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.

Population-based cancer survival in the Golestan province in the northeastern part of Iran 2007-2012.

OBJECTIVE: We studied 5-year relative survival (RS) for 14 leading cancer sites in the population-based cancer registry (PBCR) of Golestan province in the northeastern part of Iran. METHODOLOGY: We followed patients diagnosed in 2007-2012 through data linkage with different databases, including the national causes of death registry and vital statistics office. We also followed the remaining patients through active contact. We used relative survival (RS) analysis to estimate 5-year age-standardized net survival for each cancer site. Multiple Imputation (MI) method was performed to obtain vital status for loss to follow-up (LTFU) cases. RESULTS: We followed 6910 cancer patients from Golestan PBCR. However, 2162 patients were loss to follow-up. We found a higher RS in women (29.5%, 95% CI, 27.5, 31.7) than men (21.0%, 95% CI, 19.5, 22.5). The highest RS was observed for breast cancer in women (RS=49.8%, 95% CI, 42.2, 56.9) and colon cancer in men (RS=37.9%, 95% CI, 31.2, 44.6). Pancreatic cancer had the lowest RS both in men (RS= 8.7%, 95% CI, 4.1, 13.5) and women (RS= 7.9%, 95% CI, 5.0, 10.8) CONCLUSION: Although the 5-year cancer survival rates were relatively low in the Golestan province, there were distinct variations by cancer site. Further studies are required to evaluate the survival trends in Golestan province over time and compare them with the rates in the neighboring provinces and other countries in the region.

Primary Liver Cancer in Golestan Province, Northeastern Iran: 13-Year Experience of Golestan Population-Based Cancer Registry (GPCR).

BACKGROUND: Liver cancer (LC) is among the most common and fatal cancers worldwide. A four-fold increasing trend is reported for LC age-standardized mortality rate (ASMR) in Iran within 1990-2015. In the present study, we aimed to report the incidence rate of LC during the 13-year establishment of the Golestan population-based cancer registry (GPCR). METHODS: Age-standardized incidence rate (ASIR) per 100000 person-years was calculated using CanReg5 software. The Joint point regression analysis was used to assess the temporal trends in incidence rate of LC. RESULTS: During the study period, GPCR registered 575 of LC cases, of which 373 (64.9%) were men and 297 (51.6%) lived in rural areas. The mean (SD) age of LC in men and women were 60.3 (17.2) and 58.0 (17.1), respectively. The ASIR of LC was significantly higher in men than women (4.7 vs. 2.6; P value<0.01) and a minimal increasing trend in LC incidence was observed in both sexes. The incidence rate of LC was significantly higher in rural areas compared to the urbans (3.91 vs. 3.40; P value=0.04). In the last 13 years, rural population had a significant increasing trend in ASIR of LC (average annual percent change [AAPC]=7.85, P value=0.005). CONCLUSION: LC was more prevalent in men among both urban and rural populations. The results showed a significant increasing trend in rural areas that requires Golestan health care system to take action in controlling the burden of LC in rural areas.

Analysis of Competing Risks of Causes of Death in Cancer Patients from Golestan, Iran over Twelve Years (2004-2016).

BACKGROUND: Cancer-related causes of death (cancer CoD) are the main etiologies of death in cancer patients. Recent increase in survival rates of cancer patients resulted in higher risk of dying from causes other than cancer, called competing causes of death (competing CoD). We aim to characterize competing CoD among cancer patients in Golestan province, Northern Iran. METHODS: Data on cancer incidence was obtained from the Golestan population-based cancer registry (GPCR) dataset. Data on causes of death was obtained from the Golestan death registry (GDR) dataset. Using a linkage method between the GPCR and GDR dataset, we prepared the study dataset including data on vital status and causes of death in our cancer patients. The proportions of cancer CoD and competing CoD were calculated. Multivariate logistic regression analysis was considered to assess the relationship between competing CoD and other variables. RESULTS: Overall, 4,184 cancer patients died in the study population, including 2,488 men (59.9%). Cause of death in 3,455 cases was cancer and 729 cases (17.4%) died due to competing CoD. Ischemic heart disease (40.7%) was the most common competing CoD in our population. Higher survival rate was the strongest variable related to the competing CoD (adjusted OR=1.91; 95%CI: 1.61-2.26). Residence area, age group and year of death were other indicators of competing CoD in our population. CONCLUSION: Our results suggest high rates of competing CoD in our cancer patients. Competing CoD should be mentioned in cancer control planning both in clinical practice as well as in public health policy making.
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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.

