Colorectal Cancer: A Systematic Review of the Current Situation and Screening in North and Central Asian Countries

The prevalence of colorectal cancer (CRC) is increasing in the past few decades. A significant proportion of this increase is from low to middle income countries (LMIC). CRC prevalence is also increasing in North and Central Asian Countries (NCAC). Screening for colorectal cancer has decreased CRC mortality but data regarding screening practices in NCAC is limited.  A literature search was conducted in PubMed/Medline, Embase and Cochrane for current colorectal cancer screening practices in NCAC. Incidence and mortality rates were derived from public health agency websites to calculate age-standardized CRC mortality-to-incidence ratios. Web-based online break-point testing defined as statistical major changes in CRC mortality trends was completed. Among the 677 screened studies, 37 studies met the criteria for inclusion for review. CRC screening in NCAC is not organized, although most countries have cancer registries. The data availability is scarce, and most data is prior to 2017. Most studies are observational. There is minimal data about colonoscopy preparations, adenoma detection and complications rates. The polyp detection rates (PDRs) and adenoma detection rates (ADRs) seem low to optimal in this region. Commonly measured outcomes include participation rate, fecal immunochemical tests (FIT) positivity rate and cost-benefit measures. Lower mortality-to-incidence ratios is seen in countries with screening programs. Kazakhstan and Lithuania with screening programs have achieved breakpoint suggesting major changes in CRC mortality trends. Data about CRC screening varies widely within NCAC. High human developmental index (HDI) countries like Lithuania and Estonia have higher incidence of CRC and mortality. Seven NCAC have CRC screening programs with most utilizing non-invasive methods for screening. Data collection is regional and not organized. The ADR and PDR are low to optimal in this region and cancer detection rates are comparable to other high-income countries (HIC). CRC detection rate is 0.05% for screening in Kazakhstan and 0.2% for screening in Lithuania. Very limited information is available on the actual cost and logistics of implementing a CRC screening program. All NCAC have a cancer registry, with some having a high-quality registry showing national coverage with good validity and completeness. Establishing guideline-based registries and increasing screening efficacy could improve CRC outcomes in NCAC.

Incidence and Risk Factors of Colorectal Cancer in the Iranian Population: a Systematic Review

PURPOSE

Colorectal cancer (CRC) is one of the most common cancers in the world. The aim of this study was to investigate its incidence and risk factors in the Iranian population.

METHODS

A literature search was conducted in PubMed, Web of Science, Scopus, SID, and Magiran from inception until 2019. Studies that reported the incidence rate and risk factors of colorectal cancer were included in this review.

RESULTS

Twenty-one articles that reported the incidence rate and 13 that reported the risk factors were included. The incidence rate was different according to the population type, gender, age, and study year in different regions. The main risk factors for colorectal cancer were high consumption of red meat and fried food and low intake of fruits and vegetables, diabetes, a positive family history, and obesity.

CONCLUSION

The incidence of CRC has a marked variation in different parts of Iran, and various risk factors are associated with colorectal cancer. According to incidence rate and various risk factors, precise planning is needed to control colorectal cancer in the future.

Trend of gastric cancer in a province in Western Iran: A population-based study during 2001-2014

BACKGROUND

There are no studies on the trend of gastric cancer (GC) incidence in Kurdistan, a province in the west of Iran. We aimed to estimate the trend, age-standardized incidence rate (ASR), and annual percentage change (APC) of GC in this province during 2001-2014.

MATERIALS AND METHODS

The data of newly diagnosed GC patients were obtained from the regional Cancer Registering Database. The ASRs were calculated per 100,000 population during 2001-2014. Direct standardization and 95% confidence intervals (CI) were calculated by an efficient method. The temporary changes in ASRs were determined based on the APC by the joinpoint regression model.

RESULTS

Overall, 2225 newly diagnosed GC patients were identified. The ASRs ranged from 13.5 (95% CI: 10.4-17.3) to 29.0 (95% CI: 24.5-34.0). The highest ASRs were related to the men and women lived in Divandareh as 32.26 and 13.66, respectively. The respective APC value of GC incidence in women demonstrated a nonsignificant increase during 2001-2008 and a nonsignificant decrease during 2008-2014 (P = 0.1). Accordingly, the incidence of GC in men increased during 2001-2004 (P = 0.1) and decreased during 2004-2014 (P = 0.001).

