Prevalence and risk factors of colorectal cancer in Asia

Real-Time Computer-Aided Detection for colorectal neoplasia or only small polyps?

The adenoma detection rate is the constant subject of research and the main marker of quality in bowel cancer screening. However, by improving the quality of endoscopy via artificial intelligence methods, all polyps, including those with the potential for malignancy, can be removed, thereby reducing interval colorectal cancer rates. As such, the removal of all polyps may become the best marker of endoscopy quality. Thus, we present a viewpoint on integrating the computer-aided detection (CADe) of polyps with high-accuracy, real-time colonoscopy to challenge quality improvements in the performance of colonoscopy. Colonoscopy for bowel cancer screening involving the integration of a deep learning methodology (ie, integrating artificial intelligence with CADe systems) has been assessed in an effort to increase the adenoma detection rate. In this viewpoint, a few studies are described, and their results show that CADe systems are able to increase screening sensitivity. The detection of adenomatous polyps, which are associated with a potential risk of progression to colorectal cancer, and their removal are expected to reduce cancer incidence and mortality rates. However, so far, artificial intelligence methods do not increase the detection of cancer or large adenomatous polyps but contribute to the detection of small precancerous polyps.

Screening and prevention of colorectal cancer

Mortality from colorectal cancer is reduced through screening and early detection; moreover, removal of neoplastic lesions can reduce cancer incidence. While understanding of the risk factors, pathogenesis, and precursor lesions of colorectal cancer has advanced, the cause of the recent increase in cancer among young adults is largely unknown. Multiple invasive, semi- and non-invasive screening modalities have emerged over the past decade. The current emphasis on quality of colonoscopy has improved the effectiveness of screening and prevention, and the role of new technologies in detection of neoplasia, such as artificial intelligence, is rapidly emerging. The overall screening rates in the US, however, are suboptimal, and few interventions have been shown to increase screening uptake. This review provides an overview of colorectal cancer, the current status of screening efforts, and the tools available to reduce mortality from colorectal cancer.

Exosomal circRNAs: new players in colorectal cancer

Colorectal cancer (CRC) is one of the most malignant cancer types, characterized by elevated mortality rate and treatment resistance. Despite the progress achieved in the explanation of the molecular basis of the disease as well as introducing potential biomarkers in the clinical practice, further investigation is essential to identify innovative molecules that contribute to colorectal carcinogenesis. Circular RNAs (circRNAs) are a novel and unexplored RNA type, associated with various human pathological conditions. Recently, circRNAs have been identified to be enriched and stable in exosomes and can exert their functions when exosomes reach neighboring or distant cells. Increasing evidence indicates that these so called exosomal circRNAs (exo-circRNAs) act as signaling molecules to regulate cancer proliferation, metastasis, and sensitivity to radio- and chemotherapy. This review aims to discuss the latest progress in exo-circRNAs studies in CRC with an emphasis on their potential as promising diagnostic molecular markers and therapeutic targets.

Risk of colorectal cancer in patients with positive results of fecal immunochemical test performed within 5 years since the last colonoscopy

BACKGROUND/AIMS

Annual fecal immunochemical tests (FITs) are often repeated within the recommended colonoscopy surveillance intervals. However, it remains unclear whether interval FITs are useful. To answer this question, we assessed the risk of colorectal cancer (CRC) according to the interval from the last colonoscopy to an FIT.

METHODS

Using the Korean National Cancer Screening Program database, we collected data on patients who underwent FITs in 2011. Patients with positive FIT results were classified into three groups according to their previous colonoscopy interval: 0.5 to 5 years (group 1), 5 to 10 years (group 2), and ≥ 10 years or no colonoscopy (group 3). CRC incidence was defined as CRC diagnosed within 1 year after an FIT.

RESULTS

Among 177,660 patients with positive FIT results, the incidence of CRC in groups 1, 2, and 3 was 0.72% (n = 214/29,575), 1.28% (n = 116/9,083), and 3.88% (n = 5,387/139,002), respectively. The age- and sex-adjusted risk for CRC was higher in groups 2 (odds ratio [OR], 1.79; 95% confidence interval [CI], 1.43 to 2.25) and 3 (OR, 5.56; 95% CI, 4.85 to 6.38) than in group 1. Among patients who did and did not undergo a polypectomy during the previous colonoscopy, those in group 2 had a higher rate of CRC than those in group 1 (without polypectomy: 1.15% vs. 0.63%; OR, 1.79; 95% CI, 1.37 to 2.34) (with polypectomy: 2.37% vs. 0.93 %; OR, 2.30; 95% CI, 1.44 to 3.69).

CONCLUSION

In patients with positive FIT results who had undergone a colonoscopy within the past 5 years, the risk of CRC is very low, regardless of whether a polypectomy was performed, suggesting that interval FITs are not useful.

Recent Updates on Mechanisms of Resistance to 5-Fluorouracil and Reversal Strategies in Colon Cancer Treatment

5-Fluorouracil (5-FU) plus leucovorin (LV) remain as the mainstay standard adjuvant chemotherapy treatment for early stage colon cancer, and the preferred first-line option for metastatic colon cancer patients in combination with oxaliplatin in FOLFOX, or irinotecan in FOLFIRI regimens. Despite treatment success to a certain extent, the incidence of chemotherapy failure attributed to chemotherapy resistance is still reported in many patients. This resistance, which can be defined by tumor tolerance against chemotherapy, either intrinsic or acquired, is primarily driven by the dysregulation of various components in distinct pathways. In recent years, it has been established that the incidence of 5-FU resistance, akin to multidrug resistance, can be attributed to the alterations in drug transport, evasion of apoptosis, changes in the cell cycle and DNA-damage repair machinery, regulation of autophagy, epithelial-to-mesenchymal transition, cancer stem cell involvement, tumor microenvironment interactions, miRNA dysregulations, epigenetic alterations, as well as redox imbalances. Certain resistance mechanisms that are 5-FU-specific have also been ascertained to include the upregulation of thymidylate synthase, dihydropyrimidine dehydrogenase, methylenetetrahydrofolate reductase, and the downregulation of thymidine phosphorylase. Indeed, the successful modulation of these mechanisms have been the game plan of numerous studies that had employed small molecule inhibitors, plant-based small molecules, and non-coding RNA regulators to effectively reverse 5-FU resistance in colon cancer cells. It is hoped that these studies would provide fundamental knowledge to further our understanding prior developing novel drugs in the near future that would synergistically work with 5-FU to potentiate its antitumor effects and improve the patient's overall survival.

The Influence of Face Shields on the Quality of Colonoscopy in the Era of the COVID-19 Pandemic

Background/Aims

The worldwide coronavirus disease 2019 pandemic has led endoscopists to use personal protective equipment (PPE) for infection prevention. This study aimed to investigate whether wearing a face shield as PPE affects the quality of colonoscopy.

Methods

We reviewed the medical records and colonoscopy findings of patients who underwent colonoscopies at Asan Medical Center, Korea from March 10 to May 31, 2020. The colonoscopies in this study were performed by five gastroenterology fellows and four expert endoscopists. We compared colonoscopy quality indicators, such as withdrawal time, adenoma detection rate (ADR), mean number of adenomas per colonoscopy (APC), polypectomy time, and polypectomy adverse events, both before and after face shields were added as PPE on April 13, 2020.

Results

Of the 1,344 colonoscopies analyzed, 715 and 629 were performed before and after the introduction of face shields, respectively. The median withdrawal time was similar between the face shield and no-face shield groups (8.72 minutes vs 8.68 minutes, p=0.816), as was the ADR (41.5% vs 39.8%, p=0.605) and APC (0.72 vs 0.77, p=0.510). Polypectomy-associated quality indicators, such as polypectomy time and polypectomy adverse events were also not different between the groups. Quality indicators were not different between the face shield and no-face shield groups of gastroenterology fellows, or of expert endoscopists.

Conclusions

Colonoscopy performance was not unfavorably affected by the use of a face shield. PPE, including face shields, can be recommended without a concern about colonoscopy quality deterioration.

