Four years incidence rate of colorectal cancer in Iran: a survey of national cancer registry data - implications for screening

Rectal cancer survival and prognostic factors in Iranian population: A retrospective cohort study

BACKGROUND

Rectal cancer (RC) poses a significant global health challenge, causing substantial morbidity and mortality. This study aims to investigate the survival rates of RC patients and identify the factors that influence their survival. The study considers demographic characteristics, tumor features, and treatment received as the factors under consideration.

METHODS

A retrospective analysis was conducted on the medical records of 593 RC patients. Data were collected through a comprehensive review of medical records and conducting telephone interviews. Survival rates were estimated using the life table method, and subgroup comparisons were performed using the log-rank test. Cox regression analysis was utilized to assess the independent associations between RC survival time and various covariates.

RESULTS

The study cohort comprised 593 RC patients, with a predominantly male representation. The mean age at diagnosis was 58.18 years, and the majority of patients (78.6 %) underwent surgical interventions. The median age at symptom onset and diagnosis were 58 and 59 years, respectively. Survival rates at 1st, 3rd, 5th, and 10th years were estimated to be 85 %, 59 %, 47 %, and 36 %, respectively. Statistical analysis revealed several significant prognostic factors, including age, education, symptoms, and cancer stage. In the multivariate Cox proportional-hazards analysis, advanced regional stage (HR = 1.54, 95 % CI, 1.13-2.08), presence of metastasis (HR = 3.73, 95 % CI, 2.49-5.58), and age over 70 (HR = 1.65) were associated with a higher risk of mortality.

CONCLUSION

Given the alarming prognosis of RC observed in the study area and the significant delay between symptom onset and diagnosis, it is crucial to address this issue and potentially improve the survival rates of RC patients.

Colorectal adenocarcinoma in Uganda: are right-sided and left-sided colon cancers two distinct disease entities?

INTRODUCTION

In Western countries, right-sided colon cancers (RSCC) present at an older age and advanced stage. Researchers believe that there is a difference between left-sided colon cancer (LSCC) and RSCC. In Uganda, however, it is unknown whether differences exist in the pathological profile between RSCC and LSCC. The aim of this study was to determine the differences in clinicopathological characteristics between RSCC and LSCC in Ugandan patients.

METHODOLOGY

A cross-sectional study was conducted in which colorectal adenocarcinoma formalin-fixed paraffin-embedded tissue (FFPE) blocks were obtained from 2008 to 2021. Colorectal specimens were obtained from prospectively recruited patients. In the retrospective study arm, FFPE blocks and data were obtained from the archives of pathology laboratory repositories. Parameters studied included age, sex, location of the tumour, grade, stage, lymphovascular (LVI) status, and histopathological subtype between LSCC and RSCC.

RESULTS

Patients with RSCC were not older than those with LSCC (mean age, 56.3 years vs 53.5 years; p = 0.170). There was no difference in the stage between RSCC and LSCC. Poorly differentiated tumours were more commonly found in RSCC than in LSCC (18.7% vs 10.1%; p = 0.038). Moderately and poorly differentiated colonic tumours were more common with RSCC (89.3%) than with LSCC (75.1%) (p = 0.007). Younger patients had more poorly differentiated tumours than older patients (19.6% versus 8.6%; p = 0.002). LVI was more common with RSCC than with LSCC (96.8% vs 85.3%; p = 0.014). Mucinous adenocarcinoma (MAC) was more common with RSCC (15.8%) compared with LSCC (8.5%) (p = 0.056) although statistical significance was borderline.

CONCLUSIONS

Clinicopathological features of RSCCs tend to be different from those of LSCCs. RSCCs tend to be associated with MAC, a higher grade and LVI status compared to LSCC. LSCC and RSCC present predominantly with an advanced stage; therefore, national screening programmes for the early detection of CRC are necessary to reduce mortality in our Ugandan population.

A bayesian approach to model the underlying predictors of early recurrence and postoperative death in patients with colorectal Cancer

Objective

This study aimed at utilizing a Bayesian approach semi-competing risks technique to model the underlying predictors of early recurrence and postoperative Death in patients with colorectal cancer (CRC).

Methods

In this prospective cohort study, 284 patients with colorectal cancer, who underwent surgery, referred to Imam Khomeini clinic in Hamadan from 2001 to 2017. The primary outcomes were the probability of recurrence, the probability of Mortality without recurrence, and the probability of Mortality after recurrence. The patients ‘recurrence status was determined from patients’ records. The Bayesian survival modeling was carried out by semi-competing risks illness-death models, with accelerated failure time (AFT) approach, in R 4.1 software. The best model was chosen according to the lowest deviance information criterion (DIC) and highest logarithm of the pseudo marginal likelihood (LPML).

Results

The log-normal model (DIC = 1633, LPML = -811), was the optimal model. The results showed that gender(Time Ratio = 0.764: 95% Confidence Interval = 0.456–0.855), age at diagnosis (0.764: 0.538–0.935 ), T₃ stage (0601: 0.530–0.713), N₂ stage (0.714: 0.577–0.935 ), tumor size (0.709: 0.610–0.929), grade of differentiation at poor (0.856: 0.733–0.988), and moderate (0.648: 0.503–0.955) levels, and the number of chemotherapies (1.583: 1.367–1.863) were significantly related to recurrence. Also, age at diagnosis (0.396: 0.313–0.532), metastasis to other sites (0.566: 0.490–0.835), T₃ stage (0.363: 0.592 − 0.301), T₄ stage (0.434: 0.347–0.545), grade of differentiation at moderate level (0.527: 0.387–0.674), tumor size (0.595: 0.500–0.679), and the number of chemotherapies (1.541: 1.332–2.243) were the significantly predicted the death. Also, age at diagnosis (0.659: 0.559–0.803), and the number of chemotherapies (2.029: 1.792–2.191) were significantly related to mortality after recurrence.

