response or inhibit virus replication directly. The aim of this study is the evaluation of interleukin 20 polymorphism [rs1518108] in hepatitis C patients. This survey was a case-control study. By using PCR-RFLP method, 105 patients and 135 controls were studied randomly. We used SPSS-16 software for statistical analysis. A 10Tsignificant association was found between polymorphism [rs1518108] of interleukin 20 and hepatitis C patients [p=0.035] [OR=2.283]. The incidence of hepatitics C in males was observed five times more than that one females [p=0.01] [OR=5.18]. In addition, no significant association between polymorphism of genotypes and liver harms [chronic and cirrhosis] was found in this study [p=0.362]. Our findings show that variants of interleukin 20 polymorphism [rs1518108] in the population of the study are important factors for being affected by hepatitis C. The incidence of heterozygote allele CT was more than of homozygote genotype TT

Leukemia cancer mortality trend in Iran, from 1995 to 2004

Cancer is the third most common cause of death in Iran, the leukemia cancer is one of the most important causes of cancer mortality. Regarding cancer mortality, data would be important to monitor the program screening effects, earlier diagnosis, demographic data and other prognostic factors. The aim of this study was mortality rates evaluating, then leukemia cancer trends among the Iranian population within almost a period of a decade, i.e. from 1995 to 2004. National death Statistic Reported by Ministry of Health and Medical Education [MOH and ME] from 1995 to 2004, stratified by age group, sex, and cause of death, have included in this study. Leukemia cancer has expressed as the annual mortality rates/100,000, in general, and/or per gender, and age group. The general mortality rate of leukemia cancer has slightly increased within the mentioned study period, from 0.44 to 2.54, then leukemia cancer mortality has often seen in men more than women. The mortality rate of leukemia has significantly increased throughout Iran. Associated risk factors with leukemia have headmost identified for their prevention and control. So, future studies to reveal leukemia risk factors among the Iranian population would be crucial in order to control its burden

Sample size calculation in medical studies

Optimum sample size is an essential component of any research. The main purpose of the sample size calculation is to determine the number of samples needed to detect significant changes in clinical parameters, treatment effects or associations after data gathering. It is not uncommon for studies to be underpowered and thereby fail to detect the existing treatment effects due to inadequate sample size. In this paper, we explain briefly the basic principles of sample size calculations in medical studies

Statistical count models for prognosis the risk factors of hepatitis C

The aim of this study was to compare alternatives methods for analysis of zero inflated count data and compare them with simple count models that are used by researchers frequently for such zero inflated data. Analysis of viral load and risk factors could predict likelihood of achieving sustain virological response [SVR]. This information is useful to protect a person from acquiring Hepatitis C virus [HCV] infection. The distribution of viral load contains a large proportion of excess zeros [HCV-RNA under 100], that can lead to over-dispersion. This data belonged to a longitudinal study conducted between 2005 and 2010. The response variable was the viral load of each HCV patient 6 months after the end of treatment. Poisson regression [PR], negative binomial regression [NB], zero inflated Poisson regression [ZIP] and zero inflated negative binomial regression [ZINB] models were carried out to the data respectively. Log likelihood, Akaike Information Criterion [AIC] and Bayesian Information Criterion [BIC] were used to compare performance of the models. According to all criterions, ZINB was the best model for analyzing this data. Age, having risk factors genotype 3 and protocol of treatment were being significant. Zero inflated negative binomial regression models fit the viral load data better than the Poisson, negative binomial and zero inflated Poisson models

effect of 5'untranslated region polymorphism in EGF gene, rs4444903, on colorectal cancer

The purpose of this study was to determine the relationship of rs4444903 [EGF+61A/G] SNP genotype with colorectal cancer and tumor stage in an Iranian population. Epidermal growth factor [EGF] is one of the important proteins that determine survival of cells. EGF binds to its receptor on the cell surface and then activates some of the cell signaling pathway networks within cells that lead to activation or deactivation of factors which are responsible for growth and apoptosis of cells. In this study we assessed the association in EGF polymorphism rs4444903 with colorectal cancer [CRC] in Iranian population. We conducted case-control study to investigate the association of polymorphism rs4444903 in EGF, with colorectal cancer risk in Iranian population. Analyzed Polymorphism of EGF rs4444903 with restriction fragment length polymorphisms [RFLP] among two groups of subjects consisting of including 220 cases with colorectal cancer and 220 healthy individuals as controls. Mutations were confirmed in 10% of the samples by direct sequencing. The frequencies of AA, AG and GG genotypes among cases with colorectal cancer were 28.2, 46.8, and 25.0% respectively and in controls genotype frequencies were 23.2, 56.4, and 25.0%, respectively. Frequency of A allele among case group was 51.6% and for control group was 51.4%. The frequency of G allele in case and control was, respectively 48.4% and 48.6% [OR= 1.009, 95% CI= 0.775-1.315; P= 0.946]. The percentage of Stage 0, I, II, III, IV were 5%, 9.35%, 38.84%, 30.21% and 16.54%, respectively, among the cases. However, no significant association between this polymorphism and CRC stage was observed [p=0.626]. Our data suggest a SNP rs4444903 may not represent a risk factor in the development and progression of CRC among Iranian population

