Comparison of Targeted vs Random Biopsies for Surveillance of Ulcerative Colitis-Associated Colorectal Cancer

Circulating tumor DNA analysis in breast cancer: Is it ready for prime-time?

Precision Medicine is becoming the new paradigm in healthcare as it enables better resources allocation, treatment optimization with a potential side-effects reduction and consequent impact on quality of life and survival. This revolution is being catalyzed by liquid biopsy technologies, which provide prognostic and predictive information for advanced cancer patients, without the analytical and procedural drawbacks of tissue-biopsy. In particular, circulating tumor DNA (ctDNA) is gaining momentum as a clinically feasible option capable to capture both spatial and temporal tumor heterogeneity. Several techniques are currently available for ctDNA extraction and analysis, each with its preferential case scenarios and preanalytical implications which must be taken into consideration to effectively support clinical decision-making and to better highlight its clinical utility. Aim of this review is to summarize both analytical developments and clinical evidences to offer a comprehensive update on the deployment of ctDNA in breast cancer's (BC) characterization and treatment.

Role of endoscopy in the surveillance and management of colorectal neoplasia in inflammatory bowel disease

Endoscopy has become increasingly fundamental in the management of patients with inflammatory bowel disease (IBD). It is required for diagnosis, assessment of therapeutic response, postoperative follow up and in the surveillance of dysplasia. With rapid advances in technology, including high definition colonoscopy and chromoendoscopy, questions have arisen regarding the most appropriate surveillance and management strategies of colorectal neoplasia in IBD. We aim to review current surveillance strategies, explore the utility of new technologies, and examine the role of endoscopic resection, with the aim of clarifying these questions.

The inhibitory effects of Qingchang Wenzhong granule on the interactive network of inflammation, oxidative stress, and apoptosis in rats with dextran sulfate sodium-induced colitis

BACKGROUND

Ulcerative colitis (UC) is a kind of complex immune disease, the pathogenesis of which remains elusive. Destruction of the intestinal barrier, extreme inflammation, oxidative stress, and apoptosis might play key roles in the development of UC. In previous studies, we observed that Qingchang Wenzhong granule (QCWZG) had the exact effect on the remission of UC in the clinic; however, the underlying mechanism has not been identified. This study aimed to reveal the effects of QCWZG on the intestinal physical barrier and the interactive network of inflammation, oxidative stress, and apoptosis in rats with dextran sulfate sodium (DSS)-induced colitis.

METHODS

Sixty rats were randomly divided into six groups: blank group, model group, high/mild/low-dose QCWZG groups, and mesalazine group. The rats in the experimental group drank 4% DSS for 7 days and 1% DSS for the subsequent 7 days. Different medications or distilled water was supplied by intragastric administration for 7 days. The levels of colitis and indices related to inflammation, oxidative stress, and apoptosis were assessed.

RESULTS

Compared with the model group, the QCWZG group (P < 0.05) demonstrated attenuated disease activity index, colonic mucosa disease index, histological lesions, and colonic weights; lower levels of inflammatory substances, such as interleukin (IL)-1α, IL-6, tumor necrosis factor-α, and myeloperoxidase; lower levels of malondialdehyde; and increased levels of superoxide dismutase and glutathione peroxidase. The QCWZG group also demonstrated elevated expression of Bcl-2 and occluding but downregulated db expression of Bax and caspase 3 in the colon.

CONCLUSION

QCWZG could relieve rats with DSS-induced colitis from UC symptoms by improving the intestinal physical barrier, which resists the interactive network of inflammation, oxidative stress, apoptosis, and their overactivated interactions.

Strategies for Detecting Colorectal Cancer in Patients with Inflammatory Bowel Disease: A Cochrane Systematic Review and Meta-Analysis

OBJECTIVES

Patients with longstanding ulcerative colitis (UC) and colonic Crohn's disease (CD) have an increased risk of colorectal cancer (CRC). We assess the effectiveness of endoscopic surveillance in patients with inflammatory bowel disease (IBD) for diagnosing CRC and reducing CRC-related mortality.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched from inception to 19 September 2016. Randomized controlled trials (RCTs), observational cohorts, or case-control studies assessing any form of endoscopic surveillance for early CRC detection were eligible for inclusion; studies without a comparison non-surveillance group were excluded. The primary outcome was rate of CRC detection. Secondary outcomes were rate of early (Duke stage A and B) versus late (Duke stage C & D) CRC detection and rate of CRC-related death. Data were pooled using fixed or random effects models based on the degree of heterogeneity; pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the Mantel-Haenszel method.