Conclusion

According to specific results obtained from the optimal Bayesian log-normal model for terminal and non-terminal events, appropriate screening strategies and the earlier detection of CRC leads to substantial improvements in the survival of patients.

A systematic review of methods to estimate colorectal cancer incidence using population-based cancer registries

Background

Epidemiological studies of incidence play an essential role in quantifying disease burden, resource planning, and informing public health policies. A variety of measures for estimating cancer incidence have been used. Appropriate reporting of incidence calculations is essential to enable clear interpretation. This review uses colorectal cancer (CRC) as an exemplar to summarize and describe variation in commonly employed incidence measures and evaluate the quality of reporting incidence methods.

Methods

We searched four databases for CRC incidence studies published between January 2010 and May 2020. Two independent reviewers screened all titles and abstracts. Eligible studies were population-based cancer registry studies evaluating CRC incidence. We extracted data on study characteristics and author-defined criteria for assessing the quality of reporting incidence. We used descriptive statistics to summarize the information.

Results

This review retrieved 165 relevant articles. The age-standardized incidence rate (ASR) (80%) was the most commonly reported incidence measure, and the 2000 U.S. standard population the most commonly used reference population (39%). Slightly more than half (54%) of the studies reported CRC incidence stratified by anatomical site. The quality of reporting incidence methods was suboptimal. Of all included studies: 45 (27%) failed to report the classification system used to define CRC; 63 (38%) did not report CRC codes; and only 20 (12%) documented excluding certain CRC cases from the numerator. Concerning the denominator estimation: 61% of studies failed to state the source of population data; 24 (15%) indicated census years; 10 (6%) reported the method used to estimate yearly population counts; and only 5 (3%) explicitly explained the population size estimation procedure to calculate the overall average incidence rate. Thirty-three (20%) studies reported the confidence interval for incidence, and only 7 (4%) documented methods for dealing with missing data.

Conclusion

This review identified variations in incidence calculation and inadequate reporting of methods. We outlined recommendations to optimize incidence estimation and reporting practices. There is a need to establish clear guidelines for incidence reporting to facilitate assessment of the validity and interpretation of reported incidence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01632-7.

Detection Rate of Colorectal Polyps in Symptomatic Candidates of Colonoscopy: When Should We Do a Total Colonoscopy?

BACKGROUND The incidence of colorectal cancer is increasing in the northeast of Iran. Colorectal polyps are among the proposed risk factors noted, especially in the elder population. This study was designed to study the diagnosed cases of intestinal polyps detected from 2011 to 2016 in the northeast of Iran. METHODS The population consisted of symptomatic candidates referred to the colonoscopy center in Gorgan city. Based on the available colonoscopy and pathology reports, 1706 cases were enrolled after the exclusion of cases without sufficient data. RESULTS Among 1709 (55.5% males and 44.5% females) cases, 1405 cases with 1912 polyps were detected. Among them, 345 (25%) aged less than 50 years. Tubular adenoma (N = 826, 43.2%) and hyperplastic polyps (N = 519, 27.1%) were the top two histological findings. Out of 1405 patients with polyps, 660 (39.6%) polyps were detected in proximal colon (15.6% in proximal and 24% in both proximal and distal). Malignancies were detected in 13.2% (0.8% malignant polyps and 12.4% malignant masses). CONCLUSION A considerable number of colorectal adenomas in proximal colon and in patients younger than 50 years old, suggesting to schedule colorectal cancer screening from at least 10 years younger and continuing colonoscopy up to the proximal area.

Influence of Two DNA Repair Pathway Polymorphisms in Colorectal Cancer Risk in Southwest Iran

Objective:

X-ray cross-complementing group 1 (XRCC1) and 8 Oxo guanine DNA-glycosylase 1 (OGG1) genes are implicated in the repair of single-stranded breaks (SSBRs) and base excision repair (BER) pathways. Common polymorphisms in DNA repair genes are supposed to decrease the capability of DNA repair and cause genetic instability. This study was designed to investigate the association between XRCC1 (rs25487) and OGG1 (rs1052133) polymorphisms and susceptibility to colorectal cancer (CRC) in the Ahvaz city, south-west Iran.

Methods:

This case- control study comprised 150 patients and 150 controls that were selected from 2 educational hospitals in Ahvaz. They were matched for age and gender, and their genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results:

Our results indicate that the frequency of the Gln (A) allele of XRCC1 (rs25487) is significantly higher in colorectal cancer patients, compare to controls (p = 0.01, OR: 1.54, 95% CI 1.9–13.3). Significant increased risk of cancer was observed in XRCC1 (rs25487) genotypes (p = 0.001 OR: 5.3, 95% CI 1.9–14.2 for Gln / Gln), while no association was found between OGG1 (rs1052133) and colorectal cancer risk (p = 0.6).

Conclusion:

Our study suggests that XRCC1 (rs25487) polymorphism might be associated with an increasing risk of CRC in Ahvaz. It also demonstrates positive correlation between the XRCC1 (rs25487) genotypes and demographic characteristics, such as smoking and increased age in patients and control groups.

Evaluation of the Epigenetic Demethylation of NRF2, a Master Transcription Factor for Antioxidant Enzymes, in Colorectal Cancer

BACKGROUND

Epigenetic changes in CpG islands of the promoter regions of homeostasis-related genes, including nuclear factor erythroid 2-related factor 2 (NRF2), have been shown to hold a significant role in the development of colorectal cancer. Therefore, we aimed to examine the DNA demethylation pattern of the NRF2 promoter region in cancerous lesions from patients with colorectal cancer and the association of methylation status with clinicopathological features in the Iranian population.

METHODS

In this cross-sectional study, 114 colorectal tissue samples were collected. These samples included: 34 tumour tissue samples, 60 precancerous polyps, and 20 normal tissue samples. The promoter methylation status of the NRF2 gene was examined using methylation-specific PCR. Additionally, the relationship between the methylation status and the clinicopathological features was investigated.

