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Colorectal cancer (CRC) remains the second most common cause of cancer-related mortality worldwide, necessitating advancements in early detection and innovative treatment strategies. MicroRNAs (miRNAs), small non-coding RNAs involved in gene regulation, have emerged as crucial players in the pathogenesis of CRC. This review synthesizes the latest findings on miRNA deregulated in precancerous lesions and in CRC. By examining the deregulation patterns of miRNAs across different stages of CRC development, this review highlights their potential as diagnostic tools. We specifically analyse the roles and diagnostic relevance of four miRNAs—miR-15b, miR-21, miR-31, and miR-146a—that consistently exhibit altered expression in CRC. The current knowledge of their role in key oncogenic pathways, drug resistance, and clinical relevance is discussed. Despite challenges posed by the heterogeneity of the research findings on miRNA deregulation and their role in CRC, integrating miRNA diagnostics into current screening methods holds promise for enhancing personalized medicine approaches. This review emphasizes the transformative potential of miRNAs in CRC diagnosis, paving the way for improved patient outcomes and novel therapeutic paradigms. [ABSTRACT FROM AUTHOR]

Background: Colon capsule endoscopy (CCE) has gained momentum as an alternative modality for the investigation of the lower gastrointestinal tract. Of the few challenges that remain, the comparison and – eventually – matching of polyps at different timestamps leads to the potential for double reporting and can contribute to false-positive findings and inaccuracies. With the impending artificial intelligence integration, the risk of double reporting the same polyp due to the lack of information on spatial orientation underscores the necessity for establishing criteria for polyp matching. Objectives: This RAND/University of California, Los Angeles (modified Delphi) process aims to identify the key factors or components used to match polyps within a CCE video. This involves exploring the attributes of each factor to create comprehensive polyp-matching criteria based on international expert consensus. Design: A systematic qualitative study using surveys. Methods: A panel of 11 international CCE experts convened to assess a survey comprised of 60 statements. Participants anonymously rated statement appropriateness on a 1–9 scale (1–3: inappropriate, 4–6: uncertain and 7–9: appropriate). Following a virtual group discussion of the Round 1 results, a Round 2 survey was developed and completed before the final analysis. Results: The factors that were agreed to be essential for polyp matching include (1) timestamp, (2) polyp localization, (3) polyp vascular pattern, (4) polyp size, (5) time interval of the polyp appearance between the green and yellow camera, (6) surrounding tissue, (7) polyp morphology and (8) polyp surface and contour. When five or more factors are satisfied, it was agreed that the comparing polyps are likely the same polyp. Conclusion: This study has established the first complete criteria for polyp matching in CCE. While it might not provide a definitive solution for matching difficult, small and common polyps, these criteria serve as a framework to guide and facilitate the process of polyp-matching. Plain language summary: Creating criteria and standards for matching polyps (abnormal growth in the bowels) on colon capsule video analysis: an international expert agreement using the RAND (modified Delphi process) process Background: Doctors often use colon capsule endoscopy (CCE), a high-tech capsule with two cameras, to record and check for diseases in the small and large bowels as the capsule travels through the intestines. One of the most common conditions in the large bowel is polyps, which are abnormal growths in the lining of the bowel. Comparing and matching polyps in the same video from the capsule can be tricky as they look very similar, leading to the possibility of incorrectly reporting the same polyp twice or more. This can lead to wrong results and inaccuracies. The literature did not have any criteria or standards for matching polyps in CCE before. Aim: Using the RAND/UCLA (modified Delphi) process, this study aims to identify the key factors or components used to match polyps within a CCE video. The goal is to explore each factor and create complete criteria for polyp matching based on the agreement from international experts. Method: A group of 11 international CCE experts came together to evaluate a survey with 60 statements. They anonymously rated each statement on a scale from 1 to 9 (1-3: inappropriate, 4-6: uncertain, and 7-9: appropriate). After discussing the Round 1 results virtually, a Round 2 survey with the same but revised questions was created and completed before the final analysis of their agreement. Results: The main factors for matching polyps are 1) the timing when the polyp was seen, 2) where it is in the bowel, 3) its blood vessel pattern, 4) size, 5) the timing of its appearance between cameras, 6) surrounding tissue features, 7) its shape, and 8) surface features. If five or more of these factors match, the compared polyps are likely the same. Conclusion: This study establishes the first complete criteria for matching polyps in CCE. While it may not provide a definitive solution for matching challenging and small polyps, these criteria serve as a guide to help and make the process of polyp matching easier. [ABSTRACT FROM AUTHOR]

Objective: To determine the quality of colonoscopy in terms of adenoma detection rate in the existing local settings. Study Design: Cross-sectional study. Setting: Department of Gastroenterology, Liaquat National Hospital, Karachi, Pakistan. Period: February 2022 to August 2022. Methods: We analyzed patients having age 18 years or older, of any gender, and who had colonoscopy indications and were required to have a screening colonoscopy for diagnostic purposes. The number of procedures with at least one polyp or adenoma was classified as the polyp detection rate (PDR) and adenoma detection rate (ADR). Result: Total 210 patients were enrolled into the study with median age of 41.5 (29.8-56.3) years and majority were males (n=46, 69.5%). The most frequent indication for colonoscopy was constipation (n=72, 34.3%) followed by bleeding (n=78, 37.1%), chronic diarrhea (n=36, 17.1%), both constipation and diarrhea (n=21, 10%) and altered bowel habits (n=3, 1.4%). PDR and ADR were 16.2% (n=34) and 10% (n=21) respectively. Age was significantly higher among patients who were found to have polyp (p<0.001) and adenomas (p<0.001). Frequency of polyps (p=0.010) and adenomas (p=0.007) were significantly higher in male patients. Conclusion: The current research discovered a low rate of adenoma detection in people receiving colorectal cancer screening, and it did not meet the quality benchmarks that have been associated with higher rates of early diagnosis and cancer prevention. [ABSTRACT FROM AUTHOR]