Exosomal Components and Modulators in Colorectal Cancer: Novel Diagnosis and Prognosis Biomarkers

The relatively high incidence and mortality rates for colorectal carcinoma (CRC) make it a formidable malignant tumor. Comprehensive strategies have been applied to predict patient survival and diagnosis. Various clinical regimens have also been developed to improve the therapeutic outcome. Extracellular vesicles (EVs) are recently proposed cellular structures that can be produced by natural or artificial methods and have been extensively studied. In addition to their innate functions, EVs can be manipulated to be drug carriers and exert many biological functions. The composition of EVs, their intravesicular components, and the surrounding tumor microenvironment are closely related to the development of colorectal cancer. Determining the expression profiles of exocytosis samples and using them as indicators for selecting effective combination therapy is an indispensable direction for EV study and should be regarded as a novel prediction platform in addition to cancer stage, prognosis, and other clinical assessments. In this review, we summarize the function, regulation, and application of EVs in the colon cancer research field. We provide an update on and discuss potential values for clinical applications of EVs. Moreover, we illustrate the specific markers, mediators, and genetic alterations of EVs in colorectal carcinogenesis. Furthermore, we outline the vital markers present in the EVs and discuss their plausible uses in colon cancer patient therapy in combination with the currently used clinical strategies. The development and application of these EVs will significantly improve the accuracy of diagnosis, lead to more precise prognoses, and may lead to the improved treatment of colorectal cancer.

Detection of Colon Polyps in India—A Large Retrospective Cohort Study (DoCPIr)

Objective Colorectal cancer (CRC) is an emerging public health problem in Asia and India. However, there is scarcity of data on CRC and adenoma. We aimed to study prevalence and characteristics of colonic polyps in a large retrospective cohort.

Methods For this retrospective single center study, all patients with age > 18 years undergoing colonoscopy from January 2018 to December 2019 were included. Age, gender, and polyp characteristics were collected from endoscopy and histology database. Patients with incomplete histology reports and anal canal polyps were excluded. Based on histology, polyps were divided into adenocarcinoma, adenoma with advanced pathology (AAP; size > 10 mm, villous morphology or high-grade dysplasia), nonadvanced adenomas (nAAP), and nonadenomas.

Results Overall colon polyp prevalence was 10.18% (3551/34893). The mean age (standard deviation [SD]) was 51.51 (14.84) with 75.4% males, of which 128 (3.6%) were adenocarcinoma. A total of 1514 (42.64%) were adenomas; 344 (9.7%) were AAP and 1170 (32.9%) were nAAP. The remaining 1909 (53.8%) were nonadenomas. Colonic adenoma prevalence after excluding adenocarcinoma was 4.35% (1514/34893). Adenocarcinoma (68.8% vs. 31.2%), AAP (70.6% vs. 29.4%), other adenomas (75.4% vs. 24.6%), and nonadenomas (76.7% vs. 23.3%) were significantly higher in male compared with female (p < 0.05). Adenomas and adenocarcinomas were more common in left colon and rectum than right colon (p < 0.05). The mean age (SD) were significantly lower in nonadenomas than adenocarcinomas, AAP, and other adenomas (p 0.0001; 49.25 [14.84] vs. 55.97 [12.47], 54.78 [16.40], 53.76 [13.71]).

Conclusions The prevalence of colonic adenoma in India is 4.35%. Male gender and increased age were associated with increased risk of colonic adenoma and adenocarcinoma, which is more common in left colon and rectum. Prospective multicenter studies are required for evaluation of other risk factors of CRC and colonic adenomas.

Participation Rate, Risk Factors, and Incidence of Colorectal Cancer in the Screening Program Among the Population Covered by the Health Centers in Arak, Iran

Background: Colorectal cancer (CRC) is among the most common and preventable cancers, the incidence and risk factors of which are different in various populations. Objectives: The present study aims at assessing incidence rate, risk factors, and symptoms of CRC among the populations aged 50 to 70 years old covered by the health centers in Arak, as well as evaluating participation rate in the CRC screening program. Methods: The present cross-sectional study was conducted from 2016 to 2019 among all of the individuals aged 50 to 70 years old, who were referred to rural, urban, and suburban health centers in Arak for CRC screening, and their data were recorded in the Sib system. The participation rate, risk factors (family and individual history of CRC, colorectal adenoma, and inflammatory bowel disease), symptoms (lower gastrointestinal bleeding, constipation with or without diarrhea, and weight loss), and crude incidence rate of CRC were calculated in the age range. Results: The mean (SD) age of the CRC was 59.72 (5.56) years. In addition, the individuals’ participation rate in the program was about 44.2%, which was more among women (55.5%) and villagers (93.7%). Most subjects complained of constipation in the last month and CRC family history. The CRC crude incidence rates were 35.93 (95% CI: 25.55 - 50.54), 40.96 (95% CI: 29.81 - 56.29), 43.76 (95% CI: 32.22 - 59.43), and 52.84 (95% CI: 40.05 - 69.71) per 100000 individuals during 2016, 2017, 2018, and 2019, respectively. Conclusions: The participation rate in the CRC screening program was low, and the trend of the cancer crude incidence rate increased among the populations aged 50 to 70 years. Finally, informing about the recognition of the risk factors and symptoms of cancer, as well as the timely referral for screening was considered essential.

Factors Associated With Colorectal Cancer Screening Among First-Degree Relatives of Patients With Colorectal Cancer in China

BACKGROUND

First-degree relatives of patients with colorectal cancer have an elevated risk of colorectal cancer. However, the behavior and factors potential influencing first-degree relatives regarding colorectal cancer screening in China remain unknown.

OBJECTIVE

The aim of this study was to explore the screening behavior and related factors of first-degree relatives of colorectal cancer patients.

METHODS

A cross-sectional design was applied, and 201 first-degree relatives participated from August 2018 to July 2019. Data were collected about demographic information, the "Colorectal Cancer Perceptions Scale," and screening behavior of first-degree relatives. Factors associated with screening behavior were identified using logistic regression analysis.

RESULTS

Only 18.9% of first-degree relatives had participated in colonoscopy screening. Two Health Belief Model factors were the influencing factors of their participation in colorectal cancer screening. Higher possibility of colorectal cancer screening of first-degree relatives was associated with higher perceived susceptibility (odds ratio, 1.224; 95% confidence interval, 1.075-1.395) and lower perception of barriers (odds ratio, 0.880; 95% confidence interval, 0.820-0.944) of first-degree relatives.

CONCLUSIONS

Participation in colorectal cancer screening by first-degree relatives requires improvement; perceived susceptibility and perception of barriers were the most important predictors.

IMPLICATIONS FOR PRACTICE

Health professionals can enhance awareness of colorectal cancer susceptibility and address barriers to colorectal cancer screening among first-degree relatives at both individual and social levels.

Association between rs11614913 Polymorphism of The MiR-196-a2 Gene and Colorectal Cancer in The Presence of Departure from Hardy-Weinberg Equilibrium

Objective

Colorectal cancer (CRC) is the fourth most common and the second most lethal cancer worldwide. CRC mortality is increasing in Iran. In the current study, we aimed to investigate association between rs11614913 polymorphism of the miR-196-a2 gene and CRC.

Materials and Methods

In this case-control study, we assessed association of the rs11614913 polymorphism in 194 patients with CRC (case) and 286 healthy individuals (control). The expectation-maximization (EM) algorithm method was used to adjust deviation from Hardy-Weinberg equilibrium (HWE).

Results

There was no significant difference between genotypic frequencies of rs11614913 polymorphism in the control and case groups. Genotypic frequencies differed in the adjusted and unadjusted deviations from the HWE. Analysis of unadjusted and adjusted independent variables showed that age, sex, alcohol consumption, and drug use were statistically significant.

Conclusion

Our findings showed that rs11614913 polymorphism was not associated with CRC risk. Deviation from HWE affected the results. It is recommended to perform further studies to establish HWE. Ignoring the equilibrium can cause in consistencies in the results of studies.

RNA-sequencing identification and validation of genes differentially expressed in high-risk adenoma, advanced colorectal cancer, and normal controls

Distinct gene expression patterns that occur during the adenoma-carcinoma sequence need to be determined to analyze the underlying mechanism in each step of colorectal cancer progression. Elucidation of biomarkers for colorectal polyps that harbor malignancy potential is important for prevention of colorectal cancer. Here, we use RNA sequencing to determine gene expression profile in patients with high-risk adenoma treated with endoscopic submucosal dissection by comparing with gene expression in patients with advanced colorectal cancer and normal controls. We collected 70 samples, which consisted of 27 colorectal polyps, 24 cancer tissues, and 19 normal colorectal mucosa. RNA sequencing was performed on an Illumina platform to select differentially expressed genes (DEGs) between colorectal polyps and cancer, polyps and controls, and cancer and normal controls. The Kyoto Gene and Genome Encyclopedia (KEGG) and gene ontology (GO) analysis, gene-concept network, GSEA, and a decision tree were used to evaluate the DEGs. We selected the most highly expressed genes in high-risk polyps and validated their expression using real-time PCR and immunohistochemistry. Compared to patients with colorectal cancer, 82 upregulated and 24 downregulated genes were detected in high-risk adenoma. In comparison with normal controls, 33 upregulated and 79 downregulated genes were found in high-risk adenoma. In total, six genes were retrieved as the highest and second highest expressed in advanced polyps and cancers among the three groups. Among the six genes, ANAX3 and CD44 expression in real-time PCR for validation was in good accordance with RNA sequencing. We identified differential expression of mRNAs among high-risk adenoma, advanced colorectal cancer, and normal controls, including that of CD44 and ANXA3, suggesting that this cluster of genes as a marker of high-risk colorectal adenoma.

