Colorectal Cancer: Epidemiology, Risk Factors, and Prevention.

Colorectal cancer (CRC) is the third most common cancer and the second most common cause of cancer mortality worldwide. There are disparities in the epidemiology of CRC across different populations, most probably due to differences in exposure to lifestyle and environmental factors related to CRC. Prevention is the most effective method for controlling CRC. Primary prevention includes determining and avoiding modifiable risk factors (e.g., alcohol consumption, smoking, and dietary factors) as well as increasing protective factors (e.g., physical activity, aspirin). Further studies, especially randomized, controlled trials, are needed to clarify the association between CRC incidence and exposure to different risk factors or protective factors. Detection and removal of precancerous colorectal lesions is also an effective strategy for controlling CRC. Multiple factors, both at the individual and community levels (e.g., patient preferences, availability of screening modalities, costs, benefits, and adverse events), should be taken into account in designing and implementing CRC screening programs. Health policymakers should consider the best decision in identifying the starting age and selection of the most effective screening strategies for the target population. This review aims to present updated evidence on the epidemiology, risk factors, and prevention of CRC.

Breast cancer incidence trends in Golestan, Iran: An age-period-cohort analysis by ethnic region, 2004-2018.

BACKGROUND: We aimed to examine the effects of age, diagnosis year (calendar period) and birth year (cohort) on the incidence trends of breast cancer among Golestan women, Northeast Iran, 2004-2018. METHODS: Incidence data were obtained by residential status (urban/rural) and ethnic region (Turkmens/non-Turkmens). We calculated age-standardized incidence rates (ASRs) per 100,000 person-years. The estimated annual percentage change (EAPC) were calculated, and age-period-cohort (APC) models fitted to assess non-linear effects of period and cohort as incidence rate ratios (IRRs). RESULTS: The total number of female breast cancer cases in Golestan, 2004-2018, were 3853, with an overall ASR of 31.3. We found higher rates in urban population (40.5) and non-Turkmens region (38.5) compared to rural area (20.8) and Turkmens region (20.2), respectively. There were increasing trends in incidence rates overall (EAPC= 4.4; 95%CI: 2.2, 6.7), with greater changes in rural areas (EAPC=5.1), particularly among non-Turkmens (EAPC=5.8). The results of the APC analysis indicate the presence of significant non-linear cohort effects with increasing IRRs across successive birth cohorts (IRR=0.1 and IRR= 2.6 for the oldest and the youngest birth cohorts vs. the reference birth cohort, respectively). CONCLUSION: We found increasing trends in breast cancer incidence among Golestan women over the study period, with disparities in patterns and trends by residence area and ethnic region. The observed cohort effects suggest an increasing prevalence of key risk factors for breast cancer in this Iranian population. Further investigations are warranted to clarify the relationships between determinants such as reproductive factors and ethnicity in the region.

Incidence and Temporal Variations of Bone and Soft Tissue Cancers in the Golestan Province, Northern Iran, 2004-2016.

BACKGROUND: This study was conducted to evaluate the epidemiological features of bone and soft cancers in the Golestan province, Northern Iran from 2004 to 2016. METHODS: This is a descriptive cross-sectional study. All patients with primary bone and soft tissue cancers between 2004 and 2016 were included. Data were obtained from Golestan population-based cancer registry (GPCR). We calculated age-standardized incidence rates (ASRs) and reported the rates per 100000 person-year. Estimated annual percent change (EAPC) was also calculated to assess temporal trends in incidence rates of these cancers. RESULTS: The ASRs of bone cancers and soft tissue cancers were 1.33 and 1.43 per 100000 person-year, respectively. This study also showed that the ASR of bone cancer was higher in men (1.51) than women (1.15). The ASR of soft tissue cancers in the urban population (1.58) was higher than rural (1.27), and was lower in women (1.37) than men (1.49). Two peaks were seen in the incidence of bone cancer. The first peak was in the age group of 10 to 20 years and the second was in patients over 60. We did not find significant temporal trends in the incidence of bone (EAPC=-1.14; P>0.05) and soft tissue cancers (EAPC=-2.73; P>0.05) during the study period. CONCLUSION: Epidemiological features of bone and soft tissue cancers including gender, age and place of residence should be considered by health policy makers in designing cancer control programs.