Among the world’s most common cancers, colorectal cancer is the third most severe form of cancer. Early polyp detection reduces the risk of colorectal cancer, vital for effective treatment. Artificial intelligence methods such as deep learning have emerged as leading techniques for polyp image segmentation that have gained success in advancing medical image diagnosis. This study aims to provide a review of the most recent research studies that have used deep learning methods and models for polyp segmentation. A comprehensive review of deep learning-based image segmentation models is provided based on existing research studies that are essential for polyp segmentation. Convolutional neural networks, encoder–decoder models, recurrent neural networks, attention-based models, and generative models were the most popular deep learning models which play an essential role in detecting and diagnosing polyp at an early stage. Additionally, this study also aims to provide a detailed classification of prominently used polyp image and video datasets. The evaluation metrics for assessing the effectiveness of different methods, models, and techniques are identified and discussed. A statistical analysis of deep learning models based on polyp datasets and performance metrics is presented, with a discussion of future research trends and limitations. [ABSTRACT FROM AUTHOR]

In mice, Nkx2-3 homeodomain transcription factor defines the vascular specification of secondary and tertiary lymphoid tissues of the intestines. In human studies, polymorphisms in NKX2-3 have been identified as a susceptibility factor in inflammatory bowel diseases, whereas in mice, its absence is associated with protection against experimental colitis and enhanced intestinal epithelial proliferation. Here, we investigated the expression of NKX2-3 in normal, polyp, and adenocarcinoma human colon samples using immunohistochemistry and quantitative morphometry, correlating its expression with endothelial and mesenchymal stromal markers. Our results revealed that the expression of NKX2-3 is regionally confined to the lamina propria and lamina muscularis mucosae, and its production is restricted mostly to endothelial cells and smooth muscle cells with variable co-expression of CD34, alpha smooth muscle antigen (αSMA), and vascular adhesion protein-1 (VAP-1). The frequency of NKX2-3-positive cells and intensity of expression correlated inversely with aging. Furthermore, in most colorectal carcinoma samples, we observed a significant reduction of NKX2-3 expression. These findings indicate that the NKX2-3 transcription factor is produced by both endothelial and non-endothelial tissue constituents in the colon, and its expression changes during aging and in colorectal malignancies. (J Histochem Cytochem XX: XXX–XXX, XXXX) [ABSTRACT FROM AUTHOR]

Simple Summary: There has been an exponential rise in the availability of artificial intelligence systems in endoscopy in recent years. As a result, maintaining an informed understanding of the utility and efficacy of existing systems has become increasingly complex. This review aims to summarise the expanse of research in this area to guide proceduralists in making informed decisions regarding the use of artificial intelligence in colonoscopy. It focuses primarily on the application of artificial intelligence for the detection and characterisation of colorectal polyps in order to improve the efficacy of colorectal cancer screening and prevention. Colorectal cancer remains a leading cause of cancer-related morbidity and mortality worldwide, despite the widespread uptake of population surveillance strategies. This is in part due to the persistent development of 'interval colorectal cancers', where patients develop colorectal cancer despite appropriate surveillance intervals, implying pre-malignant polyps were not resected at a prior colonoscopy. Multiple techniques have been developed to improve the sensitivity and accuracy of lesion detection and characterisation in an effort to improve the efficacy of colorectal cancer screening, thereby reducing the incidence of interval colorectal cancers. This article presents a comprehensive review of the transformative role of artificial intelligence (AI), which has recently emerged as one such solution for improving the quality of screening and surveillance colonoscopy. Firstly, AI-driven algorithms demonstrate remarkable potential in addressing the challenge of overlooked polyps, particularly polyp subtypes infamous for escaping human detection because of their inconspicuous appearance. Secondly, AI empowers gastroenterologists without exhaustive training in advanced mucosal imaging to characterise polyps with accuracy similar to that of expert interventionalists, reducing the dependence on pathologic evaluation and guiding appropriate resection techniques or referrals for more complex resections. AI in colonoscopy holds the potential to advance the detection and characterisation of polyps, addressing current limitations and improving patient outcomes. The integration of AI technologies into routine colonoscopy represents a promising step towards more effective colorectal cancer screening and prevention. [ABSTRACT FROM AUTHOR]

Simple Summary: Endoscopic resection (ER) of large non-pedunculated colorectal polyps ≥ 20 mm (LNPCPs) is safe, effective and the preferred treatment compared to surgery. Predicted histopathology of an LNPCP based on size, morphology, granularity, pit pattern and location in the colo-rectum is essential when deciding upon resection technique. Post resection defect inspection and adjuvant techniques, such as thermal ablation of the margin, have been demonstrated to reduce recurrence rates. Follow-up surveillance colonoscopy can accurately identify recurrence. Endoscopic treatment of recurrence is effective. Large non-pedunculated colorectal polyps ≥20 mm (LNPCPs) comprise approximately 1% of all colorectal polyps. LNPCPs more commonly contain high-grade dysplasia, covert and overt cancer. These lesions can be resected using several means, including conventional endoscopic mucosal resection (EMR), cold-snare EMR (C-EMR) and endoscopic submucosal dissection (ESD). This review aimed to provide a comprehensive, critical and objective analysis of ER techniques. Evidence-based, selective resection algorithms should be used when choosing the most appropriate technique to ensure the safe and effective removal of LNPCPs. Due to its enhanced safety and comparable efficacy, there has been a paradigm shift towards cold-snare polypectomy (CSP) for the removal of small polyps (<10 mm). This technique is now being applied to the management of LNPCPs; however, further research is required to define the optimal LNPCP subtypes to target and the viable upper size limit. Adjuvant techniques, such as thermal ablation of the resection margin, significantly reduce recurrence risk. Bleeding risk can be mitigated using through-the-scope clips to close defects in the right colon. Endoscopic surveillance is important to detect recurrence and synchronous lesions. Recurrence can be readily managed using an endoscopic approach. [ABSTRACT FROM AUTHOR]

