Colorectal cancer screening in Asia

Why is early detection of colon cancer still not possible in 2023?

Colorectal cancer (CRC) screening is a fundamental tool in the prevention and early detection of one of the most prevalent and lethal cancers. Over the years, screening, particularly in those settings where it is well organized, has succeeded in reducing the incidence of colon and rectal cancer and improving the prognosis related to them. Despite considerable advancements in screening technologies and strategies, the effectiveness of CRC screening programs remains less than optimal. This paper examined the multifaceted reasons behind the persistent lack of effectiveness in CRC screening initiatives. Through a critical analysis of current methodologies, technological limitations, patient-related factors, and systemic challenges, we elucidated the complex interplay that hampers the successful reduction of CRC morbidity and mortality rates. While acknowledging the advancements that have improved aspects of screening, we emphasized the necessity of addressing the identified barriers comprehensively. This study aimed to raise awareness of how important CRC screening is in reducing costs for this disease. Screening and early diagnosis are not only important in improving the prognosis of patients with CRC but can lead to an important reduction in the cost of treating a disease that is often diagnosed at an advanced stage. Spending more sooner can mean saving money later.

Sedated Colonoscopy may not be Beneficial for Polyp/Adenoma Detection

BACKGROUND

Sedated colonoscopy has been increasingly selected. However, the effect of sedated colonoscopy on polyp/adenoma detection rate (PDR/ADR) remains controversial among studies.

METHODS

In this retrospective study, the medical records of 11 504 consecutive patients who underwent colonoscopy at our department from July 1, 2021 to December 31, 2022 were collected. Patients were divided into sedated and unsedated groups according to the use of intravenous sedation during colonoscopy. Overall PDR/ADR, right-side, transverse, and left-side colon PDR/ADR, and single and multiple PDR/ADR were calculated. By adjusting for age, gender, body mass index, inpatient, screening/surveillance, cecal intubation time, colonoscopy withdrawal time ≥6 min, and an endoscopist's experience ≥5 years, multivariate logistic regression analyses were performed to evaluate the association of sedated colonoscopy with overall PDR/ADR, right-side, transverse, and left-side colon PDR/ADR, and single and multiple PDR/ADR, where the absence of PDR/ADR was used as reference. Odds ratios (ORs) with their 95% confidence intervals (CIs) were calculated.

RESULTS

Overall, 2275 patients were included, of whom 293 and 1982 underwent sedated and unsedated colonoscopy, respectively. Multivariate logistic regression analyses showed that sedated colonoscopy was independently associated with lower overall PDR/ADR (OR = 0.640, 95% CI = 0.460-0.889, P = 0.008), right-side colon PDR/ADR (OR = 0.591, 95% CI = 0.417-0.837, P = 0.003), single PDR/ADR (OR = 0.659, 95% CI = 0.436-0.996, P = 0.048), and multiple PDR/ADR (OR = 0.586, 95% CI = 0.402-0.855, P = 0.005), but not transverse or left-side colon PDR/ADR.

CONCLUSION

Sedated colonoscopy may not be beneficial in terms of overall PDR/ADR, right-side colon PDR/ADR, and number of polyps/adenomas. Thus, it should be selectively recommended. Additionally, it should be necessary to explore how to improve the quality of sedated colonoscopy.

Changing Colorectal Cancer Trends in Asians: Epidemiology and Risk Factors

Once an infrequent disease in parts of Asia, the rate of colorectal cancer in recent decades appears to be steadily increasing. Colorectal cancer represents one of the most important causes of cancer mortality worldwide, including in many regions in Asia. Rapid changes in socioeconomic and lifestyle habits have been attributed to the notable increase in the incidence of colorectal cancers in many Asian countries. Through published data from the International Agency for Cancer Research (IARC), we utilized available continuous data to determine which Asian nations had a rise in colorectal cancer rates. We found that East and South East Asian countries had a significant rise in colorectal cancer rates. Subsequently, we summarized here the known genetics and environmental risk factors for colorectal cancer among populations in this region as well as approaches to screening and early detection that have been considered across various countries in the region.

CircRNAs: emerging factors for regulating glucose metabolism in colorectal cancer

Colorectal cancer is a malignant disease with a high incidence and low survival rate, and the effectiveness of traditional treatments, such as surgery and radiotherapy, is very limited. CircRNAs, a kind of stable endogenous circular RNA, generally function by sponging miRNAs and binding or translating proteins. CircRNAs have been identified to play an important role in regulating the proliferation and metabolism of CRC. In recent years, many reports have indicated that by regulating the expression of glycolysis-related proteins, such as GLUT1 and HK2, or directly translating proteins, circRNAs can promote the Warburg effect in cancer cells, thereby driving CRC metabolism. Moreover, the Warburg effect increases lactate production in cancer cells and promotes acidification of the TME, which further drives cancer progression. In this review, we summarized the remarkable role of circRNAs in regulating glucose metabolism in CRC in recent years, which might be useful for finding new targets for the clinical treatment of CRC.

Spatial and temporal patterns of colorectal cancer in Asia, 1990-2019

BACKGROUND

Asia accounts for the largest burden of colorectal cancer (CRC) worldwide. This study examines the temporal patterns of CRC in Asia in the last three decades.

METHODS

The data pertaining to CRC burden measured by incidence, mortality, and disability-adjusted-life-years (DALYs) and its risk factors for 49 countries in the Asian continent were drawn from the Global Burden of Disease 2019 study between 1990 and 2019. Mortality-to-incidence ratio (MIR) was employed as a proxy indicator of 5-year survival rates.

RESULTS

In Asia, incident cases more than tripled from 270,851 to 1.1 million, deaths tripled from 183,252 to 560,426, and DALYs more than doubled from 5 million to 13.4 million between 1990 and 2019. The age-standardized incidence rate (ASIR) increased from 14.0/100,000 to 23.9/100,000, age-standardized mortality rate (ASMR) increased from 10.1/100,000 to 12.5/100,000, and MIR decreased from 0.68 to 0.50 between 1990 and 2019. ASIR varied 10-folds across countries from 5.6/100,000 in Bangladesh to 62.0/100,000 in Taiwan in 2019 and ASMR from 4.9/1000 in Bangladesh to 30.3/100,000 in Brunei. In 2019, diet low in milk (18.7%) and whole grains (15.2%) and calcium (16.6%) were the major contributory risk factors in CRC DALYs in 2019.

CONCLUSION

CRC is a fast-rising neoplasm in Asia and its burden can be curtailed by focusing on primary prevention (e.g., diet and physical activity) and secondary prevention through screening. The policy focus and resources must be directed towards capacity building, including cancer infrastructure and quality data availability from cancer registries.

Updated epidemiology of gastrointestinal cancers in East Asia

Globally, gastrointestinal cancers represent more than one-fourth of all cancer incidence and one-third of cancer-related mortality. Although there has been much progress in screening colorectal cancer, the prognosis of other gastrointestinal cancers tends to be poor. The highest burden of gastrointestinal cancers, including stomach, liver, oesophageal and gallbladder cancers, was observed in regions in East Asia. The increasing burden of gastrointestinal cancers in East Asian regions is related to population growth, ageing and the westernization of lifestyle habits in this region. Furthermore, the rising incidence of young-onset colorectal cancer is an emerging trend in East Asia. This Review provides a comprehensive and updated summary of the epidemiology of gastrointestinal cancers in East Asia, with emphasis on comparing their epidemiology in East Asia with that in Western regions, and highlights the major risk factors and implications for prevention. Overall, to optimally reduce the disease burden incurred by gastrointestinal cancers in East Asian regions, a concerted effort will be needed to modify unhealthy lifestyles, promote vaccination against the hepatitis virus, control Helicobacter pylori, liver fluke and hepatitis virus infections, increase the uptake rate of colorectal cancer screening, enhance detection of early cancers and their precursors, and improve cancer survivorship through an organized rehabilitation programme.

Fecal Signatures of Streptococcus anginosus and Streptococcus constellatus for Noninvasive Screening and Early Warning of Gastric Cancer

BACKGROUND & AIMS

Most patients with gastric cancer (GCa) are diagnosed at an advanced stage. We aimed to investigate novel fecal signatures for clinical application in early diagnosis of GCa.

METHODS

This was an observational study that included 1043 patients from 10 hospitals in China. In the discovery cohort, 16S ribosomal RNA gene analysis was performed in paired samples (tissues and feces) from patients with GCa and chronic gastritis (ChG) to determine differential abundant microbes. Their relative abundances were detected using quantitative real-time polymerase chain reaction to test them as bacterial candidates in the training cohort. Their diagnostic efficacy was validated in the validation cohort.