Metabolic Evidence Rather Than Amounts of Red or Processed Meat as a Risk on Korean Colorectal Cancer

The incidence of colorectal cancer (CRC) has increased in Korea, a newly-industrialized Asian country, with the dramatic increase of meat intake. To assess the risks of red or processed meat consumption on CRC, we performed a case-control study with biological monitoring of urinary1-OHP, PhIP, and MeIQx for the meat exposure; dG-C8 MeIQx and dG-C8 PhIP for HCA-induced DNA adducts; and homocysteine and C-reactive protein (CRP) in blood as well as malondialdehyde (MDA) and 31fatty acids in urine for inflammation and lipid alteration. We further analyzed global DNA methylation and expression of 15 CRC-related genes. As a result, the consumption of red or processed meat was not higher in the cases than in the controls. However, urinary MeIQx and PhIP were associated with the intake of red meat and urinary 1-OHP. MDA and multiple fatty acids were related to the exposure biomarkers. Most of the 31 fatty acids and multiple saturated fatty acids were higher in the cases than in the controls. Finally, the cases showed upregulation of PTGS2, which is related to pro-inflammatory fatty acids. This study describes indirect mechanisms of CRC via lipid alteration with a series of processes including exposure to red meat, alteration of fatty acids, and relevant gene expression.

Association between the serum concentrations and mutational status of IL-8, IL-27 and VEGF and the expression levels of the hERG potassium channel gene in patients with colorectal cancer

The present study aimed to determine the diagnostic value of the serum levels and mutational status of IL-8, IL-27 and VEGF, and the expression levels of human ether-a-go-go-related gene (hERG) in patients with colorectal cancer (CRC). The serum concentrations were determined using the ELISA technique and genotype variations of IL-8, IL-27 and VEGF were examined using Sanger sequencing, and the expression levels of hERG, which encodes a potassium channel, were determined by quantitative PCR, in blood and tissue samples obtained from 80 patients with CRC and 80 healthy individuals. The results of the present study revealed that the percentage of granulocytes and serum concentrations of carcinoembryonic antigen, IL-8 and IL-27 were significantly increased, whereas the percentage of lymphocytes was decreased in patients with CRC. In total, 31 mutations in three genes (eight mutations in VEGF, 13 mutations in IL-27 and 10 mutations in IL-8) were identified in patients with CRC. The relative mRNA expression levels of hERG were also significantly upregulated in tissue and blood samples of patients with CRC compared with those of healthy individuals. In conclusion, the results of the present study indicated that the increased concentrations and genetic variations of IL-8, IL-27 and VEGF may serve important roles in the development and angiogenic processes of CRC. These changes were concomitant with the upregulation of the expression levels of the potassium channel hERG.

Orally Administrable Therapeutic Nanoparticles for the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common and lethal human malignancies worldwide; however, the therapeutic outcomes in the clinic still are unsatisfactory due to the lack of effective and safe therapeutic regimens. Orally administrable and CRC-targetable drug delivery is an attractive approach for CRC therapy as it improves the efficacy by local drug delivery and reduces systemic toxicity. Currently, chemotherapy remains the mainstay modality for CRC therapy; however, most of chemo drugs have low water solubility and are unstable in the gastrointestinal tract (GIT), poor intestinal permeability, and are susceptible to P-glycoprotein (P-gp) efflux, resulting in limited therapeutic outcomes. Orally administrable nanoformulations hold the great potential for improving the bioavailability of poorly permeable and poorly soluble therapeutics, but there are still limitations associated with these regimes. This review focuses on the barriers for oral drug delivery and various oral therapeutic nanoparticles for the management of CRC.

CTSE Overexpression Is an Adverse Prognostic Factor for Survival among Rectal Cancer Patients Receiving CCRT

The introduction of preoperative concurrent chemoradiotherapy (CCRT) increases the rate of anal preservation and allows tumor downstaging for clinical stage T3/T4 or node-positive rectal cancer patients. However, there is no precise predictive tool to verify the presence of residual tumor apart from surgical resection. The gastrointestinal (GI) tract not only digests nutrients but also coordinates immune responses. As the outermost layer of the GI tract, mucus plays a key role in mediating the interaction between the digestive and immune systems, and aberrant mucus mesh formation may cause chemoresistance by impeding drug delivery. However, the correlations among digestion-related genes, mucin synthesis, and chemoresistance remain poorly understood. In the present study, we evaluated genes related to digestion (GO: 0007586) and identified cathepsin E (CTSE), which is involved in immune regulation, as the most significantly upregulated gene associated with CCRT resistance in rectal cancer in a public transcriptome dataset (GSE35452). We recovered 172 records of rectal cancer patients receiving CCRT followed by surgical resection from our biobank and evaluated the expression level of CTSE using immunohistochemistry. The results revealed that tumors with CTSE overexpression were significantly correlated with pre-CCRT and post-CCRT positive nodal status (both p < 0.001), advanced pre-CCRT and post-CCRT tumor status (p < 0.001 and p = 0.002), perineural invasion (p = 0.023), vascular invasion (p < 0.001), and a lesser degree of tumor regression (p = 0.003). At the univariate level, CTSE overexpression was an adverse prognostic factor for all three endpoints: disease-specific survival (DSS), metastasis-free survival (MeFS) (both p < 0.0001), and local recurrence-free survival (LRFS) (p = 0.0001). At the multivariate level, CTSE overexpression remained an independent prognostic factor for poor DSS, MeFS (both p = 0.005), and LRFS (p = 0.019). Through bioinformatics analysis, we speculated that CTSE overexpression may confer CCRT resistance by forming a defensive mucous barrier. Taken together, these results suggest that CTSE overexpression is related to CCRT resistance and inferior survival in rectal cancer patients, highlighting the potential predictive and prognostic value of CTSE expression.

Increasing changes in visceral adiposity is associated with higher risk for colorectal adenoma: Multilevel analysis in a prospective cohort

BACKGROUND AND AIM

While many studies demonstrated an association between visceral adiposity and colorectal adenoma (CRA), the effect of longitudinal changes in body fat composition on CRA is unclear. We investigated the longitudinal association between changes in visceral adiposity and CRA occurrence.

METHODS

Between 2006 and 2018, 732 (62.8%) of the 1165 subjects in a prospective cohort voluntarily underwent follow-up abdominal fat computed tomography and colonoscopy. We defined incident and recurrent CRA as adenoma detected at follow-up colonoscopy from negative and positive adenoma at baseline colonoscopy, respectively. Multilevel survival analysis examined the longitudinal association between changes in visceral fat and CRA.

RESULTS

During a median follow-up of 7.4 years, 400 (54.6%) subjects developed CRA. In multivariable analysis, increasing changes in visceral adipose tissue (VAT) area were associated with higher risk of incident adenoma (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.00-1.46 for change per 10 cm² increase; HR 1.79, 95% CI 1.08-2.97 for highest vs lowest quartile, P values for trend = 0.045). Likewise, increasing changes in VAT area were independently associated with a higher risk of recurrent adenoma (HR 1.35, 95% CI 1.13-1.62 for change per 10 cm² increase; HR 1.62, 95% CI 1.04-2.52 for highest vs lowest quartile, P values for trend = 0.001). Changes in subcutaneous adipose tissue area were not independently associated with CRA.

CONCLUSION

Increasing changes in VAT area were longitudinally associated with a higher risk of incident and recurrent CRA, independent of risk factors, suggesting that visceral adiposity may be an important target in CRA prevention.