Simple Summary: Population-based colorectal cancer screening programs have increased the incidence of pT1 colorectal cancer. These incipient invasive cancers have a very good prognosis and can be treated locally, but more than half of these cases are treated with surgery due to the presence of histological criteria associated with the presence of lymph node metastasis. Only 2–10.5% of those have lymph node metastasis, and the residual tumor is present in less than 20%, leading to overtreatment. Additional surgery increases the risk of morbidity and mortality, and recent evidence shows that it may not impact the prognosis for pT1. This article reviews the limitations of histological evaluation, treatment modalities and prognosis, adverse effects, and new possibilities of endoscopic treatment. Implementation of population-based colorectal cancer screening programs has led to increases in the incidence of pT1 colorectal cancer. These incipient invasive cancers have a very good prognosis and can be treated locally, but more than half of these cases are treated with surgery due to the presence of histological high-risk criteria. These high-risk criteria are suboptimal, with no consensus among clinical guidelines, heterogeneity in definitions and assessment, and poor concordance in evaluation, and recent evidence suggests that some of these criteria considered high risk might not necessarily affect individual prognosis. Current criteria classify most patients as high risk with an indication for additional surgery, but only 2–10.5% have lymph node metastasis, and the residual tumor is present in less than 20%, leading to overtreatment. Patients with pT1 colorectal cancer have excellent disease-free survival, and recent evidence indicates that the type of treatment, whether endoscopic or surgical, does not significantly impact prognosis. As a result, the protective role of surgery is questionable. Moreover, surgery is a more aggressive treatment option, with the potential for higher morbidity and mortality rates. This article presents a comprehensive review of recent evidence on the clinical management of pT1 colorectal cancer. The review analyzes the limitations of histological evaluation, the prognostic implications of histological risk status and the treatment performed, the adverse effects associated with both endoscopic and surgical treatments, and new advances in endoscopic treatment. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC)-related mortality can be reduced through screening and early detection. The aim of any CRC screening program is to detect as many adenomas/polyps in the early stage as possible and hence, adenoma detection rate (ADR) is a key quality indicator of colonoscopy. Various methods and techniques have been studied and developed over the years to improve the quality of colonoscopy and thereby increase ADR. This ranges from use of various regimens to improve bowel preparation, defining an optimum colonoscope withdrawal time for the operator, distal attachment caps, use of different wavelength of light, colonoscope with increased degree of view to the use of modern-day artificial intelligence to improve ADR. Of all the various measures, use of distal attachment device seems an easy, cheap and readily usable technique to increase real-time ADR. A variety of such devices have been evaluated over time starting from simple transparent caps, EndoRings, Endocuff to Endocuff Vision for their effectiveness. In this review, we have provided a brief description of the various available distal attachment devices and a detailed technical overview of Endocuff and its modification the Endocuff Vision.

Background: Long intergenic non-coding RNA 460 (LINC00460) as a potential oncogene and Annexin A2 (ANXA2) as a promoter in different cancer progression processes was considered. A significant relationship between the LINC00460 and ANXA2 has been recently discovered in colorectal cancer (CRC). Therefore, defining molecular biomarkers accompanied by lesion histopathologic features can be a suggestive prognostic biomarker in precancerous polyps. This study aimed to investigate the elusive expression pattern of ANXA2 and LINC00460 in polyps. Materials and methods: The construction of the co-expression and correlation network of LINC00460 and ANXA2 was plotted. LINC00460 and ANXA2 expression in 40 colon polyps was quantified by reverse transcription-real-time polymerase chain reaction. The receiver operating characteristic (ROC) curve was designed for distinguishing the high-risk precancerous lesion from the low-risk. Further, bioinformatics analysis was applied to find the shared MicroRNA-Interaction-Targets (MITs) between ANXA2 and LINC00460, and the associated pathways. Results: ANXA2 has a high co-expression rank with LINC00460 in the lncHUB database. Overexpression of ANXA2 and LINC00460 was distinguished in advanced adenoma polyps compared to the adjacent normal samples. The estimated AUC for ANXA2 and LINC00460 was 0.88 − 0.85 with 93%-90% sensitivity and 81%-70% specificity. In addition, eight MITs were shared between ANXA2 and LINC00460. Enrichment analysis detected several GO terms and pathways, including HIF-1α associated with cancer development. Conclusion: In conclusion, the expression of the ANXA2 and LINC00460 were significantly elevated in pre-cancerous polyps, especially in high-risk adenomas. Collectively, ANXA2 and LINC00460 may be administered as potential prognostic biomarkers in patients with a precancerous large intestine lesion as an alarming issue. [ABSTRACT FROM AUTHOR]

Simple Summary: Although alterations of intestinal bacterial microbiota have been admitted as playing one of the most important roles in colorectal carcinogenesis, the links between microbiota compositional changes and premalignant colorectal polyps have still not been fully examined. Furthermore, there is a lack of knowledge in terms of defining the precise differences and the correct interpretation of tissue-derived and stool-based bacterial dysbiosis in patients with precancerous colorectal lesions. Thus, this systematic review aims, firstly, to assess whether and how the tissue-derived intestinal microbiota structure differs from the bacterial dysbiosis in fecal samples of patients with simple, advanced colorectal adenoma and carcinoma in situ, and, secondly, to propose the correct selection of each matrix in order to increase sampling accuracy and applicability in future microbiota studies and clinical practice. Alterations in gut microbiota play a pivotal role in the adenoma-carcinoma sequence. However, there is still a notable lack of the correct implementation of tissue and fecal sampling in the setting of human gut microbiota examination. This study aimed to review the literature and to consolidate the current evidence on the use of mucosa and a stool-based matrix investigating human gut microbiota changes in precancerous colorectal lesions. A systematic review of papers from 2012 until November 2022 published on the PubMed and Web of Science databases was conducted. The majority of the included studies have significantly associated gut microbial dysbiosis with premalignant polyps in the colorectum. Although methodological differences hampered the precise fecal and tissue-derived dysbiosis comparison, the analysis revealed several common characteristics in stool-based and fecal-derived gut microbiota structures in patients with colorectal polyps: simple or advanced adenomas, serrated lesions, and carcinomas in situ. The mucosal samples considered were more relevant for the evaluation of microbiota's pathophysiological involvement in CR carcinogenesis, while non-invasive stool sampling could be beneficial for early CRC detection strategies in the future. Further studies are required to identify and validate mucosa-associated and luminal colorectal microbial patterns and their role in CRC carcinogenesis, as well as in the clinical setting of human microbiota studies. [ABSTRACT FROM AUTHOR]