CONCLUSION

The incidence of GC showed nonsignificant and significant decreasing trends in women and men in Kurdistan province, respectively. Despite such decreasing trends, the Kurdistan province is still considered as one of the regions with high incidence of GC in Iran. Therefore, it is necessary to implement screening programs in the province to early diagnose GC.

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 12-year trend analysis of the incidence of gastrointestinal cancers in East Azerbaijan: last updated results of an ongoing population-based cancer registry

BACKGROUND

The most recent results of Global Cancer Statistics indicated that gastrointestinal cancers, including gastric, colorectal, esophageal, and liver cancers, are among the most commonly diagnosed cancers worldwide. Previous reports from cancer registries in East Azerbaijan have shown that there is a high incidence of gastrointestinal cancer in this region, so we performed a trend analysis to determine the pattern of change over the last decade.

METHODS

In total, 12 years of cancer registry data were collected from different sources in East Azerbaijan, and a data quality check was performed to ensure clean data. Using the 2000 World Health Organization standard population, we then generated age-standardized incidence rates (ASRs) for different cancers, and for each year from 1383 to 1394 of the Persian calendar (i.e., 19 March 2004 to 20 March 2015). Annual percent changes (APCs) and Average annual percent changes (AAPCs) in the ASRs for esophageal, gastric, small intestine, colorectal, anal, liver, gallbladder, and pancreatic cancers were calculated using Joinpoint Software (Version 4.5.0.1, June 2017).

RESULTS

An increase in most types of cancer was observed during the study period. The ASR for colorectal cancer increased from 2.9 to 13.6 per 100,000 women (APC, 9.7%) and from 2.2 to 17.8 per 100,000 men (APC, 10.2%). The ASR for gastric cancer showed a slight increasing trend from 10.5 to 13.5 per 100,000 women (APC, 1.3%) and from 3.1 to 29.9 per 100,000 men (APC, 3.2%). However, trend analysis showed a decreasing pattern for the ASR of esophageal cancer in both genders (APC,- 3%), with APCs of - 1.1% in females and - 0.4% in males.

CONCLUSIONS

The latest results of the East Azerbaijan Population-Based Cancer Registry indicate that gastrointestinal cancers remain common, with significant increasing trends in their ASRs. Improved screening and early detection are needed in this region.

PEGylated gold nanoparticles-ribonuclease induced oxidative stress and apoptosis in colorectal cancer cells

Introduction: Currently, drug-induced reactive oxygen species (ROS) mediating apoptosis pathway have extensively been investigated in designing effective strategies for colorectal cancer (CRC) chemotherapy. Bovine pancreatic ribonuclease A (RNase A) represents a new class of cytotoxic and non-mutagenic enzymes, and has gained more attention as a potential anticancer modality; however, the cytosolic ribonuclease inhibitors (RIs) restrict the clinical application of this enzyme. Nowadays, nanotechnology-based diagnostic and therapeutic systems have provided potential solutions for cancer treatments.

Methods: In this study, the gold nanoparticles (AuNPs) were synthesized, stabilized by polyethylene glycol (PEG), functionalized, and covalently conjugated with RNase A. The physicochemical properties of engineered nanobiomedicine (AuNPs-PEG-RNase A) were characterized by scanning electron microscope (SEM), dynamic light scattering (DLS), and UV-vis spectrum. Then, its biological impacts including cell viability, apoptosis, and ROS production were evaluated in the SW-480 cells.

Results: The engineered nanobiomedicine, AuNPs-PEG-RNase A, was found to effectively induce apoptosis in SW-480 cells and result in a significant reduction in cancer cell viability. Besides, the maximum production of ROS was obtained after the treatment of cells with an IC50 dose of AuNPs-PEG-RNase A.

Conclusion: Based on the efficient ROS-responsiveness and the anticancer activity of RNase A of the engineered nanomedicine, this nanoscaled biologics may be considered as a potential candidate for the treatment of CRC.