RESULTS

The frequency of NRF2 demethylation in the tumour samples was significantly higher compared to the polyp tissues (p= 0.003) and normal tissue (p= 0.009), indicating that cancerous colorectal tissues exhibit increased demethylation of the NRF2 promoter. After examining the demethylation status of tissue samples, the clinicopathological features were compared to the demethylation results. No significant association was found between NRF2 promoter demethylation and the clinicopathological features of patient samples.

CONCLUSION

Our findings suggest that the epigenetic modifications leading to NRF2 demethylation found in colorectal tumour samples may contribute to cancer progression from precancerous polyps to cancerous lesions.

Efficacy of Oxaliplatin/5-Fluorouracil/Capecitabine-Cetuximab Combination Therapy and Its Effects on K-Ras Mutations in Advanced Colorectal Cancer

Background

The aim of this study was to perform an accurate exploration on the efficacy of oxaliplatin/5-fluorouracil/capecitabine-cetuximab combination therapy and its effects on K-Ras mutations in advanced colorectal cancer.

Material/Methods

Among 96 patients who suffered metastatic colorectal cancer without mutated K-Ras, 41 patients who were receiving treatment with oxaliplatin/5-fluorouracil/capecitabine and administered cetuximab as the initial treatment comprised the observation group; the remaining 55 patients receiving cetuximab as an alternative treatment comprised the control group.

Results

The observation group experienced significantly higher objective response rates (ORRs), and disease control rates (DCRs), than the control group (P<0.05 for both). The median progression-free survival (PFS) rates of the observation group and the control groups were 11.2 months (95% confidence interval [CI]: 10.1–12.3 months) and 7.4 months (95% CI: 6.6–8.2 months). The median overall survival (OS) rates were 16.8 months (95% CI: 15.2–18.4 months) and 12.4 months (95% CI: 11.6–13.2 months), respectively. The observation group had significantly longer PFS and OS in comparison to the control group (P<0.05). The patients who underwent cetuximab treatment for ≥10 months had a slightly higher rate of K-Ras mutations than those treated with cetuximab for <10 months (9.1% versus 7.3%).

Conclusions

Oxaliplatin/5-fluorouracil/capecitabine plus cetuximab exhibited better efficacy as initial treatment than the alternative treatment; it was also highly safe. Unfortunately, some patients might develop K-Ras mutations after long duration of cetuximab treatment, suggesting that K-Ras mutations are correlated with tumor progression and depend on the duration or dose of cetuximab treatment.

The prediction incidence of the three most common cancers among Iranian military community during 2007-2019: a time series analysis

OBJECTIVE

Cancers are one of the most important public health problems in Iran. Because of the importance of cancers, the purpose of the current study was to the prediction of the future incidence of the most common cancers among Iranian military community (MC) by using the time series analysis during 2007 to 2019.

METHODS

In the current cross-sectional study, all registered cancers among Iranian MC entered the study. To select the best model of prediction, various methods including autocorrelation function (ACF), partial autocorrelation function (PACF), and Akaike information criterion (AIC) statistics were used. All analysis was performed by using ITSM, stata14, and Excel2010 software.

RESULTS

The most prevalent cancers among Iranian MC were breast, prostate, and colon cancers respectively. The time series analysis was shown that the trend of all mentioned cancers in Iranian MC will increase in the coming years.

CONCLUSIONS

The trend of most prevalent cancers among Iranian MC was increasing but the different factors like the growth of population size and improving the registration system should be regarded.

A review of incidence and mortality of colorectal, lung, liver, thyroid, and bladder cancers in Iran and compared to other countries

In Iran, a developing country in southwest Asia, an epidemiologic transition is underway from communicable to noncommunicable diseases. In Iran, cancer is the second largest group of chronic non-communicable diseases (NCDs) and the third most common cause of death following heart disease, accidents and other natural phenomena. There are some studies reporting an increasing trend in the incidence and mortality rate of a variety of cancers in Iran. Therefore, controlling and preventive interventions pertaining to cancers must be a main priority for health policy and it is recommended that the high-risk population receive earlier screening. In this review, incidence and mortality of colorectal, lung, liver, thyroid, and bladder cancers in Iran are reported.

Mapping of Stomach, Colorectal, and Bladder Cancers in Iran, 2004-2009: Applying Bayesian Polytomous Logit Model

BACKGROUND

According to the last report of Iran cancer registry, stomach, colorectal, and bladder cancers are the most prevalent cancers. The present study focused on separating the latent risk surface into shared and disease-specific components.

METHODS

In this study, data consisting of stomach, colorectal, and bladder cancers in 30 provinces of Iran during 2004-2009 are considered. These data are analyzed by polytomous logit model. The incidence of stomach cancer acts as the reference category (the surrogate for smoking). Then, the log odds are decomposed into shared and specific structured spatial and unstructured spatial components. These latent components help to detect spatial patterns of shared and disease-specific risk factors.

RESULTS

Central, Southern, Eastern, and Southwestern provinces are supposed as high-risk regions for shared risk factor for colorectal and bladder cancers. This shared risk factor is slightly associated more with bladder than with colorectal cancer. Northern, northwestern, and central regions and also three borderline provinces in southwestern are high-risk regions for colorectal cancer. Central, eastern, southern, and western strip of the country except Ilam are found as the high-risk regions of bladder cancer.

CONCLUSIONS

After considering known shared risk factor of the three cancers, it turns out that colorectal and bladder cancers have unknown shared risk factor. The significant difference in their lifestyle and eating habits could be an assumption of the risk factor.

Application of a non-parametric non-mixture cure rate model for analyzing the survival of patients with colorectal cancer in Iran

OBJECTIVES

Colorectal cancer (CRC) patients are considered to have been cured when the mortality rate of individuals with the disease returns to the same level as expected in the general population. This study aimed to assess the impact of various risk factors on the cure fraction of CRC patients using a real dataset of Iranian CRC patients with a non-mixture non-parametric cure model.

