Iranian Journal of

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  Background and Objectives : Awareness of the cancer incidence is essential for cancer prevention and control programs. Capture-recapture methods have been recommended for reducing bias and increasing the accuracy of cancer incidence estimation. This study aimed to estimate the incidence of gastric cancer by the capture-recapture method based on Ardabil population-based cancer registry data.

 Methods: All new cases of gastric cancer reported by three sources, i.e. pathology reports, death certificates, and medical records, reported to Ardabil population-based cancer registry between 2006 and 2008 were enrolled in the study. The duplicate cases based on the similarity of the first name, surname, and father's name were identified among sources. The estimated incidence was calculated by the log-linear method using the Stata 12 software.

  Results : A total 857 new cases of gastric cancer were reported from three sources. After removing duplicates, the reported incidence rate was 35.3 and 32.5 per 100,000 population for the years 2006 and 2008, respectively. The estimated incidence rate calculated by the log-linear method for these years was 96.2 and 90.4 per 100,000 population, respectively.

  Conclusion: The results showed that none of the sources of pathology reports, death certificates, and medical records, individually or collectively, fully covered the incidence of gastric cancer. We can obtain more accurate estimates of the incidence rate using the capture-recapture method.

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  Background and Objectives : Breast cancer is the second most common cancer among Iranian women. The peak age of breast cancer in Iran is one decade lower than the global estimates. The aim of this cross-sectional study was to estimate the burden of breast cancer in Iranian women in the country level.

 Methods: In this study, the CANMOD software was used for the calculation of DALYs as the sum of YLL and YLD. The required data was the population of the Iranian women, mortality due to breast cancer, incidence cases of breast cancer, and mean time of the stages of breast cancer that was obtained from the Mortality Registry System, Cancer Registry System, and expert panel views .

  Results : In this study, the total burden of breast cancer in Iranian women was 75811 years in 2009. Moreover, the years of life lost (YLL) was 54938 years while years lived with disability (YLD) was estimated 20873 years. The rate of DALYs per 100000 female population was 220.9 years. The peak age of breast cancer burden was in the age group 45-59 years. The incidence to mortality ratio was 3/2.

  Conclusion: The incidence rate, mortality rate, and the burden of breast cancer in Iranian women increased in 2009 when compared to a previous study in 2003. The findings of this study may provide Iranian health managers with some information on the determinants of the burden of breast cancer in order to design preventive measures as well as screening programs for early detection of breast cancer.

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  Background and Objectives : Various studies have reported different survival rates of patients with gastric cancer in Iran, and there is no overall estimate of the survival rate. The aim of this study was to conduct a meta-analysis of one, three, and five-year survival rate of patients with gastric cancer in Iran.

  Methods: In this study, all of the national databases including Iran Medex, Magiran, SID, and Medlib and the English databases including Google Scholar and PubMed were searched by using the keywords “stomach cancer”, “survival rate” and other Persian and English synonymous keywords, in the period 1392-1339 . Then, all articles with inclusion criteria and acceptable quality were investigated. Der Simonian and Laird random effects models were used to combine the results of all studies. Other analyses including subgroup analysis, sensitivity analysis, and assessment of publication bias were performed by using the funnel plot, and Beg’s and Egger’s tests. Finally, the data was analyzed using STATA software.

  Results: Of the 235 articles found in the initial search, nine studies were eligible for this study. According to these studies, one, three and five-years survival rate of patients with gastric cancer was 0.57 (95% CI: 0.45-0.70), 0.29 (95% CI: 0.22-0.37), 0.17 (95% CI: 0.13-0.21), respectively.

  Conclusion : Researches conducted in different parts of Iran are limited and there are no exact statistics on the survival rate in other parts of Iran. Therefore, further studies in the whole country are required to obtain more precise estimates of the survival and factors affecting it.

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  Background & Objectives : Gastric cancer has a low survival and remains a serious threat to the health of human life, especially in developing countries such as Iran. The present study was performed to estimate the main effective factors in the survival rate of patients with gastric cancer in the Province of Kohgilouyeh & Boyerahmad.