Colorectal cancer incidence trends in Golestan, Iran: An age-period-cohort analysis 2004-2018.

BACKGROUND: We investigated the effects of factors including age, birth year (cohort) and diagnosis year (period) on colorectal cancer (CRC) incidence trends in Golestan, Northeast of Iran, 2004-2018. METHODS: We obtained data on incidence cases of CRC from the Golestan Population-based Cancer Registry by sex and area of residence (urban/rural). Age-standardized incidence rates (ASRs) were calculated using the World standard population and presented per 100,000 person-years. We calculated the estimated annual percentage change (EAPC) with 95 % confidence intervals (95 % CI) fitted age-period-cohort (APC) models to assess non-linear period and cohort effects as incidence rate ratios (IRRs). RESULTS: Overall, 2839 new cases of CRC (ASR = 13.7) were registered in the GPCR over 2004-2018. Our findings suggested significantly increasing trends in CRC incidence rates from 2004 to 2018 (EAPC = 3.7; 95%CI: 0.4, 7.1), with the greatest changes occurring in rural women (EAPC= 4.7; 95%CI: 0.4, 9.2). We observed a strong cohort effect with a consistent increase in the IRR across successive birth cohorts, starting with the oldest birth cohort (1924) (IRR= 0.1 versus the reference birth cohort of 1955) through to the most recent cohort born in 1983 (IRR= 1.9). The largest cohort effects were found among rural females (IRR = 0.0, and IRR = 2.5 for the oldest and the youngest birth cohorts vs. the reference birth cohort, respectively). CONCLUSION: The increasing trends in CRC rates in Golestan are largely driven by generational changes in exposure to underlying risk factors. Further investigations are warranted to deliver effective prevention strategies for the control of CRC in Golestan.

Esophageal and gastric cancer incidence trends in Golestan, Iran: An age-period-cohort analysis 2004 to 2018.

Golestan province in the northeast of Iran is part of the Asian esophageal cancer belt and is known as a high-risk area for esophageal (EC) and gastric cancers (GC). Data on incident cases of EC and GC during 2004 to 2018 were obtained from the Golestan Population-based Cancer Registry (GPCR). The age-standardized incidence rates (ASRs) were calculated and presented per 100 000 person-years. The estimated annual percentage change (EAPC) with 95% confidence interval (95% CI) were calculated. We also fitted age-period-cohort (APC) models to assess nonlinear period and cohort effects as incidence rate ratios (IRRs). Overall, 3004 new cases of EC (ASR = 15.7) and 3553 cases of GC (ASR = 18.3) were registered in the GPCR. We found significant decreasing trends in incidence rates of EC (EAPC = -5.0; 95% CI: -7.8 to -2.2) and less marked nonsignificant trends for GC (EAPC = -1.4; 95% CI: -4.0 to 1.4) during 2004 to 2018. There was a strong cohort effect for EC with a consistent decrease in the IRR across successive birth cohorts, starting with the oldest birth cohort (1924; IRR = 1.9 vs the reference birth cohort of 1947) through to the most recent cohort born in 1988 (IRR = 0.1). The marked declines in EC incidence rates in Golestan relate to generational changes in its underlying risk factors. Despite favorable trends, this population remains at high risk of both EC and GC. Further studies are warranted to measure the impact of the major risk factors on incidence with a view to designing effective preventative programs.

Five-year relative survival and determinants of excess mortality in patients with head and neck and thyroid cancers: A population-based study from Golestan province, Northern Iran.