METHODS

This study was conducted on the medical records of 512 patients who were definitively diagnosed with CRC at Taleghani Hospital, Tehran, Iran from 2001 to 2007. A non-mixture non-parametric cure rate model was applied to the data after using stepwise selection to identify the risk factors of CRC.

RESULTS

For non-cured cases, the mean survival time was 1,243.83 days (95% confidence interval [CI], 1,174.65 to 1,313.00) and the median survival time was 1,493.00 days (95% CI, 1,398.67 to 1,587.33). The 1- and 3-year survival rates were 92.9% (95% CI, 91.0 to 95.0) and 73.4% (95% CI, 68.0 to 79.0), respectively. Pathologic stage T1 of the primary tumor (estimate=0.58; p=0.013), a poorly differentiated tumor (estimate=1.17; p<0.001), a body mass index (BMI) between 18.6 and 24.9 kg/m2 (estimate=-0.60; p=0.04), and a BMI between 25.0 and 29.9 kg/m2 (estimate=-1.43; p<0.001) had significant impacts on the cure fraction of CRC in the multivariate analysis. The proportion of cured patients was 64.1% (95% CI, 56.7 to 72.4).

CONCLUSIONS

This study found that the pathologic stage of the primary tumor, tumor grade, and BMI were potential risk factors that had an impact on the cure fraction. A non-mixture non-parametric cure rate model provides a flexible framework for accurately determining the impact of risk factors on the long-term survival of patients with CRC.

Down-Regulated LncRNA-HOTAIR Suppressed Colorectal Cancer Cell Proliferation, Invasion, and Migration by Mediating p21

BACKGROUND AND AIM

HOX transcript antisense intergenic RNA (HOTAIR) is a relatively well-understood RNA, which plays a central role in the pathogenesis of various tumors. The aim of the present study was to investigate the effect by which HOTAIR acts to influence the biological processes of colorectal cancer (CRC) through p21.

METHODS

Reverse transcription quantitative polymerase chain reaction and Western blot methods were employed to provide verification regarding the changes in HOTAIR, PCNA, Ki67, p21, cyclin E, and CDK2 among the CRC tissues and cells. The correlation between the clinicopathological characteristics of patients and expression of HOTAIR and p21 was subsequently evaluated, followed by an analysis into the effects of HOTAIR on the biological processes of M5 cells.

RESULTS

HOTAIR was found to be expressed at high levels, while p21 was determined to be at a low level among both the CRC tissues and the CRC cell lines. The expressions of HOTAIR and p21 were determined to be related to lymph node metastasis, tumor node metastasis, Dukes staging, distant metastases, histological types, and the degree of differentiation. Cells transfected with HOTAIR siRNA displayed inhibited rates of proliferation, invasion, and migration, as well as decreased cyclin E and CDK2, while apoptosis and p21 were increased.

CONCLUSION

The principal findings demonstrated that down-regulation of HOTAIR elicits an inhibitory effect on proliferation, invasion, and migration, while promoting the apoptosis of CRC cells through the up-regulation of p21. We believe that HOTAIR could represent a novel target for the treatment of CRC.

Design, expression and evaluation of novel chimeric protein constructed from colorectal tumor-associated antigen

There were 134,000 new diagnosis and 49,000 deaths in 2016 due to colorectal cancer. Similar to most cancers, early diagnosis increases the chance of successful treatment. Detection of tumor-associated antigens or the immune response against such markers is one of the most common methods of diagnosis. In that regard, we aimed to design and express a chimeric protein from the most common tumor-associated antigens in colorectal cancer and assess its ability to detect the immune response in comparison with the parental tumor-associated antigens in patient's sera. Through bioinformatics approaches a chimeric protein from carcinoembryonic antigen (CEA) and carbohydrate antigen 19.9 (CA19-9) was designed and expressed in E. coli (BL21DE3). Proper folding, expression levels and immune reactivity were assessed by western blot, ELISA and immunohistochemistry. Recombinant proteins functionality and immune reactivity were confirmed by ELISA and Western blot. Results showed that recombinant CEA, recombinant CA19.9 and chimeric protein of CEA- CA19.9 have strong reactivity with antibodies in the sera of colorectal cancer patients, whereas no reactivity was seen with the sera of healthy volunteers. Significantly stronger immune reactivity was seen with the chimeric protein than each of the CEA or CA19.9 alone. Overall, it was concluded that the designed recombinant proteins in this study could be used to detect autoantibodies produced against the colorectal tumor-associated antigens. The chimeric CEA-CA19.9 protein shows a stronger reactivity with the sera antibodies of colorectal cancer patients that CEA or CA19.9 alone.

Cancer research priorities and gaps in Iran: the influence of cancer burden on cancer research outputs between 1997 and 2014

OBJECTIVES

As a developing country, Iran is experiencing the increasing burden of cancers, which are currently the third leading cause of mortality in Iran. This study aims to demonstrate that cancer research in Iran concentrates on the cancer research priorities based on the global burden of disease (GBD) reports.

STUDY DESIGN

Descriptive evaluation of all cancers disability-adjusted life years (DALYs) was performed using GBD data. Also a comprehensive search was conducted using cancer-associated keywords to obtain all cancer-related publications from Iran, indexed in Web of Science.

METHOD

Multiple regression analysis and correlation coefficients (R²) were used to evaluate the possible associations between cancer research publications and GBD.

RESULTS

During 1996-2014, the majority of cancer-related publications in Iran focused on breast cancer, leukaemia and stomach cancer, respectively. This study found hypothetical correlations between cancer publications in Iran in line with the burden of cancer as reported by GBD. Particularly, correlations between years lived with disability (YLD) and cancer-related publications were more obvious.

CONCLUSION

This study introduces a new outline in setting cancer research priorities in the region.

Factors Affecting Survival in Patients with Colorectal Cancer in Shiraz, Iran

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer in the world, and the fourth in Iran in both genders. The aim of this study was to find predictive factors for CRC survival.