RESULTS

Significant enrichments of Streptococcus anginosus (Sa) and Streptococcus constellatus (Sc) in GCa tumor tissues (P < .05) and feces (P < .0001) were observed in patients with intraepithelial neoplasia, early and advanced GCa. Either the signature parallel test Sa∪Sc or single signature Sa/Sc demonstrated superior sensitivity (Sa: 75.6% vs 72.1%, P < .05; Sc: 84.4% vs 64.0%, P < .001; and Sa∪Sc: 91.1% vs 81.4%, P < .01) in detecting early GCa compared with advanced GCa (specificity: Sa: 84.0% vs 83.9%, Sc: 70.4% vs 82.3%, and Sa∪Sc: 64.0% vs 73.4%). Fecal signature Sa∪Sc outperformed Sa∪CEA/Sc∪CEA in the discrimination of advanced GCa (sensitivity: 81.4% vs 74.2% and 81.4% vs 72.3%, P < .01; specificity: 73.4% vs 81.0 % and 73.4% vs 81.0%). The performance of Sa∪Sc in the diagnosis of both early and advanced GCa was verified in the validation cohort.

CONCLUSION

Fecal Sa and Sc are noninvasive, accurate, and sensitive signatures for early warning in GCa. (ClinicalTrials.gov, Number: NCT04638959).

Efficacy and safety of berberine in preventing recurrence of colorectal adenomas: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Berberine(BBR) is a kind of isoquinoline alkaloids extracted from the rhizomes of Coptis chinensis Franch., which was the main active ingredient. Accumulating evidence has shown that it has potential pharmacological effects in preventing the recurrence of colorectal adenomas.

AIM OF THE STUDY

The roles of BBR in the overall recurrence of colorectal adenoma have still not been assessed because of the limitations of the available data and the restriction of a single study. Therefore, we evaluated the effectiveness and safety of BBR in preventing the recurrence of colorectal adenomas through a systematic review and meta-analysis of available data.

MATERIALS AND METHODS

We searched four English databases (PubMed (MEDLINE), the Cochrane Central Register of Controlled Trials (CENTRAL), Embase and Web of Science) and four Chinese language databases (Chinese Biomedicine (CBM), China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP) and the WanFang Database) from their inception through October 2020. Meta-analysis was performed with RevMan5.3 software after data extraction and the quality of studies assessment.

RESULTS

Three randomized controlled clinical trials were included with 1076 patients. Our results illustrated that 1-year and 2-year supplementation with BBR was associated with lower recurrence rate of colorectal adenoma (RR 0.69, 95% CI 0.57 to 0.84, p=0.0001; RR 0.75, 95% CI 0.64 to 0.88, p=0.0004). The relative risk of oral BBR for 1 year and 2 years is not comparable, for 2-year efficacy outcomes were assessed in all participants who had at least one colonoscopy with pathological evaluation after baseline (lots of participants completed the first colonoscopy but discontinued during the second follow-up interval.). Moreover, the results also suggest that BBR had more adverse events than placebo (RR 2.91, 95% CI 1.24 to 6.85, p=0.01). Through the full-text reading, no serious adverse events were observed, and constipation was the most common event which disappears once the drug is discontinued.

CONCLUSION

Generally, the present study indicated that BBR has a comparable therapeutic effect on the prevention of colorectal adenomas recurrence. Adverse reactions are worthy of attention which requires additional studies to obtain a precise conclusion.

PROSPERO REGISTRATION NO

CRD42020209135.

Prognostic Nomogram of Prognosis-Related Genes and Clinicopathological Characteristics to Predict the 5-Year Survival Rate of Colon Cancer Patients

Background: The Cancer Genome Atlas (TCGA) has established a genome-wide gene expression profile, increasing our understanding of the impact of tumor heredity on clinical outcomes. The aim of this study was to construct a nomogram using data from the TCGA regarding prognosis-related genes and clinicopathological characteristics to predict the 5-years survival rate of colon cancer (CC) patients. Methods: Kaplan-Meier and Cox regression analyses were used to identify genes associated with the 5-years survival rate of CC patients. Cox regression was used to analyze the relationship between the clinicopathological features and prognostic genes and overall survival rates in patients with CC and to identify independent risk factors for the prognosis of CC patients. A nomogram for predicting the 5-years survival rate of CC patients was constructed by R software. Results: A total of eight genes (KCNJ14, CILP2, ATP6V1G2, GABRD, RIMKLB, SIX2, PLEKHA8P1, and MPP2) related to the 5-years survival of rate CC patients were identified. Age, stage, and PLEKHA8P1 were independent risk factors for the 5-years survival rate in patients with CC. The accuracy, sensitivity and specificity of the nomogram model constructed by age, TNM staging, and PLEKHA8P1 for predicting the 5-years survival of rate CC patients were 83.3, 83.97, and 85.79%, respectively. Conclusion: The nomogram can correctly predict the 5-year survival rate of patients with CC, thus aiding the individualized decision-making process for patients with CC.

Effect of antifoaming agent on benign colorectal tumors in colonoscopy: A meta-analysis

BACKGROUND

Although several trials have shown that the addition of antifoaming agents to polyethylene glycol (PEG) can improve bowel preparation, whether PEG plus antifoaming agents have a beneficial role in the detection of benign tumors during colonoscopy has yet to be confirmed. Our aim was to clarify whether adding simethicone to PEG solution could improve the detection of benign colorectal tumors.

AIM

To clarify whether adding simethicone to PEG solution could improve the detection of benign colorectal tumors.

METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched for articles published prior to September 2019. The outcomes included the detection rates of colorectal adenomas and polyps.

RESULT

Twenty studies were eligible. Although there was no difference in the colorectal adenoma detection rate (ADR), a significant effect of simethicone for diminutive adenomas (< 10 mm) was revealed in the group taking simethicone. We also found that simethicone could significantly improve the ADR in the proximal colon but did not affect the colorectal polyp detection rate. Furthermore, the subgroup analyses revealed a beneficial effect of simethicone on the ADR among Asians (P = 0.005) and those with an ADR < 25% (P = 0.003). Moreover, it was a significant finding that the low dose simethicone was as effective as the high dose one with respect to the detection of benign colorectal tumors.

CONCLUSION

In summary, the addition of simethicone to PEG might improve the detection of diminutive adenomas in the right colon by colonoscopy in Asia. Low-dose simethicone was recommended for the detection of benign colorectal tumors. However, large clinical trials are necessary to validate our results and determine the ideal dose of simethicone.

NLRP3 Promotes Colorectal Cancer Cell Proliferation and Metastasis via Regulating Epithelial Mesenchymal Transformation

BACKGROUND

Nucleotide-binding domain Leucine-rich Repeat Protein 3 (NLRP3) plays a regulatory role in the immune and inflammatory responses, and has been implicated in Colorectal Cancer (CRC) progression and metastasis. However, the underlying molecular mechanisms have not been fully elucidated.

METHODS

In this study, we analyzed the expression levels of NLRP3 in human CRC tissues, and performed functional assays in CRC cell lines and a subcutaneous tumor model to elucidate its role in the development and progression of CRC.

RESULTS

In this study, we found that NLRP3 was significantly upregulated in human CRC tissues and was associated with tumor size and invasion, lymph node metastasis, venous invasion, neural invasion and TNM staging. Furthermore, knockdown of NLRP3 in CRC cells inhibited their migration and growth in vitro and in vivo, and reversed Epithelial-Mesenchymal Transition (EMT) in vitro.

CONCLUSION

Our findings indicate that NLRP3 likely regulates CRC metastasis by activating the EMT program, and is a potential therapeutic target.

Impact of simethicone on bowel cleansing during colonoscopy in Chinese patients

BACKGROUND

Four-liter polyethylene glycol (PEG) solutions are effective for bowel cleansing, but their large volume might hinder patient compliance. Due to the unique features of Asians, 4 L PEG might be a suboptimal bowel preparation in predominantly ethnically Asian countries. In view of this, a balance should be achieved between the volume and effectiveness. The ideal bowel cleansing regimen for a colonoscopy has yet to be determined in a Chinese population.

AIM

To compare the cleansing efficacy of 3 L PEG plus simethicone with 4 L PEG.

METHODS

A total of 291 patients were randomly allocated to two groups: Group 1 (n = 145) received 4 L split-dose PEG (4-P); group 2 (n = 146) received 3 L split-dose PEG plus simethicone (3-PS). Bowel-cleansing efficacy was evaluated by endoscopists using the Boston bowel preparation scale (BBPS) and the bubbles score.