RESULTS

Five observational studies evaluating 7199 IBD patients were included; no RCTs met criteria for inclusion. There are limited new studies evaluating this clinical question (last included study published 2014). There was a significantly higher rate of cancer detection in the non-surveillance group (3.2%, 135/4256) compared to the surveillance group (1.8%, 53/2895) (OR 0.58 (95% CI: 0.42-0.80), p < 0.001). In four pooled studies, there was a significantly lower rate of CRC-associated death in the surveillance group (8.5%, 15/176) compared to the non-surveillance group (22.3%, 79/354) (OR 0.36 (95% CI: 0.19-0.69), p = 0.002). In two pooled studies, there was a significantly higher rate of early-stage CRC detection in the surveillance group (15.5%, 17/110) compared to the non-surveillance group (7.7%, 9/117) (OR 5.40 (95% CI: 1.51-19.30), p = 0.009).

CONCLUSIONS

Colonoscopic surveillance in IBD is associated with a reduction in CRC development and CRC-associated death, as well as increased detection of early-stage CRC.

Real-life chromoendoscopy for dysplasia surveillance in ulcerative colitis

AIM

To evaluate the use of chromoendoscopy for surveillance of ulcerative colitis in a real-life community hospital setting.

METHODS

Patients with extensive ulcerative colitis, having disease duration of more than 8 years and who presented between the years of 1999 to 2013, were offered enrolment in this single cohort prospective study. All participants underwent standard bowel preparation with sodium phosphate and chromoendoscopy. Two expert endoscopists, novice to chromoendoscopy, evaluated each segment of the colon with standard-definition colonoscopes after spray application of 0.4% indigo carmine. All observed lesions were recorded and evaluated before being removed and/or biopsied. In addition, nontargeted biopsies were taken from each segment of the colon. The dysplasia detection rate and dysplasia detection yield were ascertained.

RESULTS

A total of 21 neoplastic lesions (2 carcinomas, 4 of high-grade dysplasia and 15 of low-grade dysplasia) and 27 nondysplastic lesions were detected in 16 of the total 67 patients (70% male; median disease duration: 17 years; median age at diagnosis: 25 years; 92% aminosalicylate-treated). The dysplasia detection rate was 10.5% (7/67 patients). The dysplasia detection yield was 20.8% (10/48) for targeted biopsies and 3.5% (11/318) for nontargeted biopsies. The sensitivity and specificity for the macroscopic evaluation of neoplasia using chromoendoscopy were 48% [95% confidence interval (CI): 26%-70%] and 96% (95%CI: 93%-98%), respectively. The positive predictive and negative predictive values were 42% (95%CI: 27%-59%) and 97% (95%CI: 95%-98%), respectively. A total of 19/21 dysplastic lesions were detected in mucosa with histologic inflammation.

CONCLUSION

Chromoendoscopy seems to be of value for dysplasia surveillance of ulcerative colitis in a community hospital setting. The yield of non-targeted biopsies is negligible.

Comprehensive analysis identifying aberrant DNA methylation in rectal mucosa from ulcerative colitis patients with neoplasia

Background

There are no biomarkers to facilitate the identification of patients with ulcerative colitis (UC) who are at high risk for developing colorectal cancer (CRC). In our current study, we used rectal tissues from UC patients to identify aberrant DNA methylations and evaluated whether they could be used to identify UC patients with coexisting colorectal neoplasia.

Results

Using a training set, we identified 484 differentially methylated regions (DMRs) with absolute delta beta-values > 0.1 in rectal mucosa by using the ChAMP algorithm. Next, pathway enrichment analysis was performed using 484 DMRs to select coordinately methylated DMRs, resulting in the selection of 187 aberrant DMRs in rectal tissues from UC-CRC. Then, the Elastic Net classification algorithm was performed to narrow down optimal aberrant DMRs, and we finally selected 11 DMRs as biomarkers for identification of UC-CRC patients. The 11 chosen DMRs could discriminate UC patients with or without CRC in a training set (area under the curve, 0.96) and the validation set (area under the curve, 0.81).