MATERIALS AND METHODS

Medical records of 570 patients referred to the radiotherapy oncology department of Shiraz Namazi hospital from 2005 to 2010 were retrospectively analysed. Data were collected by reviewing medical records, and by telephone interviews with patients. Survival analysis was performed using the Cox's regression model with survival probability estimated with Kaplan-Meier curve. The log-rank test was used to compare survival between strata. Data was analyzed with Stata 12.

RESULTS

The five-year survival rate and the mean survival time after cancer diagnosis were 58.5% and 67±1.4 months. On multivariate analysis, age of diagnosis, disease stage and primary tumor site, lymphovascular invasion and type of treatment (in colon cancer) were significant factors for survival.

CONCLUSIONS

Age of diagnosis and type of treatment (adjuvant therapy in patients with colon cancer) were two modifiable factors related to survival of CRC patients. Therefore earlier diagnosis might help increase survival.

Association between proto-oncogene mutations and clinicopathologic characteristics and overall survival in colorectal cancer in East Azerbaijan, Iran

Background

Colorectal cancer (CRC) is the third-most common cancer in Iran. The increasing incidence of CRC in the past three decades has made it a major public health burden in the country. This study aimed to determine any relationship of specific mutations in CRCs with clinicopathologic aspects and outcome of patients.

Materials and methods

This study was conducted on 100 CRC patients by the case-only method. Polymerase chain-reaction products were analyzed by Sanger sequencing, and sequence results were compared with the significant KRAS and BRAF gene mutations in the My Cancer Genome database. Logistic regression models were used to detect associations of clinicopathologic characteristics with each of the mutations. Kaplan–Meier and Cox regression models were constructed to estimate overall survival in patients.

Results

A total of 26 subjects (26%) had heterozygote-mutant KRAS, and mutations were not detected in the amplified exon of BRAF in both tumor and normal tissues of the 100 CRCs. Rectal tumors had 1.53-fold higher likelihood of KRAS mutations than colon tumors, and men had 1.37-fold higher odds than women. The presence of metastasis increased the likelihood of KRAS mutations 2.36-fold over those with nonmetastatic CRCs. Compared to patients with KRAS wild-type cancers, those with KRAS mutations had significantly higher mortality (hazard ratio 3.74, 95% confidence interval 1.44–9.68; log-rank P=0.003).

Conclusion

Better understanding of the causality of CRC can be established by combining epidemiology and research on molecular mechanisms of the disease.

Effective Targeting Survivin, Caspase-3 and MicroRNA-16-1 Expression by Methyl-3-pentyl-6-methoxyprodigiosene Triggers Apoptosis in Colorectal Cancer Stem-Like Cells

Over-expression of the proto-oncogene survivin in colorectal cancer stem cells (CCSCs) is thought to be one the primary causes for therapy failure. It has also been reported that tumor suppressor miR-16-1 is down-regulated in colorectal cancer (CRC) cells. Therefore, the search for new anti-proliferative agents which target survivin or miR-16-1 in CCSCs is warranted. Several studies have shown that prodigiosin isolated from cell wall of Serratia marcescens induces apoptosis in different kinds of cancer cells. Here, we investigated the effects of prodigiosin on HCT-116 cells that serve as a model for CRC initiating cells with stem-like cells properties. HCT-116 cells were treated with 100, 200 and 400 nM prodigiosin after which cell number, viability, growth-rate, survivin and miRNA-16-1 expression, caspase-3 activation and apoptotic rate were evaluated. Prodigiosin decreased significantly growth-rate in a dose-and time-dependent manner. After a 48 h treatment with 100, 200 and 400 nM prodigiosin, growth-rates were measured to be 84.4 ± 9.2 %, 58 ± 6.5 % and 46.3 ± 5.2 %, respectively, compared to untreated cells. We also found that treatment for 48 h with indicated concentrations of prodigiosin resulted in 41 %, 54.5 % and 63 % decrease in survivin mRNA levels and induced 32 %, 48 % and 61 % decrease in survivin protein levels as well as resulted in 128.3 ± 10 %, 178.7 ± 6.1 % and 205 ± 7.6 % increase in caspase-3 activation respectively compared to untreated cells. Prodigiosin caused a significant increase in miRNA-16-1 expression at a concentration of 100 nM and treatment with different concentrations of prodigiosin resulted in 2.2- to 3-fold increase in miRNA-16-1/survivin ratios compared to untreated cells. An increase in number of apoptotic cells ranging from 28.2 % to 86.8 % was also observed with increasing prodigiosin concentrations. Our results provide the first evidence that survivin and miRNA-16-1 as potential biomarkers could be targeted in CRC initiating cells with stem-like cells properties by prodigiosin and this compound with high pro-apoptotic capacity represents the possibility of its therapeutic application directed against CCSCs.

Promoter hypermethylation and downregulation of the FAS gene may be involved in colorectal carcinogenesis

Aberrant DNA methylation has been investigated in carcinogenesis and as biomarker for the early detection of colorectal cancer (CRC). The present study aimed to define the methylation status in the regulatory elements of two proapoptotic genes, Fas cell surface death receptor (FAS) and BCL2-associated X protein (BAX). DNA methylation analysis was performed in tumor and adjacent normal tissue using HpaII/MspI restriction digestion and methylation-specific polymerase chain reaction (PCR). The results observed downregulation of the FAS and BAX genes in the CRC tissues compared with the adjacent normal samples. Furthermore, demethylation using 5-aza-2'-deoxycytidine treatment followed by reverse-transcription quantitative PCR were performed on the HT-29 cell line to measure BAX and FAS mRNA expression following demethylation. The 5-aza-2'-deoxycytidine treatment resulted in significant FAS gene upregulation in the HT-29 cell line, but no significant difference in BAX expression. Furthermore, analysis of CpG islands in the FAS gene promoter revealed that the FAS promoter was significantly hypermethylated in 53.3% of tumor tissues compared with adjacent normal samples. Taken together, the results indicate that decreased expression of the FAS gene due to hypermethylation of its promoter may lead to apoptotic resistance, and acts as an important step during colorectal carcinogenesis.