RESULTS

Although there were no significant differences in the total BBPS score or the adequate rate of bowel preparation between the two groups, the BBPS score of the right-side colon was significantly higher in the 3-SP group (2.37 ± 0.54 vs 2.21 ± 0.78; P = 0.04). Moreover, the use of simethicone significantly reduced bubbles in all colon segments (P < 0.001). The mean withdrawal time was significantly shorter in the 3-PS group (8.8 ± 3.4 vs 9.6 ± 2.3; P = 0.02). Furthermore, significantly more proximal adenomas were detected in the 3-PS group (53.6% vs 45.7%; P = 0.03). In addition, the proportions of patients with nausea and bloating were significantly lower in the 3-SP group (P < 0.01 for both). More patients in the 3-PS group expressed willingness to repeat the bowel preparation (87.7% vs 76.6%, P = 0.01).

CONCLUSION

Three-liter PEG shows satisfactory bowel cleansing despite the decrease in dosage, and addition of simethicone with better bubble elimination and enhanced patient acceptance offers excellent potential impact on the detection of proximal adenomas in Chinese patients.

Metformin Inhibits the Urea Cycle and Reduces Putrescine Generation in Colorectal Cancer Cell Lines

The urea cycle (UC) removes the excess nitrogen and ammonia generated by nitrogen-containing compound composites or protein breakdown in the human body. Research has shown that changes in UC enzymes are not only related to tumorigenesis and tumor development but also associated with poor survival in hepatocellular, breast, and colorectal cancers (CRC), etc. Cytoplasmic ornithine, the intermediate product of the urea cycle, is a specific substrate for ornithine decarboxylase (ODC, also known as ODC1) for the production of putrescine and is required for tumor growth. Polyamines (spermidine, spermine, and their precursor putrescine) play central roles in more than half of the steps of colorectal tumorigenesis. Given the close connection between polyamines and cancer, the regulation of polyamine metabolic pathways has attracted attention regarding the mechanisms of action of chemical drugs used to prevent CRC, as the drug most widely used for treating type 2 diabetes (T2D), metformin (Met) exhibits antitumor activity against a variety of cancer cells, with a vaguely defined mechanism. In addition, the influence of metformin on the UC and putrescine generation in colorectal cancer has remained unclear. In our study, we investigated the effect of metformin on the UC and putrescine generation of CRC in vivo and in vitro and elucidated the underlying mechanisms. In nude mice bearing HCT116 tumor xenografts, the administration of metformin inhibited tumor growth without affecting body weight. In addition, metformin treatment increased the expression of monophosphate (AMP)-activated protein kinase (AMPK) and p53 in both HCT116 xenografts and colorectal cancer cell lines and decreased the expression of the urea cycle enzymes, including carbamoyl phosphate synthase 1 (CPS1), arginase 1 (ARG1), ornithine trans-carbamylase (OTC), and ODC. The putrescine levels in both HCT116 xenografts and HCT116 cells decreased after metformin treatment. These results demonstrate that metformin inhibited CRC cell proliferation via activating AMPK/p53 and that there was an association between metformin, urea cycle inhibition and a reduction in putrescine generation.

Proteome Analyses Reveal S100A11, S100P, and RBM25 Are Tumor Biomarkers in Colorectal Cancer

PURPOSE

The prognosis for colorectal cancer (CRC) patients is drastically impacted by the presence of lymph node or liver metastases at diagnosis or resection. On this basis it is sought to identify novel proteins as biomarkers and determinants of CRC metastasis.

EXPERIMENTAL DESIGN

Proteomic analyses are undertaken using primary tissues from ten Chinese CRC patients presenting with or without liver metastases and immunohistochemistry used to validate selected proteins in an independent patient cohort.

RESULTS

Comparing CRC against paired normal adjacent tissues identifies 1559 differentially expressed proteins (DEPs) with 974 upregulated and 585 downregulated proteins, respectively. The highest number of DEPs is selectively associated with metastatic tumors (519 upregulated and 267 downregulated proteins, respectively) with a smaller number of unique DEPs identified only in non-metastatic CRC cases (116 upregulated and 29 downregulated proteins, respectively). The remaining DEPs are commonly expressed in both non-metastatic and metastatic tumors. The upregulation of three representative DEPs (S100A11, S100P, and RBM25) is confirmed using immunohistochemistry against 154 CRC tissues embedded in a tissue microarray.

CONCLUSIONS AND CLINICAL RELEVANCE

The data reveal both previously identified CRC biomarkers along with novel candidates which provide a ready resource of DEPs in CRC for further investigation.

The health belief model and colorectal cancer screening in the general population: A systematic review

Colorectal cancer screening saves lives and is cost-effective. It allows early detection of the pathology, and enables earlier medical intervention. Despite clinical practice guidelines promoting screening for average risk individuals, uptake remains suboptimal in many populations. Few studies have examined how sociobehavioural factors influence screening uptake in the context of behaviour change theories such as the health belief model. This systematic review therefore examines how the health belief model's constructs are associated with colorectal cancer screening. Four databases were systematically searched from inception to September 2019. Quantitative observational studies that used the health belief model to examine colorectal screening history, intention or behaviour were included. A total of 30 studies met the criteria for review; all were of cross-sectional design. Perceived susceptibility, benefits and cues to action were directly associated with screening history or intention. Perceived barriers inversely associated with screening history or intention. The studies included also found other modifying factors including sociodemographic and cultural norms. Self-report of screening history, intention or behaviour, convenience sampling and lack of temporality among factors were common limitations across studies. The health belief model's associations with colorectal cancer screening uptake was consistent with preventive health behaviours in general. Future studies should examine how theory-based behavioural interventions can be tailored to account for the influence of socioecological factors.

Diagnostic Value of Combining miRNAs, CEA Measurement and the FOBT in Colorectal Cancer Screening

Introduction

Colorectal cancer (CRC) is one of the most common illnesses that seriously threatens human health; many papers have reported that microRNAs (miRNAs) are promising biomarkers for cancer detection. However, miRNAs have not been used in clinical practice even though they are superior to the currently used screening tools, such as the fecal occult blood test (FOBT) and carcinoembryonic antigen (CEA) measurement.

Methods

In this study, we focused on the usefulness of a panel of miRNAs and the combination of miRNAs with the FOBT and CEA measurement, the currently used general diagnosis methods, to improve the accuracy of CRC diagnosis.

Results

The results showed that the miRNA panel has great potential value as a diagnostic biomarker with high specificity and sensitivity, and further analysis demonstrated that the miRNA panel had higher sensitivity and specificity than the FOBT and CEA measurement, even when these methods were combined. More importantly, although the miRNA panel is superior to the FOBT and CEA measurement, it cannot replace them.

Conclusions

In this research, we investigated whether complementarity exists between the miRNA panel and the FOBT and CEA measurement for CRC diagnosis. Interestingly, the results indicated that the FOBT and CEA measurement could improve the positivity rate of the miRNA panel as a biomarker and vice versa.

Selective targeting of the TLR4 co-receptor, MD2, prevents colon cancer growth and lung metastasis

Toll-like receptor (TLR) signaling is an emerging pathway in tumor cell invasion and metastasis. Myeloid differentiation protein-2 (MD2) contributes to ligand recognition and activation of TLRs in response to exogenous microbial insults or endogenous agents. We hypothesized that blocking MD2 using a specific inhibitor would prevent TLR4-mediated inflammatory responses and metastatic cancer growth. Here, we report that a MD2 inhibitor, L6H21, inhibited migration and invasion of LPS-activated colon cancer CT26.WT cells. These activities were accompanied by inhibition of nuclear factor-κB (NF-κB) activation, and thereby inhibition of the production of pro-inflammatory cytokines and adhesive molecules in colon cancer cells. Furthermore, L6H21 inhibited CT26.WT metastasis to the lung in BALB/c mice as well as suppressed colitis-induced colon cancer induced by azoxymethane/dextran sulfate sodium (AOM/DSS). Taken together, our results demonstrated that L6H21 suppressed tumor invasion and metastasis through blocking TLR4-MD2/NF-κB signaling axis. These findings reveal that inhibition of MD2 may be an important target for the development of colon cancer therapies.

Proteomics analysis of colon cancer progression

BACKGROUND

The aim of this pilot study was to identify proteins associated with advancement of colon cancer (CC).

METHODS

A quantitative proteomics approach was used to determine the global changes in the proteome of primary colon cancer from patients with non-cancer normal colon (NC), non-adenomatous colon polyp (NAP), non-metastatic tumor (CC NM) and metastatic tumor (CC M) tissues, to identify up- and down-regulated proteins. Total protein was extracted from each biopsy, trypsin-digested, iTRAQ-labeled and the resulting peptides separated using strong cation exchange (SCX) and reverse-phase (RP) chromatography on-line to electrospray ionization mass spectrometry (ESI-MS).