Copy Number Variants Captured by the Array Comparative Genomic Hybridization in a Cohort of Patients Affected with Hereditary Colorectal Cancer in Sri Lanka: The First CNV Analysis Study of the Hereditary Colorectal Cancer in the Sri Lankan Population

INTRODUCTION

Hereditary non-polyposis colorectal cancer (HNPCC), is an autosomal dominant disorder characterized by the development of multiple cancer types. Molecular diagnosis of HNPCC requires the precise identification of pathogenic germline variants in DNA mismatch repair (MMR) genes. Next Generation Sequencing (NGS) is now the gold standard test in practice, to identify these variants. However, large genomic rearrangements (LGR) in cancer predisposing genes (CPGs) are missed by NGS. This may lead to underestimation of the frequency of the variants, misleading the genetic diagnosis and delaying intervention in high risk individuals. Hence this study was aimed at identifying the presence of large genomic alterations that could explain the missing heritable risk of colon cancer in affected patients with family history strongly suggestive of hereditary colorectal cancer in Sri Lanka.

METHODS

A cohort of six patients affected with hereditary colorectal cancer who tested negative for pathogenic variants in next generation sequencing studies was investigated using Sure Print G3 Human CGH 4x180K microarray platform. Agilent Genomic-Workbench-v7.0.4.0 software was used to identify the Copy Number Variants (CNV). Four healthy individuals (>55years) were used as controls.  Annotations of the CNV regions which were observed were done using the database of Genomic Variants.

RESULTS

We identified 150 CNVs including regions of both genomic gains and losses in the patient cohort.  There was no difference in the average number or the average genomic burden of CNVs identified in the patients versus the controls.  CNVs were residing on the positions of 1q21.2, 2q37.3, 2p11.2-p11.1, 5q13.2, 6p12.3, 7q31.33, 7p14.1, 14q32.33, 15q11.1-11.2, 16p11.2, 22q11.22, 22q13.1 that were assessed by the array platform used in the study. CNVs in any of the well-known common CPG s or CNVs that reside on or in close proximity to genes corresponding to MMR pathway were not identified. We found several distinct pathways that have previously been identified as having a direct association with the progression of HNPCC.

CONCLUSION

This study shows that CNVs are likely contributors to the colorectal cancer predisposition in a small but significant proportion of patients affected with hereditary colorectal cancer in this cohort. Further studies have to perform to get a better understanding on the contribution of CNVs to the cancer predisposition in this cohort of patients in the Sri Lankan population.

Use of Antiplatelet Agents Decreases the Positive Predictive Value of Fecal Immunochemical Tests for Colorectal Cancer but Does Not Affect Their Sensitivity

Previous studies have evaluated the effects of antithrombotic agents on the performance of fecal immunochemical tests (FITs) for the detection of colorectal cancer (CRC), but the results were inconsistent and based on small sample sizes. We studied this topic using a large-scale population-based database. Using the Korean National Cancer Screening Program Database, we compared the performance of FITs for CRC detection between users and non-users of antiplatelet agents and warfarin. Non-users were matched according to age and sex. Among 5,426,469 eligible participants, 768,733 used antiplatelet agents (mono/dual/triple therapy, n = 701,683/63,211/3839), and 19,569 used warfarin, while 4,638,167 were non-users. Among antiplatelet agents, aspirin, clopidogrel, and cilostazol ranked first, second, and third, respectively, in terms of prescription rates. Users of antiplatelet agents (3.62% vs. 4.45%; relative risk (RR): 0.83; 95% confidence interval (CI): 0.78–0.88), aspirin (3.66% vs. 4.13%; RR: 0.90; 95% CI: 0.83–0.97), and clopidogrel (3.48% vs. 4.88%; RR: 0.72; 95% CI: 0.61–0.86) had lower positive predictive values (PPVs) for CRC detection than non-users. However, there were no significant differences in PPV between cilostazol vs. non-users and warfarin users vs. non-users. For PPV, the RR (users vs. non-users) for antiplatelet monotherapy was 0.86, while the RRs for dual and triple antiplatelet therapies (excluding cilostazol) were 0.67 and 0.22, respectively. For all antithrombotic agents, the sensitivity for CRC detection was not different between users and non-users. Use of antiplatelet agents, except cilostazol, may increase the false positives without improving the sensitivity of FITs for CRC detection.

Schistosoma japonicum Associated With Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide, with increasing prevalence in Asian countries with a crude incidence of 21.1 per 100,000. Schistosoma is a genus of trematodes that infect millions of humans, affecting multiple organs, notably the intestines, liver, and bladder. Those trematodes may cause chronic inflammation in the affected organ leading to long-term complications such as fibrosis and neoplasia. There is rising evidence that infection with Schistosoma japonicum is correlated with the liver and CRC in endemic Asian countries. It is reported that chronic infection with Schistosomiasis raises the risk of CRC by 3 times. Less commonly seen outside of endemic areas, we present a case of S. japonicum-associated CRC in the United States in a woman with sigmoid adenocarcinoma and Schistosoma japonicum infection.

Survival of colorectal cancer patients in Brunei Darussalam: comparison between 2002-09 and 2010-17

Background

Colorectal cancer (CRC) is a major cause of cancer-related mortality worldwide. It is the second leading cause of cancer death in men and women in Brunei Darussalam in 2017, posing a major burden on society.

Methods

This retrospective cohort study (n = 1035 patients diagnosed with CRC in Brunei Darussalam from 1st January 2002 until 31st December 2017) aims to compare the overall survival rates of CRC patients (2002–2017), to compare survival rates between two study periods (2002–2009 and 2010–2017) and to identify prognostic factors of CRC. Kaplan-Meier estimator and log-rank tests were performed to analyse the overall survival rates of CRC patients. Multiple Cox regression was performed to determine the prognostic factors of CRC with adjusted hazard ratios (Adj. HRs) reported.

Results

The 1-, 3- and 5-year survival rates of CRC patients are 78.6, 62.5, and 56.0% respectively from 2002 to 2017. The 1-, 3-, and 5-year survival rates of CRC patients for 2002–2009 are 82.2, 69.6, and 64.7%; 77.0, 59.1, and 51.3% for 2010–2017 respectively. A significant difference in CRC patients’ survival rate was observed between the two study periods, age groups, ethnic groups, cancer stages, and sites of cancer (p < 0.05). The Adjusted Hazard Ratios (Adj. HRs) were significantly higher in the 2010–17 period (Adj. HR = 1.78, p < 0.001), older age group ( ≥ 60 years) (Adj. HR = 1.93, p = 0.005), distant cancer (Adj. HR = 4.69, p < 0.010), tumor at transverse colon and splenic flexure of colon (Adj. HR = 2.44, p = 0.009), and lower in the Chinese(Adj. HR = 0.63, p = 0.003).

Conclusion

This study highlights the lower survival rates of CRC patients in 2010–2017, Malays, older patients, distant cancer, and tumors located at the latter half of the proximal colon (transverse colon), and predominantly LCRC (splenic flexure, descending colon, sigmoid colon, overlapping lesion colon and colon (NOS), as well as the rectosigmoid junction and rectum (NOS)). Age, ethnicity, cancer stage, and tumor location are significant prognostic factors for CRC. These findings underscore the importance of public health policies and programmes to enhance awareness on CRC from screening to developing strategies for early detection and management, to reduce CRC-associated mortality.

Comparison of the effects and prognosis of concurrent and staged resections for the treatment of resectable colorectal cancer liver metastasis

OBJECTIVE

To compare the effects and prognosis of concurrent and staged resections for the treatment of resectable colorectal cancer liver metastasis (CRLM).

METHODS

A prospective study was conducted on 118 patients with CRLM. The 59 cases in the observation group received concurrent resections, while the 59 cases in the control group received staged resections. The operation time, intraoperative blood loss, length of hospital stay, hospital cost, postoperative complications, 5-year survival rate and 3-year progression-free survival rate were recorded for all patients. Factors that affect the prognosis of CRLM patients were analyzed.

RESULTS

The length of hospital stay, operation time, intraoperative blood loss, hospital cost were significantly lower in the observation group than in the control group (P<0.001). The two groups were equivalent with respect to postoperative complications, 5-year survival rate and 3-year progression-free survival rate (P>0.05). Independent risk factors affecting the prognosis of CRLM included the number of liver metastasis, whether resection is feasible after recurrence, and RAS genotype (P<0.05).

CONCLUSION

Compared to staged resection for CRLM, concurrent resection has shorter operation time, less blood loss, and shorter length of hospital stay, while postoperative complications, long-term efficacy and survival benefits are comparable. Furthermore, the study has found that the number of liver metastasis, whether or not resection is feasible after recurrence, and RAS genotype are risk factors affecting the prognosis of CRLM.