BACKGROUND: We aimed to assess relative survival (RS) and determinants of excess mortality rate in patients with head and neck squamous cell carcinomas (HNSCC) and thyroid cancer in Golestan province, Northern Iran. METHODS: We recruited new primary HNSCC and thyroid cancer cases from Golestan, 2006-2016. Five-year age-standardized RS with their 95% confidence intervals (CIs) were calculated. The relationships between different variables with excess mortality rates were assessed by estimating adjusted excess hazard ratios (aEHRs) with their 95% CIs. RESULTS: Overall, 718 cases of HNSCC and 386 thyroid cancer cases were enrolled. Five-year age-standardized RS (95% CI) were 36% (31-41) and 61% (52-69) in HNSCC and thyroid cancer patients, respectively. There were significant relationship between excess mortality rates in HNSCC patients with metastasis (aEHR= 3.31; 95%CI: 2.26-4.84), treatment type (4.19; 2.54-6.91, for no treatment as compared to receiving both surgery and chemoradiotherapy), age (2.16; 1.57-2.96, for older age group) and smoking (2.00; 1.45-2.75, for smokers as compared to non-smokers). Determinant of the excess mortality in thyroid cancer patients included metastasis (19.65; 8.08-47.79), tumor morphology (12.27; 4.62-32.58, for anaplastic cancer as compared to papillary cancer), treatment type (8.95, 4.13-19.4, for no treatment as compared to receiving both surgery and iodine therapy) and age (2.31; 1.17-4.54, for older age group). CONCLUSION: Our findings suggested low RS for thyroid cancer in our population, while the estimates for HNSCC were comparable with other population. Metastasis, treatment type and age were determinants of mortality both in thyroid and HNSCC patients.

Incidence, Time Trends and Geographical Distribution of Leukemia and Multiple Myeloma in Golestan Province, Northern Iran, 2004-2017.

BACKGROUND: Leukemia and multiple myeloma (MM) are the most common hematologic malignancies in Iran. This paper describes the geographic and temporal changes in their incidence in Golestan, northern Iran. METHODS: Data on cases of leukemia and MM during 2004-2017 were obtained from the Golestan Population-based Cancer Registry (GPCR). The GPCR is a dynamic database of Golestan residents diagnosed with primary cancers. Age-standardized incidence rates (ASRs) (per 100000) of leukemia and MM were calculated using direct standardization method considering the world standard population. We used Joinpoint regression to assess incidence trends using the average annual percent change (AAPC). RESULTS: In total, 2119 new cases of leukemia and MM were registered by the GPCR during 2004-2017. The ASRs of leukemia were 9.71 and 6.70 in males and females, respectively, while the rates were lower for MM: 2.66 and 1.97 in males and females, respectively. The incidence rates of leukemia suggested an increasing trend in urban population (AAPC=2.73; P value=0.154), while in rural area, the incidence rates were slightly decreasing (AAPC=- 0.73; P value=0.658). There were high incidence areas of leukemia in the central and western regions of Golestan. CONCLUSION: Our results suggested high incidence rates of leukemia and MM in the Golestan province. We also found geographical diversities and increasing trends in the incidence of leukemia in the urban population. Exposure to occupational and environmental carcinogens including pesticides may partly explain high rates and the observed trends. Further investigations should be considered to clarify these points in our population.

Building a Cancer Biobank in a Low-Resource Setting in Northern Iran: the Golestan Cancer Biobank.

BACKGROUND: We aim to present the development and the initial results of the Golestan Cancer Biobank (GoCB), in a low resource setting in northern Iran. METHODS: The GoCB protocol and its standard operation procedures (SOP) were developed according to internationally accepted standards and protocols with some modifications considering the limited resources in our setting. The main biological samples collected by the GoCB include blood sample, urine sample, fresh endoscopy tissue sample, fresh surgical tissue sample and formalin fixed paraffin embedded (FFPE) tissue sample. The GoCB collects patients' demographic data, tumor characteristics as well as data on risk factors. We developed a specific GoCB software for management of patient data and biological sample information. The GoCB dataset is annually linked with the Golestan cancer registry dataset to add complementary data (e.g., survival data). RESULTS: The GoCB started collection of data and biological samples in December 2016. By November 2020, a total number of 1217 cancer patients participated in the GoCB. The majority of the GoCB participants (n = 942, 77%) were those with gastrointestinal and breast cancers. Data on risk factors were successfully collected in 684 (56.2%) of the participants. Overall, 3563 samples were collected from the GoCB participants and 730 samples were used in 7 national and international research projects. CONCLUSION: We considered specific strategies to overcome major limitations, especially budget shortage, in the development and maintenance of a cancer-specific biological repositories in our setting. The GoCB may be considered as a model for the development of biobank in low- and middle-income countries (LMICs).