  Methods: All cases of gastric cancer in Kohgiloyeh and Boyerahmad recorded in Provinces of Fars and Kohgiloyeh and Boyerahmad cancer registry were enrolled in this study. The impact of the independent variables on the survival was estimated by single and multivariate Cox regression controlled for the probable confounding variables. Survival analysis was performed using Kaplan Meier curves, the log-rank test, and Wilcoxon test to compare the results. Analysis of the data was performed by SPSS 19, and P-values less than 0.05 were considered significant.

 Results: Among the 348 studied patients, 75.6% were male and the rest (24.4%) were female. In general, in this study, 1, 2, 3, 4, and 5-year survival rate of the patients was 37, 27, 20, 19, and 18%, respectively. By combining these end variables in regression models, three risk groups were identified. In the high risk group, the cumulative survival rate was 0% at the end of the fifth year.

 Conclusion: Execution of the down-staging program through public education, considering the low survival rate in this province seems essential especially for high-risk groups such as farmers, ranchers and regional nomadic populations.

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Background and Objectives: completeness of registration is used as one of the measures of the quality of a cancer registry, which is the degree to which reportable incident cases of cancer in the population of interest is actually recorded in the registry.

Methods: After removing the duplicates, a total of 471 new cases of esophagus cancer reported by three sources of pathology reports, medical records, and death certificates to Ardabil Province Cancer Registry Center in 2006 and 2008 were enrolled in the study. The incidence rate was estimated based on the capture-recapture method and the use of the log-linear models. BIC, G2 and Akaike statistics were used to select the best-fit model.

Results: In this study, a model with linkage between pathology reports and medical records and a model with death certificates alone, independent of the previous two sources, was the best fitted model. The estimated total completeness of esophagus cancer in 2006 and 2008 was 36% .The source that had the most completeness for esophagus cancers was pathology reports with 21.17%. The estimated incidence rate calculated by the log-linear method for the years 2006 and 2008 was 49.71 and 53.87 per 100,000 population, respectively.

Conclusion: Based on the obtained results, it can be concluded that the low degree of completeness in Ardabil Province requires some changes in data abstracting and case finding such as the use of personal national code and electronic health records to create a more accurate cancer registry.

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Background and Objectives: Breast cancer is one of the most common cancers among women and is the second main cause of death after lung cancer. The objective of this study was to use the Bayes model to analyze the prognostic effects on the survival of the women with breast cancer after surgery in the south of Iran.

Methods: The date was collected 1192 women who had breast cancer in Namazi Hospital Research Center between 2001 and 2006. The complete information of only 1148 of them was registered. Parametric Bayes and Bayes Cox methods were used. Considering 0.05 as the level of significance, the data analysis was done using the WinBUGS14 software.

Results: The mean age of the patients (at the time of diagnosis) was 47 years in this study. Cox one-variable analysis showed a significant relationship between survival and smoking (P=0.009), bone metastasis (P=0.01), the number of lymph nodes (P=0.001), the tumoral level of malignancy (P=0.001), the surgical method (P=0.015), financial status (P=0.025), and the tumor size (P=0.001). By fitting Bayes models the variables tumor size, level of malignancy and number of lymph nodes were significant.   

Conclusion: The results showed that clinicopathological features of cancer had a significant role in the survival of the patients.

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Background and Objectives: Colorectal cancer is the fourth leading cause of cancer death worldwide.  Annually 1430000 cases would be diagnosed and half of these people would die of the disease. In Iran, colorectal cancer is the fifth common cancer among men and is the thirdamong women. This study was designed to estimate survival rates for patients with colorectal cancer and related factors.  

Methods: During the 1384 to 1388 years 24,807 patients diagnosed with colorectal cancer were recorded in the Cancer Registry of the Ministry of Health and Medical Education. Age, gender, marital status, education, occupation, place of residence, tumor diagnosis, the clinical and demographic factors in colorectal cancer as effective on survival entered in Aalen’s additive hazard model and diagram Aalen's was used to study the effects of these factors over time. R 3.2.0 software was used for data analysis.