Conclusions

In conclusion, we identified 11 DMRs that could identify UC patients with CRC complications. Prospective studies should further confirm the validity of these biomarkers.

Methods

We performed genome-wide DNA methylation profiles in rectal mucosal tissues (n = 48) from 24 UC-CRC and 24 UC patients in a training set. Next, we performed comprehensive DNA methylation analysis using rectal mucosal tissues (n = 16) from 8 UC-CRC and 8 UC patients for validation.

Advanced endoscopic imaging for diagnosis of inflammatory bowel diseases: Present and future perspectives

Crohn's disease and ulcerative colitis are chronic inflammatory bowel diseases (IBD) causing severe damage of the luminal gastrointestinal tract. Differential diagnosis between both disease entities is sometimes awkward requiring a multifactorial pathway, including clinical and laboratory data, radiological findings, histopathology and endoscopy. Apart from disease diagnosis, endoscopy in IBD plays a major role in prediction of disease severity and extent (i.e. mucosal healing) for tailored patient management and for screening of colitis-associated cancer and its precursor lesions. In this state-of-the-art review, we focus on current applications of endoscopy for diagnosis and surveillance of IBD. Moreover, we will discuss the latest guidelines on surveillance and provide an overview of the most recent developments in the field of endoscopic imaging and IBD.

High Risk of Advanced Colorectal Neoplasia in Patients With Primary Sclerosing Cholangitis Associated With Inflammatory Bowel Disease

BACKGROUND & AIMS

Patients with inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC, termed PSC-IBD) are at increased risk for colorectal cancer, but their risk following a diagnosis of low-grade dysplasia (LGD) is not well described. We aimed to determine the rate of advanced colorectal neoplasia (aCRN), defined as high-grade dysplasia and/or colorectal cancer, following a diagnosis of indefinite dysplasia or LGD in this population.

METHODS

We performed a retrospective, longitudinal study of 1911 patients with colonic IBD (293 with PSC and 1618 without PSC) who underwent more than 2 surveillance colonoscopies from 2000 through 2015 in The Netherlands or the United States (9265 patient-years of follow-up evaluation). We collected data on clinical and demographic features of patients, as well as data from each surveillance colonoscopy and histologic report. For each surveillance colonoscopy, the severity of active inflammation was documented. The primary outcome was a diagnosis of aCRN during follow-up evaluation. We also investigated factors associated with aCRN in patients with or without a prior diagnosis of indefinite dysplasia or LGD.

RESULTS

Patients with PSC-IBD had a 2-fold higher risk of developing aCRN than patients with non-PSC IBD. Mean inflammation scores did not differ significantly between patients with PSC-IBD (0.55) vs patients with non-PSC IBD (0.56) (P = .89), nor did proportions of patients with LGD (21% of patients with PSC-IBD vs 18% of patients with non-PSC IBD) differ significantly (P = .37). However, the rate of aCRN following a diagnosis of LGD was significantly higher in patients with PSC-IBD (8.4 per 100 patient-years) than patients with non-PSC IBD (3.0 per 100 patient-years; P = .01). PSC (adjusted hazard ratio [aHR], 2.01; 95% CI, 1.09-3.71), increasing age (aHR 1.03; 95% CI, 1.01-1.05), and active inflammation (aHR, 2.39; 95% CI, 1.63-3.49) were independent risk factors for aCRN. Dysplasia was more often endoscopically invisible in patients with PSC-IBD than in patients with non-PSC IBD.

CONCLUSIONS

In a longitudinal study of almost 2000 patients with colonic IBD, PSC remained a strong independent risk factor for aCRN. Once LGD is detected, aCRN develops at a higher rate in patients with PSC and is more often endoscopically invisible than in patients with only IBD. Our findings support recommendations for careful annual colonoscopic surveillance for patients with IBD and PSC, and consideration of colectomy once LGD is detected.

Updates in colorectal cancer screening in inflammatory bowel disease

PURPOSE OF REVIEW

This review article will discuss the risk of colorectal cancer (CRC) in patients with inflammatory bowel disease (IBD), as well as the current recommendations for CRC screening and surveillance in patients with ulcerative colitis or Crohn's colitis involving one-third of the colon.