Cancer in Iran 2008 to 2025: Recent incidence trends and short-term predictions of the future burden.

Policymakers require estimates of the future number of cancer patients in order to allocate finite resources to cancer prevention, treatment and palliative care. We examine recent cancer incidence trends in Iran and present predicted incidence rates and new cases for the entire country for the year 2025. We developed a method for approximating population-based incidence from the pathology-based data series available nationally for the years 2008 to 2013, and augmented this with data from the Iranian National Population-based Cancer Registry (INPCR) for the years 2014 to 2016. We fitted time-linear age-period models to the recent incidence trends to quantify the future cancer incidence burden to the year 2025, delineating the contribution of changes due to risk and those due to demographic change. The number of new cancer cases is predicted to increase in Iran from 112 000 recorded cases in 2016 to an estimated 160 000 in 2025, a 42.6% increase, of which 13.9% and 28.7% were attributed to changes in risk and population structure, respectively. In terms of specific cancers, the greatest increases in cases are predicted for thyroid (113.8%), prostate (66.7%), female breast (63.0%) and colorectal cancer (54.1%). Breast, colorectal and stomach cancers were the most common cancers in Iran in 2016 and are predicted to remain the leading cancers nationally in 2025. The increasing trends in incidence of most common cancers in Iran reinforce the need for the tailored design and implementation of effective national cancer control programs across the country.

SARS-CoV-2 antibody seroprevalence in the general population and high-risk occupational groups across 18 cities in Iran: a population-based cross-sectional study.

BACKGROUND: Rapid increases in cases of COVID-19 were observed in multiple cities in Iran towards the start of the pandemic. However, the true infection rate remains unknown. We aimed to assess the seroprevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 18 cities of Iran as an indicator of the infection rate. METHODS: In this population-based cross-sectional study, we randomly selected and invited study participants from the general population (from lists of people registered with the Iranian electronic health record system or health-care centres) and a high-risk population of individuals likely to have close social contact with SARS-CoV-2-infected individuals through their occupation (from employee lists provided by relevant agencies or companies, such as supermarket chains) across 18 cities in 17 Iranian provinces. Participants were asked questions on their demographic characteristics, medical history, recent COVID-19-related symptoms, and COVID-19-related exposures. Iran Food and Drug Administration-approved Pishtaz Teb SARS-CoV-2 ELISA kits were used to detect SARS-CoV-2-specific IgG and IgM antibodies in blood samples from participants. Seroprevalence was estimated on the basis of ELISA test results and adjusted for population weighting (by age, sex, and city population size) and test performance (according to our independent validation of sensitivity and specificity). FINDINGS: From 9181 individuals who were initially contacted between April 17 and June 2, 2020, 243 individuals refused to provide blood samples and 36 did not provide demographic information and were excluded from the analysis. Among the 8902 individuals included in the analysis, 5372 had occupations with a high risk of exposure to SARS-CoV-2 and 3530 were recruited from the general population. The overall population weight-adjusted and test performance-adjusted prevalence of antibody seropositivity in the general population was 17·1% (95% CI 14·6-19·5), implying that 4 265 542 (95% CI 3 659 043-4 887 078) individuals from the 18 cities included were infected by the end of April, 2020. The adjusted seroprevalence of SARS-CoV-2-specific antibodies varied greatly by city, with the highest estimates found in Rasht (72·6% [53·9-92·8]) and Qom (58·5% [37·2-83·9]). The overall population weight-adjusted and test performance-adjusted seroprevalence in the high-risk population was 20·0% (18·5-21·7) and showed little variation between the occupations included. INTERPRETATIONS: Seroprevalence is likely to be much higher than the reported prevalence of COVID-19 based on confirmed COVID-19 cases in Iran. Despite high seroprevalence in a few cities, a large proportion of the population is still uninfected. The potential shortcomings of current public health policies should therefore be identified to prevent future epidemic waves in Iran. FUNDING: Iranian Ministry of Health and Medical Education. TRANSLATION: For the Farsi translation of the abstract see Supplementary Materials section.