Incidence of Malignant Brain and Central Nervous System Tumors in Golestan, Iran, 2004-2013.

BACKGROUND: Brain and other central nervous system (CNS) tumors represent almost 3% of all new cancer cases worldwide and comprise a heterogeneous group of tumors with varying epidemiologic and clinical characteristics. The aim of this study is to present the distribution and trends in brain and other CNS cancer incidence in Golestan, Iran during a 10-year period. METHODS: Data on primary brain and other CNS cancers diagnosed between 2004 and 2013 were obtained from the Golestan population-based cancer registry (GPCR) dataset. We computed age-standardized incidence rates (ASRs) per 100000 personyears. In order to assess changes in incidence over time, we calculated the estimated annual percentage change (EAPC) and corresponding 95% confidence intervals (CIs) to detect significant trends. RESULTS: Over the 10-year period (2004-2013), the incidence of brain and other CNS cancer was observed to increase for all ages (EAPC: 1.13, 95% CI: -6.06, 8.87). After 2008, the trends appear to have stabilized. Incidence rates were higher in males than females (ratio: 1.2) and glioblastoma was the most common tumor subtype (15.1% of all malignant tumors). CONCLUSION: Trends and patterns in the burden of brain and other CNS cancer require careful monitoring alongside future research to increase our understanding of potential risk factors.

Completeness and Accuracy of Death Registry Data in Golestan, Iran.

BACKGROUND: We aimed to evaluate completeness and accuracy of the Golestan Death Registry (GDR) to identify cancer-related causes of death (CCoD). METHODS: The GDR data (2004-2015) were compared with cancer data collected from clinical/pathological sources (the considered gold standard) by the Golestan Population-Based Cancer Registry (GPCR). Using a linkage method, matched cases, including subjects with CCoD and those with ill-defined cause of death (ICoD) (garbage codes), were identified and entered into the final analysis as study subjects. The completeness (percentage of study subjects with CCoD) and accuracy (number of subjects with correct CoD from the total number of study subjects) of the GDR were calculated. RESULTS: In total, 3,766 matched cases were enrolled. Overall, the completeness and accuracy of the GDR for identifying CCoD were 92.7% and 53.2%, respectively. There were variations by cancer site and age group, with completeness and accuracy highest for brain cancer (96.3%) and leukaemia (79.8%) while the lowest accuracy was observed for colorectal cancer (29.9%). The completeness and accuracy of GDR was higher in patients aged under 60 years (95.7% and 53.6%, respectively). We also found higher completeness (93.7%) and accuracy (55.8%) in residents of rural areas. CONCLUSION: Linkage of death registry data with cancer registry data can be a significant resource for evaluating quality of the death registry data. Our findings suggested that completeness of the GDR for identifying CCoD is reasonable, but accuracy is relatively low. Access to clinical and pathological data from other sources and enhanced training of death certifiers can improve the present situation.

Epidemiology of Head and Neck Cancers in Northern Iran: A 10-Year Trend Study From Golestan Province.