RECENT FINDINGS

Given that most cases of CRC are thought to arise from dysplasia, previous guidelines have recommended endoscopic surveillance with random biopsies obtained from all segments of the colon. However, recent evidence has suggested that the majority of dysplastic lesions in patients with IBD are visible, and data have been supportive of chromoendoscopy with targeted biopsies of visible lesions rather than traditional random biopsies. There have also been efforts to endoscopically remove resectable visible dysplasia and only recommend surgery when this is not possible.

SUMMARY

Patients with long-standing ulcerative colitis or Crohn's colitis involving at least one-third of the colon are at increased risk for developing CRC and should undergo surveillance colonoscopy using new approaches and techniques.

Chromoendoscopy for Dysplasia Surveillance in Inflammatory Bowel Disease

Long-standing ulcerative colitis (UC) and extensive Crohn's colitis confer increased risk for development of colorectal cancer. Screening and surveillance colonoscopy programs aim to identify, resect, or detect dysplasia or colorectal cancer. Dysplastic lesions can be removed by endoscopic resection and patients with unresectable lesions can be referred for colectomy at an earlier stage, with the goal of reducing overall morbidity and mortality from colorectal cancer. Surveillance colonoscopy for patients with inflammatory bowel disease (IBD) is endorsed by multiple specialty societies. High-definition endoscopy systems provide improved image resolution, and application of dilute indigo carmine or methylene blue for chromoendoscopy can provide increased contrast. International specialty society guidelines differ in their recommendations regarding use of chromoendoscopy for dysplasia surveillance, with some guidelines advocating a risk-stratified surveillance strategy. In this review, we discuss chromoendoscopy technique, training, implementation, yield as compared with standard-definition and high-definition white light colonoscopy, and positioning of this technique in clinical practice.

Early detection of ulcerative colitis-associated colorectal cancer

Colitis-associated colorectal cancer (CACC) is one of the most serious complications of inflammatory bowel disease (IBD), particularly in ulcerative colitis (UC); it accounts for approximately 15% of all-causes mortality among IBD patients. Because CACC shows a worse prognosis and higher mortality than sporadic colorectal cancer, early detection is critical. Colonoscopy is primarily recommended for surveillance and several advanced endoscopic imaging techniques are emerging. In addition, recent studies have reported on attempts to develop clinically relevant biomarkers for surveillance using various biosamples, which may become high-performance screening tools in the future, so the best approach and technique for cancer surveillance in long-standing UC patients remain under debate. This review gives a comprehensive description and summary about what progress has been made in terms of early CACC detection.

Chromoendoscopy versus autofluorescence imaging for neoplasia detection in patients with longstanding ulcerative colitis (FIND-UC): an international, multicentre, randomised controlled trial

BACKGROUND

Patients with longstanding ulcerative colitis undergo regular dysplasia surveillance because they have an increased colorectal cancer risk. Autofluorescence imaging and chromoendoscopy improve dysplasia detection. The aim of this study was to determine whether autofluorescence imaging should be further studied as an alternative method for dysplasia surveillance in patients with longstanding ulcerative colitis.

METHODS

This prospective, international, randomised controlled trial included patients from an ulcerative colitis-dysplasia surveillance cohort from five centres in the Netherlands and the UK. Eligible patients were aged 18 years or older who were undergoing dysplasia surveillance after being diagnosed with extensive colitis (Montreal E3) at least 8 years before study start or with left-sided colitis (Montreal E2) at least 15 years before study start. Randomisation (1:1) was minimised for a previous personal history of histologically proven dysplasia and concomitant primary sclerosing cholangitis. The coprimary outcomes were the proportion of patients in whom at least one dysplastic lesion was detected and the mean number of dysplastic lesions per patient. The relative dysplasia detection rate, calculated as the ratio of the detection rates by autofluorescence imaging and chromoendoscopy, needed to be more than 0·67 (using an 80% CI) for both primary outcomes to support a subsequent large non-inferiority trial. Outcomes were analysed on a per-protocol basis. The trial is registered at the Netherlands Trial Register, number NTR4062.