Human Epidermal Growth Factor Receptor Expression in Colorectal Cancer and Its Relationship with Clinicopathological Characteristics

BACKGROUND

Some recent studies reported human epidermal growth factor receptor (HER-2/neu) as a marker that can be used in immunological studies of colorectal carcinoma for predicting the prognosis and the treatment. Therefore, we aimed to investigate the frequency of HER-2 expression in patients with colorectal cancer, and explore the relationship between clinicopathological prognostic factors and its expression based on immunohistochemical analysis.

METHODS

This study included 50 patients with a histologically proven diagnosis of colorectal carcinoma who received surgery at Imam Khomeini Hospital affiliated to Mazandaran University of Medical Sciences. First, HER-2/neu protein expressions were detected by immunohistochemistry and then the data extracted from recorded files.

RESULTS

The median age of the patients was 60.2±13.9 years (range: 25-93 years). There was no significant relationship between size of tumor, age, sex, lymph node metastases, distant metastasis, differentiation, and stage of the disease with positive expression of HER-2 in this study.

CONCLUSION

No significant relationship between expression of HER-2 and clinicopathological prognostic factors was found in our study. Further comprehensive and prospective trial with standard method to evaluate the role of HER-2 expression among patients with colorectal cancer is needed.

Survival of Colorectal Cancer in the Presence of Competing- Risks - Modeling by Weibull Distribution

BACKGROUND

Colorectal cancer (CRC) is the commonest malignancy in the lower gastrointestinal tract in both men and women. It is the third leading cause of cancer-dependent death in the world. In Iran the incidence of colorectal cancer has increased during the last 25 years.

MATERIALS AND METHODS

In this article we analyzed the survival of 447 colorectal patients of Taleghani hospital in Tehran using parametric competing-risks models. The cancers of these patients were diagnosed during 1985 - 2012 and followed up to 2013. The purpose was to assess the association between survival of patients with colorectal cancer in the presence of competing-risks and prognostic factors using parametric models. The analysis was carried out using R software version 3.0.2.

RESULTS

The prognostic variables included in the model were age at diagnosis, tumour site, body mass index and sex. The effect of age at diagnosis and body mass index on survival time was statistically significant. The median survival for Iranian patients with colorectal cancer is about 20 years.

CONCLUSIONS

Survival function based on Weibull model compared with Kaplan-Meier survival function is smooth. Iranian data suggest a younger age distribution compared to Western reports for CRC.

Increased colorectal cancer incidence in Iran: a systematic review and meta-analysis

BACKGROUND

Colorectal cancer is the third most common cancer in Iran. The increasing trend of colorectal cancer incidence in Iran and the close relationship with the geographical location are the underlying reasons for this study.

METHODS

DATA SOURCE

Eleven databases, including MEDLINE, EMBASE, SCOPUS, and four other databases, for articles in Persian were searched from April 2014 to October 2014. Additional data were obtained from an online survey of the Central Library of Tabriz Faculty of Medicine.

STUDY ELIGIBILITY CRITERIA

In this systematic review and meta-analysis, we included studies reporting different measures of incidence, age-standardized incidence rates, and crude incidence rates. All rates (per 100,000 person-years) were standardized to the world standard population.

STUDY APPRAISAL AND SYNTHESIS METHODS

A preliminary review of the title and abstracts of these articles was used to exclude any that were clearly irrelevant. The full text review determined whether the article was relevant to our topic. All the potentially relevant manuscripts were reviewed by two other investigators (S.D., M.G.). A total of 39 studies (10 Persian and 29 English articles) from different provinces and diverse areas of Iran, were analyzed in this study using comprehensive meta-analysis software. For accuracy studies, we used estimated rates for males and females with 95 % confidence intervals.

RESULTS

Age-standardized incidence rates were obtained based on the random effects model and were 8.16 (95 % CI: 6.64 to 9.68) and 6.17 (95 % CI: 5.01 to 7.32) for males and females, respectively. The random crude rates were 5.58 (95 % CI: 4.22 to 6.94) for males and 4.01 (95 % CI: 3.06 to 4.97) for females.

CONCLUSIONS

Colorectal cancer incidence rates rise due to individual and environmental risk factors as well as improvement in the registry system and increase in access to health services. A more executed organized and structured system for collecting cancer data, in all cities and rural areas of the country, is an essential priority.

Demographic survey of four thousand patients with 10 common cancers in North Eastern Iran over the past three decades

BACKGROUND

Cancer is a major cause of mortality in developing countries and correct and valid information about the epidemiology of this disease is the first step in the planning of health care in each region. The aim of this study was to determine the relative frequency, mean age and sex ratio of the most 10 common non-skin cancers in the world and Iran, among patients referred to an oncology clinic.

MATERIALS AND METHODS

This descriptive study was conducted in Mashhad, north east of Iran. The data obtained from the records of patients referred to the private oncology center between the years of 1985-2012." According to the latest report of GLOBOCAN study commonest malignancies included were lung, breast, colorectal, prostate, stomach, liver, cervix, esophageal, bladder cancers and Non-Hodgkin lymphoma.

RESULTS

A total of 4,606 cases were analyzed. The mean age was 55.5±13.8years (male: 59.5±13.9, female: 52.6±12.9). Overall, breast cancer (1,264 cases, relative frequency of 27.4%) was the most prevalent cancer; however the mean ages of diagnosis were not significantly different between 5-year time period divisions (p=0.290). The most common cancer in men was esophageal cancer (26.3%).The lowest mean age was related to women diagnosed with breast cancer (48.5±11.8) and men with non-Hodgkins lymphoma (48.4±17.8). There were statistically significant differences between the mean age of men and women with gastric (p=0.003) and esophageal cancers (p<0.001). Male to female sex ratios in our study for bladder, lung and stomach cancers were 6.57, 2.60 and 2.50 respectively.