Results: Stage of tumor had a significant association with survival rates. In this study 1 to 5 year survival rate for patients with stage II tumors, was 100%, 98%, 96%, 93% and 93% respectively and for patients with stage III tumors 99%, 97%, 94%, 90% and 84%, respectively.

Conclusion: In spite of using Cox model in survival analysis by many researchers, Aalen’s model may yield new insights in prognostic studies of survival time of patients with colorectal cancer over time. Our results suggest that early detection of patients in primary stage is important to increase survival.

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Background and Objectives: Reproductive factors are in close relationship with breast carcinogenesis. This matched case-control study was conducted to study the association of reproductive risk factors with the risk of breast cancer (BC) among women in Tehran and northwest of Iran.

Methods: This hospital-based case-control study was performed on a total of 432 patients diagnosed with BC with confirmed histopathology who were recruited from hospitals affiliated with Shahid Beheshti and Tabriz University of Medical Sciences between 2007 and 2012, and 543 regionally matched controls without a prior history of BC.

Results: The average number of pregnancy and breast-fed children were significantly higher in cases than controls (P<0.01). The duration of breast-feeding was longer in patients (18.0±8.4 months) than controls (16.0±9.1; P<0.001). Most of the patients were diagnosed with BC above the age of 48 years old which was higher than the mean age of the recruited matched controls. Older age was associated with a 3.87 higher risks of BC development (95% CI: 2.94-5.10). The higher frequency of lactation in patients was significantly associated with the elevated risk (OR=2.22, 95% CI 1.62-3.04). The duration of breast-feeding within14-24 months was correlated with OR=0.52 to protect BC development during the reproductive age
(<48 years) (95% CI: 0.32-0.86). 

Conclusion: High frequency of pregnancy, lactation, and older ages at first pregnancy are associated with the risk of BC, while older age at puberty, menopause, and longer duration of breast-feeding (age above 48 years) have inverse associations with the risk of BC.

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Background and Objectives: Breast cancer is one of the most common malignancies in women which accounts for the highest number of deaths after lung cancer. The aim of the current study was to compare the logistic regression and classification tree models in determining the risk factors and prediction of breast cancer.

Methods: We used from the data of a case-control study conducted on 303 patients with breast cancer and 303 controls. In the first step, we included 16 potential risk factors of breast cancer in both the logistic regression and classification tree models. Then, the area under the ROC curve (AUC), sensitivity, and specificity indexes were used for comparing these models.

Results: From 16 variables included in the models, 5 variables were statistically significant in both models. Sensitivity, specificity, and AUC was 71%, 69%, and 74.7% for the logistic regression and 63.3%, 68.8%, and 71.1% for the classification tree, respectively.

Conclusion: The obtained results suggest that the classification tree has more power for separating patients from healthy people. Menopausal status, number of breast cancer cases in the family, and maternal age at the first live birth were significant indicators in both models.

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Background and Objectives: Colorectal cancer is the third most common cancer in men and the second most common cancer in women in the world. The colorectal cancer screening program was conducted in Iran as a pilot in the late 2010 with the aim of reducing the burden of colorectal cancer. The aim of this study was to evaluate the colorectal cancer screening program in Iran.

Methods: This cross-sectional study was conducted on data from the pilot colorectal cancer screening programs. First, the indicators of the colorectal cancer screening program were determined through a comprehensive review of scientific databases, interviews with experts and implementation of pilot evaluation. Then, the indicators were calculated through descriptive analysis using SPSS version 18.

Results: The indicators and their values were as follows: coverage rate 33.04%, participation rate 53.3%, percentage of consulted people 99.6%, percentage of blood samples 37%, percentage of colonoscopy 54.8%, cancer detection rate 2.7%, and polyp detection rate 18.1%. Among people who gave blood samples 1.6% had familial adenomatous polyposis (FAP) syndrome, 43.06% had hereditary no polyposis colorectal cancer (HNPCC) syndrome, and 29% were sporadic cases.