Estimation of average diagnosis and treatment costs of hepatitis C

the objective of this study was to estimate the average cost of diagnosis and treatment of hepatitis C among patients based on their treatment regime, during the one course of treatment and six-month after stopping that. Hepatitis C virus [HCV] infection is a major cause of liver-related morbidity and mortality worldwide and a major public health problem. All data for this cross-sectional study were collected from medical records of 200 patients with hepatitis C, who referred to a private gastroenterology clinic between years 2005 through 2009. Information related to the 200 patients was extracted from their medical records and finally, 77 patients of them, who their treatment was not interfering with any other disease entered in this study. Therefore diagnosis and treatment costs of these patients were calculated. Attributable costs were reported as purchasing power parity dollars [PPP$]. Mean costs of diagnosis and treatment in one course of treatment and six month after that with standard interferon plus ribavirin [INF-RBV] exceeds 3,850 PPP$ and for patients who treated with peg-interferon plus ribavirin [PEG-RIBV] was 16,494 PPP$. Also in both types of treatment, medication cost was found to be a dominant cost component. Hepatitis C represents a very important and potentially costly disease to managed care organizations. Patients with this disease require expensive drug therapies and consume significant health care resources

[Association of the insulin gene polymorphism and colorectal cancer]

Some studies have determined that polymorphism in insulin gene are associated with increased insulin level and resistant to insulin and also cause to increase risk of colorectal cancer [CRC]. The goal of this study was to evaluate incidence of the insulin gene polymorphism [rs689] in an Iranian population and to investigate the role of this polymorphism in increased risk of CRC. Genotyping of the insulin gene were determined in a series of 110 colorectal cancer patients and 110 controls by using polymerase chain reaction and restriction fragment length polymorphism genotyping assays [PCR-RFLP]. P value for genotype AT compared with AA, was 0.052 [OR=1.88, CI=0.99-3.5] and TT versus AA was 0.57 [OR=1.33 CI=0.48- 3.6]. The results showed that the insulin gene polymorphism [rs689] is not a predisposing factor to increased risk to CRC [P=0.14]. Incidence of mutant allele between patients and controls had no significant differences [OR=1.53 95% CI=0.98- 2.39, Pe=0.057]. These findings suggest that the insulin gene polymorphism [rs689] is not associated with increased risk of CRC

How to control confounding effects by statistical analysis

A Confounder is a variable whose presence affects the variables being studied so that the results do not reflect the actual relationship. There are various ways to exclude or control confounding variables including Randomization, Restriction and Matching. But all these methods are applicable at the time of study design. When experimental designs are premature, impractical, or impossible, researchers must rely on statistical methods to adjust for potentially confounding effects. These Statistical models [especially regression models] are flexible to eliminate the effects of confounders

History of upper gastrointestinal cancers in relatives: a community-based estimate

The present study aimed to evaluate the prevalence of positive family history of these cancers in a large population-based sample of Tehran province, capital of Iran. Upper gastrointestinal [UGI] cancers [gastric and esophagus cancer] constitute a major health problem worldwide. A family history of cancer can increase the risk for developing cancer and recognized as one of the most important risk factors in predicting personal cancer risk. This study designed as a cross-sectional survey in general population [2006-2007] of Tehran province. Totally 7,300 persons [age>= 20 years] sampled by random sampling on the basis of the list of postal, of whom 6,700 persons agreed to participate [response rate 92%]. Respondents were asked if any first-degree [FDR] or second-degree [SDR] relatives had gastric or esophageal cancer. Totally, 6,453 respondents [48% male] entered to the study. The mean age of responders with positive FH was significantly higher than those with negative FH [P<0.05]. In total, 341 respondents [5.3%] reporting a history of UGI cancers in their relatives, 134[2.1%] in FDRs, and 207[3.2%] in SDRs. Our findings showed that the reported prevalence of FH of UGI cancers was relatively low and varied by specific respondent characteristics such as age and sex. However, the estimates of prevalence presented here are likely to be conservative compared with actual prevalence because of self-reported data gathering