Pre-operative laparoscopic staging of gastric cancer in patients who are candidates for neo-adjuvant chemotherapy: A Cross Sectional Study

Objective The aim of this study is to evaluate the laparoscopic method in gastric cancer staging before surgery in patients undergoing Neo-adjuvant chemotherapy. Methods This was a cross-sectional study on patients with T3-T4 and node positive non-metastatic gastric adenocarcinoma who was candidates for neo-adjuvant chemotherapy. The patients were excluded from the study when they were not in the condition to continue the study. All eligible patients underwent metastases work up by abdominal, pelvic and chest CT scans and then received neo-adjuvant chemotherapy. Pre-operative laparoscopy was performed before definitive surgery. The collected data was analyzed using SPSS software. The statistical significance, sensitivity, specificity and predictive values were calculated from this data. Results In this study, out of 50 patients, 26 (52%) were male. The mean age of the patients was 62.44 ± 12.136 years. Most tumors were located in one-third distal of stomach (21 patients, 42%). The accuracy of the laparoscopic method, to determine the degree of involvement of the lymph nodes, revealed that the method had a sensitivity of 84%, a specificity of 47.62%, a positive likelihood ratio (PLR) of 1.6, a negative likelihood ratio (NLR) of 0.33%, a positive predictive value of 65.62% and a negative predictive value of 71.43%. The accuracy of the laparoscopic method, regarding determining the presence or absence of metastasis, revealed that the method had a sensitivity, specificity, positive predictive value, and a negative predictive value of 100%. Conclusion Based on the evidence of this study, and other studies in this field, it seems that the use of a step-by-step combination methods in gastric cancer staging would be logical. Alone, no singular method would be sufficient in providing the physician with sufficient information to successfully stage the tumor and thus determine the appropriate treatment. Therefore, the combination of methods should be used which, in view of the economic constraints of health systems, would be recommended for high-risk patients for metastasis (N+/ T3-T4), diagnostic pre-operative laparoscopy.

Determining Risk Factors for Gastric and Esophageal Cancers between 2009-2015 in East-Azarbayjan, Iran Using Parametric Survival Models

Background: Esophageal cancer (EC) and Gastric cancer (GC) have been identified as two of the most common cancers in the northeastern regions of Iran. The increasing rates of these types of cancers requires attention. This study aims to assess the potential risk factors for these two cancers and then determine shared risk factors between them in a population of Iranian patients using parametric survival models. Methods: This retrospective cohort study was conducted using 127 patients with EC and 184 patients with GC in East Azarbaijan, Iran who were diagnosed and registered during the years 2009-2010 in Iran’s National Cancer Control Registration Program and were followed for five years. Parametric survival models were used to find the risk factors of the patients. Akaike Information Criteria was used to identify the best parametric model in this study. Interaction analysis was used to determine shared risk factors between EC and GC. Results: The mean (±standard deviation) age of diagnoses for EC and GC were 66.92(±11.95) and 66.5(±11.5) respectively. The survival time ranges of GC patients was (0.07-70.33) and the survival time ranges were from 0.10 to 69.03 months for EC patients. Multivariable Log- logistic model showed that being married (OR=2.25, 95% CI: 1.33 - 3.81) for EC patients and Esophagectomy surgery for EC (OR: 1.62, 95% CI: 1.04 – 2.55) and GC (OR: 1.60, 95% CI: 1.02 – 2.53) had significant effects on survival. Age at the time of diagnosis, job status, and Esophagectomy surgery were statistically comparable regarding their magnitude of effect on survival of two cancers (all Ps>0.05). Conclusion: Esophagectomy surgery and being married were important risk factors in EC and GC. The log-logistic model was the most appropriate statistical approach to identify significant risk factors on survival of both cancers.

A 25-year trend in gastrointestinal cancers in northern Iran (1991-2016)

BACKGROUND

Identifying the incidence of cancer helps in planning and prioritizing resources for its screening, prevention, treatment and diagnosis. This study aimed at investigating a 25-year trend in gastrointestinal cancer in northern Iran during 1991-2016.