Conclusion: The screening program in Iran has differences with other countries which have affected the indicators.

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Background and Objectives: The cancer of the pancreatic head and Ampulla of Vater is a malignant disease usually seen in advanced stages with symptoms caused by stomach and biliary obstruction. Curative treatment is possible in the early stage. Unfortunately, most symptomatic patients are in the advanced stage and have an unrespectable tumor; therefore, they should undergo palliative surgery. This study was performed to determine the complications and survival rate of patients who underwent palliative surgery for advanced stages of cancer in the Ampulla Vater and pancreatic head.

Methods: In this study, 49 patients with advanced stages of cancer in the Ampulla of Vater and pancreatic head who had undergone palliative surgery from 2003 to 2014 at Baqiyatallah Hospital were studied and the complications and survival rate were determined.

Results: Eleven patients (22.44%) underwent biliary bypass, 6 (12.24%) underwent gastric bypass, and 32 (65.32) underwent both procedures. Twelve (24.49%) patients developed complications. Anastomotic leak and peritonitis were the most common complications seen in 6 (12.2%). Seven patients (14.28%) died in the hospital. The mean survival was 5.47 ± 8.38 months. Upon follow up, survival was significantly longer in older patients (P=0.01).

Conclusion: In one-fourth of the patients with advanced stages of cancer, palliative surgery of the pancreatic head and Ampulla of Vater caused complications, and the mean survival rate was less than six months. The results of this study recommend the use of less invasive procedures such as biliary stenting in the advanced stages of the disease.

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Background and Objectives: Colorectal cancer is the fourth most common cancer and the fifth cause of cancer-related mortality in Iran. This study aimed to determine the incidence of colorectal cancer in men and women and to investigate its relationship with the human development index (HDI) and its components in Iranian provinces.
Methods: This ecological study was conducted to assess the correlation between age-specific incidence of colorectal cancer in men and women and the Human Development Index. We used the data of the Iranian Cancer Registry and Statistical Centre of Iran. We used a bivariate correlation method to assess the correlation of ASR and HDI. P values less than 0.05 were considered significant. All reported P-values are two-sided. Statistical analyses were performed using the SPSS software version 23.
Results: The highest incidence of colorectal cancer in men was seen in Tehran (78.16), Eastern Azerbaijan (41.14), and Semnan (62.13), and the highest incidence of colorectal cancer in women was seen in Tehran (47.18), Semnan (80.14), and Eastern Azerbaijan (82.12), respectively. The results showed that the incidence of colorectal cancer in men (r = 0.605) and women (r = 0.661) had a positive significant correlation with the Human Development Index (P<0.001).
Conclusion: The incidence of colorectal cancer was high in provinces with a higher human development index. Therefore, evaluation of the incidence of cancer by the Human Development Index and its components can be used to show a clearer picture of the distribution of cancer in each country and may be useful for cancer prevention plans.

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Background and Objectives: Breast cancer is the leading cause of death from cancer among women. In developing countries, the patients’ survival is less than developed countries. Metastasis, as an intermediate event, affects the survival of breast cancer patients. This study aimed to evaluate the survival of patients after surgery considering metastasis, as the intermediate event, using the illness-death model.
Methods: In this study, 165 cases of Iranian breast cancer patients who underwent surgery during 2006-2014 were investigated. The patients’ characteristics and their intermediate and final status were collected from their medical records. The illness-death model was used to assess prognostic factors in all stages of disease.
Results: The risk of metastasis in patients with tumor size between 2-5 cm was 3.8 times higher than patients whose tumors were below 2 cm (P=0.009). Patients who had 3 to 6 lymph nodes involved were 3.1 times more likely to have metastases that those with less than 2 lymph nodes (P=0.003). Also, the grade of tumor and HER-2 had a significant role in metastasis (P=0.04).
Conclusion: Using the illness-death model that is suitable for the analysis of such data, it was found that lymph node involved and tumor size had a significant role in metastasis. So, early detection of cancer is required to prevent metastasis and death.

