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

Determinants of early-onset colorectal cancer: a multicenter case-control study in Iran

BACKGROUND

We aimed to study the risk factors of early-onset colorectal cancer (CRC) incidence in the Iranian population. Early onset CRC in Iran is a relevant health issue that deserves further epidemiological efforts to be defined and controlled as far as possible. Early age screening of low-tract of the intestine would be particularly useful in families of colorectal cancer patients.

METHODS

We analyzed data from a multicenter hospital-based case-control study in Iran (The Iranian Study of Opium and Cancer). Sociodemographic and lifestyle information was collected using validated questionnaires. Multivariate logistic regressions estimated the odds ratios (OR) and 95% confidence intervals (CIs) for the association of early-onset CRC in individuals under the age of 50 and potential risk factors, including physical activity, socioeconomic status, body shape at age 15, dietary factors, vitamin D, cigarettes and waterpipe smoking, opium use and family history of CRC. Additionally, a subgroup analysis was conducted for individuals with a very young age of CRC onset (i.e. <35 years).

RESULTS

We analyzed data of 189 developed CRC below age 50 (99 colon and 90 rectum), and 66 patients under the age 35 (13 colon and 21 rectum). Early CRC was inversely associated with vegetables (OR, 0.59; 95% CI, 0.38-0.92 for 422-576 g/day) and vitamin D (OR, 0.49; 95% CI, 0.26-0.94), and positively associated with red meat intake (OR, 1.80; 1.15-2.83 per 25.65 g/day). Vegetables (OR, 0.51; 95% CI, 0.27-0.98 for 576 g/day), red meat (OR, 2.05; 95% CI, 1.11-3.79 for 25.65 g/day), vitamin D (OR, 0.29; 95% CI, 0.10-0.86) and opium use (OR, 2.61; 95% CI, 1.01-6.74) were associated with early rectum cancer. Results were heterogeneous by cancer site for high fruit and vegetables intakes and cigarette smoking. Family history was associated with CRC (OR, 3.16; 95% CI, 1.29-10.9) and rectum cancer (OR, 3.22; 95% CI, 1.24-14.4) in subjects younger than 35, and, to a lesser extent, with CRC and rectum cancer before age 50.

CONCLUSION

Early-onset CRC was related to the intake of vegetables, vitamin D and red meat in Iran. Early-onset rectum cancer was associated with regular opium use. Family history was associated with early CRC and early rectum cancer, particularly below the age of 35.

Statistical methods for measuring trends in colorectal cancer incidence in registries: A systematic review

Background

Monitoring cancer trends in a population is essential for tracking the disease’s burden, allocating resources, and informing public health policies. This review describes variations in commonly employed methods to estimate colorectal cancer (CRC) incidence trends.

Methods

We performed a systematic literature search in four databases to identify population-based studies reporting CRC incidence trends, published between January 2010 and May 2020. We extracted and described data on methods to estimate trends and assess model validity, and the software used.

Results

This review included 145 articles based on studies conducted in five continents. The majority (93%) presented visual summaries of trends combined with absolute, relative, or annual change estimates. Fourteen (10%) articles exclusively calculated the relative change in incidence over a given time interval, presented as the percentage of change in rates. Joinpoint regression analysis was the most commonly used method for assessing incidence trends (n= 65, 45%), providing estimates of the annual percentage change (APC) in rates. Nineteen (13%) studies performed Poisson regression and 18 (12%) linear regression analysis. Age-period-cohort modeling- a type of generalized linear models- was conducted in 18 (12%) studies. Thirty-nine (37%) of the studies modeling incidence trends (n=104, 72%) indicated the method used to evaluate model fitness. The joinpoint program (52%) was the statistical software most commonly used.

Conclusion

This review identified variation in the calculation of CRC incidence trends and inadequate reporting of model fit statistics. Our findings highlight the need for increasing clarity and transparency in reporting methods to facilitate interpretation, reproduction, and comparison with findings from previous studies.

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.

Incidence of Colorectal Cancer and Adenomatous Polyps After a Two-Step Screening in Isfahan Province, Iran in 2018

PURPOSE

The aim of this study was to estimate the incidence of colorectal cancers in Iran. The results of this study are based on a screening program that is being implemented in Isfahan province.

MATERIAL AND METHODS

In this study, about 137,000 people were screened for colorectal cancer and adenomatous polyps in 2 steps during the year 2018.

RESULTS

Based on the findings of this study, the incidence of adenomatous polyps was reported to be 389 (95% CI, 365-422) per 100,000 population. The incidence of adenomatous polyps was reported to be 483 (95% CI, 446-520) and 316 (95% CI, 286-346) in men and women, respectively (p < 0.001). Also, the incidence of colorectal cancer was reported to be 33 (95% CI, 23-42) per 100,000 population. The incidence of colorectal cancer in men and women was reported to be 41 (95% CI, 30-51) and 26 (95% CI, 17-34), respectively, indicating a statistically non-significant difference (p = 0.29).