METHODS

This research was a trend analysis. The study population was one thousand five hundred and thirty-five cancer patients referring to Shahid Rajai Hospital in Babolsar, northern Iran, as the only center for radiotherapy in the North of Iran, during 1991-2016. SPSS version 22 was used for entering data and t-test, ᵡ2 and ANOVA were used for analyzing data in the significant level of ≤0.05.

RESULTS

The highest incidence of stomach cancer was 111 (35%) in 2011 and the lowest incidence was 44 (16.3%) in 1996, The highest frequency of esophageal cancer was reported 137(56.1%) cases in 1991 and the lowest frequency was 78 (26.3%) cases in 2016, while the highest incidence of colorectal cancer was 109 (36.7%) cases in 2016 and its lowest frequency was 32 (16.3%) in 1996. There was also a significant difference in the frequency of gastrointestinal cancers in different studied years (p <0.001).

CONCLUSION

The trends in the incidence of stomach and colorectal cancers in northern Iran were increasing while esophageal cancer was decreasing.

Cancer incidence in the East Azerbaijan province of Iran in 2015-2016: results of a population-based cancer registry

Background

Few countries in the Middle East have a population-based cancer registry, despite a clear need for accurate cancer statistics in this region. We therefore established a registry in the East Azerbaijan province, the sixth largest province in northwestern Iran.

Methods

We actively collected data from 20 counties, 62 cities, and 44 districts for the period between 20^th March 2015 and 19^th March 2016 (one Iranian solar year). The CanReg5 software was then used to estimate age-standardized incidence rates (ASRs) per 100,000 for all cancers and different cancer types.

Results

Data for 11,536 patients were identified, but we only analyzed data for 6655 cases after removing duplicates and non-residents. The ASR for all cancers, except non-melanoma skin cancer, was 167.1 per 100,000 males and 125.7 per 100,000 females. The most common cancers in men were stomach (ASR 29.7), colorectal (ASR 18.2), bladder (ASR 17.6), prostate (ASR 17.3), and lung (ASR 15.4) cancers; in women, they were breast (ASR 31.1), colorectal (ASR 13.7), stomach (13.3), thyroid (ASR 7.8), and esophageal (ASR 7.1) cancers. Both the death certificate rate (19.5%) and the microscopic verification rate (65%) indicated that the data for the cancer registry were of reasonable quality.

Conclusion

The results of the East Azerbaijan Population-based Cancer Registry show a high incidence of cancer in this province, especially gastrointestinal cancers.

Concentrations of arsenic and lead in rice (Oryza sativa L.) in Iran: A systematic review and carcinogenic risk assessment

Exposure to heavy metals such as arsenic (As), lead (Pb), and cadmium (Cd) in either the short or the long term can cause cancers in humans. Dietary intake and consumption of rice (Oryza sativa L.) is increasing in Iran, and several studies on the concentration of heavy metals in rice have been carried out in this country in recent years. In this perspective, the main objective of the present study was to investigate, even via a meta-analysis of the existing literature, the presence of As and Pb in rice from many geographical areas in Iran, as well as to estimate the carcinogenic risk of these heavy metals in rice consumers. The results of the present ten years-spanning systematic review indicate that 21 reports, collecting a total of 2088 samples, were performed between 2008 and October 2017. The minimum and maximum concentration of As was observed in the Golestan area (0.01 ± 0.01 mg/kg d.w) and the Gillan region (3 mg/kg d.w); and Pb in the Shahrekord (0.07 ± 0.02 mg/kg d.w) and Mazandaran (35 mg/kg d.w). The meta-analysis of data showed that pooled concentration of As in the rice was 0.04 (95%CI: 0.02-0.06 mg/kg d.w), which resulted lower than the National Standard (NS) limits. However, the pooled concentration of Pb in the rice was 0.38 (95%CI: 0.25-0.5 mg/kg d.w), i.e., higher than NS limits. The heterogeneity was significant between As (I² = 63%, P value = .003) and Pb (I² = 96%, P value < .001) studies. The carcinogenic risk assessment showed that minimum and maximum incremental lifetime cancer risk (ILCR) of As was in the 45-54 (4.53 × 10^-2) and 15-24 (5.50 × 10^-2) year age groups consumers; and Pb, 45-54 (2.442 × 10^-3) and 15-24 (2.96 × 10^-3), respectively. The overall carcinogenesis risk of As (4.864 × 10^-2) was 18.5 times higher than Pb (2.623 × 10^-3). All age groups consumers of rice content of As and Pb are at considerable carcinogenesis risk (ILCR > 10^-3). Therefore a decreased level of heavy metals in rice cultivation should be encouraged and performed in next planning.