FINDINGS

Between Aug 1, 2013, and March 10, 2017, 210 patients undergoing colonoscopy surveillance for longstanding ulcerative colitis were randomised for inspection with either autofluorescence imaging (n=105) or chromoendoscopy (n=105). Dysplasia was detected in 13 (12%) patients by autofluorescence imaging and in 20 patients (19%) by chromoendoscopy. The relative dysplasia detection rate of autofluorescence imaging versus chromoendoscopy for the proportion of patients with ulcerative colitis with at least one dysplastic lesion was 0·65 (80% CI 0·43-0·99). The mean number of detected dysplastic lesions per patient was 0·13 (SD 0·37) for autofluorescence imaging and 0·37 (1·02) for chromoendoscopy (relative dysplasia detection rate 0·36, 80% CI 0·21-0·61). Adverse events were reported for two patients in the autofluorescence imaging group (one patient had intraprocedural mild bleeding, and one patient had abdominal pain) and for three patients in the chromoendoscopy group (two patients had intraprocedural mild bleeding, and one patient had perforation).

INTERPRETATION

Autofluorescence imaging did not meet criteria for proceeding to a large non-inferiority trial. Therefore, existing autofluorescence imaging technology should not be further investigated as an alternative dysplasia surveillance method.

FUNDING

Olympus Europe and Olympus Keymed.

Predicting outcomes to optimize disease management in inflammatory bowel disease in Japan: their differences and similarities to Western countries

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disease of the gastrointestinal tract, with increasing prevalence worldwide. IBD Ahead is an international educational program that aims to explore questions commonly raised by clinicians about various areas of IBD care and to consolidate available published evidence and expert opinion into a consensus for the optimization of IBD management. Given differences in the epidemiology, clinical and genetic characteristics, management, and prognosis of IBD between patients in Japan and the rest of the world, this statement was formulated as the result of literature reviews and discussions among Japanese experts as part of the IBD Ahead program to consolidate statements of factors for disease prognosis in IBD. Evidence levels were assigned to summary statements in the following categories: disease progression in CD and UC; surgery, hospitalization, intestinal failure, and permanent stoma in CD; acute severe UC; colectomy in UC; and colorectal carcinoma and dysplasia in IBD. The goal is that this statement can aid in the optimization of the treatment strategy for Japanese patients with IBD and help identify high-risk patients that require early intervention, to provide a better long-term prognosis in these patients.

An Update on Surveillance in Ulcerative Colitis

PURPOSE OF REVIEW

Patients with long-standing ulcerative colitis have an increased risk for the development of colorectal cancer (CRC). Colitis-related dysplasia appears to confer the greatest risk. Colonoscopic surveillance to detect dysplasia has been advocated by gastrointestinal societies. The aim of surveillance is the reduction of mortality and morbidity of CRC through detection and resection of dysplasia or detecting CRC at an earlier and potentially curable stage. Traditional surveillance has relied on mucosal assessment with targeted biopsy of visible lesions and random biopsy sampling on the premise that dysplasia was not visible at endoscopy. Advances in optical technology permitting increased detection of dysplasia and evidence that most dysplasia is visible has had practice-changing implications.

RECENT FINDINGS

Emerging evidence favours chromoendoscopy (CE) for dysplasia detection and is gaining wider acceptance through recent international (International Consensus Statement on Surveillance and Management of Dysplasia in Inflammatory Bowel Disease (SCENIC)) recommendations and endorsed by many gastrointestinal societies. Adoption of CE as the gold standard of surveillance has been met with by scepticism, from conflicting data, operational barriers and the need to understand the true impact of increasingly higher dysplasia detection on overall CRC mortality. Valid debate notwithstanding, implementation of a risk stratification protocol that includes CE is an effective approach allowing earlier detection of dysplasia and colorectal neoplasia, determination of surveillance intervals with appropriate allocation of resources and limiting morbidity from CRC and colonoscopy itself. Further prospective data should define the true and long-term impact of dysplasia detection with modern techniques.

Results of a 36-year surveillance program for ulcerative colitis-associated neoplasia in the Japanese population

BACKGROUND AND AIM

Surveillance colonoscopy has been carried out for patients with long-standing ulcerative colitis who have an increased risk for colorectal cancer. The aim of the present study was to determine the incidence of and the risk factors for neoplasia.

METHODS

We evaluated 289 ulcerative colitis patients who underwent surveillance colonoscopy between January1979 and December 2014. Cumulative incidence of neoplasia and its risk factors were investigated. Clinical stage and overall survival were compared between the surveillance and non-surveillance groups.

RESULTS

Cumulative risk of dysplasia was 3.3%, 12.1%, 21.8%, and 29.1% at 10, 20, 30 and 40 years after the onset of ulcerative colitis, respectively. Cumulative risk of colorectal cancer was 0.7%, 3.2%, 5.2%, and 5.2% at 10, 20, 30 and 40 years from the onset of ulcerative colitis, respectively. Total colitis was a risk factor for neoplasia (P = 0.015; hazard ratio, 2.96).