Epidemiological features of gastro-esophageal reflux disease in Iran based on general population

The aim of this study was to evaluate the epidemiology of GERD base on population study in Tehran providence. Gastro-esophageal reflux disease [GERD] is a common and chronic problem. Recent reports from developing counties indicate increment in the incidence and prevalence of the disease over the past. This study was a cross-sectional household survey conducted from May 2006 to December 2007 in Tehran province, Iran. Participants completed a valid gastro-esophageal reflux Questionnaire. The questionnaire included personal and family characteristics such as age, gender, and educational status. In addition, interviewers asked them regarding 10 GI symptoms. Altogether 18180 individuals participated in this cross-sectional study. The mean +/- SD age of participant was 38.7 +/- 17.1 and 9072 [49.9%] were women. The prevalence of GERD was 8.85 [8.43-9.26]. There was significant relationship between age, sex, marital and educational status with GERD. GERD symptoms were more common in women, older people, individuals with low education and married people. There was overlap between GERD, irritable bowel syndrome [IBS] and uninvestigated dyspepsia [UD]. According to our finding although the prevalence of GERD in our population is less than other studies, this prevalence is increasing in recent years

Bloating in irritable bowel syndrome

The purpose of this study was to describe the occurrence of self report bloating and related factors n patients with irritable bowel syndrome [IBS]. Bloating symptoms are common in patients with IBS and have significant impact on normal daily function. This study was a community-based cross-sectional survey that conducted using a valid questionnaire base on Rome III criteria. Univariate analysis was used for investigation about distribution of self reported bloating according to demographic and psychological factors in irritable bowel syndrome patients. Out of 18180 subjects under study, 198 cases met criteria for the diagnosis of the irritable bowel syndrome according to criteria ROME III and 61.6% reported bloating symptoms. Bloating symptoms were more prevalent among patients with intermittent symptoms and diarrhea that in patients with constipation. Catastrophic events and depression were independent risk factors for bloating. Findings of this study support the clinical impression regarding the high prevalence of bloating symptoms in patients with irritable bowel syndrome. Further studies are needed to understand the role of physiological and psychological factors and their interaction in development of bloating in irritable bowel syndrome patients

[Prevalence of norovirus infection and determination of the dominant genogroup in children with acute gastroenteritis in Tehran, 2008-2009]

One of the most important pathogens responsible for acute gastroenteritis is Human Norovirus [NoV], causing >85% of all nonbacterial outbreaks of gastroenteritis reported in Europe. NoVs are members of the Family Caliciviridae. There are three infectious genogroups; genogroups I and II are recognized as the major cause of NoVs infections in humans. The aim of this study was to determine the rate of pediatric diarrhea caused by NoVs infection in children under 10 years with acute gastroenteritis admitted in Mofid Children's Hospital. During May 2008 to May 2009 we collected 204 stool samples from children under 10 years with acute gastroenteritis. RNA was extracted and RT-PCR was performed using specific primers. Using these primers we could distinguish between genogroup I and II of NoVs. Stool samples of 23 children [11.3%] were positive for NoVs RNA and 6 positive samples belonged to genogroup I [26%], 74% belonged to the genogroup II. The mean age of NoVs infected patients was 4 +/- 2.8 years. The results revealed the role of NoVs as one of the viral agents responsible for gastroenteritis in children. It also demonstrates the predominance of genogroup II of Norovirus

Economic burden of gastro-oesophageal reflux disease and dyspepsia: a community-based study

Gastro-oesophageal reflux disease [GERD] and dyspepsia are common digestive disorders that inflict serious harm, burden and economic consequences on individuals worldwide. The aim of this study was to estimate the direct and indirect economic burden of GERD and dyspepsia in the whole population of Tehran, the capital of Iran. The study was performed on a total of 18,180 adult subjects [age > 18 years] taken as a random sample in Tehran province, Iran [2006-2007]. A valid and reliable questionnaire was used to enquire about the symptoms of GERD, dyspepsia and the frequency of the utilization of health services including physician visits, hospitalisations and productivity loss due to GERD/dyspepsia symptoms in the preceding 6 months. GERD was found in 518 [41.9% males] patients and dyspepsia in 404 patients [38.9% males]. Further 1007 subjects had both GERD and dyspepsia. The total direct costs of disease per patient for GERD, dyspepsia and their overlap were PPP$97.70, PPP$108.10 and PPP$101.30, respectively [PPP, purchasing power parity dollars]. The total indirect cost of disease per patient was PPP$13.7, PPP$12.1 and PPP$32.7, for GERD, dyspepsia and their overlap, respectively. According to our results, hospitalisation and physician visits were the main cost of disease that could be minimized by revision of the insurance business in Iran