Distinctive Clinico-Pathological Characteristics of Colorectal Cancer in Sabahan Indigenous Populations

Background:

Malaysia is an ethnically diverse nation, comprising Malay, Chinese, Indian and indigenous groups. However, epidemiological studies on colorectal cancer have mainly focused on the three main ethnic groups. There is evidence that the clinico-pathological characteristics of some cancers may differ in indigenous populations, namely that they occur earlier and behave more aggressively. We aimed to determine if there were similar differences in colorectal cancer, focusing on the indigenous populations of Sabah.

Methods:

Histopathological reports of all patients diagnosed with colorectal carcinoma from January 2012 to December 2016 from public hospitals in Sabah were retrieved from the central computerized database of the Pathology Department of Queen Elizabeth Hospital in Kota Kinabalu, Sabah. Supplementary data was obtained from patients’ case files from each hospital. Clinico-pathological data were analysed using the IBM SPSS Statistical Software Version 23 for Windows for descriptive statistics (mean, median, ASR, AR, relative risk) and inferential statistics (Chi square test).

Results:

A total of 696 patients met the inclusion criteria. The median age for colorectal cancer in Sabah was 62 years (95% CI 60.3 to 62.3), with an age specific incidence rate of 21.4 per 100 000 population. The age specific incidence rate in the indigenous populations was 26.6 per 100 000, much lower than the Chinese, at 65.0 per 100 000. The risk of colorectal cancer occurring before the age of 50 was three times higher in the indigenous population compared to the Chinese. The tumours were mainly left-sided (56.5%), adenocarcinoma in histology (98.4%) and moderately differentiated (88.7%). Approximately 79.2% of patients received curative treatment.

Conclusion:

Indigenous populations in Sabah develop colorectal cancer at an earlier age, and present at more advanced stages. This has implications for screening and therapeutic strategic planning.

Hereditary, environmental, and dietary risk factors of colorectal cancer: a case-control study in the Algerian East

Colorectal carcinoma (CRC) is the second most common cancer diagnosed in Algeria. The incidence and the mortality rate of CRC have increased so that the nation now ranks third in Africa in both these variables. Many environmental and genetic factors are suspected to play an important role in the development of the disease. This study aimed to identify the risk factors for CRC in Algeria. We performed a case-control study in five Medical Oncology Services in this region: Tebessa, Batna, Annaba, Setif, and Constantine, from 2016 to 2019. Altogether, 200 patients diagnosed with CRC and 200 age-matched controls without any diagnosis of cancer were included. Study participants were interviewed about environmental, dietary, and hereditary risk factors, i.e., family history of cancer, using a questionnaire. Results showed a significant association between high educational level and a decreased risk of CRC. Diagnoses of any cancer or of CRC in first-degree or in second- or third-degree relatives also were significantly associated with CRC risk. Occupational exposures showed a significant link with an increased risk of CRC, as did obesity, alcohol consumption, and passive smoking. Yogurt, cereals, sugar, butter, and margarine consumption were significant protective factors, while cheese, dried fruits, red meat, juice, and fizzy drink consumption was associated with increased risk. Our findings suggest a benefit of public health campaigns to enhance awareness about CRC and to encourage healthy dietary choices and avoidance of non-dietary risk factors.

Comparison of Risk of Metachronous Advanced Colorectal Neoplasia in Patients with Sporadic Adenomas Aged < 50 Versus ≥ 50 years: A Systematic Review and Meta-Analysis

No specific recommendations are available for the surveillance of young patients aged <50 years undergoing polypectomy. We aimed to compare the risk of metachronous advanced colorectal neoplasia (ACRN) between patients aged ≥50 years and those aged <50 years who underwent polypectomy. Studies published between January 1980 and June 2020 that examined the risk of metachronous ACRN were searched. We performed a meta-analysis for the metachronous ACRN risk in patients with sporadic colorectal adenomas according to the age groups (≥50 vs. <50 years). Eight individual studies were included in the meta-analysis. The risk of metachronous ACRN was higher in patients aged ≥50 years than in those aged <50 years without significant heterogeneity (odds ratio (OR) (95% CI): 1.62 (1.34–1.96), I² = 14%). The impact of the age group on the risk of metachronous ACRN was identified in both the low-risk (LRA) and high-risk (HRA) adenoma groups (≥50 vs. <50 years: LRA, OR 1.88 (95% CI 1.30–2.70); HRA, OR 1.50 [95% CI 1.13–2.00]). In conclusion, patients aged <50 years had a lower risk of metachronous ACRN than older patients. Young patients with sporadic adenomas do not require more intensive surveillance; rather, the surveillance interval may be extended in these patients.

Apolipoprotein M promotes growth and inhibits apoptosis of colorectal cancer cells through upregulation of ribosomal protein S27a

Colorectal cancer (CRC) is one of the frequent malignant tumors and has a high mortality-to-incidence ratio. Apolipoprotein M (ApoM), a lipoprotein superfamily member, is primarily bound to high-density lipoprotein (HDL) particles. Our previous studies opined that ApoM crucially modulates CRC progression, but its role in CRC has not been elucidated. Here, lentivirus infection technology was used to overexpress ApoM in Caco-2 cells. Cell growth, apoptosis as well as clone formation assays were performed to explore the biological influences of ApoM in Caco-2 cells. Differentially expressed genes were analyzed via GeneChip microarrays and Quantitative real-time PCR (qPCR) along with Western blotting were applied to verify the results. Ribosomal protein S27a (RPS27A) expression in CRC and tumor-adjacent tissues was detected by qPCR, and its correlation with clinicopathologic characteristics was explored. Our results showed that ApoM overexpression could promote Caco-2 cell proliferation and inhibit apoptosis. The microarray evaluation uncovered 2671 genes, which were differentially expressed, including RPS27A. The qPCR as well as the Western blotting data showed that ApoM overexpression significantly increased the expression of RPS27A. Moreover, RPS27A expression was remarkably higher in CRC tissues in contrast with the tumor-adjacent tissues and was positively correlated with the ApoM level in tumor tissues, and higher RPS27A expression was associated with smaller tumors and lower T stage. Functional recovery experiments indicated that knockdown of RPS27A counteracted the apoptosis inhibition and clone formation promotion induced by ApoM overexpression in Caco-2 cells. In conclusion, ApoM promotes CRC cell growth and inhibits apoptosis through upregulation of RPS27A.

Dietary Intake as Determinant Nongenetic Factors to Colorectal Cancer Incidence and Staging Progression: A Study in South Sulawesi Population, Indonesia

Reports from various population-based studies indicate that the incidence of colorectal cancer may be strongly affected by dietary patterns of the respective populations. The nature of dietary patterns of specific Indonesia population on the risk of colorectal cancer might differ from previously published data with the global population. Therefore, we conducted a study where the dietary pattern in colorectal cancer patient cohorts was compared to age- and population-matched control. We documented 89 colorectal cancer cases and among 173 individuals from the South Sulawesi population. A series of logistic regression and Fisher's exact tests were utilized to test associations of dietary intakes and colorectal cancer risk as well as colorectal cancer staging. Our data demonstrate that vegetable (p-value = 8.70 × 10^-26, OR = 0.49) and fruit (p-value = 7.59x10^-5, OR = 0.70) intakes are associated with the reduced risk of colorectal cancer incidence. Conversely, acidic food, reheated food, meat, spicy food, and alcohol are associated with the increment case of cancer. Moreover, meat intake (p-value < 0.01) shows a significant association with cancer staging progression. Common dietary pattern is a determinant aspect to the colorectal cancer incidence as well as its staging progression.

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.

Risk of Colorectal Cancer in Patients With Attention-Deficit Hyperactivity Disorder: A Nationwide, Population-Based Cohort Study

Background: The association between attention-deficit hypersensitivity disorder (ADHD) and the risk of developing colorectal cancer (CRC) is, as yet, to be investigated, and thus, we have conducted this nationwide, cohort study to examine the association in patients from Taiwan. Methods: In this study, 798 individuals with newly diagnosed ADHD and 2,394 (1:3) age-, gender-, and index year- matched controls without ADHD were enrolled, between 2000 and 2013, from the Longitudinal Health Insurance Database, a subset of the National Health Insurance Research Database in Taiwan. The cumulative incidence of CRC was assessed in each cohort by the Kaplan-Meier method. The multivariate Cox proportional hazards model was used to estimate the crude, and the adjusted hazards ratios (HRs) with 95% confidence intervals (CIs), was conducted to estimate the association between ADHD and CRC. Results: The Kaplan-Meier analysis revealed that the cumulative incidence of CRC was significantly higher in patients with ADHD than in those without it (log rank test, p < 0.001). After adjustments for age, gender, comorbidities, and other covariates, the ADHD group was associated with an increased risk of CRC in comparison to the non-ADHD group (adjusted HR = 3.458, 95% CI = 1.640-7.293, p < 0.001). In addition, the usage of methylphenidate was not associated with the risk of developing CRC in patients with ADHD. Conclusion: This retrospective cohort study depicts the evidence that ADHD was associated with the increased risk of CRC. Further studies are needed to confirm the association and the underlying mechanisms.