CONCLUSIONS

Our surveillance colonoscopy program revealed the incidence and risk factors of ulcerative colitis-associated neoplasias in the Japanese population. Total colitis is a risk factor for neoplasia.

Feasibility of restorative proctocolectomy in patients with ulcerative colitis-associated lower rectal cancer: A retrospective study

BACKGROUND/OBJECTIVE

Restorative proctocolectomy (RP) may improve quality of life in patients with ulcerative colitis (UC)-associated lower rectal cancer to a greater extent than total proctocolectomy. However, patients with UC-associated cancer often have flat mucosal lesions that make it extremely difficult to endoscopically delineate the tumor margins. Therefore, there is a potential risk of residual tumor and local recurrence after RP in patients with UC-associated lower rectal cancer. The aim of this study was to assess the feasibility of RP in patients with UC-associated cancer of the lower rectum.

METHODS

We retrospectively identified nine patients who had undergone RP for UC-associated lower rectal cancer at the Niigata University Medical and Dental Hospital between January 2000 and December 2016. The incidence of flat mucosal cancer, distal margin status, and oncologic outcomes were evaluated in the nine patients.

RESULTS

Eight (89%) of the nine patients had flat mucosal cancer in the lower rectum. The median length of the distal margin was 22 mm (range 0-55 mm). No patient developed local or distant recurrence during follow-up. One patient had a positive distal margin. This patient underwent annual pouchoscopy, but had no local recurrence and died of pancreatic cancer 81 months after RP. The remaining eight patients were alive at the final observation. Five-year and 10-year overall survival rates in the nine patients were 100% and 66.7%, respectively.

CONCLUSION

Patients with UC-associated lower rectal cancer often have lesions of the flat mucosal type. However, RP is feasible and not necessarily contraindicated in such patients.

Endoscopic Surveillance in Inflammatory Bowel Disease

Introduction

Endoscopy is a key technique for the surveillance of patients with inflammatory bowel diseases (Crohn's disease (CD) and ulcerative colitis). Indication to perform endoscopy for surveillance includes assessment of response to therapy, postoperative surveillance, and surveillance for intraepithelial neoplasia.

Methods

In addition to personal experience, a literature search was performed and the guidelines were consulted.

Results and Conclusion

Endoscopy is the gold standard in the long-term assessment of mucosal healing and in the short-term control of response to intensified therapy. For postoperative surveillance in CD, mucosal changes (as graded by the Rutgeerts score) are predictive of clinical recurrence. For neoplasia surveillance, virtual chromoendoscopy has not (yet) replaced conventional chromoendoscopy. Surveillance can be optimized by the use of high-definition endoscopes as well as (pan-)chromoendoscopy and requires time to scrutinize the mucosa. This approach seems to be superior to random biopsies.

A Panel of Methylated MicroRNA Biomarkers for Identifying High-Risk Patients With Ulcerative Colitis-Associated Colorectal Cancer

BACKGROUND & AIMS

Methylation of specific microRNAs (miRNAs) often occurs in an age-dependent manner, as a field defect in some instances, and may be an early event in colitis-associated carcinogenesis. We aimed to determine whether specific mRNA signature patterns (MIR1, MIR9, MIR124, MIR137, MIR34B/C) could be used to identify patients with ulcerative colitis (UC) who are at increased risk for colorectal neoplasia.

METHODS

We obtained 387 colorectal tissue specimens collected from 238 patients with UC (152 without neoplasia, 17 with dysplasia, and 69 with UC-associated colorectal cancer [UC-CRC]), from 2 independent cohorts in Japan between 2005 and 2015. We quantified methylation of miRNAs by bisulfite pyrosequencing analysis. We analyzed clinical data to determine whether miRNA methylation patterns were associated with age, location, or segment of the colorectum (cecum, transverse colon, and rectum). Differences in tissue miRNA methylation and expression levels were compared among samples and associated with cancer risk using the Wilcoxon, Mann-Whitney, and Kruskal-Wallis tests as appropriate. We performed a validation study of samples from 90 patients without UC and 61 patients with UC-associated dysplasia or cancer to confirm the association between specific methylation patterns of miRNAs in non-tumor rectal mucosa from patients with UC at risk of UC-CRC.