Trends in the Incidence of Stomach Cancer in Golestan Province, a High-risk Area in Northern Iran, 2004-2016.

BACKGROUND: We aimed to present the temporal and geographical trends in the incidence of stomach cancer in the Golestan province, a high-risk area in Northern Iran. METHODS: This study was conducted on stomach cancer cases registered in the Golestan Population-based Cancer Registry (GPCR) during 2004-2016. Age-standardized incidence rates (ASRs) per 100000 person-years were calculated. The Joinpoint regression analysis was used to calculate the average annual percent changes (AAPC). We also calculated the contribution of population aging, population size and risk to the overall changes in incidence rates. RESULTS: Overall, 2964 stomach cancer patients were registered. The ASR of stomach cancer was significantly higher in men (26.9) than women (12.2) (P<0.01). There was a significant decreasing trend in incidence of stomach cancer in men (AAPC=-1.80, 95% CI: -3.30 to-0.28; P=0.02). We found a higher ASR of stomach cancer in the rural (21.4) than urban (18.1) (P=0.04) population, as well as a significant decreasing trend in its rates (AAPC=-2.14, 95% CI: -3.10to-1.17; P<0.01). The number of new cases of stomach cancer increased by 22.33% (from 215 in 2004 to 263 in 2016), of which 18.1%, 25.1% and -20.9% were due to population size, population aging and risk, respectively. Our findings suggest a higher rate for stomach cancer in eastern areas. CONCLUSION: We found high incidence rates as well as temporal and geographical diversities in ASR of stomach cancer in Golestan, Iran. Our results showed an increase in the number of new cases, mainly due to population size and aging. Further studies are warranted to determine the risk factors of this cancer in this high-risk population.

Recent cancer incidence trends and short-term predictions in Golestan, Iran 2004-2025.

BACKGROUND: We examine recent trends in the major cancers occurring in the Golestan province, a high-risk region for upper gastrointestinal cancers in Northern Iran, and provide short-term cancer predictions of the future cancer burden. METHODS: New cancer cases diagnosed in Golestan 2004-2016 were obtained from the Golestan population-based cancer registry (GPCR) database, and age-standardized rates by cancer site, year and sex calculated per 100,000 person-years. Using IARC's DepPred package we fitted time-linear age-period models to the available GPCR data to predict the cancer incidence burden in the year 2025. We calculated the contribution of demographic changes versus changes in risk to the overall changes in incidence from 2016 to 2025. RESULTS: The number of new cancer cases (excluding non-melanoma skin cancers) in 2025 is predicted to increase by 61.3% from 2678 cases in 2016 to 4319 cases. While a 17.6% reduction in the number of esophageal cancer cases is predicted by 2025, the number of new cases for each of the remaining major cancers is predicted to increase over the next decade, including cancers of the stomach (a 36.1% increase from 2016 to 2025), colorectum (56.2%), lung (67.8%), female breast (93.2%), prostate (101.8%) and leukemia (96.1%). The changes in the population structure and risk contributed 37.8% and 23.5% respectively, to the overall increase in incidence. CONCLUSION: Other than for the major upper gastrointestinal cancer types, the incidence rates of common cancers observed in the province are on the rise, reinforcing the need for continuous surveillance, as well as the design and implementation of effective cancer control programs.

Descriptive Epidemiology of Lymphoma in Northern Iran: Results from the Golestan Registry 2004-2013.