CONCLUSIONS

The results showed that breast cancer tends to be found in younger female patients and bladder cancer appears more often in men. Screening in target population in addition to early diagnosis may reduce death and disability.

Prevalence and characteristics of colorectal polyps in symptomatic and asymptomatic Iranian patients undergoing colonoscopy from 2009-2013

BACKGROUND

Colorectal cancer is the third most common type of cancer in males and the second in females in Iran. Males are more likely to develop CRC than women and age is considered as a main risk factor for colorectal cancer. Prevalence of colorectal cancer has been increasing in Asian countries.

AIM

The object of this study was to determine the clinical and pathology characteristics of colorectal polyps in Iranian patients and to investigate the variation between our populations with other populations.

MATERIALS AND METHODS

A total of 167 patients with colorectal polyps were included in our study. All underwent colonoscopy during 2009-2013 and specimens were taken through polypectomy and transferred to pathology. All data in patient files including pathology reports were collected and analyzed by SPSS 16 software. A two-tailed test was used and a P-value of <0.05 was considered significant.

RESULTS

Mean age of participants was 57±15. Some 84 were females (50.3%) and 83 males (49.7%). Total of 225 polyps were detected which 119 (52.9%) were in males and 106 (47.1%) were in females. Solitary polyps were observed in 124 patients (74%), 26 (15.6%) had two polyps and 17 (10.1%) with more than two polyps (three to five). Rectosigmoid was the site of most of the polyps (63.1%), followed by 19.6% in the descending colon, 7.6% in the transverse, 5.8% in the ascending, and 3.1% in the cecum, data being missing in two cases.

CONCLUSIONS

Recto sigmoid was site of most of the polyps. The most prevalent type of lesion was adenomatous polyps detected in 78 (34.7%). Mixed hyperplastic adenomatous type observed in 70 (31.1%). This high prevalence of adenomatous polyps in Iranian patients implies the urgent need for screening plans to prevent further healthcare problems with colorectal cancer in the Iranian population.

Increasing Trend in Colorectal Cancer Incidence in the Southeast of Iran 2003-2013: A Population Based Cancer Registry Study

Rates based on age-adjusted incidence of colorectal cancers over a 10-year period in Kerman, the biggest province of Iran, were estimated from 2003 to 2013. Data were obtained from the population-based cancer registry unit of Kerman University of Medical Sciences (CR-KMU). Information included age, sex, city, ICD-O and year of registry. Our trend analyses cover 3.91% of the Iranian population. The data set comprised cases diagnosed from 2003 to 2013.The population of over 20 years was interpolated using 2003 and 2010 censuses. Then, truncated age-adjusted incidence rates were calculated. Increase was noted from 2003-2009 to 2010-2013 for 731 cancer cases considered in the analysis. The increases was most prominent in 2009. Totally, the frequency of the cancer was greater in males. Moreover, calculating truncated age-adjusted incidence rate indicated that the most prevalent age of colorectal incidence was in the 50-59 year age group except in 2007-2008 and 2012- 2013, when greatest incidences occurred in people aged 60-69 years. Our data revealed that the incidence rates of colorectal cancer have increased over the past decade in our region of Iran.

Colorectal cancer in iran: molecular epidemiology and screening strategies

Purpose. The increasing incidence of colorectal cancer (CRC) in the past three decades in Iran has made it a major public health burden. This study aimed to report its epidemiologic features, molecular genetic aspects, survival, heredity, and screening pattern in Iran. Methods. A comprehensive literature review was conducted to identify the relevant published articles. We used medical subject headings, including colorectal cancer, molecular genetics, KRAS and BRAF mutations, screening, survival, epidemiologic study, and Iran. Results. Age standardized incidence rate of Iranian CRCs was 11.6 and 10.5 for men and women, respectively. Overall five-year survival rate was 41%, and the proportion of CRC among the younger age group was higher than that of western countries. Depending on ethnicity, geographical region, dietary, and genetic predisposition, mutation genes were considerably diverse and distinct among CRCs across Iran. The high occurrence of CRC in records of relatives of CRC patients showed that family history of CRC was more common among young CRCs. Conclusion. Appropriate screening strategies for CRC which is amenable to early detection through screening, especially in relatives of CRCs, should be considered as the first step in CRC screening programs.

Mortality determinants in colorectal cancer patients at different grades: a prospective, cohort study in Iran

BACKGROUND

Colorectal cancer (CRC) is an important cause of mortality and morbidity in many communities worldwide. This population based study was conducted to assess determinants of colorectal mortality in Iranian patients.

MATERIALS AND METHODS

A cohort of 1,127 cases of confirmed colorectal cancer registered in a population based registry covering 10 referral hospital in Tehran, Iran, were followed for five years. Information about tumor characteristics, smoking status and family history were collected at base line and survival status were followed every six months by contacting patient or next of kin (if patients died during the follow-up). The cause of death for each case was validated by verbal autopsy and referring to patient medical records at the time of death. The data were analyzed by Stata software using univariate and multivariate analysis (Cox regression). In building the model a p value of less than 5% was considered as significant.

RESULTS

The age at diagnosis was 53.5±14 years. Sixty one percent were male. Colorectal mortality among the patients was 96.9 person-years among men and 83 person-years among women. Seventy five percent of patients lived for 2.72 years, 50% for 5.83, and 25% for 13 years after the diagnosis of colorectal cancer. The age at diagnosis was significantly different between men and women (p<0.03). Higher tumor grade predicted higher death rate; the adjusted hazard ratios were 1.79 (95%CI, 0.88-3.61), 2.16 (95%CI, 1.07-4.37), and 3.1 (95%CI, 1.51-6.34) for grades II, III, and IV respectively when they were compared with grade I as reference. Ethnicity, marital status, family history of cancer, and smoking were related to survival with different degrees of magnitude.