BACKGROUND: In Saudi Arabia, colorectal cancer (CRC) is the most common cancer in males and the third most common cancer in females. The current gold standard for colorectal cancer diagnosis is colonoscopy. Several concerns regarding the balance of ordering colonoscopy procedures for patients presenting with signs and symptoms. There are also several concerns regarding over-ordering the procedure when unnecessary. The current study aimed to evaluate the association between colorectal cancer and colonoscopic conditions in Saudi patients. METHODS: A 10-year cross-sectional study was conducted at Alnoor Specialty Hospital, Makkah, over the last ten years. Colonoscopy reports of patients were evaluated to identify the colonoscopy manifestations associated with mass, polyps, and bleeding. RESULTS: The current study evaluated 2158 cases admitted to the hospital for colonoscopic diagnosis. Results indicated that most of the patients were males (55.4%). Additionally, results showed a significant statistical association between tumor and bleeding, polyp, and hemorrhage. Moreover, it highlighted the association between polyps and bleeding, inflammation, and diverticulosis. CONCLUSION: CRC screening in Saudi Arabia is comprehensive; however, there are a few areas for improvement, including standardization of colorectal cancer pathology reporting to improve the health system's quality. Also, the current study identified conditions that are significantly associated with reported colon polyps and tumors, which could aid in stratifying patients selected for screening via colonoscopy. [ABSTRACT FROM AUTHOR]

Background and aims: Current studies have shown that polyp recurrence occurs after colonic adenomas polypectomy (AP), but the difference in recurrence risk between patients in patients older than 50 years and younger than 50 years has not been clearly studied. Methods: 490 patients after AP were enrolled in the study. The patients were classified according to age (<50 years old or ≥50 years old), and then further categorized according to the baseline adenoma characteristics: Group 1: 1-2 non-advanced adenomas (NAAs) 1-5 mm in size; Group 2: =3 NAAs, 1-5 mm; Group 3: 1-2 NAAs, 6-9 mm; Group 4: =3 NAAs, 6-9 mm; and Group 5: advanced adenomas. Results: During a mean follow-up interval of 2.52 years (2.51 years for =50 years old and 2.55 years for patients <50 years old), NAA recurrence was detected in 147 patients (30.0%). Overall, the hazard ratio (HR) for NAA recurrence after AP was higher in patients ≤50 years old than that in patients <50 years old (HR, 1.774, P = 0.003). For patients <50 years old, HRs (Group 2-5 vs. G1, respectively) for NAA recurrence were 0.744 (P = 0.773), 3.885 (P = 0.007), 5.337 (P = 0.003), and 3.334 (P = 0.015). For patients ≤50 years old, HRs (Group 2-5 vs. G1, respectively) for NAA recurrence were 1.033 (P = 0.965), 1.250 (P = 0.405), 2.252 (P = 0.015), and 1.887 (P = 0.009). For G1, the risk of NAA recurrence was significantly higher in patients ≤50 years old (HR, 2.932, P = 0.011) than that in patients <50 years old; for G2-G5, the risk was similar in the two age groups (P > 0.05). Conclusions: For patients <50 years old with less than 3 NAAs that are 1-5mm in size, the recurrence rate of NAA is less than that of patients ≤50 years old with the same index colonoscopy findings. When the adenomas are ≤5 mm, or their number exceeds 3, they have similar recurrence risk as that for patients ≤50 years old. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC)-related mortality can be reduced through screening and early detection. The aim of any CRC screening program is to detect as many adenomas/polyps in the early stage as possible and hence, adenoma detection rate (ADR) is a key quality indicator of colonoscopy. Various methods and techniques have been studied and developed over the years to improve the quality of colonoscopy and thereby increase ADR. This ranges from use of various regimens to improve bowel preparation, defining an optimum colonoscope withdrawal time for the operator, distal attachment caps, use of different wavelength of light, colonoscope with increased degree of view to the use of modern-day artificial intelligence to improve ADR. Of all the various measures, use of distal attachment device seems an easy, cheap and readily usable technique to increase real-time ADR. A variety of such devices have been evaluated over time starting from simple transparent caps, EndoRings, Endocuff to Endocuff Vision for their effectiveness. In this review, we have provided a brief description of the various available distal attachment devices and a detailed technical overview of Endocuff and its modification the Endocuff Vision. [ABSTRACT FROM AUTHOR]

Background: The association between intraductal papillary mucinous neoplasms (IPMNs) and colorectal cancer (CRC) and polyps is controversial. Objectives: To compare the prevalence of CRC and colorectal polyps among patients with IPMN and matched average risk individuals. Methods: A match cross-sectional historical study comparing colonoscopy findings of 310 patients with IPMN cysts who underwent at least one colonoscopy examination from 2004 through 2019, with 310 age- and gender-matched average risk participants who underwent a screening colonoscopy. CRC and polyps were assessed in both groups. The prevalence and odds ratio were calculated. Results: CRC was diagnosed in 16 of 310 patients with IPMN (5.2%), and at least one polyp was detected in 96 patients (31%). The prevalence of CRC was greater among patients with IPMN than in matched individuals [5.2% versus 1.3%, p = 0.012, prevalence odds ratio (POR) 4, confidence interval (CI) 1.29–16.44]. The overall prevalence of polyps was not higher among patients with IPMN than in matched individuals (31% versus 26.8%, p = 0.291, POR 1.22, CI 0.85–1.76). However, the prevalence of colorectal adenomas with high-grade dysplasia was higher in patients with IPMN than in matched individuals (4.2% versus 1%, p = 0.02, POR 4.33, CI, 1.19–23.7). The prevalence of large polyps (i.e. more than 20 mm in size) was also greater in patients with IPMN than in matched individuals (6.1% versus 1.9%, p = 0.011, POR 3.6, CI, 1.29–12.40). Conclusion: Patients with IPMN have a significantly higher prevalence of CRC and advanced polyps than the average risk population. In view of our findings, we suggest that once the diagnosis of IPMN is made, special consideration of CRC should be undertaken. [ABSTRACT FROM AUTHOR]