BACKGROUND: There is currently little known about the epidemiology of lymphomas in Iran. The aim of this paper is to describe the geographic and time variations in incidence rates of lymphomas in the Golestan province between 2004 and 2013. METHODS: The Golestan Population-based Cancer Registry (GPCR) routinely registers primary cancer patients from all sources (e.g. pathology centers, hospitals, etc.) throughout the Golestan province. We obtained data on newly-diagnosed lymphomas in Golestan during 2004-2013 from the GPCR dataset. Crude rates and age standardized incidence (ASR) rates (per 100000) of lymphomas were estimated, joinpoint regression was used to quantify incidence trends and average annual percent changes (AAPCs) were calculated. RESULTS: In total, 898 new cases of lymphoma were registered in the GPCR during 2004-2013. The ASR of Hodgkin lymphoma (HL) was 1.5 and 1.1 in males and females, respectively, while corresponding non-Hodgkin lymphoma (NHL) rates were greater, at 6.5 and 3.4 in males and females, respectively. Our results indicated a significant difference in the trends of HL between males (AAPC = -3.2) and females (AAPC = 3.6, P value = 0.001). The incidence rates of lymphoma were considerably higher in the urban population (ASR = 7.3) compared to those residing in rural areas (ASR = 5.3, P value = 0.054). We also found higher incidence rates for both HL and NHL in the western parts of the Golestan province. CONCLUSION: The incidence rates of lymphoma in the Golestan province are relatively high and vary geographically, with a higher incidence observed in the western area. Such differences may reflect unknown lifestyle and environmental determinants linked to ethnic susceptibility differing between the two areas.

Increasing trends of lung cancer in Golestan province, Northern Iran (2004-2016).

INTRODUCTION: We aimed to present the time trends and geographical distribution of lung cancer in Golestan province, a high-risk area for pulmonary tuberculosis (TB) in Northern Iran (2004-2016). METHODS: Data on incident primary lung cancers were obtained from the Golestan population-based cancer registry. The data were analyzed by CanReg-5 software to calculate the age-standardized incidence rates (ASRs). We used Joinpoint software for time trend analysis. Average annual percent changes were calculated. The contribution of population aging, population growth and risk to the overall changes in incidence of lung cancer were determined using partitioning analysis. RESULTS: Overall, 1829 cases of lung cancer were registered by the GPCR during 2004-2016, of which 1274 (69.7%, ASR in 2016 = 21.3) were men and 555 (30.3%, ASR in 2016 = 11.4) were women. The results of Joinpoint regression suggested a significant increasing trend in incidence of lung cancer in Golestan province during 2004 and 2016 (AAPC = 3.74; p-value = 0.01) with more prominent increasing in rural population (AAPC = 4.93; p-value<0.01). The number of new cases of lung cancer increased by 131.6% (from 98 in 2004 to 227 in 2016), of which 34.1%, 22.3% and 75.3% were due to population size, population aging and risk, respectively. Hot points of lung cancer were found in western parts of the Golestan. CONCLUSION: With high incidence rates and increasing trends of lung cancer, further studies are warranted to clarify the role of TB and other risk factors on its burden in this population.

Marked increase in breast cancer incidence in young women: A 10-year study from Northern Iran, 2004-2013.

INTRODUCTION: Breast cancer is the most frequent cancer among women worldwide. Breast cancer incidence in young women is a health issue of concern, especially in middle-income countries such as Iran. The aim of this study is to report the breast cancer incidence variations in Golestan province, Iran, over a 10-year period (2004-2013). METHODS: We analyzed data from the Golestan Population-based Cancer Registry (GPCR), which is a high-quality cancer registry collecting data on primary cancers based on standard protocols throughout the Golestan province. Age-standardized incidence rates (ASRs) and age-specific incidence rates per 100,000 person-years were calculated. Time trends in ASRs and age-specific rates were evaluated using Joinpoint regressions. The average annual percentage change (AAPC) with correspondence 95% confidence intervals (95%CIs) were calculated. RESULTS: A total of 2106 new breast cancer cases were diagnosed during the study period. Most cases occurred in women living in urban areas: 1449 cases (68%) versus 657 cases (31%) in rural areas. Statistically significant increasing trends were observed over the 10-year study period amongst women of all ages (AAPC = 4.4; 95%CI: 1.2-7.8) as well as amongst women in the age groups 20-29 years (AAPC = 10.0; 95%CI: 1.7-19.0) and 30-39 years (AAPC = 5.1; 95%CI: 1.4-9.0). CONCLUSION: The incidence of breast cancer increased between 2004 and 2013 in Golestan province amongst all age groups, and in particular amongst women aged 20-39 years. Breast cancer should be considered a high priority for health policy making in our community.