CONCLUSIONS

Among many factors related to survival among the colorectal patients, tumor grade and smoking showed the highest magnitudes of association.

Clinicopathological features of colon adenocarcinoma in Qazvin, Iran: a 16 year study

BACKGROUND

Colorectal cancer (CRC) was the fourth most commonly diagnosed cancer in Iran between 2000 and 2009, with adenocarcinoma (AC) as the most common histological type. Demographic, topographic and histological variables are important in the epidemiology and biology of cancer. The aim of this study was to investigate clinicopathological features of colon adenocarcinomas in Qazvin, Iran.

MATERIALS AND METHODS

With a retrospective design, patient records of two pathology wards from March 1997 to March 2013 were studied with regard to anatomical location and histological classification. A broader anatomical grouping was also used including distal vs proximal regions and right sided vs left sided tumors. Data were analyzed using T-test and chi-square test.

RESULTS

118 (50.9%) male and 114 (49.1%) female patients were included in the study. Mean age was 57.3±14.7 years, with 29.2% under 50 years. There was no significant gender difference for age at diagnosis. The rectum (56%) and sigmoid colon (25%) were the most frequent anatomical locations. Proximal cases accounted for 18.6% in males and 8.8% in females (p=0.02). AC was more prevalent than other usual types in younger patients. The proportion of proximal cancer was 1.7% in first eight years of the study period vs 12.1% in the second one (p=0.005). A similar trend was also seen in right sided colon cancers (p=0.018).

CONCLUSIONS

Young people are also at risk for the cancer with poor prognosis. Screening programs and weight loss in obese individuals can reduce incidence and complications of CRC.

A metabolic study on colon cancer using (1)h nuclear magnetic resonance spectroscopy

Background. Colorectal carcinoma is the third cause of cancer deaths in the world. For diagnosis, invasive methods like colonoscopy and sigmoidoscopy are used, and noninvasive screening tests are not very accurate. We decided to study the potential of ¹HNMR spectroscopy with metabolomics and chemometrics as a preliminary noninvasive test. We obtained a distinguishing pattern of metabolites and metabolic pathways between colon cancer patient and normal. Methods. Sera were obtained from confirmed colon cancer patients and the same number of healthy controls. Samples were sent for ¹HNMR spectroscopy and analysis was carried out Chenomex and MATLAB software. Metabolites were identified using Human Metabolic Data Base (HDMB) and the main metabolic cycles were identified using Metaboanalyst software. Results. 15 metabolites were identified such as pyridoxine, orotidine, and taurocholic acid. Main metabolic cycles involved were the bile acid biosynthesis, vitamin B6 metabolism, methane metabolism, and glutathione metabolism. Discussion. The main detected metabolic cycles were also reported earlier in different cancers. Our observations corroborated earlier studies that suggest the importance of lowering serum LCA/DCA and increasing vitamin B6 intake to help prevent colon cancer. This work can be looked upon as a preliminary step in using ¹HNMR analysis as a screening test before invasive procedures.

Survival of colorectal cancer patients in the presence of competing-risk

BACKGROUND

Colorectal cancer (CRC) is considered to be a main cause of malignancy-related death in the world, being commonly diagnosed in both men and women. It is the third leading cause of cancer dependent death in the world and there are one million new cases diagnosed per year. In Iran the incidence of colorectal cancer has increased during the last 25 years and it is the fifth cause of cancer in men and the third in women.

MATERIALS AND METHODS

In this article we analyzed the survival of 475 colorectal patients of Taleghani hospital in Tehran with the semi-parametric competing-risks model.

RESULTS

There were 55% male cases and at the time of the diagnosis most of the patients were between 48 and 67 years old. The probability of a patient death from colorectal cancer with survival of more than 25 years was about 0.4. Body mass index, height, tumour site and gender had no influence.

CONCLUSIONS

According to these data and by using semi-parametric competing-risks method, we found out that only age at diagnosis has a significant effect on these patient survival time.

Prevalence of colorectal polyps in a group of subjects at average-risk of colorectal cancer undergoing colonoscopic screening in Tehran, Iran between 2008 and 2013

BACKGROUND

Colorectal cancer (CRC) is one of the prime causes of mortality around the globe, with a significantly rising incidence in the Middle East region in recent decades. Since detection of CRC in the early stages is an important issue, and also since to date there are no comprehensive epidemiologic studies depicting the Middle East region with special attention to the average risk group, further investigation is of significant necessity in this regard.

AIM

Our aim was to investigate the prevalence of preneoplastic and neoplastic lesions of the colon in an average risk population.

MATERIALS AND METHODS

A total of 1,208 eligible asymptomatic, average- risk adults older than 40 years of age, referred to Firuzgar Hospotal in the years 2008-2012, were enrolled. They underwent colonoscopy screening and all polypoid lesions were removed and examined by an expert gastrointestinal pathologist. The lesions were classified by size, location, numbers and pathologic findings. Size of lesions was measured objectively by endoscopists.

RESULTS

The mean age of participants was 56.5±9.59 and 51.6% were male. The overall polyp detection rate was 199/1208 (16.5 %), 26 subjects having non-neoplastic polyps, including hyperplastic lesions, and 173/1208 (14.3%) having neoplastic polyps, of which 26 (2.15%) were advanced neoplasms .The prevalence of colorectal neoplasia was more common among the 50-59 age group. Advanced adenoma was more frequent among the 60-69 age group. The majority of adenomas were detected in the distal colon, but a quarter of advanced adenomas were found in the proximal colon; advance age and male gender was associated with the presence of adenoma.

CONCLUSIONS

It seems that CRC screening among average-risk population might be recommended in countries such as Iran. However, sigmioidoscopy alone would miss many colorectal adenomas. Furthermore, the 50-59 age group could be considered as an appropriate target population for this purpose in Iran.