ObjectiveFor individuals with 1-2 small (

How metabolome changes influence the early process of colorectal cancer (CRC) development remains unknown. We conducted a 1:2 matched nested case–control study to examine the associations of pre-diagnostic plasma metabolome (profiled using LC–MS) with risk of CRC precursors, including conventional adenomas (n = 586 vs. 1141) and serrated polyps (n = 509 vs. 993), in the Nurses' Health Study (NHS) and NHSII. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). We used the permutation-based Westfall and Young approach to account for multiple testing. Subgroup analyses were performed for advanced conventional adenomas (defined as at least one adenoma of ≥ 10 mm or with high-grade dysplasia, or tubulovillous or villous histology) and high-risk serrated polyps that were located in the proximal colon or with size of ≥ 10 mm. After multiple testing correction, among 207 metabolites, higher levels of C36:3 phosphatidylcholine (PC) plasmalogen were associated with lower risk of conventional adenomas, with the OR (95% CI) comparing the 90th to the 10th percentile of 0.62 (0.48–0.81); C54:8 triglyceride (TAG) was associated with higher risk of serrated polyps (OR = 1.79, 95% CI: 1.31–2.43), and phenylacetylglutamine (PAG) was associated with lower risk (OR = 0.57, 95% CI:0.43–0.77). PAG was also inversely associated with advanced adenomas (OR = 0.57, 95% CI: 0.36–0.89) and high-risk serrated polyps (OR = 0.54, 95% CI: 0.32–0.89), although the multiple testing-corrected p value was > 0.05. Our findings suggest potential roles of lipid metabolism and phenylacetylglutamine, a microbial metabolite, in the early stage of colorectal carcinogenesis, particularly for the serrated pathway. [ABSTRACT FROM AUTHOR]

Background: Colonic masses are clinically important because some of them are malignant and others have a tendency to become malignant such as polyps. CT pneumocolon may have a role in the evaluation and diagnosis of these masses. Objective: To determine the accuracy of computed tomography (CT) pmeumocolon in the detection of colonic masses compared with colonoscopy. Patients and Methods: A total of 60 patients with colorectal symptoms underwent evaluation for the presence of colorectal neoplasms by using both colonoscopy and CT pneumocolon and a comparison was made between them. Results: On colonoscopy, 10 out of 60 patients were having a negative colonoscopy. The results of colonoscopy of the other 50 patients were as follow; three out of fifty colonoscopies revealed invasive colorectal carcinomas in threse patients. The remaining 47 colonoscopies for 47 patients revealed benign polyps. The sizes of these polyps were as follows; (6 polyps were ?1 cm in diameter), (17 polyps were 6-9 mm), and (24 polyps were =5 mm). CT pneumocolon detected all 3 malignant masses seen and biopsied by colonoscopy, but only (28 single polyps) which according to their size (4 polyps were = 1cm), (11 polyps were 6-9 mm) and (13 polyps =5 mm), this gives CT pneumocolon a sensitivity of (63%), specificity of (70%) and accuracy (63%). Conclusion: CT pneumocolon has high sensitivity and specificity for a detection of largesized masses, but not for small ones. CT pneumocolon may be suitable for investigating patients with symptomatic colorectal masses noninvasively. [ABSTRACT FROM AUTHOR]

Clear or involved resection margins have significant bearings on the outcome of colorectal cancer cases. There are two aspects of resection margins: longitudinal and circumferential. Pathological staging for rectal and colonic tumour specimens is a useful tool for providing continuous feedback to surgeons and may serve to improve the quality of surgery and pathology reporting. It is expected that a good pathology report will evaluate and audit the quality of other services such as radiology, surgery, and oncology. The aim of this paper is to outline how this parameter can be audited by surgeons and pathologists to improve both communication and standards.

Advances in endoscopic technology have led to increased success in colorectal cancer (CRC) screening and polyp management, with reduction of CRC incidence and mortality. Despite these advances, CRC is still one of the leading causes of cancer deaths, and half of all CRC develops from lesions that were missed during colonoscopy while one-fifth of CRC arise from prior incomplete resection. Techniques to improve polyp detection are needed, along with optimization of complete resection of any abnormal lesions that are found. This article will review the currently available endoscopic resection techniques and will discuss where they fit in the management of polyps of different sizes and types, such as pedunculated versus nonpedunculated, and those with or without suspected invasion. [ABSTRACT FROM AUTHOR]

Background: Multiple guidelines have recommended performing surveillance colonoscopies after resection of colorectal cancer. However, there has been debate about the optimal frequency of endoscopic surveillance and its yield. Objective: The objective of this study was to explore the adherence and the yield of surveillance colonoscopy in our population. Design: This was a retrospective cohort study. Setting: This study was carried out in two tertiary care centers in Riyadh of all patients who were found to have colon cancer on colonoscopy. Patients and Methods: All patients who were found to have colon cancer on colonoscopy at one center from January 2016 to July 2019 and the second center from April 2012 to April 2019 were included in the study. The main outcome measures were as follows: rate of adherence to surveillance colonoscopies as well as the rate of synchronous and metachronous tumors identified. The sample size was not calculated. Results: A total of 280 patients were identified with a mean age of 64.5 years (standard deviation: 13.1), 61.4% were male, and the majority (72%) of the original cancers were left sided (rectum – 25.45%, rectosigmoid – 13.45%, sigmoid – 25.82%, and descending colon – 7.27%). Surveillance was performed in 55.7%, 17.9% did not attend their scheduled procedures, 2.1% refused, while there was no clear reason in 8.9%. Surveillance was not applicable to 15.3% of the study population. Over the course of three rounds of surveillance, the timing of the procedures was in line with recommendations in 66.8% in the first round while it was 20% in the second and third rounds. The procedures were normal in 69%, 71.9%, and 90% of the first, second, and third rounds, respectively. Meta chronous adenocarcinoma was seen in 2.6% and synchronous adenocarcinoma in 0.6% during the first round. Adenocarcinoma was found in 5 out of 75 patients in the second round and 1 out of 10 in the third round. Conclusion: The attrition rate and deviation from timing suggested by guidelines are high. Furthermore, the yield of surveillance colonoscopies for important findings is clinically relevant. The limitations of this study were as follows: retrospective, probability of unmeasured confounders, as well possibility of attrition bias. [ABSTRACT FROM AUTHOR]