RESULTS

Database searching of the MS/MS data resulted in the identification of 2777 proteins which were clustered into groups associated with disease progression. Proteins which were changed in all disease stages including benign, and hence indicative of the earliest molecular perturbations, were strongly associated with spliceosomal activity, cell cycle division, and stromal and cytoskeleton disruption reflecting increased proliferation and expansion into the surrounding healthy tissue. Those proteins changed in cancer stages but not in benign, were linked to inflammation/immune response, loss of cell adhesion, mitochondrial function and autophagy, demonstrating early evidence of cells within the nutrient-poor solid mass either undergoing cell death or adjusting for survival. Caveolin-1, which decreased and Matrix metalloproteinase-9, which increased through the three disease stages compared to normal tissue, was selected to validate the proteomics results, but significant patient-to-patient variation obfuscated interpretation so corroborated the contradictory observations made by others.

CONCLUSION

Nevertheless, the study has provided significant insights into CC stage progression for further investigation.

Proteomics analysis of colon cancer progression

BACKGROUND

The aim of this pilot study was to identify proteins associated with advancement of colon cancer (CC).

METHODS

A quantitative proteomics approach was used to determine the global changes in the proteome of primary colon cancer from patients with non-cancer normal colon (NC), non-adenomatous colon polyp (NAP), non-metastatic tumor (CC NM) and metastatic tumor (CC M) tissues, to identify up- and down-regulated proteins. Total protein was extracted from each biopsy, trypsin-digested, iTRAQ-labeled and the resulting peptides separated using strong cation exchange (SCX) and reverse-phase (RP) chromatography on-line to electrospray ionization mass spectrometry (ESI-MS).

RESULTS

Database searching of the MS/MS data resulted in the identification of 2777 proteins which were clustered into groups associated with disease progression. Proteins which were changed in all disease stages including benign, and hence indicative of the earliest molecular perturbations, were strongly associated with spliceosomal activity, cell cycle division, and stromal and cytoskeleton disruption reflecting increased proliferation and expansion into the surrounding healthy tissue. Those proteins changed in cancer stages but not in benign, were linked to inflammation/immune response, loss of cell adhesion, mitochondrial function and autophagy, demonstrating early evidence of cells within the nutrient-poor solid mass either undergoing cell death or adjusting for survival. Caveolin-1, which decreased and Matrix metalloproteinase-9, which increased through the three disease stages compared to normal tissue, was selected to validate the proteomics results, but significant patient-to-patient variation obfuscated interpretation so corroborated the contradictory observations made by others.

CONCLUSION

Nevertheless, the study has provided significant insights into CC stage progression for further investigation.

Age at menarche and risk of colorectal adenoma

BACKGROUND/AIMS

Limited data are available regarding the association between age at menarche and the risk of colorectal adenoma. Therefore, we aimed to evaluate the relationship between reproductive factors including age at menarche and the risk of colorectal adenoma.

METHODS

A cross-sectional study was performed on asymptomatic female subjects who underwent colonoscopy between 2010 and 2014 as part of a comprehensive health screening program in Korea. The association between reproductive factors including age at menarche and the presence of adenomas was assessed using multivariate logistic regression analysis.

RESULTS

Among 32,620 asymptomatic female subjects, the proportion of patients with menarche at 10 to 11, 12 to 13, 14 to 15, 16 to 17, and 18 to 19 years of age was 4.1%, 31.7%, 45.4%, 14.9%, and 4.0%, respectively. Age at menarche was not significantly associated with the risk of any adenoma (adjusted odds ratio [AOR], 0.99; 95% confidence interval [CI], 0.97 to 1.02; p = 0.500) or advanced adenoma (AOR, 0.98; 95% CI, 0.91 to 1.04; p = 0.468) after adjusting for confounding factors. Age at menarche was not significantly associated with the risk of adenoma even among similar age groups. In addition, parity, use of female hormones, and menopause were not associated with the risk of adenoma.

CONCLUSION

Age at menarche, parity, use of female hormones, and menopause were not significantly associated with the risk of colorectal adenoma. Our findings indicate that reproductive factors including age at menarche do not affect the development of colorectal adenoma.

Identification of differentially expressed genes and biological characteristics of colorectal cancer by integrated bioinformatics analysis

Colorectal cancer (CRC) ranks as one of the most common malignant tumors worldwide. Its mortality rate has remained high in recent years. Therefore, the aim of this study was to identify significant differentially expressed genes (DEGs) involved in its pathogenesis, which may be used as novel biomarkers or potential therapeutic targets for CRC. The gene expression profiles of GSE21510, GSE32323, GSE89076, and GSE113513 were downloaded from the Gene Expression Omnibus (GEO) database. After screening DEGs in each GEO data set, we further used the robust rank aggregation method to identify 494 significant DEGs including 212 upregulated and 282 downregulated genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed by DAVID and the KOBAS online database, respectively. These DEGs were shown to be significantly enriched in different cancer-related functions and pathways. Then, the STRING database was used to construct the protein-protein interaction network. The module analysis was performed by the MCODE plug-in of Cytoscape based on the whole network. We finally filtered out seven hub genes by the cytoHubba plug-in, including PPBP, CCL28, CXCL12, INSL5, CXCL3, CXCL10, and CXCL11. The expression validation and survival analysis of these hub genes were analyzed based on The Cancer Genome Atlas database. In conclusion, the robust DEGs associated with the carcinogenesis of CRC were screened through the GEO database, and integrated bioinformatics analysis was conducted. Our study provides reliable molecular biomarkers for screening and diagnosis, prognosis as well as novel therapeutic targets for CRC.

Molecular mutation characteristics of mismatch and homologous recombination repair genes in gastrointestinal cancer

Gastrointestinal cancer is one of the most common types of cancer with high mortality rates. Mutations in several genes are reportedly involved in the progression of gastrointestinal cancer, including tumor protein 53 (TP53), APC regulator of WNT signaling pathway (APC), KRAS proto-oncogene GTPase (KRAS) and erb-b2 receptor tyrosine kinase 2 (ERBB2). Most notably, there are numerous mutations in DNA repair genes, including mismatch repair (MMR) and homologous recombination (HR) genes. The focus of the present study was to investigate the effects of MMR and HR gene mutations on genomic instability in gastrointestinal cancer. Using targeted capture and massively parallel genomic sequencing, 137 gastrointestinal cancer patients were analyzed for somatic single-nucleotide variants (SNVs) and insertion-deletion (indel) mutations in the exon regions of 183 cancer driver genes, including 4 MMR genes [MutL homolog MLH1, MLH2, MLH6 and PMS1 homolog 2, mismatch repair system component (PMS2)] and 15 HR genes [BRCA1 DNA repair associated (BRCA1), BRCA2 DNA repair associated (BRCA2), ATM serine/threonine kinase (ATM), phosphatase and tensin homolog, BLM RecQ like helicase, FA complementation group A, FA complementation group C, FA complementation group D2, FA complementation group E, FA complementation group F, FA complementation group G, nibrin, partner and localizer of BRCA2 and Werner syndrome RecQ like helicase]. A number of frequently mutated genes, including but not limited to, mechanistic target of rapamycin kinase, neurofibromin 1, APC and, in particular, DNA repair genes, including PMS2, ATM and BRCA2, were identified. Frequency analysis was performed based on the SNVs and indels in the 183 genes to indirectly indicate the relative status of genomic instability in each patient. Correlation analysis suggested that MMR and HR gene mutations directly affected the count of SNVs and indels. Overall, 56 of the gastrointestinal cancer patients (40%) were found to have an inactivation mutation (stopgain/frameshift/splicing) in one or more of the four MMR genes, whereas 112 patients (82%) harbored at least one HR gene inactivation mutation. In addition, patients with MMR or HR inactivation variants had more SNVs and indels compared with patients with no such mutations. No other clinical characteristics (including sex and age) appeared to have a statistically significant impact. Further analysis indicated that different MMR or HR genes exerted distinct effects on genomic instability. The results obtained in the current study may lay a foundation for investigations into the tumorigenic process and for the development of novel therapeutic strategies for the treatment of gastrointestinal cancer.

The Rise of Colorectal Cancer in Asia: Epidemiology, Screening, and Management

PURPOSE OF REVIEW

Colorectal cancer (CRC) remains the third most commonly diagnosed cancer globally, and its incidence and mortality rates have been on the rise in Asia. In this paper, we summarize the recent trends and screening challenges of CRC in this region.