RESULTS

Among patients with UC without neoplasia, rectal tissues had significantly higher levels of methylation levels of MIR1, MIR9, MIR124, and MIR137 than in proximal mucosa; levels of methylation were associated with age and duration of UC in rectal mucosa. Methylation of all miRNAs was significantly higher in samples from patients with dysplasia or CRC compared with samples from patients without neoplasia. Receiver operating characteristic analysis revealed that methylation levels of miRNAs in rectal mucosa accurately differentiated patients with CRC from those without. Methylation of MIR137 in rectal mucosa was an independent risk factor for UC-CRC. Methylation patterns of a set of miRNAs (panel) could discriminate discriminate UC patients with or without dysplasia or CRC in the evaluation cohort (area under the curve, 0.81) and the validation cohort (area under the curve, 0.78).

CONCLUSIONS

In evaluation and validation cohorts, we found specific miRNAs to be methylated in rectal mucosal samples from patients with UC with dysplasia or CRC compared with patients without neoplasms. This pattern also associated with patient age and might be used to identify patients with UC at greatest risk for developing UC-CRC. Our findings provide evidence for a field defect in rectal mucosa from patients with UC-CRC.

Use and barriers to chromoendoscopy for dysplasia surveillance in inflammatory bowel disease

Traditionally, patients with inflammatory bowel disease (IBD) have been thought to be at increased risk of developing colitis-associated colorectal cancer. Although there are recent data suggesting that rates of colitis-associated cancer in IBD patients is declining, current guidelines still recommend regular dysplasia surveillance for early detection and prevention of neoplasia in patients with IBD. White-light endoscopy with random biopsies has been the traditional approach for dysplasia detection; however, newer technologies and approaches have emerged. One method, dye-based chromoendoscopy, has the potential to detect more dysplasia. However, longitudinal data to showing a benefit in morbidity or mortality from the use of chromoendoscopy are still lacking. Many societies have included recommendation on the use of chromoendoscopy with targeted biopsies as a method of surveillance for colitis - associated colorectal cancer. This narrative review seeks to outline data on dysplasia detection as well as barriers to the implementation of dye-based chromoendoscopy for the prevention and early detection of colitis-associated colorectal cancer.

Endoscopic Surveillance in Long-standing Colitis

OPINION STATEMENT

There is a relative increase in the risk of colon cancer in patients with inflammatory bowel disease (IBD) affecting the colon, and endoscopic surveillance is advocated to mitigate this risk. The current standard practice is to survey this high-risk patient population using colonoscopy. Chromoendoscopy with targeted biopsies has emerged as the colonoscopy modality recommended by the major societies to optimize dysplasia detection. Studies over the past year support the improved yield from targeted as compared to random biopsies and improved dysplasia detection from chromoendoscopy as compared to white light endoscopy. Ongoing efforts should focus on the implementation of chromoendoscopy as the primary modality for colorectal cancer surveillance in IBD. Our review will describe current status and provide an update on the recent literature on surveillance colonoscopy in patients with IBD.

Dysplasia and colorectal cancer surveillance in inflammatory bowel disease

Inflammatory bowel disease (IBD) patients are at an increased risk of developing colorectal cancer (CRC), a devastating complication of which intestinal dysplasia is the precursor. Considerable progress has been made to determine CRC risk in IBD, identification & management of dysplasia and preventative methods. Traditionally, surveillance colonoscopies with random colonic biopsies was used. However recent data suggests that chromoendoscopy is a better method of surveillance. Using 5-aminosalicylic acid agents primarily for chemoprevention is an ongoing debate however, when prescribed along with other strategies to control inflammation, their use is considered of benefit. This review presents current understanding of risk factors of neoplasia focusing on dysplasia and preventive strategies. Areas covered: PubMed search was done using key words to assess current evidence. Along with genetics, risk factors, strategies that modify the risk of dysplasia, and CRC in IBD are discussed in detail. Expert commentary: The role of our strategies in modifying CRC risk needs further assessment. Future research should aim to fill knowledge gaps such as high quality evidence for Chromoendoscopy and development of molecular markers for dysplasia detection. Our ultimate goal would be to eliminate CRC and is possible by better understanding of key pathogenic mechanisms in IBD.