Importance of miR-299-5p in colorectal cancer

Background

MicroRNAs (miRNAs) are effective regulators of gene expression that play a pivotal role in the pathogenesis of colorectal cancer (CRC) and various other cancers. The high prevalence of aberrant miRNA expression in CRC suggests that they can be used as biomarkers and anticancer molecules for therapeutic purposes. There is evidence that microRNA-299-5p (miR-299-5p) is associated with vital cell processes (e.g. epithelial-mesenchymal transition, proliferation, and tumorigenicity) and its improper expression with tumorigenesis in many types of human cancer. This prospective study investigated the contribution of miR-299-5p to CRC tumorigenesis.

Methods

The real-time reverse transcription-polymerase chain reaction was used to examine miR-299-5p expression levels prospectively in 40 sample pairs of CRC tissue and adjacent noncancerous tissue (>2 cm from cancer tissue). The ability of miR-299-5p to function as a tumor marker was also examined.

Results

The expression levels of miR-299-5p were significantly downregulated in the group of CRC samples compared with matched noncancerous tissue samples. No significant relationship was found between miR-299-5p expression levels and clinicopathological features. Receiver operating characteristic analysis gave an area under the curve of 71% for miR-299-5p with 68% sensitivity and 78% specificity (P=0.001).

Conclusion

The miRNA miR-299-5p may be considered as a tumor marker in CRC and could be of assistance as a potential predictive biomarker in the diagnosis of this cancer.

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.

The Value of miR-299-5p in Diagnosis and Prognosis of Intestinal-Type Gastric Adenocarcinoma

MicroRNAs (miRNAs) are a class of non-coding RNAs, containing about 22 nucleotides and having a pivotal function in various cellular processes. The oncogenic and tumor suppressor roles of miRNAs have been identified in cancers especially in gastric cancer, which is one of the most prevalent cancers. MiR-299-5p is located in the imprinted Dlk1-Dio3 region in chromosome 14q32. Aberrant expression of miR-299-5p was determined in solid and blood cancers. The current study was performed to assess the expression pattern of miR-299-5p in intestinal-type gastric adenocarcinoma and compare it with the normal adjacent counterparts. The expression level of miR-299-5p was investigated in forty fresh specimens which were obtained from gastric cancer patients during endoscopy. Moreover, the association of aberrant expression of miR-299-5p and clinicopathological features, as well as the susceptibility of miR-299-5p as a tumor marker, was determined. The result of qRT-PCR revealed the downregulation of miR-299-5p in intestinal-type gastric adenocarcinoma compared with adjacent tumor-free tissues (P < 0.001); this misregulation can be used as a tumor marker. Analysis of miR-299-5p misregulation did not reveal a significant correlation with clinical features. The result obtained from the present study revealed the significant downregulation of miR-299-5p in intestinal-type gastric adenocarcinoma which is consistent with previous studies showing miR-299-5p downregulation in other types of cancers. The data obtained from the current study suggest basic information which can be very helpful for future research in the field of diagnosis and treatment of gastric cancer.

Poor knowledge of colorectal cancer in Brunei Darussalam

BACKGROUND

Colorectal cancer (CRC) is the most common gastrointestinal cancer and the incidence is increasing in many developing countries. While it can be detected early and even prevented through screening and removal of premalignant lesions, there are barriers to screening which include low level of knowledge and awareness of CRC. This study assessed the level of knowledge of CRC in Brunei Darussalam.

MATERIALS AND METHODS

A total of 431 (262 male and 161 female) subjects participated in this questionnaire study. Subjects were scored on their knowledge of signs/symptoms (maximum 10 correct answers) and known risk factors for CRC (maximum 10 correct answers) and were categorised into poor (0-2), moderate (3-4) and satisfactory (5-10). Comparisons were made between the various patient factors.