BACKGROUND: Golestan province, in Northern Iran, is a high-risk area for esophageal squamous cell carcinoma (SCC). SCC is also the most common histological type of cancers of the head and neck region including cancers of oral cavity, oropharynx, hypopharynx and larynx. We aimed to present the incidence rate of head and neck SCC (HNSCC) in Golestan province during 2004 and 2013. METHODS: Data on HNSCC were obtained from Golestan population-based cancer registry (GPCR). Quality control and data analysis were performed using CanReg software. Age standardized incidence rates (ASRs) were calculated using the world standard population. The ASRs were presented per 100000 person-years for different genders, residence places and years. RESULTS: During the 10-year period from 2004-2013, 434 cases of HNSCC were registered. 327 (75.3%) of these cases were male, 51.2% (222 cases) lived in urban areas and 351 (80.9%) of the total HNSCCs occurred in the larynx. Overall, the ASR of HNSCCs in Golestan province was 4.8. The ASR of HNSCCs was more than two-fold higher in male (6.6) than female (3.0). Our results showed an increasing trend in ASR of larynx cancer during the study period both in male and female. CONCLUSION: We found relatively high rates of larynx cancer in Golestan province. Our results also showed higher rates of HNSCC in males and urban population. Considering common risk factors between HNSCCs and esophageal cancer, further studies are needed to clarify different aspects of HNSCCs (including epidemiology and risk factors) in this high-risk population.

Epidemiology of female reproductive cancers in Iran: results of the Gholestan Population-based Cancer Registry.

BACKGROUND: Malignancies of the female reproductive tract are estimated to be the third most common group of cancers in women. OBJECTIVES: We here aimed to present their epidemiological features in Golestan province located in Northeast of Iran. MATERIALS AND METHODS: Data on primary female reproductive cancers diagnosed between 2004-2010 were obtained from Golestan Population-based Cancer Registry (GPCR). CanReg-4 and SPSS software were used for data entry and analysis. Age standardized incidence rates (ASR) (per 100,000 person-years) were calculated using the world standard population. Poisson regression analysis was used to compare incidence rates. P-values of less than 0.05 were considered as significant. RESULTS: A total of 6,064 cancer cases were registered in Golestan females in the GPCR during 2004-2010, of which 652 cases (11%) were female reproductive cancers. Cancers of the ovary (ASR=6.03) and cervix (ASR=4.97) were the most common. We found significant higher rates in females living in cities than in villages. Our results showed a rapid increase in age specific incidence rates of female reproductive cancers at the age of 30 years. CONCLUSIONS: We found significant higher rates of female reproductive cancers among residents of cities than villages. Differences in the prevalence of risk factors including reproductive behavior between the two populations may partly explain such diversity. Our results also showed a rapid increase in incidence rates of these cancers in young age females. Further studies are warranted to determine risk factors of female reproductive cancers in our population.

Epidemiology of leukemia and multiple myeloma in Golestan, Iran.

BACKGROUND: The aim of this paper was to present the incidence rates of leukemia and multiple myeloma (MM) in Golestan province located in northeastern Iran during 2004-2009. MATERIALS AND METHODS: This was a descriptive cross-sectional study. Data on newly diagnosed (incident) leukemia and MM cases were obtained from collected from Golestan population-based cancer registry. Data was entered into CanReg-4 software. Age standardized incidence rates (ASR) (per 100000 person-years) for leukemia and MM were calculated. Data on Golestan population was obtained from the data of Iranian national census in 2006. RESULTS: Totally, 11036 new cancer cases were registered in GPRC from 2004-2009. Leukemia and MM accounted for 693 and 124 of cases, respectively. The mean age in patients with leukemia and MM was 43.8 and 62.4 years, respectively. The ASRs for leukemia among men and women were 10.4 and 7.8, respectively (p<0.001). The ASRs for MM were 2.1 and 2 in men and women, respectively (p=0.93). The rate of leukemia was significantly higher in rural areas (p=0.02) whereas the incidence of MM was higher in urban areas (p<0.001). CONCLUSIONS: Our results showed a high incidence rate of leukemia in Golestan province of Iran. The incidence of leukemia was significantly higher in males and residents of rural areas. High exposure to pesticides and other agricultural related products may be a possible explanation for epidemiological pattern of leukemia in this area. Determining and controlling important risk factors, especially environmental factors, of leukemia may lead to decrease in its burden in Golestan province of Iran.

Predictors of Colorectal Cancer Survival in Golestan, Iran: A Population-based Study.