Pathogenic Germline Mutations of DNA Repair Pathway Components in Early-Onset Sporadic Colorectal Polyp and Cancer Patients

Simple Summary

Colorectal cancer (CRC) screening by immuno-fecal occult blood tests (iFOBTs) begins at age 50 in average-risk persons. However, the incidence of early-onset CRC has risen; of the cases, at least half are sporadic CRC without a family history. The authors of this study found a high percentage of de novo germline mutation in young sporadic CRC patients, as well as in sporadic colorectal polyp and control groups. All the mutated genes contribute to various DNA-repair pathways, hinting that a loss of genomic integrity play a crucial role in the development of CRC. The early identification of cancer-susceptible individuals by multigene panels in younger individuals who may be missed under current iFOBT screening could contribute to preventing CRC.

Abstract

Given recent increases in the proportion of early-onset colorectal cancer (CRC), researchers are urgently working to establish a multi-gene screening test for both inherited and sporadic cancer-susceptible individuals. However, the incidence and spectrum of germline mutations in young sporadic CRC patients in East Asian countries and, especially, in sporadic polyp carriers and normal individuals are unknown. Peripheral blood samples were collected from 43 colonoscopy-proved normal controls and from 50 polyp patients and 49 CRC patients with no self-reported family history of cancer. All participants were under 50 years old. Next-generation sequencing with a panel of 30 CRC-associated susceptibility genes was employed to detect pathogenic germline mutations. The germline mutation carrier rates were 2.3%, 4.0%, and 12.2% in the normal, polyp, and cancer groups, respectively. A total of seven different mutations in six DNA repair pathway-related genes (MLH1, BRCA1, BRCA2, CHEK2, BLM, and NTHL1) were detected in nine participants. One frameshift mutation in BRCA2 and one frameshift mutation in the CHEK2 gene were found in a normal control and two colorectal polyp patients, respectively. One young sporadic CRC patient carried two heterozygous mutations, one in MLH1 and one in BRCA1. Three mutations (MLH1 p.Arg265Cys, MLH1 p.Tyr343Ter and CHEK2 p.Ile158TyrfsTer10) were each found in two independent patients and were considered “founder” mutations. This is the first report to demonstrate high percentage of germline mutations in young sporadic colorectal polyp, CRC, and general populations. A multi-gene screening test is warranted for the proactive identification of cancer-predisposed individuals.

Expression of Main Toll-Like Receptors in Patients with Different Types of Colorectal Polyps and Their Relationship with Gut Microbiota

Abnormal activation of Toll-like receptor (TLRs) signaling can result in colon cancer development. The aim of this study was to investigate the expression of important TLRs in different histological types of colorectal polyps and evaluate their relationship with intestinal microbiota. The expression levels of TLR2, 3, 4, and 5 were analyzed in intestinal biopsy specimens of 21 hyperplastic polyp (HP), 16 sessile serrated adenoma (SSA), 29 tubular adenoma (TA), 21 villous/tubulovillous (VP/TVP) cases, and 31 normal controls. In addition, selected gut bacteria including Streptococcus bovis, Enterococcus faecalis, Enterotoxigenic Bacteroides fragilis (ETBF), Fusobacterium nucleatum, Porphyromonas spp., Lactobacillus spp., Roseburia spp., and Bifidobacterium spp. were quantified in fecal samples using absolute qRT PCR, and, finally, the association between TLRs and these gut microbiota- was evaluated by Spearman’s correlation coefficient. Higher expression of TLR2 and TLR4 in VP/TVP and TA, and lower expression levels of TLR3 and TLR5 in all type of polyps were observed. The differences in TLR expression patterns was not only dependent on the histology, location, size, and dysplasia grade of polyps but also related to the intestinal microbiota patterns. TLR2 and TLR4 expression was directly associated with the F. nucleatum, E. faecalis, S. bovis, Porphyromonas, and inversely to Bifidobacterium, Lactobacillus, and Roseburia quantity. Furthermore, TLR3 and TLR5 expression was directly associated with Bifidobacterium, Roseburia, and Lactobacillus quantity. Our results suggest a possible critical role of TLRs during colorectal polyp progression. An abnormal regulation of TLRs in relation to gut microbial quantity may contribute to carcinogenesis.

Extricating the Association Between the Prognostic Factors of Colorectal Cancer

PURPOSE

Colorectal cancer (CRC) is one of the recurring and lethal gastrointestinal tract disease rankings as the primary cause of worldwide morbidity and mortality. In general, the tumour node metastasis (TNM) and Dukes classification assist in diagnosis, prognosis and treatments of CRC along with haematological examinations and tumour demographic characterisations in patients.

METHODS

The present investigation is carried out on clinically acknowledged sixty-five CRC patients based on haematological findings and are sorted into stages using TNM and Dukes. The present study is to find the association between haematological findings, demographic characters, differentiation position, lymph node invasion and tumour node metastasis in CRC patients in accordance with their age.

RESULTS

We observed significant (p < 0.05) nexus between lymph node metastasis and tumour node metastasis on the basis of tumour's differentiation demographic positioning and age of the individuals.

CONCLUSION

Earlier location tracing and medicinal treatment or surgery lessen the chance of CRC morbidity and mortality along with prolonging survival rate via prognostic factors and disease position determination.

Interval Cancer Rate and Diagnostic Performance of Fecal Immunochemical Test According to Family History of Colorectal Cancer

Background: The potential role of the fecal immunochemical test (FIT) in individuals with a family history of colorectal cancer (CRC) remains unclear. We assessed interval cancer rate (ICR) after the FIT and FIT diagnostic performance according to family history of CRC. Methods: Using the Korean National Cancer Screening Program Database, we collected data on subjects who underwent the FIT between 2009 and 2011. The interval cancer rate (ICR) was defined as the number of subjects diagnosed with CRC within 1 year after the FIT per 1000 subjects with negative FIT results. Results: Of 5,643,438 subjects, 224,178 (3.97%) had a family history of CRC. FIT positivity rate (6.4% vs. 5.9%; adjusted relative risk (aRR) 1.11; 95% confidence interval (CI) 1.09–1.13) and ICR (1.4 vs. 1.1; aRR 1.43 (95% CI 1.27–1.60)) were higher in these subjects than in those with no such history. These results were the same regardless of whether subjects had undergone colonoscopy within the last 5 years before the FIT. However, the diagnostic performance of the FIT for CRC, as measured using the area under the operating characteristic curve, was similar between subjects without a family history and those with one (85.5% and 84.6%, respectively; p = 0.259). Conclusion: the FIT was 1.4 times more likely to miss CRC in subjects with a family history than in those without (aRR 1.43 for ICR), although its diagnostic performance was similar between the two groups. Our results suggest that for individuals with a family history of CRC, colonoscopy should be preferred over FIT for both screening and surveillance.

Colorectal Cancer Genetics, Incidence and Risk Factors: In Search for Targeted Therapies

Each year, colorectal cancers (CRCs) affect over a quarter of a million people. The risk of developing CRC in industrialized nations is approximately 5%. When the disease is localised, treatment success rates range from 70-90%; however, advanced CRC has a high mortality rate, consistently ranking in the top three causes of cancer-related deaths. There is a large geographic difference in global distribution, and CRC is predominantly associated with developed countries and a Western lifestyle and diet. As such, the developed world accounts for more than 63% of all cases of CRC. Geographic variations also predict cancer outcomes, which differ between racial and ethnic groups. This variation is due to inequalities in wealth, differences in the exposure to risk factors and barriers to high-quality cancer prevention, early detection and treatment. The aim of this paper was to review CRC in low- and middle-income countries such as South Africa, India, Brazil and China, and compare them with high-income countries such as the United States of America and the United Kingdom. It is important to note that these economically less developed countries, with historically low CRC rates, are experiencing an increased frequency of CRC. The review also discusses biological markers and genetic pathways involved in the development of colorectal cancer. Genes known to be responsible for the most common forms of inherited CRCs have also been identified but more remain to be identified. This would provide more candidate genes to be added to known biomarkers. CRC burden can be controlled through the widespread application of existing knowledge, such as reduced smoking habits, vaccination, early detection and promoting physical activity, accompanied by a healthy diet. An increased understanding of the molecular mechanisms and events underlying colorectal carcinogenesis will enable the development of new targets and therapeutic drugs.