RESULTS

Overall, 54.1% could not name any CRC signs/symptoms or associated risk factors. Most were not aware of any screening modalities. The overall scores for CRC signs/symptoms and risk factors were 1.3±1.39 (range 0-6) and 0.6±1.05 (range 0-5) respectively. Overall, the breakdown of scores was: poor (78.1%), moderate (20.3%) and satisfactory (6.2%) for signs/symptoms and poor (93.2%), moderate (6.2%) and satisfactory (0.7%) for risk factors. Higher level of education, female gender and non-Malay race were associated with higher scores for both signs/symptoms and knowledge of screening modality; however the overall scores were low.

CONCLUSIONS

Our study showed that the general knowledge of CRC in Brunei Darussalam is poor. Being female, with higher levels of education and non-Malay race were associated with higher scores, but they were still generally poor. More needs to be done to increase the public knowledge and awareness of CRC.

Spatial analysis of common gastrointestinal tract cancers in counties of Iran

BACKGROUND

Gastrointestinal tract cancers are among the most common cancers in Iran and comprise approximately 38% of all the reported cases of cancer. This study aimed to describe the epidemiology and to investigate spatial clustering of common cancers of the gastrointestinal tract across the counties of Iran using full Bayesian smoothing and Moran I Index statistics.

MATERIALS AND METHODS

The data of the national registry cancer were used in this study. Besides, indirect standardized rates were calculated for 371 counties of Iranand smoothed using Winbug 1.4 software with a full Bayesian method. Global Moran I and local Moran I were also used to investigate clustering.

RESULTS

According to the results, 75,644 new cases of cancer were nationally registered in Iran among which 18,019 cases (23.8%) were esophagus, gastric, colorectal, and liver cancers. The results of Global Moran's I test were 0.60 (P=0.001), 0.47 (P=0.001), 0.29 (P=0.001), and 0.40 (P=0.001) for esophagus, gastric, colorectal, and liver cancers, respectively. This shows clustering of the four studied cancers in Iran at the national level.

CONCLUSIONS

High level clustering of the cases was seen in northern, northwestern, western, and northeastern areas for esophagus, gastric, and colorectal cancers. Considering liver cancer, high clustering was observed in some counties in central, northeastern, and southern areas.

Characteristics of young colorectal cancer in Brunei Darussalam: an epidemiologic study of 29 years (1986-2014)

BACKGROUND

Colorectal cancer (CRC) is the most common gastrointestinal cancer and the incidence is increasing. CRC is more common with increasing age, but a proportion occurs in young adults, termed young CRC. This study assessed the incidence and the demographic of young CRC in Brunei Darussalam.

MATERIALS AND METHODS

All histologically proven CRC between 1986 and 2014 registered with the Department of Pathology cancer registry were reviewed and data extracted for analyses. Young CRC was defined as cancer in patients aged less than 45 years. The various population groups were categorized into locals (Malays, Chinese and Indigenous) and expatriates.

RESULTS

Over the study period, there were 1,126 histologically proven CRC (mean age 59.1 ± 14.7 years, Male 58.0%, Locals 91.8% and 8.2% expatriates). Young CRC accounted for 15.1% with the proportion declining over the years, from 29% (1986-1990) to 13.2% (2011-2014). The proportion of young CRC was highest among the indigenous (30.8%), followed by the expatriates (29.3%), Malays (14.3%) and lowest among the Chinese (10.8%). The mean age of young CRC was 35.9 ± 6.2; lowest among the indigenous (33.5 ± 6.7), expatriate (34.9 ± 6.0) groupd and the Malays (35.6 ± 6.5) compared to the Chinese (38.6 ± 4.6), a similar trend being observed in the non-young CRC groups. There were no difference between the genders and tumor locations (rectum or colon) between the young and the non-young CRC cases. Female young CRC was significantly younger than male (p<0.05) without any significant variation between the various population groups (p>0.05).

CONCLUSIONS

Our study showed that the young CRC accounted for 15.1% of all CRC with declining trend observed over recent years. Young CRC was more common among indigenous, expatriates and Malays and least common among the Chinese. There were no differences in the gender and tumor locations.