OBJECTIVES: We aimed to investigate factors associated with colorectal cancer survival in Golestan, Iran. METHODS: We used a population based cancer registry to recruit study subjects. All patients registered since 2004 were contacted and data were collected using structured questionnaires and trained interviewers. All the existing evidences to determine the stage of the cancer were also collected. The time from first diagnosis to death was compared in patients according to their stage of cancer using the Kaplan-Meir method. A Cox proportional hazard model was built to examine their survival experience by taking into account other covariates. RESULTS: Out of a total of 345 subjects, 227 were traced. Median age of the subjects was 54 and more than 42% were under 50 years old. We found 132 deaths among these patients, 5 of which were non-colorectal related deaths. The median survival time for the entire cohort was 3.56 years. A borderline significant difference in survival experience was detected for ethnicity (log rank test, p=0.053). Using Cox proportional hazard modeling, only cancer stage remained significantly associated with time of death in the final model. CONCLUSIONS: Colorectal cancer occurs at a younger age among people living in Golestan province. A very young age at presentation and what appears to be a high proportion of patients presenting with late stage in this area suggest this population might benefit substantially from early diagnoses by introducing age adapted screening programs.

Cancer incidence in Golestan Province: report of an ongoing population-based cancer registry in Iran between 2004 and 2008.

BACKGROUND: Golestan Province, at the western end of the Asian esophageal cancer (EC) belt in northeastern Iran, was reported to have one of the highest worldwide rates of EC in the 1970s. We have previously shown a declining incidence of EC in Golestan during the last decades. This study reports additional new results from the Golestan Population-based Cancer Registry (GPCR). METHODS: The GPCR collected data from newly diagnosed (incident) cancer cases from all 68 public and private diagnostic and therapeutic centers in Golestan Province. CanReg-4 software was used for data entry and analysis based on the guidelines of the International Agency for Research on Cancer (IARC). Age-standardized incidence rates (ASR) of cancers were calculated using the 2000 world standard population. RESULTS: From 2004 through 2008, 9007 new cancer cases were reported to the GPCR. The mean (SD) age was 55.5 (18.6) years, and 54% were diagnosed in men. The ASRs of all cancers were 175.3 and 141.1 per 100,000 person-years for males and females, respectively. Cancers of the stomach (ASR:30.7), esophagus (24.3), and lung (15.4) were the most common cancers in males. In females, breast cancer (ASR:26.9) was followed by malignancies of the esophagus (19.1) and stomach (12.4). The diagnosis of cancer was based on histopathological reports in 71% and on death certificate only in 9% of cases. CONCLUSIONS: The EC incidence rate continues to decline in Golestan, while the incidence rates of stomach, colorectal, and breast cancers continue to increase.

Healthcare utilization in patients with esophageal cancer in a high risk area in northeast of Iran.

INTRODUCTION: Golestan, a province located north of Persian Gulf in northeastern part of Iran is a well known area for high risk of esophageal cancer (EC) in the world. There is no information about healthcare utilization in populations residing in the area. This study was conducted to assess utilization of healthcare and its associated factors among esophageal cancer patients in this region as well as to address ethical implication of this utilization. METHODS: All new cases of EC in Golestan province during year of 2007 were recruited. Seven diagnostic and five therapeutic services were used to assess diagnostic utilization index (DUI), and therapeutic utilization index (TUI), respectively. Multivariate regression analysis was used to assess the relationship between variables and DUI or TUI. P-value of less than 0.05 was considered as statistically significant. RESULTS: Tow hundred twenty three, patients were enrolled with mean (Standard Deviation) age of 64.3 (12.5) years with 57.8% male. We observed that occupation (P<0.01), ethnicity (P<0.01) and sex (P=0.03) were strongly associated with DUI. Insurance coverage (P<0.01), place of residency (P<0.01), and occupation (P=0.01) were associated with TUI. CONCLUSION: We concluded that several factors contribute to disparity in healthcare utilization in the studied population.