Colorectal cancer is common and can be devastating, with long-term survival rates vastly improved by early diagnosis. Colon capsule endoscopy (CCE) is increasingly recognised as a reliable option for colonic surveillance, but widespread adoption has been slow for several reasons, including the time-consuming reading process of the CCE recording. Automated image recognition and artificial intelligence (AI) are appealing solutions in CCE. Through a review of the currently available and developmental technologies, we discuss how AI is poised to deliver at the forefront of CCE in the coming years. Current practice for CCE reporting often involves a two-step approach, with a 'pre-reader' and 'validator'. This requires skilled and experienced readers with a significant time commitment. Therefore, CCE is well-positioned to reap the benefits of the ongoing digital innovation. This is likely to initially involve an automated AI check of finished CCE evaluations as a quality control measure. Once felt reliable, AI could be used in conjunction with a 'pre-reader', before adopting more of this role by sending provisional results and abnormal frames to the validator. With time, AI would be able to evaluate the findings more thoroughly and reduce the input required from human readers and ultimately autogenerate a highly accurate report and recommendation of therapy, if required, for any pathology identified. As with many medical fields reliant on image recognition, AI will be a welcome aid in CCE. Initially, this will be as an adjunct to 'double-check' that nothing has been missed, but with time will hopefully lead to a faster, more convenient diagnostic service for the screening population. [ABSTRACT FROM AUTHOR]

Abstract Background Research in the field of relation between microbes and colorectal carcinogenesis has gained increasing interest in past years. Recently, link between microbial biofilm and carcinogenesis in colon was demonstrated by several authors indicating that biofilm not only is a key player in carcinogenesis, but also may contribute to the understanding of side-specific colon cancer—right sided colon cancer versus left sided. In this article, we briefly highlight the major findings of the research of biofilm and carcinogenesis and demonstrate our findings of colonic cancer tissue and colonic polyp examined for biofilm. Case presentation Colonic cancer tissue from a patient with a right-sided colon cancer, and an adenoma tubular polyp were examined for biofilm formation by flourescens in situ hybridization. In cancer tissue we found biofilm formation on the surface epithelium but surprisingly also deep into the crypts. No biofilms were found in tubular polyp tissue. Conclusions To our knowledge, this is the first-time biofilm formation deep into colonic crypts are demonstrated in a patient with right-sided colon cancer. This may indicate that bacterial biofilm may have a key role in carcinogenesis.

Background and Aims: There is conflicting evidence regarding the impact of hypothetical cumulative fatigue after performing too many endoscopic procedures on both polyp and adenoma detection rates (PDR, and ADR, respectively). The aim of this study is to evaluate the effect of successive endoscopic procedures on PDR and ADR. Methods: A retrospective cross-sectional study was undertaken among consecutive patients on whom colonoscopy and/or esophagogastroduodenoscopy were performed between January 2012 and August 2014. Data regarding polyp and adenoma detection, cecal intubation, and bowel cleansing quality as well as demographical data of subjects were extracted. Endoscopic procedures were classified according to the time slots of the procedures throughout the endoscopy session in three groups: from the 1st to 4th endoscopy study (round 1), from the 5th to the 8th study (round 2), above the 9th study (round 3). We compared PDR and ADR among rounds. Results: Overall, 3388 patients were enrolled. Median age was 50 years (range 18–95) and 52.39% were female. There was a significant difference in terms of PDR among rounds (36.83%, 41.24%, and 43.38%, respectively, p = 0.007) and a non-significant numerical difference when ADR was compared (23.2%, 25.71%, and 26.78%, p = 0.07). On multivariate analysis, ADR was significantly associated with age (odds ratio [OR] 1.02 [1.01–1.03]), and male sex (OR 1.64 [1.38–1.94]). Conclusion: Theoretical endoscopist's fatigue due to cumulative performance of endoscopies does not diminish colonoscopy quality. Both PDR and ADR seem to improve after endoscopist's cumulative rounds of performed endoscopies. This could be due to a "warm-up" effect. [ABSTRACT FROM AUTHOR]

There are multiple indications for luminal imaging of the colon. From assessment of known disease, to diagnosing new pathology; intra-luminal visualisation is the mainstay of gastrointestinal diagnosis. Colonoscopy and radiological imaging are currently the most frequently deployed diagnostic methods. However, both have an associated risk profile, have significant resource pressures and are not universally tolerated. Colon capsule endoscopy (CCE) offers an adjunct to these diagnostic options. In this narrative review the utility of CCE is described. Its current uses, potential benefits and future developments are also discussed. [ABSTRACT FROM AUTHOR]

Background: The pre-colonoscopy diet traditionally involves 24 h of a clear liquid diet (CLD) in combination with a lavage solution; however, this preparation is poorly tolerated.Aim: To compare the impact on the quality of bowel cleansing and tolerability of a CLD versus a low-residue diet (LRD).Methods: We performed a randomized trial. Subjects were randomized to CLD or LRD the day before of elective colonoscopy. All subjects received a 4-L preparation of single-dose PEG beginning 16 h prior to colonoscopy. The Boston bowel preparation scale was used to evaluate bowel cleansing; an adequate-quality preparation was defined as a score ≥ 2 per segment.Results: A total of 205 subjects were included with a mean age (SD) of 55.6 (12.6) years; 133 (64.9%) of them were female. A total of 105 subjects were randomized to receive CLD and 100 to LRD. No significant differences in bowel preparation quality were observed between groups according to the section of colon: right colon (70% vs. 73%, p = 0.08), transverse colon (82% vs. 79%, p = 0.062), or left colon (80% vs. 78.7%, p = 0.28). There was a tendency toward less-frequent nausea (p = 0.08) and vomiting (p = 0.07) in patients with LRD. No differences between groups regarding ADR (12% vs. 10%) were noted.Conclusions: An LRD before colonoscopy resulted in a tendency toward improved tolerability by patients, with no differences in the quality of bowel preparation. [ABSTRACT FROM AUTHOR]