RECENT FINDINGS

In 2018, Asia had the highest proportions of both incident (51.8%) and mortality (52.4%) CRC cases (all genders and ages) per 100,000 population in the world. In addition, there has been a rising trend of this disease across Asia with some regional geographic variations. This rise in CRC can be attributed to westernized dietary lifestyle, increasing population aging, smoking, physical inactivity, and other risk factors. In curbing the rising trend, Japan, South Korea, Singapore, and Taiwan have launched nationwide population-based screening programs. CRC screening across this region has been found to be effective and cost-effective compared with no screening at all. The emergence of new therapies has caused a reduction in case fatality; however, these new options have had a limited impact on cure rates and long-term survival due to the great disparity in treatment capacity/resources and screening infrastructures among Asian countries with different degrees of economic development. CRC is still rising in Asia, and implementation of screening is necessary for moderate- to high-incidence countries and construction of treatment capacity is the priority task in low-incidence and low-income countries. Unless countries in Asia implement CRC screening, the incidence and mortality rates of this disease will continue to rise especially with the rapidly rising population growth, economic development, westernized lifestyle, and increasing aging.

A Rural-Urban Comparison of Knowledge, Risk- Factors and Preventive Practices for Colorectal Cancer among Adults in Lagos State

Objective:

To assess and compare the knowledge, risk-factors and preventive practices for colorectal cancer among adults in Lagos State.

Material and methods:

This was a cross-sectional comparative study conducted among 607 respondents selected from one rural (Ikorodu) and one urban (Surulere) LGA using a multistage sampling technique. Data were collected using a pre-tested questionnaire administered by trained research assistants between April and September 2017.Data was analyzed using Epi-info statistical software version 3.5.1. Univariate and bivariate analysis was carried out and -p values of ≤0.05 were considered statistically significant.

Results:

Respondents’ knowledge of colorectal cancer was generally low, (rural-78.2%, urban- 62.2%, p<0.001). Urban respondents were significantly more knowledgeable than their rural counterparts (rural- 21.8%, urban- 37.8%, p<0.001). The presence of CRC risk-factors were higher among urban respondents (urban-49.3%, rural-42.6%, p= 0.09), however this difference was not statistically significant. Preventive practices were generally poor in both groups, although more (18.1%) urban respondents significantly took preventive actions against CRC compared with rural (6.9%) respondents, (p<0.001).Increasing levels of education were significantly associated with higher knowledge level in both groups (p≤0.05).

Conclusion:

The level of knowledge of colorectal cancer was generally poor in both groups but significantly poorer among rural respondents. The presence of known risk- factor was higher among urban respondents while preventive practices were poor in both groups.

Notch pathway is involved in the suppression of colorectal cancer by embryonic stem cell microenvironment

Objectives: Recently, embryonic microenvironment is being known for its non-permissive property for tumor growth. However, the regulatory mechanism to maintain the balance between differentiation and tumorigenicity of cancer cell in microenvironment is not well understood.

Materials and Methods: qRT-PCR was performed to detect the levels of gene expression in HT29, LoVo and Caco-2 colorectal cancer cells, and Western blot was used to measure the protein levels. Cell migration and apoptosis were measured by Transwell and flow cytometry assays. Cancer cell markers were detected using immunohistochemical staining. In vivo tumor formation assay was conducted by subcutaneous injection of embryonic microenvironment-treated cancer cells.

Results: Colorectal cancer cell lines were treated with human embryonic stem cell conditioned culture and then collected for in vivo tumor formation assay and in vitro assays assessing the aggressive properties. We found exposure of cancer cells in human ES cultures resulted in inhibition of growth, migration of tumor cells. Moreover, we found that manipulation of Notch pathway in the ES cells microenvironment could influence the stemness of tumor. We specifically discovered that some factor in the embryonic microenvironment could suppress Notch1 pathway in the cancer cells, leading to a reduction in tumorigenesis and invasiveness.

Conclusions: This study may provide another evidence to understand the crosstalk between tumor cells and embryonic environment and may offer new therapeutic strategies to inhibit colorectal cancer progression.

Coelomic Fluid of Lumbricus rubellus Synergistically Enhances Cytotoxic Effect of 5-Fluorouracil through Modulation of Focal Adhesion Kinase and p21 in HT-29 Cancer Cell Line

Coelomic fluid of Lumbricus rubellus (CFL) has attracted interest due to its pharmacological properties, including antitumor effect. Furthermore, it is necessary to evaluate the response to treatment with new cancer therapeutic agents. This study aims to investigate whether the combination of CFL and 5-fluorouracil could reduce FAK protein level and iCa²⁺ and enhance p21 level. Furthermore, it is necessary to evaluate the response to treatment with new cancer therapeutic agents. After 24 hours of treatment, it was necessary to assess the percentage of apoptosis, FAK, and p21 protein expression by flow cytometry. iCa²⁺ concentration was measured using immunofluorescence. The combination therapy of CFL with 5-fluorouracil potently suppressed six treatment groups were included in this study. HT-29 cell lines were cultured and divided into six groups: group 1 was treated with vehicle (negative control), groups 2-5 were treated with 5-fluorouracil, groups 3-5 were treated with either CFL 5, 10, or 20 µg/ml immediately after 5-fluorouracil, and group 6 was treated with CFL 20 µg/ml, the progression of colorectal cancer. Combination of CFL and 5-fluorouracil significantly decreased FAK expression (p<0.05), iCa²⁺ (p<0.05), and increased p21 expression (p<0.05) in HT-29 cells. Our results suggest that CFL has an anticancer potential in colorectal cancer when combined with 5-fluorouracil.

Meeting report from the joint IARC-NCI international cancer seminar series: a focus on colorectal cancer

Despite significant progress in our understanding of the etiology, biology and genetics of colorectal cancer, as well as important clinical advances, it remains the third most frequently diagnosed cancer worldwide and is the second leading cause of cancer death. Based on demographic projections, the global burden of colorectal cancer would be expected to rise by 72% from 1.8 million new cases in 2018 to over 3 million in 2040 with substantial increases anticipated in low- and middle-income countries. In this meeting report, we summarize the content of a joint workshop led by the National Cancer Institute and the International Agency for Research on Cancer, which was held to summarize the important achievements that have been made in our understanding of colorectal cancer etiology, genetics, early detection and treatment and to identify key research questions that remain to be addressed.

Rab1A promotes proliferation and migration abilities via regulation of the HER2/AKT-independent mTOR/S6K1 pathway in colorectal cancer

Colorectal carcinoma (CRC) is one of the most common malignancies worldwide and the second leading cause of cancer-related deaths in the US. Recently, Rab1A has been reported to be an activator of mTORC1 and p-S6K1, which is downstream of mTORC1. However, the association between Rab1A and p-S6K1 in CRC remains elusive. In the present study, we first demonstrated that Rab1A was overexpressed in CRC tissues and Rab1A overexpression was positively related to lymph node invasion, degree of differentiation, venous invasion and tumor-node-metastasis (TNM) stage. In both TNM stage I–II and III–IV patients, Rab1A-positive patients had a shorter survival time than Rab1A-negative patients. Furthermore, in univariate and multivariate analyses, only Rab1A expression was verified as an independent prognostic factor for survival in CRC patients. The level of p-S6K1 was markedly high in CRC tissues and Rab1A expression level had a positive association with p-S6K1 level. In addition, high levels of both Rab1A and p-S6K1 were associated with a poorer prognosis compared with low expression of either Rab1A or p-S6K1 level. Moreover, high levels of both Rab1A and p-S6K1 were associated with a poorer prognosis than patients with high levels of either Rab1A or p-S6K1 alone. Finally, knockdown of Rab1A expression inhibited migration and proliferation of SW480 and HCT116 cell lines by targeting regulation of p-S6K1. Thus, our findings indicate that Rab1A plays an important role in CRC and may provide a therapeutic target for CRC, particularly for mTORC1-targeted therapy-resistant cancers.

Factors influencing colonoscopy behaviour among Koreans with a positive faecal occult blood tests

OBJECTIVE

Colonoscopy is important for colorectal cancer (CRC) screening in individuals with a positive faecal occult blood test (FOBT). The purpose of the present study was to identify factors affecting the colonoscopy screening behaviour of FOBT-positive individuals, based on the health belief model (HBM).

METHODS

This study involved a cross-sectional survey of 213 individuals aged 50 years or older who underwent CRC screening at a general hospital in Seoul, Korea, as part of the Korean National Cancer Screening Programme and who tested positive on FOBT. The questionnaire was created based on HBM instruments. The collected data were analysed using descriptive statistics, and factors associated with adherence to colonoscopy were examined using logistic regression analysis.

RESULTS

Of the FOBT-positive individuals, 44.1% adhered to colonoscopy. Three of the six evaluated HBM-driven factors (perceived seriousness, perceived barriers and health motivation) significantly differed between colonoscopy-adherent and non-adherent subjects. Perceived seriousness and perceived barriers were the most important factors influencing colonoscopy screening behaviour.

CONCLUSION

For early detection and prevention of CRC, colonoscopy screening behaviour should improve among FOBT-positive individuals. To this aim, education on the graveness of CRC should be provided, and barriers to CRC screening should be addressed.