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Background and Objectives: Colon cancer is the third most common cancer in the world and the fourth most common cancer in Iran. It is very important to predict the cancer outcome and its basic clinical data. Due to to the high rate of colon cancer and the benefits of data mining to predict survival, the aim of this study was to survey two widely used machine learning algorithms, Bagging and Support Vector Machines (SVM), to predict the outcome of colon cancer patients.
Methods: The population of this study was 567 patients with stage 1-4 of colon cancer in Namazi Radiotherapy Center, Shiraz in 2006-2011. Three hundred and thirty eight patients were alive and 229 patients were dead. We used the Support Vector Machines (SVM) and Bagging methods in order to predict the survival of patients with colon cancer. The Weka software ver 3.6.10 was used for data analysis.
Results: The performance of two algorithms was determined using the confusion matrix. The accuracy, specificity, and sensitivity of the SVM was 84.48%, 81%, and 87%, and the accuracy, specificity, and sensitivity of Bagging was 83.95%, 78%, and 88%, respectively.
Conclusion: The results showed both algorithms have a high performance in survival prediction of patients with colon cancer but the Support Vector Machines has a higher accuracy.

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Background and Objectives: Breast cancer is the most common cancer in Iran. It can be prevented by rapid diagnosis of the disease. Thus, it is necessary to determine the causal relationships between variables related to breast cancer. Bayesian network is a data mining tool that shows the causal relationship between different variables. In this paper, a Bayesian network was applied to find causal relationships between breast cancer variables using a genetic algorithm in a graphical model. 
 
Methods: in this applied study, data were collected from 900 breast cancer patients in Kerman Province from 1999 to 2008. For data analysis, we used a probabilistic graphical model representing the causal relationship between variables.
 
Results: The results showed that surgery was the most important treatment for breast cancer. Based on the conditional and marginal probabilities, the women who underwent surgery had higher hopes of living longer. Moreover, 81% of the patients who did not undergo surgery only received chemotherapy or radiotherapy were less likely to have long lives.
 
Conclusion: People aged 40-65 years are more likely to have breast cancer. Moreover, the variables of age, surgery, chemotherapy, and radiotherapy had a direct effect on the status of the patients and there were direct edges from these variables to the status of the patients.

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Background and Objectives: The purpose of this study was to predict the mortality rate of colorectal cancer in Iranian patients and determine the effective factors  on the mortality of patients with colorectal cancer using random forest and logistic regression methods.
 
Methods: Data from 304 patients with colorectal cancer registry from the Gastroenterology and Liver Research Center of Shahid Beheshti University of Medical Sciences during the years 2009 to 2014 were used as a retrospective study. Data analysis was performed using random forest and logistic regression methods. To analyze the data, R software version 3.4.3 was considered.
 
Results: Ten important variables related to colorectal cancer deaths were selected by random forest method. Several criteria such as the area under the characteristic curve (AUC) were used to compare the random forest method with logistic regression. According to both criteria, five important variables ranked by random forest were Cancer stage, age of diagnosis, patient's age, HLA, and degree of differentiation (tumor differentiation). In terms of different criteria, the random forest method had better performance than logistic regression (Area under the ROC curve for random forest and logistic regression methods was: 98%; 80% respectively).
 
Conclusion: Variables such as Cancer stage, age of diagnosis, patient's age, HLA, and degree of differentiation are considered as the most important factors affecting mortality in colorectal cancer, that the patients' longevity can be increased with the early diagnosis of cancer and screening programs.
 

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Background and Objectives: Cervical cancer is one of the five most common cancers in Iranian women. Considering the impact of HIV on cervical cancer and the low rate of cervical cancer screening in HIV positive women, this study was conducted to review the barriers to cervical cancer screening in HIV positive women.
 
Methods: In this systematic review, data were retrieved from Magiran, SID, Irandoc, Prequest, OVID, ScienceDirect, PubMed, Web of Science and Scupos databases from January 2000 to January 2018. The following keywords and their combination were used: cervical cancer screening, Pap smear, HIV-positive women, and barriers. The NOS (Newcastle-Ottawa Scale) checklist was used to evaluate the quality of the selected articles and the articles that scored more than six were included in the study.
 