[Frequency of colorectal cancer in healthy individual's relatives: a cross-sectional population-based study]

Family history of colorectal cancer has been shown to be related to the risk of developing colorectal cancer. This risk depends on the number of affected relatives and the age at diagnosis. In this study we aimed to estimate the frequency of a positive family history of colorectal cancer in a random sample from Tehran population. This study was a community-based cross-sectional survey conducted from May 2006 to December 2007 in Tehran province, Iran. A total of 5,500 peoples [age >/= 20 years] drawn up randomly by random sampling according to postal codes and invited to participate in the study. All participants completed a detailed health data registry form on family history status of colorectal cancer. The mean age of men with a positive family history was significantly different from men with negative family history. There was no significant difference between mean age of women responders with or without positive family history. Among all participants [n=5,500], 162 responders [2.9%] had a history of colorectal cancer. Of 162, 67 responders [1.22%] had one and 4[0.07%] had two or more first-degree relative with colorectal cancer. Of 5,500 participants, 18 subjects [0.33%] reported having two or more first-degree relative with colorectal cancer or one first-degree relative with colorectal cancer diagnosed at age<50 years. Four subjects [0.07%] had three or more first-degree relative with colorectal cancer. Based on the findings, we estimate that more than 570,000 subjects in the Iran in the age group >/= 20 years have at least two to three times increased risk of developing colorectal cancer which should be identified and encourage to participate in screening and surveillance protocols of colorectal cancer

Functional bowel disorders in Iranian population using Rome III criteria

To study the prevalence and risk factors of functional bowel disorders [FBD] in Iranian community using Rome III criteria. This study was a cross-sectional household survey conducted from May 2006 to December 2007 in Tehran province, Iran, including 18, 180 participants who were selected randomly and interviewed face-to-face by a validated questionnaire based on Rome III criteria. In all, 1.1% met the Rome III criteria for irritable bowel syndrome [IBS], 2.4% for functional constipation [FC], and 10.9% of the participants had any type of FBD. Among participants with functional dyspepsia, 83.3% had FBD; the majority cases were unspecified functional bowel disorder [U-FBD]. Of the subjects fulfilling the IBS criteria, IBS with constipation [52%] was the most frequent subtype. In the multivariate analysis, women had a higher risk of any FBDs than men, except for functional diarrhea [FD]. The prevalence of FBD, FC and FD increased and IBS decreased with increasing age. Marital status was only associated with a decrease in the risk of FBD and FD, respectively. IBS subtypes compared with FC and FD. There was no significant difference between FC and IBS with constipation [IBS-C], except for self-reported constipation; while, IBS with diarrhea [IBS-D] had more symptoms than FD. This study revealed a low rate of FBDs among the urban population of Tehran province. The ROME III criteria itself, and the problems with interpretation of the data collection tool may have contributed in underestimating the prevalence of FBD. In addition the reliability of recall over 6 months in Rome III criteria is questionable for our population

[Evaluation of 4-year survival in familial and non familial colorectal cancer]

Colorectal cancer in the world is located in the third position among common cancers in both sexes. It is the second cancer which has the most mortality .The incidence of this cancer in the last decades has transcended trend in our population. The aim of this study was comparison of 4-year survival between sporadic and hereditary colorectal cancer. In this descriptive-analytic study, 121 patients with colorectal cancer were collected including 61 patients with sporadic and 60 individuals with HNPCC who were referred to research cancer gastroenterology and liver diseases of Taleghani hospital during 2004-2008. Survival rate was estimated using the Kaplan Meier method and compared with log rank test. Multivariate analysis was performed using the Cox regression analysis. 4-year survival in sporadic colorectal cancer and HNPCC showed a significant difference. The rate of survival in HNPCC patients was 82.5%, while it was 56.4% [p=0.044] in sporadic colorectal cancer. Age of diagnosis in sporadic patients was higher than hereditary group. Odds ratio of sporadic colorectal cancer for tumor location was 2.93 [95%CI: 1.06-8.11] compared HNPCC [p=0.038]. The result of this study was compatible with the previous studies. The result showed that the rate of survival in patients with HNPCC is higher than sporadic cases