Efficacy and safety of celecoxib on the incidence of recurrent colorectal adenomas: a systematic review and meta-analysis

BACKGROUND

Celecoxib has previously been shown to be effective in reducing recurrent colorectal adenomas, but its long-term effects are unknown. In addition, safety issues are of major concern. Therefore, we examined the efficacy and safety of celecoxib as a chemopreventive agent along with its posttreatment effect.

METHODS

We performed a meta-analysis based on a systematic review of randomized controlled trials (RCTs) comparing celecoxib at various doses (400 mg once daily, 200 mg twice daily, and 400 mg twice daily) vs placebo in persons with history of colorectal adenomas. Several databases were searched from inception up to April 2018. Long-term follow-ups of RCTs were also included to evaluate posttreatment effect. Primary outcome was the incidence of recurrent colorectal adenomas. Various safety outcomes were evaluated, especially cardiovascular (CV) events. Risk-benefit integrated analyses were also performed.

RESULTS

A total of three RCTs (4,420 patients) and three post-trial studies (2,159 patients) were included in the analysis. Use of celecoxib at any dose for 1-3 years significantly reduced the incidence of recurrent advanced adenomas (risk ratio, 0.42 [95% CI, 0.34-0.53]) and any adenomas (0.67 [95% CI, 0.62-0.72]) compared with placebo. Subgroup analysis on different dosing suggested a greater effect with 400 mg twice daily. However, celecoxib 400 mg twice daily significantly increased the risk of serious adverse (1.2 [95% CI, 1.0-1.5]) and CV events (3.42 [95% CI, 1.56-7.46]), while celecoxib at 400 mg/day, especially with once daily dosing, did not increase CV risk (1.01 [95% CI, 0.70-1.46]). Analysis of post-trial studies indicated that the treatment effect disappeared (1.15 [95% CI, 0.88-1.49]) after discontinuing celecoxib for >2 years.

CONCLUSION

Celecoxib 400 mg once daily dosing could potentially be considered as a viable chemopreventive option in patients with high risk of adenomas but with low CV risk. Long-term trials on celecoxib at a dose of ≤400 mg either once or twice daily are warranted.

An enrichment model using regular health examination data for early detection of colorectal cancer

Objective

Challenges remain in current practices of colorectal cancer (CRC) screening, such as low compliance, low specificities and expensive cost. This study aimed to identify high-risk groups for CRC from the general population using regular health examination data.

Methods

The study population consist of more than 7,000 CRC cases and more than 140,000 controls. Using regular health examination data, a model detecting CRC cases was derived by the classification and regression trees (CART) algorithm. Receiver operating characteristic (ROC) curve was applied to evaluate the performance of models. The robustness and generalization of the CART model were validated by independent datasets. In addition, the effectiveness of CART-based screening was compared with stool-based screening.

Results

After data quality control, 4,647 CRC cases and 133,898 controls free of colorectal neoplasms were used for downstream analysis. The final CART model based on four biomarkers (age, albumin, hematocrit and percent lymphocytes) was constructed. In the test set, the area under ROC curve (AUC) of the CART model was 0.88 [95% confidence interval (95% CI), 0.87-0.90] for detecting CRC. At the cutoff yielding 99.0% specificity, this model's sensitivity was 62.2% (95% CI, 58.1%-66.2%), thereby achieving a 63-fold enrichment of CRC cases. We validated the robustness of the method across subsets of test set with diverse CRC incidences, aging rates, genders ratio, distributions of tumor stages and locations, and data sources. Importantly, CART-based screening had the higher positive predictive value (1.6%) than fecal immunochemical test (0.3%).

Conclusions

As an alternative approach for the early detection of CRC, this study provides a low-cost method using regular health examination data to identify high-risk individuals for CRC for further examinations. The approach can promote early detection of CRC especially in developing countries such as China, where annual health examination is popular but regular CRC-specific screening is rare.

Influence of Obesity and Metabolic Abnormalities on the Risk of Developing Colorectal Neoplasia

BACKGROUND

Obesity and metabolic syndrome are risk factors for colorectal neoplasia (CRN). However, the association between metabolically healthy obese (MHO) or metabolically unhealthy non-obese (MUNO) status and the risk of CRN remains unclear.

AIMS

We aimed to elucidate the association between MHO or MUNO status and the risk of CRN.

METHODS

A total of 139,023 asymptomatic subjects who underwent a primary screening colonoscopy were categorized into 4 groups according to obesity and metabolic status: metabolically healthy non-obese (MHNO), MHO, MUNO, and metabolically unhealthy obese (MUO).

RESULTS

Mean participant age was 41.0 years, and the proportion of men was 65.3%. Among men, the risk of overall CRN increased in MHO (adjusted odds ratio [AOR] 1.22, 95% confidence intervals [CI] 1.12-1.33), MUNO (AOR 1.25, 95% CI 1.18-1.31), and MUO groups (AOR 1.47, 95% CI 1.40-1.54) compared with the MHNO group, whereas the risk of advanced CRN (ACRN) increased in MUNO (AOR 1.16, 95% CI 1.002-1.33) and MUO groups (AOR 1.49, 95% CI 1.31-1.70), but not in the MHO group (AOR 0.92, 95% CI 0.70-1.21). Moreover, among non-obese men, the risk of overall CRN and ACRN linearly increased with an increasing number of metabolic abnormalities. However, among women, only the MUO group had an increased risk of overall CRN (AOR 1.34, 95% CI 1.21-1.47) and no other significant associations were observed.

CONCLUSIONS

Poor metabolic health, regardless of obesity, is an independent risk factor for CRN in men. Our results suggest that men with metabolic abnormalities should be considered as a high-risk group for colorectal cancer, even if they are not obese.

Intestinal microbiota, chronic inflammation, and colorectal cancer

In addition to genetic and epigenetic factors, various environmental factors, including diet, play important roles in the development of colorectal cancer (CRC). Recently, there is increasing interest in the intestinal microbiota as an environmental risk factor for CRC, because diet also influences the composition of the intestinal microbiota. The human intestinal microbiota comprises about 100 trillion microbes. This microbiome thrives on undigested dietary residues in the intestinal lumen and produces various metabolites. It is well known that the dietary risk factors for CRC are mediated by dysbiosis of the intestinal microbiota and their metabolites. In this review, we describe the bacterial taxa associated with CRC, including Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, Escherichia coli, and butyrate-producing bacteria. We also discuss the host-diet interaction in colorectal carcinogenesis.

Knowledge and Awareness of Colorectal Cancer Early Warning Signs and Risk Factors among University Students in Jordan

In the present study, we aimed to assess the level of awareness regarding CRC warning signs and risk factors among undergraduate students. A cross-sectional survey using standardized questionnaire developed by the Cancer Research Center in the UK was carried out in three different public universities in Jordan including Jordan University of Science and Technology, Yarmouk University, and AL al-Bayt University over a 5-month period. Volunteers were asked about their knowledge regarding CRC symptoms, risk factors, and their behaviors regarding seeking medical advice. Findings revealed that response rate was 80.1%. Vast majority of responders were female (70.9%) and 18.2% of them were studying medical-related specialties. Regarding CRC symptoms, 14.3% of responders experienced poor knowledge, 52.9% have fair knowledge, and 32.8% have good knowledge. Abdominal pain was the most recognized warning signs where 70.8% of responders could recall it. In addition, risk factors awareness was lower than warning signs awareness. About 36.1% of responders have poor knowledge, 47.4% had fair knowledge, and 16.5% had good knowledge. Unhealthy diet was the most recognized risk factor where 32.3% of responders could recall it. Moreover, females were more aware regarding CRC symptoms. Similar findings were obtained for participants who were aged 20 years or more and for those who had previous experience of cancer. Students who were studying medical-related specialties were more aware of both CRC symptoms and risk factors than those who studying other specialties. Furthermore, regarding time to seek medical attention we found that 60.6% of volunteers would seek medical advice within 1 week of noticing CRC symptoms and 12% would seek it within 2 weeks. The mean duration for seeking medical advice was found to be 1.9 weeks. University students' awareness level of CRC is poor, and therefore, extended attention should be attempted to enhance the awareness of CRC via continuous education programs, lectures, or campaigns to encourage the early detection CRC.

Effectiveness of a Tailored Colorectal Cancer Educational Seminar in Enhancing the Awareness, Knowledge, and Behavior of Korean Americans Living in the Los Angeles Koreatown Area

BACKGROUND

Improving rates of colorectal cancer (CRC) screening can reduce CRC-related mortality, which is estimated to cause about 50,630 deaths in the U.S. by the end of 2018. There is a noted increasing prevalence of CRC among Korean Americans. Although CRC screening has been widely implemented, Korean Americans over the age of 50 have the lowest rates of proper CRC screening, compared to those of other Asian ethnicities. Barriers, such as language and culture, may be making participation in screening procedures difficult for those with immigrant backgrounds. Thus, this study aimed to determine whether proper CRC education can enhance awareness, knowledge, and behavior in screening among Korean Americans living in the Los Angeles Koreatown area.