Stressful life events and risk of colorectal cancer: a case-control study of Iran

BACKGROUND

Very few analytical studies are available on any association between stressful life events (SLE) and colorectal cancer (CRC), at least in Iran. The aim of this case control study was to determine the association between stressful life events (SLE) and colorectal cancer.

MATERIALS AND METHODS

This study was conducted in four hospital colonoscopy units in Tabriz city of Iran including 414 participants aged 40-75 years: 207 cases with CRC confirmed by pathology and colonoscopy findings and 207 controls free of neoplastic conditions were selected (from the same hospitals at the same period for the cases and after matching for age and sex). Stressful life events were assessed using a 43-item Holmes and Rahe Life Events Questionnaire. Multivariate logistic regression was used to estimate adjusted odds ratios for SLE and risk of CRC.

RESULTS

The stressful life event mean score in the case group was 141.3, in contrast to 63.8 in the control group (p<0.011). After adjusting for confounders, death of dear ones increased the risk of CRC (OR: 2.49; 95%CI: 1.41-5.13). Other types of stressful life events (family and husband disputes, serious occupational problems, unemployment of >6 months, and Serious financial problems) were also associated with CRC, but without statistical significance.

CONCLUSIONS

According to our findings, it seems that SLE may increase the risk of CRC.

Epidemiology and trend of common cancers in Iran (2004-2008)

BACKGROUND

Cancer is one of the most important causes of mortality worldwide. It includes approximately 13% of death cases. This study aimed to investigate the incidence trend of common cancers in Iran during 2004-2008 to improve reporting distribution the disease.

METHODS

This was a retrospective study. The study population was all cases of cancer diagnosed in Iran during 2004-2008. The crude incidence rate of cancers was calculated per 100 000 people by age groups and sex. Age-standardised incidence rates (ASRs) were calculated using direct standardisation and the world standard population. Data were analysed using SPSS (version 17) and Microsoft Office Excel 2007.

RESULTS

In this study, a total of 301 055 cases of cancer were diagnosed. ASRs were 60.51 and 84.51 in women and men respectively. Most common cancers in men were skin (ASR = 18.85), stomach (15.02), bladder (ASR = 11.25), prostate (ASR = 8.93) and colorectal (ASR = 8.29). Most common cancers in women were breast (ASR = 18.24), skin (ASR = 12.01), colorectal (ASR = 7.75), stomach (ASR = 7.05) and haematocyte (ASR = 4.01).

CONCLUSION

A significant increase was observed in the incidence of cancers in the country. Therefore, it is necessary to perform screening, early diagnosis and treatment in early stages of cancers.

Temporal Epidemiological Assessment of Colorectal Cancer Incidence and Mortality in East Kazakhstan, 2004-2013

Colorectal cancer incidence and mortality in Kazakhstan are relatively high but exact statistics have hitherto been lacking and trends over time are unclear. The present study was therefore undertaken to retrospectively assess data for East Kazakhstan, accessed from the central registration office, for the period 2004-2013. Approximate age standardized data for incidence and mortality were generated and compared across age groups, gender and year. It was determined that during the studied period 3,417 new cases of colorectal cancer were registered and 2,259 died of this pathology. Average cancer cancer incidence and mortality over the ten years were 24.1/105 and 15.9/105 respectively, and the overall ratio of mortality/incidence (M/I) was 0.69:1 (range 0.58-0.73). Both incidence and mortality tended to remain constant in both males and females. The male to female ratios also did not significantly vary over time but a trend for improvement of the mortality to incidence ratio was observed, especially for rectum. Whether this might be related to screening remains unclear. These preliminary data indicate that whereas colorectal cancer continues to be important, change in environmental factors are not having a great impact on incidence in East Kazakhstan.

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.

Application of Bayesian Multilevel Space-Time Models to Study Relative Risk of Esophageal Cancer in Iran 2005-2007 at a County Level

BACKGROUND

Reported age standardized incidence rates for esophageal cancer in Iran are 0.88 and 6.15 for females and males, at fifth and the eighth ranks, respectively, of cancers overall. The present study aimed to map relative risk using more realistic and less problematic methods than common estimators.