Building cancer registries in a lower resource setting: The 10-year experience of Golestan, Northern Iran.

INTRODUCTION: The Golestan population-based cancer registry (GPCR) was established in Golestan province, Northern Iran, within the Asian belt with predominance of upper-gastrointestinal cancers. We aimed to present the experiences of the registry in a resource-limited setting over the 10 years since its inception (2004-2013). METHODS: The GPCR was established as a research project to enable sustainable funding. A clear plan was developed for use of the GPCR data. New primary cancers were registered based on international standards, indices of data quality were routinely assessed and age-standardized incidence rates (ASR) per 100,000 person-years calculated using IARC's CanReg-5 software. RESULTS: Overall, 19807 new cancer cases were registered during the study period, an average of 1981 cases per annum, with overall ASR of 175.0 and 142.4 in males and females, respectively. The GPCR data suggested gastrointestinal and breast cancers as the most common malignancies in Golestan province. We observed increasing incidence rates of breast and colorectal cancers but declining trends of esophageal cancer. Overall, indices of data quality were within acceptable ranges. CONCLUSIONS: The GPCR data have been included in IARC's Cancer Incidence in Five Continents series, were used in 21 research projects, and published as 30 research papers. The key ingredients for the successful establishment and maintenance of the GPCR included sustainable sources of funding, a clear action plan for the use of data as well as stakeholder cooperation across all areas of the registration. The GPCR may be considered as a model for planning population-based cancer registries in lesser-resourced settings.

Endoscopic screening for precancerous lesions of the esophagus in a high risk area in Northern Iran.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a major health problem in many developing countries including Iran. ESCC has a very poor prognosis, largely due to late diagnosis. As a first step in developing an early detection and treatment program, we conducted a population-based endoscopic screening for ESCC and its precursor lesion, esophageal squamous dysplasia (ESD) in asymptomatic adults from Golestan Province, northern Iran, a high-risk area for ESCC, to evaluate the feasibility of such a program and to document the prevalence and risk factor correlates of ESD. METHODS: This cross-sectional study was conducted among participants of the Golestan Cohort Study (GCS), a population-based cohort of 50,000 adults in eastern Golestan Province. Randomly selected GCS participants were invited by telephone. Those who accepted were referred to a central endoscopy clinic. Eligible subjects were consented and then asked to fill in a brief questionnaire. Detailed information about selected risk factors was obtained from the GCS main database. Endoscopic examination with Lugol's iodine staining was performed, biopsies were taken from unstained lesions as well as the normally stained mucosa of the esophagus, and the biopsies were diagnosed by expert pathologists according to previously described criteria. RESULTS: In total, 1906 GCS subjects were invited, of whom only 302 subjects (15.8%) were successfully enrolled. Esophagitis (29.5%) and ESD (6.0%) were the most common pathological diagnoses. Turkmen ethnicity (adjusted OR = 8.61; 95%CI: 2.48-29.83), being older than the median age (OR = 7.7; 95% CI: 1.99-29.87), and using deep frying cooking methods (OR = 4.65; 95%CI: 1.19-18.22) were the strongest predictors for ESD. There were significant relationships between esophagitis and smoking (p-value<0.001), drinking hot tea (P value = 0.02) and lack of education (P value = 0.004). CONCLUSION: We observed a low rate for participation in endoscopic screening. Overall prevalence of ESD was 6.0%. Developing non-endoscopic primary screening methods and screening individuals with one or more risk factors may improve these rates.

Marked increase in the incidence rate of esophageal adenocarcinoma in a high-risk area for esophageal cancer.