DESIGN

This study was conducted among 100 self-identified Korean Americans between the ages of 45-75, who voluntarily participated in this study through local community outreach from January to June 2018. Educational brochures were provided for those in the control group, while those in the intervention group attended an additional short educational seminar. All participants were asked to complete a questionnaire after, and data were collected on site.

RESULTS

We found that intervention had a significant effect on awareness regarding colorectal polyps (OR (odds ratio): 22.47; 95% CI: 6.42-78.62; p-value <0.001) and fecal occult blood tests (FOBTs)/stool blood test (OR, 245.37; 95% CI: 34.55-1742.75; p-value <0.001). Willingness for CRC screening in following 6 months significantly increased (OR: 87.17; 95% CI: 19.01-399.63; p-value <0.001). Knowledge on options for CRC screening (OR: 126.63; 95% CI: 23.61-679.07; p-value <0.001) and stool blood tests (OR: 157.17; 95% CI: 18.02-1370.41; p-value <0.001) were significantly enhanced. In additional univariate analysis, we found that Korean Americans with higher level of education, birthplace in US or better general health showed better CRC awareness or knowledge.

CONCLUSION

There is a significant gap in our knowledge and understanding of the contributing factors that may be leading to low CRC screening rates in Korean Americans. This study suggests that well-tailored educational seminars can overcome certain barriers to screening and improve CRC knowledge and awareness, which is critical to achieving greater screening compliance. Our findings provide important references for designing effective strategies to increasing CRC screening rates among Korean Americans.

The risk of colorectal neoplasia can be different according to the types of family members affected by colorectal cancer

BACKGROUND AND AIM

A family history of colorectal cancer (CRC) is an important risk factor for CRC, but more detailed data are needed to prepare effective screening guidelines. We aimed to evaluate the risk of colorectal neoplasia (CRN) among individuals with different relatives affected by CRC (the first-degree relatives [FDRs] or the second-degree relatives or the first cousins) and to assess the effects of family histories according to age groups (30-39, 40-49, and ≥ 50 years).

METHODS

A cross-sectional study was performed on 98 562 asymptomatic examinees aged ≥ 30 years who underwent colonoscopy as part of a health checkup.

RESULTS

Mean age of the study population was 41.4 years, and the prevalence of CRN was 15.7%. Participants with ≥ 1 FDRs and ≥ 2 FDRs affected by CRC had a higher risk of CRN than those with no family history of CRC, while those with ≥ 1 second-degree relatives or first cousins affected did not. In the 30-39 and 40-49 years age groups, a family history of CRC in parents was a risk factor for CRN and advanced CRN, but not in siblings. By contrast, in the ≥ 50 age group, participants with affected siblings (reference group) had a significantly higher risk for advanced CRN than those with affected parents (adjusted odds ratio; 95% confidence interval: 0.39; 0.16-0.94 in father and 0.43; 0.18-0.995 in mother).

CONCLUSIONS

The risk of CRN can be different according to the types of family members affected, and the impact of such family histories can be different according to age.

Monitoring colorectal cancer following surgery using plasma circulating tumor DNA

Postoperative monitoring for patients with colorectal cancer (CRC) requires sensitive biomarkers that are associated with medical response and adjuvant therapy following surgery. Conventional tumor biomarkers [including carcinoembryonic antigen (CEA), CA19-9 and CA125] are widely used, but none of the markers provide high sensitivity or specificity. Previous studies indicated that circulating tumor DNA (ctDNA) is useful for postoperative monitoring of patients with cancer. However, the majority of previous studies involved patients with lung cancer, and therefore further studies are required which investigate patients with CRC. The present study enrolled 11 patients with CRC. All patients underwent surgery, and a number of patients were treated with postoperative chemotherapy. Tumor tissues and serial blood samples were collected from each patient, and somatic mutations of each sample were obtained using next-generation sequencing. The mutation landscape and dynamic changes in mutations for each patient were analyzed, and these results were compared with the changes of CEA levels. A number of driver genes were selected, including tumor protein P53 (TP53), APC and KRAS, to monitor the postoperative outcome of the 11 patients with CRC. Driver mutations were detected in preoperative plasma in 7 patients, with markedly decreased mutation rates detected in postoperative plasma compared with preoperative plasma. Driver mutations were not detected in 4 patients in the preoperative or postoperative plasma. In 1 patient with metastatic rectal cancer, the rate of TP53 mutation increased from 8.95 (preoperative) to 71.4% (postoperative), and a new phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α mutation emerged. This patient succumbed to mortality six months following surgery, however there were no marked changes in CEA levels during periodic detection of CEA levels. In summary, ctDNA has a high sensitivity and specificity in prediction of the prognosis of patients with CRC.

Clinical risk stratification model for advanced colorectal neoplasia in persons with negative fecal immunochemical test results

OBJECTIVES

The fecal immunochemical test (FIT) has low sensitivity for detecting advanced colorectal neoplasia (ACRN); thus, a considerable portion of FIT-negative persons may have ACRN. We aimed to develop a risk-scoring model for predicting ACRN in FIT-negative persons.

MATERIALS AND METHODS

We reviewed the records of participants aged ≥40 years who underwent a colonoscopy and FIT during a health check-up. We developed a risk-scoring model for predicting ACRN in FIT-negative persons.

RESULTS

Of 11,873 FIT-negative participants, 255 (2.1%) had ACRN. On the basis of the multivariable logistic regression model, point scores were assigned as follows among FIT-negative persons: age (per year from 40 years old), 1 point; current smoker, 10 points; overweight, 5 points; obese, 7 points; hypertension, 6 points; old cerebrovascular attack (CVA), 15 points. Although the proportion of ACRN in FIT-negative persons increased as risk scores increased (from 0.6% in the group with 0-4 points to 8.1% in the group with 35-39 points), it was significantly lower than that in FIT-positive persons (14.9%). However, there was no statistical difference between the proportion of ACRN in FIT-negative persons with ≥40 points and in FIT-positive persons (10.5% vs. 14.9%, P = 0.321).

CONCLUSIONS

FIT-negative persons may need to undergo screening colonoscopy if they clinically have a high risk of ACRN. The scoring model based on age, smoking habits, overweight or obesity, hypertension, and old CVA may be useful in selecting and prioritizing FIT-negative persons for screening colonoscopy.

Bufalin suppresses colorectal cancer cell growth through promoting autophagy in vivo and in vitro

Specific groups in Asia, including the Chinese, are more susceptible to colorectal cancer (CRC). The best strategy for anticancer drug action is to induce cancer cell apoptosis and autophagy. Bufalin is a potent inducer of apoptosis in some human cancer cell lines, but bufalin has barely been evaluated in colorectal cancer cells as a potent autophagy inducing agent. The aim of this study was to investigate the roles and interactions of bufalin in autophagy and the effects of the drug on human colorectal cancer. We applied bufalin and autophagy inhibitors (CQ and 3-MA) in LoVo cells to investigate their potential anticancer bioactivity under certain concentrations of bufalin to monitor autophagy and cell proliferation in vivo and in vitro. Bufalin induced autophagy of LoVo and inhibited proliferation of LoVo cells. Bufalin inhibited the expression of autophagy-related (ATG) proteins and tumor growth in vivo. Our studies identified that bufalin could potentially be a small molecule inhibitor for cancer therapy.

Specific groups in Asia, including the Chinese, are more susceptible to colorectal cancer (CRC).

Mutations in KRAS codon 12 predict poor survival in Chinese patients with metastatic colorectal cancer

KRAS mutations serve a function in tumorigenesis of colorectal cancer (CRC) and guide the use of targeted drugs. However, the prognostic value of KRAS mutations and their subtypes remain controversial. The present study aimed to investigate the correlations between KRAS mutations and clinicopathological characteristics, and their prognostic significance in Chinese patients with metastatic CRC (mCRC). A total of 135 patients with mCRC were analyzed for KRAS mutations. Mutations in codon 12 and 13 were identified in 45 (33.3%) patients. Only 3 patients harbored a mutation of V600E. Compared with male patients, KRAS codon 12 mutations were more common in female patients (P<0.05). KRAS codon 13 mutations tended to arise in right-sided compared with left-sided colon cancer (P<0.05). Survival analysis was performed in 101 patients receiving primary tumor resection. Compared with KRAS codon 12 wild-type, codon 12 mutations were markedly correlated with a poorer survival (log-rank P=0.002). No prognostic significance was revealed in codon 13 mutations. In univariate analysis, mortality risk was significantly increased by subtypes of G12D and G12V [hazard ratio (HR) =2.313, 95% confidence interval (CI) =1.069-5.004, P=0.03; HR=2.621, 95% CI=1.057-6.497, P=0.04, respectively]. The results of the present study suggested that codon 12 mutations, in particular G12D and G12V, predicted a negative prognosis in Chinese patients with mCRC. These findings require further confirmation via prospective studies with larger samples.