MATERIALS AND METHODS

In this ecological investigation, the studied population consisted of all esophageal cancer patients in Iran from 2005 to 2007. The Bayesian multilevel space-time model with three levels of county, province, and time was used to measure the relative risk of esophageal cancer. Analyses were conducted using R package INLA.

RESULTS

The total number of registered patients was 7,160. According to the results, the three-level model with adjustment for risk factors of physical activity and smoking had the best fit among all models .The overall temporal trend was significantly increasing. At county level, Ahar, Marand, Salmas, Bojnoord, Saghez, Sarakhs, Shahroud and Torbatejam had the highest relative risks. Physical activity was found to have significant direct association with risk of developing esophageal cancer.

CONCLUSIONS

Given to great variation across geographical areas, many different factors affect the incidence of esophageal cancer. Conducting further studies at the individual level in areas with high incidence could provide more detailed information on risk factors of esophageal cancer.

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.

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.

Incidence of cancers in Kuzestan province of iran: trend from 2004 to 2008

BACKGROUND

Cancer is an increasing cause of mortality and morbidity worldwide. Incidences of common cancers has been growing in different provinces of Iran in recent years but trends in Khuzestan which shares a border with Iraq and is located in south west of Iran have not been investigated. This study aimed to assess secular changes in incidences of common cancers in Khuzestan province from 2004 to 2008.

MATERIALS AND METHODS

Data were collected from Khuzestan cancer registry which is a branch of Iranian Ministry of Health Cancer Registry (http://ircancer.ir) for the period 2004-2008. Data were presented as incidence rates by site, sex, age, using the crude rate and age-standardized rate (ASR) per 105 persons. A direct method of standardization was applied according to the WHO guideline and data analysis was performed using the SPSS package.

RESULTS

During the 2004-2008 period, 14,893 new cases of cancer were registered in Khuzestan cancer registry. The age- standardized incidence rate of all cancers was 153.7 per 105 in males and 156.4 per 105 in females. The incidence was increased over the period of five years. The most incident cancers among males were skin cancer (ASR =18.7/105), stomach cancer (ASR13.8/105), lung cancer (ASR12.9/105), leukemia (ASR=12.6/105) and prostate cancer (ASR=12.4/105). In females, the most incident cancers were breast cancer (ASR=41/105), skin cancer (ASR=16.4/105), colorectal cancer (ASR=10.0/105), leukemia (ASR=8.1/105) and lung cancer (ASR=6.9/105).

CONCLUSIONS

Incidences of various cancers are rising in Khuzestan. It is necessary to develop and implement comprehensive cancer control programs in this region which could be monitored and evaluated by the future trend data from cancer registry.

Effects of p53 codon 72 and MDM2 SNP309 polymorphisms on gastric cancer risk among the Iranian population

BACKGROUND

Development of gastric cancer (GC) is a multistep process that requires alterations in the expression of oncogenes and tumor suppressor genes, occurring over several decades. The p53 tumor suppressor protein is involved in cell-cycle control, apoptosis and DNA repair. One of the most important regulators of p53 is MDM2, which acts as a negative regulator in the p53 pathway. Based on the key role of p53 and MDM2 in tumor suppression, polymorphisms that cause change in their function might affect cancer risk. We therefore elevated associations of the polymorphisms of p53 (R72P) and MDM2 (SNP309) with GC in Iran.

MATERIALS AND METHODS

A total of 104 patients with gastric cancer and 100 controls were recruited. Genomic DNA was extracted from fresh gastric samples. Genotyping of the p53 and MDM2 genes was performed using allele specific PCR (AS-PCR).

RESULTS

There was no significant difference between the p53 codon 72 polymorphism distribution in control and patient groups (p=0.54), but the G allele of MDM2 was found to be over-represented in patients (p=0. 01, Odds Ratio=2. 08, 95% Confidence Interval= 1.37-4.34).

CONCLUSIONS

The p53 R72P seems not to be a potential risk factor for development of GC among Iranian patients, but our data suggest that MDM2 SNP309 might modify the risk related to GC.

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.