Results: From 145 selected articles, 21 were included in the review based on the inclusion criteria. The most common reported screening barriers were the costs of test, lack of awareness, low education level, younger age, lack of information about screening centers, and fear of sampling. 
 
Conclusion: Considering the barriers to cervical cancer screening, increasing the level of awareness of the HIV-positive women, preparing free Pap smear services, and providing easier access to health centers for this high risk group could lead to early detection of cervical cancer.

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Background and Objectives: In survival analysis, using the Cox model to determine the effective factors requires the assumptions whose failure of leads to biased results. The aim of this paper was to determine the factors affecting the survival of metastatic gastric cancer patients using the non-parametric method of Randomized Survival Forest (RSF) model and to compare its result with the Cox model.
 
Methods: In this retrospective cohort study, 201 patients with metastatic gastric cancer were evaluated in Hamadan Province. Patient survival was calculated from diagnosis to death or end of study. Demographic characteristics (such as gender and age) and clinical variables (including stage, tumor size, etc.) were extracted from the patient records. Factors affecting survival were determined using the Cox model and RSF. Data analysis was performed using the R3.4.3 software and RandomForestSRC and survival packages.
 
Results: The mean (SD) age of patients was 61.5 (12.9) years old. The Cox model showed that chemotherapy (p=0.033) was effective in survival, and the results of fitting the RSF model showed that the most important variables affecting survival were type of surgery, location of metastasis, chemotherapy, age, tumor grade, surgery, number of involved lymph nodes, sex and radiotherapy. Based on the model appropriateness, the RSF model with log-rank split rule had a better performance compared to the Cox model.
 
Conclusion: If the number of variables is high and there is a relationship between the variables, the RSF method identifies the important and effective variables on survival with high accuracy without requiring restrictive assumptions compared to the Cox model.

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Background and Objectives: Cancer is a complex disease with a lengthy and expensive course of treatment that causes many problems for the community. Knowledge of oral cancer plays an important role in early diagnosis. The aim of this study was to determine the level of knowledge about the symptoms and risk factors of oral cancer and assess the related factors.
 
Methods: In this study, 671 parents of primary school children were randomly selected from primary schools in four districts of Tehran. The participants were asked to answer questions related to demographic characteristics and knowledge of the risk factors and symptoms of oral cancer. Data analysis was done using Poisson regression model and multi-level Poisson regression model using SPSS and STATA software. The AICI Akaike Information Criterion (AIC) was applied to evaluate the models.
 
Results: The mean score of knowledge was 3.7 with a standard deviation of 6.7. Among the studied variables, female gender, advanced age, a higher SES score, and a higher welfare index had positive effects on oral cancer knowledge (P <0.05).
 
Conclusion: The results of this study showed that demographic, social and economic factors of parents were effective on oral cancer. It can be statistically concluded that a multilevel Poisson regression model is more suitable for analyzing this data.
 

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Background and Objectives: The incidence of colorectal cancer has increased significantly in Iran in recent decades. The pattern of occurrence varies in different populations. A study was conducted to perform a spatial analysis of colorectal cancer and some of its risk factors in Iran using GIS.
 
Methods: The data of this descriptive-analytic study included colorectal cancer incidence as a dependent variable and physical activity, Body Mass Index and smoking as independent variables recorded by the Cancer Department, Center for Non-Communicable Diseases Management, the Ministry of Health and Medical Education and the care system for non-communicable disease risk factors according to province and gender in 2009. Data was analyzed using the ArcGIS 10.3 software and spatial correlation analysis, hot spots analysis, and geographic weighted regression model.
 
Results: The spatial relationship between the disease and some of its risk factors was confirmed by the model of geographical weight regression, according to which the northern and central provinces had the highest risk of colorectal cancer compared to other regions of the country.
 
Conclusion: The results of this study showed that spatial analysis could be useful in identifying disease patterns, prioritizing the factors affecting it, and controlling the disease through strategic planning and interventions.