Radiological staging of rectal cancer in a resource limited setting

Objective

Current guidelines on rectal cancer (RC) management recommend pre-operative MRI for loco-regional staging and CT for staging of metastases. This allows appropriate selection of patients for chemo-radiotherapy (CRT). However, MRI is not freely available in many low-income countries. We assessed the status of pre-operative imaging for RC in Sri Lanka and evaluated the performance of CT in RC staging.

Results

A pre-tested interview-administered questionnaire was used to assess the pre-operative use of MRI and CT in RC. CT findings from 37 RC patients were then compared with histopathology findings. Of the 64 surgeons interviewed, 57 (89.1%) did not request an MRI for their RC patients. Reasons cited included limited availability and long waiting times due to competing health needs. A CT was requested by all. In RC, the overall accuracy of CT for T staging was 43.2% and 29.7% of T1–T2 tumours were over-staged as T3. The overall accuracy of CT for regional lymph node staging was 70.3%. In summary, CT alone is not suitable for RC staging in any setting. It leads to over-staging and patients may thus receive unnecessary CRT. Steps must be taken to improve access to pre-operative MRI among Sri Lankan RC patients.

Obesity Has a Stronger Relationship with Colorectal Cancer in Postmenopausal Women than Premenopausal Women

BACKGROUND

To examine the relationship between obesity measured by waist circumference (WC) and body mass index (BMI) and the incidence of colorectal cancer in premenopausal and postmenopausal women.

METHODS

A total of 1,418,180 premenopausal and 4,854,187 postmenopausal women without cancer at baseline and ages over 40 were identified using the Korean National Health Insurance System Cohort during 2009 to 2014. The hazard ratio (HR) for colorectal cancer incidence was assessed according to menopausal state using Cox proportional hazards models.

RESULTS

During a mean follow-up period of 7.2 years, 7,094 and 57,449 colorectal cancer cases occurred in premenopausal and postmenopausal women, respectively. Compared with the reference group (WC 65-75), the HRs [95% confidence interval (CI)] of colorectal cancer in WC <65, 75-85, 85-95, and >95 groups were 1.01 (0.91-1.11), 1.02 (0.97-1.07), 1.09 (1.00-1.18), and 1.31 (1.12-1.52), respectively, in premenopausal women and 1.01 (0.95-1.17), 1.09 (1.07-1.12), 1.19 (1.00-1.18), and 1.30 (1.25-1.35), respectively, in postmenopausal women. Compared with the reference group (BMI 18.5-22.9), HRs (95% CI) for colorectal cancer in BMI <18.5, 23-25, 25-30, and >30 groups were 0.99 (0.87-1.14), 0.99 (0.94-1.06), 0.98 (0.92-1.04), and 1.06 (0.92-1.20), respectively, in premenopausal women. In postmenopausal women, those values were 0.99 (0.93-1.05), 1.05 (1.03-1.08), 1.11 (1.09-1.13), and 1.20 (1.16-1.25), respectively.

CONCLUSIONS

WC is associated with the risk of colorectal cancer in both groups of women, but this association was stronger in postmenopausal women than in premenopausal women. BMI increased the incidence of colorectal cancer only in postmenopausal women IMPACT: Obesity has a stronger relationship with colorectal cancer in postmenopausal women than in premenopausal women.

circPDSS1 Stimulates the Development of Colorectal Cancer via Activating the Wnt/β-Catenin Signaling

Objective

This study aims to illustrate the role of circPDSS1 and the Wnt/β-catenin signaling in the development of colorectal cancer (CRC).

Patients and Methods

Cancerous mucosa and normal paracancerous mucosa tissues more than 5 cm away from the tumor were surgically collected from 56 CRC patients. circPDSS1 levels in collected tissues and CRC cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The influence of circPDSS1 on clinical features of CRC patients was analyzed. After knockdown of circPDSS1 in HCT-8 and HCT-116 cells, phenotype changes were examined by Transwell, tube formation and wound healing assay. Western blot and rescue experiments were finally performed to uncover the role of circPDSS1 and the Wnt/β-catenin signaling in the development of CRC.

Results

circPDSS1 was upregulated in CRC mucosa tissues than controls. High level of circPDSS1 predicted high rates of lymphatic metastasis and distant metastasis, and poor prognosis in CRC patients. Knockdown of circPDSS1 attenuated migratory ability and angiogenesis in CRC cells. Protein levels of key genes in the Wnt/β-catenin signaling, including β-catenin, GSK-3β, c-Myc, MMP-9 and cyclin D1 were downregulated in CRC cells transfected with sh-circPDSS1. Overexpression of β-catenin reversed the role of circPDSS1 in attenuating migratory ability and angiogenesis in CRC cells.

Conclusion

Upregulated circPDSS1 in CRC is closely linked to lymphatic metastasis, distant metastasis and overall survival. It stimulates the migratory ability and angiogenesis in CRC cells via activating the Wnt/β-catenin signaling.

The association between Ki-67 expression and the clinical pathological characteristics of colorectal cancer: A protocol for a systematic review and meta-analysis

BACKGROUND

This study will explore the association between Ki-67 expression and clinical pathological characteristics (CPC) of colorectal cancer (CC).

METHODS

We will search relevant studies from electronic databases (Cochrane Library, PUBMED, EMBASE, Scopus, Cumulative Index to Nursing and Allied Health Literature, China Biology Medicine, and China National Knowledge Infrastructure) from beginning to April 1, 2020 without language and publication time limitations. We will consider all case-controlled studies (CCSs) or randomized controlled studies (RCSs) investigating the association between Ki-67 expression and CPC of CC. We will appraise study quality of CCSs by Newcastle-Ottawa Scale, and RCSs by Cochrane risk of bias tool. Statistical analysis will be carried out by Review Manager 5.3 software.

RESULTS

The present study will explore the association between Ki-67 expression and CPC of CC.

CONCLUSION

Its findings may summarize scientific evidence of the association between Ki-67 expression and CPC of CC, and may provide helpful evidence for clinical practice.Systematic review registration: PROSPERO CRD42020173795.

The incidence and patterns of colorectal cancers in Sri Lanka from 2001 to 2010: Analysis of national cancer registry data

OBJECTIVES

The incidence of colorectal cancer (CRC) has been increasing in many Asian countries. This study aims to analyse trends in CRC incidence and histological patterns in Sri Lanka.

METHODS

All newly diagnosed patients with CRC in Sri Lanka during 2001-2010 included in the National Cancer Registry were analysed for trends in incidence using Joinpoint regression software.

RESULTS

A total of 7,694 CRC (male:female = 1.02:1, mean age = 58.7 years) were analysed. The incidence of CRC in Sri Lanka has increased from a WHO age-standardised rate of 2.9/100,000 in 2001 (95%-confidence interval [95%-CI]: 2.64-3.16) to 6.08/100,000 in 2010 (95%-CI: 5.71-6.44). This is an estimated annual percentage change (EAPC) of 8.9 (95%-CI: 7.5-10.4). The proportional increase in incidence was observed to be greater for females (2.8 to 5.6, EAPC: 9.4 (95%-CI: 7.7-11.2), p < .05) than males (3.02 to 6.62, EAPC: 8.5 (95%-CI: 6.9-10.2), p < .05).

CONCLUSIONS

Similar to other Asian countries, a significant increase in the incidence of CRC was observed in Sri Lanka. Rate of the increase may have been artificially inflated due to better case reporting and diagnostic scrutiny. Future studies focussing on trends in tumour stage and fatality will help shed light on changing patterns in the burden of CRC in Sri Lanka.