Background: The Cancer Council posits that the size of adenomas is a more robust marker of risk than histological characteristics. The purpose of our study is to assess the accuracy of estimation of polyp size at colonoscopy amongst different levels of endoscopists and compare this with histopathological size. Methods: A retrospective review of prospectively collected data was performed. Specimens were included if they were (i) from patients aged 18 years or older, (ii) polyp obtained at colonoscopy, (iii) measured in quantitative units and (iv) the largest eligible polyp per patient. Results: A total of 92 patients were included. Our results demonstrate that the relationship between the histological size of a polyp and an endoscopist's estimate depended upon seniority level (P = 0.001). Senior consultants tended to overestimate lesion size (P < 0.001), fellows/junior consultants tended to underestimate size (P = 0.010), whilst registrars' estimates demonstrated no systematic difference from histological size (P = 0.518). The ratio of a senior consultant's estimate of polyp size to histological size was on average 74% with their estimates ranging from 31% to 173%. The corresponding estimates are 123% (32–470%) for fellows/junior consultants and 107% (35–334%) for registrars. Conclusion: Our study demonstrates that senior consultants are more precise with more junior endoscopists having a great degree of variability in their practice. It is evident that there is a relationship between proceduralist experience and polyp size estimation. It is, therefore, important to consider the ways in which we can mitigate this learning curve and continue to develop technology to improve our accuracy. [ABSTRACT FROM AUTHOR]

Background: Increasing evidence suggests that conventional adenomas (CAs) and serrated polyps (SPs) represent two distinct groups of precursor lesions for colorectal cancer (CRC). The influence of common genetic variants on risk of CAs and SPs remain largely unknown.Methods: Among 27 426 participants within three prospective cohort studies, we created a weighted genetic risk score (GRS) based on 40 CRC-related single nucleotide polymorphisms (SNPs) identified in previous genome-wide association studies; and we examined the association of GRS (per one standard deviation increment) with risk of CAs, SPs and synchronous CAs and SPs, by multivariable logistic regression. We also analysed individual variants in the secondary analysis.Results: During 18-20 years of follow-up, we documented 2952 CAs, 1585 SPs and 794 synchronous CAs and SPs. Higher GRS was associated with increased risk of CAs [odds ratio (OR) = 1.17, 95% confidence interval (CI): 1.12-1.21] and SPs (OR = 1.09, 95% CI: 1.03-1.14), with a stronger association for CAs than SPs (Pheterogeneity=0.01). An even stronger association was found for patients with synchronous CAs and SPs (OR = 1.32), advanced CAs (OR = 1.22) and multiple CAs (OR = 1.25). Different sets of variants were associated with CAs and SPs, with a Spearman correlation coefficient of 0.02 between the ORs associating the 40 SNPs with the two lesions. After correcting for multiple testing, three variants were associated with CAs (rs3802842, rs6983267 and rs7136702) and two with SPs (rs16892766 and rs4779584).Conclusions: Common genetic variants play a potential role in the conventional and serrated pathways of CRC. Different sets of variants are identified for the two pathways, further supporting the aetiological heterogeneity of CRC. [ABSTRACT FROM AUTHOR]

Colorectal adenomas are the usual precursors to carcinoma in sporadic and hereditary colorectal cancers (CRC).A total of 220 CRC patients (stages 0, I, and II) were randomized prospectively in a double-blind pilot study of calcium chemoprevention by using recurrent colorectal adenomas as a surrogate end point. This trial is still in progress, and we report the preliminary findings on adenoma recurrence rates.Synchronous adenomas were present in 60% of patients, and cancer confined in a polyp was present in 23% of patients. The overall cumulative adenoma recurrence rate was 31% (19% in the first year, 29% for 2 years, and 35% for 3 years). The recurrence rates were greater for patients with synchronous adenomas: 38% at 3 years (P =.01). Lower stage was associated with higher adenoma recurrence rates (P =.04). Factors including age, sex, site of primary cancer, and whether the cancer was confined to a polyp were not significantly associated with differences in adenoma recurrence rates.The substantial adenoma recurrence rate in patients resected of CRC justifies colonoscopic surveillance on a periodic basis. Patients with higher rates of adenoma recurrences, such as CRC with synchronous adenomas, are ideal subjects for chemoprevention trials.

Fecal Immunochemical Test (FIT) is one of the leading modalities for colorectal cancer screening. Studies show that FIT is highly sensitive for the detection of colorectal cancer (CRC) but not similarly accurate for detection of pre-cancerous advanced adenomas (AA). We studied the performance metrics of FIT for the detection of CRC and AA in a health maintenance organization (HMO) cohort screening program. Retrospective cohort study of asymptomatic persons of screening age belonging to a HMO. Endoscopy and pathology reports of those who tested positive were used to calculate the positive predictive value (PPV) of FIT, and characterize endoscopic findings on colonoscopy. Between 1995 and 2017, 3000 persons had screening fecal occult testing as part of their Employee Health Care plan. Of those, 150 had a positive qualitative FIT (cutoff 10 µg hemoglobin/g feces). All underwent colonoscopy, and median time to colonoscopy was 27 days. 4 (2.6%) had carcinoma (2 stage IIIA and 2 stage IIIB), 106 (70.6%) had adenomas of which 40 (26.6% of the total cohort) had advanced adenomas (≥1 cm, villous features, or high-grade dysplasia) giving a PPV for AA and carcinoma of 29% and 3% respectively. When stratified by age, the PPV of AA; carcinoma was [50–59 (21.7%; 0.0%)], [60–69 (14.6%; 4.2%)], [70–79 (42.6%; 2.1%)], [80–89 (33.3%; 11.1%)]. The performance characteristics of FIT testing are acceptable for population screening in resource-limited settings. The results of this study are helpful when discussing expectations prior to colonoscopy in people with positive FIT. [ABSTRACT FROM AUTHOR]

Background: Colorectal cancer is the fourth most common cancer in the UK. The vast majority of colorectal cancers develop from polyps. Polypectomy is an endoscopic therapy that interrupts the sequence by which a polyp develops into cancer. Methods: A review was conducted of the published literature and clinical guidelines relevant to colonic polypectomy, with an aim to introduce basic concepts of colorectal polyp assessment and management and to describe potential complications of polypectomy. Findings: Through optical lesion assessment, it is possible to identify polyps with malignant potential. A number of techniques can be used to attempt removal, the goal of which is complete histological eradication in the safest way possible. Conclusion: Endoscopic polypectomy is a relatively safe intervention that is protective against colorectal cancer. Increasingly, nurses in the UK are being trained to perform polypectomy, particularly within the Bowel Scope service, which is part of the Bowel Cancer Screening Programme aimed at early diagnosis and removal of pre-cancerous, distal colorectal lesions. [ABSTRACT FROM AUTHOR]