Colorectal cancer screening with the fecal immunochemical test in persons aged 30 to 49 years: focusing on the age for commencing screening

BACKGROUND AND AIMS

The fecal immunochemical test (FIT) can be an alternative screening method for colorectal cancer in individuals aged <50 years. However, debate continues concerning the age at which commencing FIT is beneficial.

METHODS

We reviewed the records of participants who had undergone a colonoscopy and FIT as part of a comprehensive health screening program. To determine the age for commencing screening via FIT, participants aged <50 years were classified into 4 age subgroups as follows: 30 to 34, 35 to 39, 40 to 44, and 45 to 49 years. Average-risk participants aged 50 to 59 years comprised the control group.

RESULTS

We analyzed the data of 19,808 participants aged 30 to 49 years and 2233 average-risk participants aged 50 to 59 years. The advanced colorectal neoplasia (ACRN) prevalence in average-risk participants aged 50 to 59 years was 3.8%. In the subgroups of FIT-positive participants, the proportion of participants with ACRN was 2.9% (95% confidence interval [CI], 1.1%-7.4%), 9.7% (95% CI, 5.8%-15.6%), 7.7% (95% CI, 4.5%-12.8%), and 14.6% (95% CI, 8.7%-23.5%) in groups 30 to 34, 35 to 39, 40 to 44, and 45 to 49 years, respectively. The proportion of FIT-positive participants with ACRN in the groups aged 35 to 39, 40 to 44, and 45 to 49 years was higher than that in average-risk participants aged 50 to 59 years (P = .001, P = .014, and P < .001, respectively), whereas that in FIT-positive participants aged 30 to 34 years was not (P = .566).

CONCLUSION

FIT-positive individuals aged 35 to 49 years had a higher risk of ACRN compared with average-risk individuals aged 50 to 59 years. FIT-positive individuals aged 35 to 49 years may benefit from screening colonoscopy, thus justifying the possibility of commencing FIT from age 35 years.

Association Between Low Relative Muscle Mass and the Risk of Colorectal Neoplasms

GOALS

We aimed to ascertain whether low relative muscle mass is associated with colorectal neoplasm (CRN) risk.

BACKGROUND

CRN and sarcopenia have common pathophysiological mechanisms such as insulin resistance, chronic inflammation, and physical inactivity. However, the direct relationship between the 2 diseases has not been investigated.

STUDY

A cross-sectional study was performed on 81,885 examinees who underwent colonoscopy as part of a health check-up. The skeletal muscle mass index (SMI) [SMI (%)=total skeletal muscle mass (kg)/body weight (kg)×100] was estimated using a bioelectrical impedance analyzer.

RESULTS

Of 81,885 participants, 52,272 were men and 29,613 were women. The prevalence rate of CRN in subjects in quartiles 1, 2, 3, and 4 of SMI was 22.8%, 20.5%, 18.2%, and 14.9% among men, and 14.8%, 11.8%, 9.7%, and 8.2% among women, respectively (Ptrend<0.001). In a multivariable-adjusted model, the inverse associations between SMI and prevalence of CRN remained significant. In men, the adjusted odds ratios (95% confidence interval) for overall CRN comparing each of the quartiles 1, 2, and 3 of SMI with the quartile 4 were 1.41 (1.32 to 1.52), 1.24 (1.16 to 1.33), and 1.12 (1.04 to 1.20), and those for advanced CRN were 1.64 (1.34 to 2.01), 1.38 (1.12 to 1.70), and 1.12 (0.90 to 1.40), respectively (all Ptrend<0.001). In women, those for overall CRN were 1.18 (1.04 to 1.33), 1.15 (1.01 to 1.30), and 1.05 (0.93 to 1.20), respectively (Ptrend=0.006).

CONCLUSIONS

Relative muscle mass was negatively associated with CRN prevalence, supporting low muscle mass as an independent risk factor for CRN. Our results may provide a novel insight into the mechanisms linking low muscle mass and CRN.

Knowledge Attitude and Practice of Colorectal Cancer among School Teachers in Al-Ahsa Saudi Arabia

Background:

Colorectal cancer is the second leading cause of deaths among cancers affecting both men and women in the United States. Annually, about 140,000 Americans are diagnosed with colorectal cancer, and more than 50,000 people die from it. In Saudi Arabia, this cancer ranks first among men and third among women. Nevertheless, this type of cancer is one of the most preventable types of cancer.

Objective:

The aim of this study was to assess the level of colorectal cancer awareness among teaching staff (educators) in Al-Ahsa, Saudi Arabia.

Methodology:

The current cross-sectional study was conducted in teaching staff in Al-Ahsa, Eastern province, Saudi Arabia, from February 2017 to May 2017. A self-administered questionnaire was used for data collection and SPSS (version 24) was run for data analysis.

Result:

A total of 367 teachers (165 males and 202 females) were recruited for the present investigation. The participants aged from 25 to 55 years and most of them were married (87%). The majority had inadequate knowledge about risk factors of colon cancer. No significant difference was observed between people living in urban and rural areas regarding knowledge of risk factors for colorectal cancer (p≥0.05). Concerning colorectal cancer screening tests, 39% of men and 42% of women were unaware; although, 12.8% of the participants reported a positive family history of colon cancer. In General, participants with higher education level had higher level of awareness on colon cancer.

Conclusions:

The findings of this study demonstrated that most of educators, including men and women are unaware of colon cancer risk factor. Furthermore, their knowledge of colon cancer signs, symptoms, and screening methods were inadequate. With respect to our findings, enhancement of colon cancer knowledge among educators is recommended using health education campaign in Al-Ahsa.

Quantitation of faecal Fusobacterium improves faecal immunochemical test in detecting advanced colorectal neoplasia

OBJECTIVE

There is a need for an improved biomarker for colorectal cancer (CRC) and advanced adenoma. We evaluated faecal microbial markers for clinical use in detecting CRC and advanced adenoma.

DESIGN

We measured relative abundance of Fusobacterium nucleatum (Fn), Peptostreptococcus anaerobius (Pa) and Parvimonas micra (Pm) by quantitative PCR in 309 subjects, including 104 patients with CRC, 103 patients with advanced adenoma and 102 controls. We evaluated the diagnostic performance of these biomarkers with respect to faecal immunochemical test (FIT), and validated the results in an independent cohort of 181 subjects.

RESULTS

The abundance was higher for all three individual markers in patients with CRC than controls (p<0.001), and for marker Fn in patients with advanced adenoma than controls (p=0.022). The marker Fn, when combined with FIT, showed superior sensitivity (92.3% vs 73.1%, p<0.001) and area under the receiver-operating characteristic curve (AUC) (0.95 vs 0.86, p<0.001) than stand-alone FIT in detecting CRC in the same patient cohort. This combined test also increased the sensitivity (38.6% vs 15.5%, p<0.001) and AUC (0.65 vs 0.57, p=0.007) for detecting advanced adenoma. The performance gain for both CRC and advanced adenoma was confirmed in the validation cohort (p=0.0014 and p=0.031, respectively).

CONCLUSIONS

This study identified marker Fn as a valuable marker to improve diagnostic performance of FIT, providing a complementary role to detect lesions missed by FIT alone. This simple approach may improve the clinical utility of the current FIT, and takes one step further towards a non-invasive, potentially more accurate and affordable diagnosis of advanced colorectal neoplasia.

Gender Differences in Factors Associated With Colorectal Cancer Screening: A National Cross-Sectional Study in Korea

The rate of and factors influencing colorectal cancer screening differs by gender. We aimed to determine the behaviors for and predict the factors influencing self-reported colorectal cancer screening in Korean adults. Secondary analysis was performed with data from the cross-sectional 2012 Community Health Survey. We examined the relationship between gender and self-reported screening using data for 115 045 adults aged ≥50 years; 62.4% of men and 65.5% of women underwent colorectal cancer screening. In the multivariate logistic regression analysis, men with private insurance and who attended regular health checkups were more likely to undergo screening; men who were employed, ate salty food, were older, or smoked were less likely. Women with private insurance, who lived with a spouse, were more educated, were housewives, or attended regular health checkups were more likely, and older women were less likely to undergo screening. Therefore, gender-specific interventions are needed to encourage colorectal cancer screening.