BACKGROUND: Esophageal cancer (EC) is the eighth common cancer worldwide. Esophageal squamous cell carcinoma (ESCC) and adenocarcinoma (EAD) are the most common histologic types of EC. Many recent reports showed an increasing trend in EAD and a decreasing trend in ESCC in many Western countries. Golestan Province in northeastern Iran has been known as a high-risk area for EC. The aim of this study was to describe the time trend of EAD in this area between 2000-2009. METHODS: Data on cancer cases were obtained from Golestan Population-based Cancer Registry. Analysis was done using Joinpoint software. To examine the incidence trends, the annual percent change was calculated. The possibilities of anatomic and histologic misclassification were considered by assessing the trend of ESCC and gastric adenocarcinoma.  RESULTS: A total number of 1186 histologically-confirmed EC cases were recruited. The incidence rate of EAD showed a significant increasing trend. There was no significant trend in the incidence of ESCC during the study period. A significant increase in the incidence rate of gastric adenocarcinoma   was observed during the period of 2000-2005, followed by a plateau during the period of 2005-2009. CONCLUSIONS: We found a significant increasing trend in the incidence rate of EAD. We find no evidence to support an alternative explanation including anatomic and histologic misclassification. So, the observed rise in the incidence of EAD seems to be real. Therefore, designing and implementation of control programs, including control of preventable risk factors of EAD, should be considered in this high- risk area.

Aflatoxin contamination of wheat flour and the risk of esophageal cancer in a high risk area in Iran.

BACKGROUND: Golestan province in northeastern Iran has been known as a high-risk area for esophageal cancer (EC). This study was conducted to assess aflatoxin (AF) contamination of wheat flour (WF) samples in high and low EC-risk areas of Golestan province. METHODS: Four WF samples were collected randomly from each of 25 active silos throughout the province in 2009. The levels of AFs were measured using the High-performance liquid chromatography method. Using the data of EC rates obtained from Golestan population-based cancer registry, the province was divided into high and low risk areas for EC. Student t-test and multivariate regression analysis were used to compare the levels of aflatoxins as well as the condition of silos between the two areas. RESULTS: One hundred WF samples were collected. The mean levels of total aflatoxin and aflatoxin B1 was 1.99 and 0.53 ng g(-1), respectively. The levels of total AF (p = 0.03), AFG2 (p = 0.02) and AFB1 (p = 0.003) were significantly higher in samples obtained from high risk area. Multivariate regression analysis showed that humidity of silo was the most important source of difference between silos of the two areas (p = 0.04). CONCLUSION: We found a positive relationship between AF level of WF samples and the risk of EC. So, AF contamination may be a possible risk factor for EC in our region. We also found that humidity of silos was the most important determinant of AF contamination of WF. Intensive control of silos conditions including humidity and temperature are needed especially in high EC-risk areas.

Epidemiology of Helicobacter pylori infection among Iranian children.

BACKGROUND AND STUDY AIMS: Infection with Helicobacter pylori (HP) either in children or in adults is a risk factor for gastric cancer. The Golestan province located in northeast Iran has been known to be a high-risk area for oesophageal and gastric cancers. This study was conducted to assess the epidemiology of this infection in the children of Golestan. PATIENTS AND METHODS: This study was carried out in 2009 on healthy children (1-15years) of the Golestan province. Serum immunoglobulin G (Ig G) antibody against HP was tested in these children and positive samples were tested for anti-cytotoxin-associated antigen A (anti-CagA) antibody. To assess the relationship between HP infection and the risk of gastric cancer, the Golestan province was divided into high- and low-risk areas based on the incidence rate of gastric cancer. The chi-squared test was used to assess the relationship between variables. RESULTS: Totally, 194 subjects were recruited. The prevalence of HP infection in our area was 50.5%. The prevalence of HP infection was significantly higher in the high-risk than in the low-risk area for stomach cancer (p=0.004). The seropositivities of HP (p=0.03) and CagA (p=0.04) were significantly lower in children <5years than in others. CONCLUSION: Our results showed a high prevalence of HP infection in children of the Golestan province of Iran. We also found a significant positive relationship between childhood HP infection and the risk of gastric cancer. Hence, childhood HP infection may be considered a possible determinant of gastric cancer in this high-risk area. Implementation of preventive programmes may help to reduce the burden of childhood HP infection and, consequently, gastric cancer in this area.