As clinical testing for Mendelian causes of colorectal cancer (CRC) is largely driven by recognition of family history and early age of onset, the rates of such findings among individuals with prevalent CRC not recognized to have these features is largely unknown. We evaluated actionable genomic findings in community-based participants ascertained by three phenotypes: (1) CRC, (2) one or more adenomatous colon polyps, and (3) control participants over age 59 years without CRC or colon polyps. These participants underwent sequencing for a panel of genes that included colorectal cancer/polyp (CRC/P)-associated and actionable incidental findings genes. Those with CRC had a 3.8% rate of positive results (pathogenic or likely pathogenic) for a CRC-associated gene variant, despite generally being older at CRC onset (mean 72 years). Those ascertained for polyps had a 0.8% positive rate and those with no CRC/P had a positive rate of 0.2%. Though incidental finding rates unrelated to colon cancer were similar for all groups, our positive rate for cardiovascular findings exceeds disease prevalence, suggesting that variant interpretation challenges or low penetrance in these genes. The rate of HFE c.845G>A (p.Cys282Tyr) homozygotes in the CRC group reinforces a previously reported, but relatively unexplored, association between hemochromatosis and CRC. These results in a general clinical population suggest that current testing strategies could be improved in order to better detect Mendelian CRC-associated conditions. These data also underscore the need for additional functional and familial evidence to clarify the pathogenicity and penetrance of variants deemed pathogenic or likely pathogenic, particularly among the actionable genes associated with cardiovascular disease. [ABSTRACT FROM AUTHOR]

Background: Polyp occurrence in the colon or rectum often raises question and distress for patients and their family. Due to the proven effects of geographic variations and nutritional habits on the incidence of these polyps, the difference in Iranian lifestyle habits, and the cost of screening, conducting an accurate study on aforementioned factors looks essential. In the current study, we aimed to assess various characteristics of this important group of disease. Materials and Methods: In this research work, sex, age, location, and macroscopic and pathologic features of 295 specimens from 200 patients, which are sent to the pathology unit of Shohada-e-Tajrish Referral Hospital (2014–2016) as a colonic polyp or reported as a colonic polyp, were investigated. Results: Our results are similar to Western countries revealing the polyp prevalence is greater in men and higher in >50 years old, located more in rectum, commonly with sessile appearance and the most pathologic types are adenomatous and hyperplastic polyps. The prevalence of ascending colon polyps rises after 50 years old (P = 0.007). There is a meaningful relationship between age and macroscopic features (P = 0.02). Polyps which are sent from >50-year-old patients and the right side of the colon carry a higher risk for malignancy (P = 0.00). Pedunculated polyps are more prone to be neoplastic (P = 0.00). The prevalence of pedunculated polyps and right-sided polyps, which were sent from the right side, is more in men. Sessile serrated polyps/adenomas were more common in men and were located in the proximal part of the colon (P = 0.005), although unexpectedly two of them were sent from the sigmoid colon. As expected, villous adenomas just were sent from the distal part of the colon and rectum. Two phytobezoars were sent as a colonic polyp. Polyposis syndromes have low incidence; their prevalence was equal in both age (P = 0.124) and sex (P = 1). Conclusions: Based on our research work, further studies into the characteristics of polyps in Iranian lifestyle habits would be of great interest. [ABSTRACT FROM AUTHOR]

Introduction: Colorectal cancer (CRC) is a common malignancy, ranking fourth among the causes of cancer-related deaths globally. Its incidence has increased in recent decades, and now more than one million CRC patients are diagnosed and thousands die annually. The 5-year survival rate varies with the stage at diagnosis, are approximately 90% in the early stages of disease, and less than 10% in advanced disease. Non-alcoholic fatty liver disease (NAFLD), which is a major cause of chronic liver disease, and characterized by the accumulation of fat in hepatocytes, has also emerged as a risk factor for CRC, and to be related with the development of colorectal polyps. Areas covered: The purpose of this current review is to summarize the main findings of studies that have investigated the role of NAFLD in development of CRC. Expert opinion: Various molecular pathways are altered during the development of NAFLD, which are also important in CRC tumorigenesis. There is growing body of evidence showing the potential role of activation of pro-inflammatory, disruption of anti-inflammatory pathways, increasing the activity of pathways involved in cell proliferation/survival. Thus targeting these dysregulated pathways via novel inhibitors can be a potential therapy for CRC prevention in cases with NAFLD. [ABSTRACT FROM AUTHOR]

Background: Colonoscopy is the gold‐standard investigation for direct luminal visualization of the large bowel. Studies have shown the efficacy of computed tomography colonography (CTC) is equivalent to colonoscopy in both cancer and polyp detection. Methods: A retrospective review of patients undergoing CTC from January 2013 to October 2014 was performed. Patient demographics, indication for investigation, computed tomography findings, optical colonoscopy findings and histology results were recorded. Results: Seven hundred and fifty‐eight CTC were performed. Three hundred and seventeen patients were male (42%) and 441 (58%) were female. Endoscopy was advised in 209 cases. One hundred and twenty (16%) were deemed suspicious for cancer of whom 96 (80%) had optical colonoscopy. A total of 12 colorectal cancers were detected. Potential polyps were noted in 58 cases (8%). Forty‐four patients underwent endoscopy (75%) and 17 polyps confirmed (38%). Two patients had foci of invasive cancer histologically. Significant extracolonic findings were identified in 60%, including five cases of gastric carcinomas. The most common other findings were gallstones and hernias. Conclusion: The rate of colorectal cancer detection in this study was 2%. The rate of biopsy proven cancer was 10% following a suspicious colonogram. Endoscopic correlation was not obtained in 20% of cases of radiological suspicion. CTC is as efficacious as optical colonoscopy for colorectal cancer and polyp detection. [ABSTRACT FROM AUTHOR]