Consumption evaluation of one apple flesh a day in the initial phases prior to adenoma/adenocarcinoma in an azoxymethane rat colon carcinogenesis model

Colorectal cancer (CRC) is the fourth cancer with the most new cases reported in 2018 worldwide. Consumption of fruit and vegetables is a protective factor against the risk of CRC. Beyond this, flavonoids could orchestrate these healthy effects. Apart from containing the typical apple flavonoids, red-fleshed apples also contain anthocyanins, mainly cyanidin-3-O-galactoside (Cy3Gal). Through an azoxymethane rat carcinogenesis model, a study was carried out in order to assess the possible protective effects of apple polyphenols, with special attention to anthocyanins. In addition, apart from negative and positive controls, a group with chemotherapy with 5-fluorouracil (5FU) was included to compare their performance against the output collected from the animal treatments with white-fleshed apple (WF), red-fleshed apple (RF) and Cy3Gal (AE). Although the 5FU group presented the best performance towards aberrant crypt foci (ACF) inhibition (70.1%), rats fed with white-fleshed apples ('Golden Smoothee') were able to achieve 41.3% ACF inhibition, while none of the challenged treatments (WF, RF and AE) suffered mucin depletion in their colonocytes. Expression changes of 17 genes related to CRC were assessed. In detail, the ACF inhibition phenotype detected in 5FU and WF groups could be explained through the expression changes detected in the apoptosis-related genes of Aurka, p53 and Cox2. Moreover, in the apple consumption groups (WF and RF), a reduced protein expression of matrix metalloproteinases with gelatinase activity (MMP-2 and 9) was detected. Overall, our study suggests an effect of apple polyphenols and apple anthocyanin Cy3Gal against colon carcinogenesis, retarding/diminishing the appearance of the precancerous markers studied.

Hospital-Based Preliminary Observations of Dietary Intake and Physical Activity in Saudi Patients with Colorectal Polyps: A Call for Nutrition Care Integration after Polypectomy Procedure

Aim: In Saudi Arabia, the incidence of colorectal cancer (CRC) is increasing. Lifestyle modification, including diet and physical activity, is as important as the standard procedure of colonoscopy screening in reducing CRC development. I explored the dietary intake, physical activity, and selected nutritional biomarkers in Saudi patients with colorectal polyps, a precursor of CRC. Methods: Thirty polypectomy patients (aged 35–84 years) were recruited from an endoscopy unit at King Abdulaziz University Hospital. Demographic, anthropometric, physical activity, and food frequency data were collected. Plasma C-reactive protein, serum 25-hydroxy vitamin D, and folate levels were measured. Results: The median body mass index (BMI) of the patients was within the overweight cut-off range. The median consumption of carbohydrate and protein was within the recommended dietary allowance (RDA). Median fat consumption was above the RDA, while median fiber intake was below the RDA. Patients met the recommended servings/day of fruits, vegetables, dairy products, and protein but exceeded the recommended intake of fats and sweets. Most patients were non-active, with an inadequate level of serum vitamin D. Conclusion: We observed several risk factors previously associated with CRC, including low levels of physical activity, serum vitamin D, and fiber intake, and high BMI and fat intake among polypectomy patients.

Incidence, Clinico-demographic Profiles and Survival Rates of Colorectal Cancer in Northern Malaysia: Comparing Patients Above and Below 50 Years of Age

Background:

While the world witnesses an increasing trend of young-onset colorectal cancer (CRC), the information regarding the impact of age on CRC is limited in Malaysia. This study aimed to compare the incidence, clinic-demographic profiles and survival rates of CRC between patients above and under 50 years of age in northern Malaysia.

Methods:

This was a registry-based, cross-sectional study. All the CRC cases reported by 18 hospitals to the National Cancer Patient Registry - Colorectal Cancer (NCPR-CC) between January 2007 and December 2017 were included in the analysis. The patients were categorized by age into the above-50 and under-50 groups. The changes in the age-standardized incidence and mortality rates of both the age groups were determined using the time-series analysis, and the impact of age on the mortality risk was assessed using the Cox regression analysis.

Results:

Of the 6,172 CRC patients enrolled in the NCPR-CC, 893 (14.5%) were in the under-50 group. As compared with their older counterparts, the patients in the under-50 group were more likely to be female, be of Malay ethnicity, be non-smokers, have a family history of CRC, and present late for treatment. The age-standardized incidence and mortality rates of CRC in the under-50 group remained stable over the years, while a decreasing trend was clearly seen in the mortality rates of CRC in the above-50 group (p=0.003). Nevertheless, the two age groups also did not differ in the mortality risk (adjusted hazards ratio: 1.10; 95% CI: 0.90, 1.36).

Conclusion:

Young-onset CRC constituted a considerable proportion of CRC cases in Malaysia. However, in contrast with the findings of most studies, it demonstrated neither an uptrend in age-standardized incidence rates nor a higher mortality risk. Our findings suggest the need to upscale and lower the recommended age for CRC screening in Malaysia.

Lactobacillus fermentum V3 ameliorates colitis-associated tumorigenesis by modulating the gut microbiome

Lactobacillus spp., a common probiotic used as a dietary supplement, is good for the digestive system. However, its anti-cancer activity still remains unclear. In this study, we aim to examine the effect of Lactobacillus fermentum, Lactobacillus acidophilus and Lactobacillus rhamnosus on azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colitis-associated cancer. Male ICR mice were injected with 10 mg/kg AOM and 2.5% DSS via drinking water, and then fed with different Lactobacillus (1 × 10⁸ CFU/day) for 14 weeks. The colonic tissues were collected for biomedical analysis, and gut microbiota profiling was detected by next generation high-throughput sequencing comparing to the 16S rRNA gene. We found that pretreatment with Lactobacillus fermentum (Lac.ferm) significantly inhibits colonic tumor formation (P < 0.05) and markedly decreases pro-inflammatory cytokines in AOM/DSS-induced mice. Furthermore, 16S rRNA sequencing data showed that Lac.ferm altered the composition of gut microbiota by reducing the percentage of Bacteroides. Moreover, linear discriminant analysis scores revealed that Lactobacillus fermentum within phylum Firmicutes was the prominent species existing in the Lac.ferm-treated group. Overall, the above findings suggest that dietary Lac.ferm could modulate the gut microbial community, which might be beneficial to alleviating colon cancer progression.

Soy Metabolism by Gut Microbiota from Patients with Precancerous Intestinal Lesions

BACKGROUND

Colorectal cancer (CRC) requires the presence of a variety of factors predisposing a tumorigenic milieu. Excluding familial clustering and hereditary CRC syndromes, the development of sporadic CRC from precancerous lesions is influenced by tissue inflammation, modulation of intestinal immunity, hormones, dietary habits and gut microbiota composition. As concerning the last two aspects, the intestinal presence of equol, the most biologically active metabolite of the soy isoflavone daidzein and the presence of a genetic determinant of gut microbiota able to metabolize daidzein, seem to lower the CRC risk. It has been hypothesized that the anaerobic microorganisms of the Bacteroides genus play a role in equol production.

AIM

To evaluate the presence of (i) anaerobic gut microbiota and (ii) the urinary levels of soy isoflavones (daidzein, genistein and equol) in patients with and without precancerous lesions, challenged with a daidzein-rich soy extract.

METHODS

Consecutive subjects undergoing colonoscopy participated to the study. Feces were collected from all patients one week before colonoscopy for gut microbiota studies. After the endoscopy examination and the histological evaluation, 40 subjects, 20 with sporadic colorectal adenomas (SCA/P group) and 20 without proliferative lesions (control group) were enrolled for the study. Urine levels of soy isoflavones daidzein, genistein and their metabolite equol, were determined by high performance liquid chromatographic (HPLC) analysis and gut microbiota analysis was performed by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) procedure.

RESULTS

Seventeen different bacterial species were identified in the fecal samples of the forty subjects participating to the study. Ten bacterial species resulted anaerobic Gram-negative bacteria, all belonging to the Bacteroides genus. A significant difference of bacteria species was evidenced in the fecal samples of the two groups of subjects. Particularly important was the evidence of Parabacteroides distasonis, Clostridium clostridioforme and Pediococcus pentasaceus only in control fecal samples, such as the presence of Bacteroides fragilis and Prevotella melaningenica only in SCA/P fecal samples. Concerning the soy isoflavones levels, no statistically significant differences were revealed in the genistein and daidzein urinary levels between the two groups of subjects. On the contrary, urinary equol levels were undetectable in ten SCA/P subjects and in two controls; moreover, when present, the levels of urinary equol were significantly lower in SCA/P subjects compared to controls (0.24 ± 0.27 mg/24 hrs vs. 21.25 ± 4.3 mg/24 hrs, respectively, p = 1.12 × 10^-6).

CONCLUSIONS

Our results suggest that the presence of anaerobic Bacteroides in the colon, and the production of equol from soy, could determine a milieu able to contrast the development of colonic mucosa proliferative lesions.