CONCLUSION

Based on the result of this study, despite a low participation rate of the target population in the screening program, the incidence of adenomatous polyps and colorectal cancer is relatively high in the average-risk population.

Spatio-temporal analysis of colorectal cancer using a geographic information system in the Iranian military community during the period 2007-2016

INTRODUCTION

Colorectal cancer (CRC) is one of the most prevalent cancers among Iranian people. The study of spatio-temporal distribution of disease has an important role in the design of disease prevention programmes. The purpose of the current study was to describe the spatio-temporal distribution of CRC in the Iranian military community as a sample of the Iranian population.

METHODS

In the current ecological study, all registered cancer cases in the Iranian military community during the period 2007-2016 were considered. To identify hotspots, Getis-Ord Gi statistics were used. All analyses were performed using ArcGIS 10.5 and Excel 2010.

RESULTS

The highest incidences of CRC in 2007-2008, 2009-2010 and 2011-2012 were recorded in Kermanshah province. The highest incidences of CRC in 2013-2014 were seen in Kermanshah, Ghilan, Tehran and North Khorasan. In 2007-2008 and 2009-2010, hotspots were detected in West Azarbayjan. In 2011-2012, hotspots were detected in Zanjan and Qazvin. In 2013-2014, a hotspot was detected in Qazvin. Finally, West Azerbaijan was the hotspot for CRC in 2015-2016.

CONCLUSIONS

The incidence of CRC in men was higher than in women. Also it appeared that North and North West Iran were risk areas for this disease, and so these areas should be considered in the design of disease prevention programme for this cancer type. Additionally, the determination of individual risk factors in the aforementioned geographical areas can play an important role in the prevention of this type of cancer.

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.

Temporal Trends of Incidence of Colorectal Cancer in Isfahan, Iran, 2000-2011

Background:

Case finding was improved to the population-based method at the Isfahan Cancer Registry (ICR) during 2005–2008. However, its effects on the number of registered colorectal cancer (CRC) cases and patients’ age are not investigated. Therefore, present study designed to investigate the effect of that improvement on the trend of incidence of CRC, and age of CRC cases in ICR's catchment area.

Methods:

Data from the ICR were retrieved by years for 2000–2011. Annual age-standardized incidence rates (ASRs), truncated ASRs and 95% confidence intervals (95% CIs) were estimated for both genders. Rates were standardized based on the 2000 world standard population. Trends were analyzed, and significant change-points were identified using Joinpoint Regression software. Age of CRC cases compared between periods before and after the improvement.

Results:

A total of 2902 CRC cases had been registered by ICR. Estimated ASRs (95% CI) for 2000 and 2011 were 3.47 (3.45, 3.50) and 10.22 (10.19, 1025) per 100,000 persons, respectively. Two significant change-points were identified (i.e., at 2003 and 2006). However, estimated average annual percent change was as 11. There was no significant difference between mean of patients’ age before and after the time of improvement (P = 0.88).

Conclusions:

Trends of incidence of CRC had been rising in central Iran for males and females, during 2000–2011. It seems that the estimated slope for this trend had been partially artificial and significantly affected by the improvement of case-finding method. However, the improvement had no effect on the patients’ age.

Estimation and Projection of Prevalence of Colorectal Cancer in Iran, 2015-2020

Background:

Population aging and more prevalent westernized lifestyle would be expected to result in a markedly rising burden of colorectal cancer (CRC) in the future years. The aim of this study is to estimate the limited-time prevalence of CRC in Iran between 2015 and 2020.

Materials and Methods:

Aggregated CRC incidence data were extracted from the Iranian national cancer registry (IR.NCR) reports for 2003–2009 and from GLOBOCAN-2012 database for 2012. Incidence trends were analyzed by age groups, genders, histopathologic, and topographic subtypes to estimate annual percentage changes. Incidence was projected for 2020. The prevalence was estimated applying an adopted version of a previously introduced equation to estimate limited–time prevalence based on the incidence and survival data. Monte Carlo sensitivity analyses were applied to estimate 95% uncertainty levels (ULs). In each scenario, incidence, survival, annual percentage changes, and completeness of case ascertainment at IR.NCR were replaced under pre-assumed distributions.

Results:

Number of estimated within 1, 2-3 and 4-5-year CRC patients in 2015 were 13676 (95% UL: 10051–18807), 20964 (15835–28268), and 14485 (11188–19293), respectively. Estimated 5-year prevalence for 2020 (99463; 75150–134744) was 2.03 times of that for 2015. Highest 5-year prevalence was estimated in ages 55–59 for females and 75 + for males. Adenocarcinoma (41376; 31227 55898) was the most prevalent histologic subtype. The most prevalent tumor location was colon (30822, 23262–41638).

Conclusion:

A substantial growth in the prevalence of CRC survivors is highly expected for future years in Iran. Establishment of specialized institutes is highly recommended to provide medical and especially social supports for Iranian CRC survivors.