Stereomicroscopic features of colitis-associated tumors in mice: Evaluation of pit pattern

Patients with longstanding ulcerative colitis have an increased risk of colorectal cancer. Mouse models for colitis-associated tumors are indispensable for the development of novel strategies for prevention and intervention, as well as an improved understanding of the mechanisms underlying tumor formation. The present study examined whether stereomicroscopic observations with dye-application were able to detect and discriminate tumors in a colitis-associated tumor model in mice. Colonic tumors were induced in C57BL/6 mice by 15 cycles of treatment with dextran sulfate sodium (DSS) in drinking water. The mice were then divided into 4 groups: normal mice fed a control diet, normal mice fed an iron-supplemented diet, 0.7% DSS mice fed an iron diet and 1.5% DSS mice fed an iron diet. The entire colons were characterized with respect to both morphology and histology. The pit pattern architecture was analyzed using stereomicroscopy with dye agents (0.2% indigo carmine or 0.06% crystal violet). The tumor histology was graded as negative, indefinite or positive for dysplasia. The positive category was divided into two subcategories: low-grade dysplasia (LGD) and high-grade dysplasia (HGD). The tumor incidences and multiplicity were significantly higher in mice fed an iron diet and 1.5% DSS compared with in mice fed an iron diet and 0.7% DSS. Compared with LGD, HGD was predominantly located in the distal colon, was larger in size and had a higher incidence of elevated lesions (Is and IIa) and a lower incidence of flat lesions (IIb). In regards to the pit pattern, HGD had a high incidence of V_I pits and a low incidence of IV, III_L and II pits. In conclusion, evaluation of the pit pattern using stereomicroscopy with dye-application is useful for detecting and discriminating neoplastic changes in DSS mice and may further our understanding of the mechanisms that induce tumor formation in patients with ulcerative colitis and the characterization of pharmaceutical responses.

Usefulness of confocal laser endomicroscopy to diagnose ulcerative colitis-associated neoplasia

Chromoendoscopy, narrow-band imaging (NBI), and confocal laser endomicroscopy (CLE) have been introduced in ulcerative colitis (UC)-associated neoplasia surveillance. We aimed to determine the ability of CLE to differentiate among UC-associated neoplasia (differentiated type or undifferentiated type), sporadic adenoma, and circumscribed regenerative lesions. Of 665 patients with UC, we carried out probe-based CLE (pCLE) on 12 patients with suspected UC-associated neoplasia in addition to magnifying chromoendoscopy with crystal violet and NBI. We compared pCLE findings with pathological diagnoses. pCLE could differentiate UC-associated differentiated cancer from other pathologies such as solitary adenoma and non-neoplastic circumscribed regenerative lesions on the basis of back-to-back orientation of crypts (P = 0.048), and UC-associated undifferentiated cancer from other pathologies on the basis of dark trabecular architecture (P = 0.015). Sensitivity, specificity, and accuracy of combination of back-to-back orientation of crypts and dark trabecular architecture for carcinoma or dysplasia were 100%, 83%, and 92%, respectively. In vivo microscopic observation with pCLE was helpful to evaluate the suspected UC-associated neoplasia.

Surveillance for dysplasia in patients with ulcerative colitis: Discrepancy between guidelines and practice

BACKGROUND AND AIM

The risk of developing colorectal cancer is higher in patients with ulcerative colitis (UC) than in the general population. Guidelines recommend surveillance colonoscopy (SCS) to reduce mortality; however, few studies have assessed physicians' adherence to guidelines. This study was aimed to clarify the current status of SCS and adherence to guidelines through the characteristics of cancer/dysplasia surveillance for UC patients in Japan.

METHODS

A questionnaire was mailed to 541 physicians who attended meetings on inflammatory bowel disease.

RESULTS

The respondents encountered a median of 100 UC cases. Thirty percent of the respondents had never managed a UC patient with cancer. Fifty-one percent of the respondents had never diagnosed colorectal cancer with UC. Forty-seven percent of the respondents considered extensive colitis and left-sided colitis as indications for SCS, and 38% carried out SCS regardless of the disease extent. Sixty-three percent of the respondents started SCS at 7-10 years after UC onset, whereas 20% started SCS at 3 years or less. Fifty-two percent of the respondents obtained targeted biopsies only, and chromoendoscopy was used by 49% of the respondents as a special technique for surveillance. Median number of biopsies at SCS was five per patient; it was three among patients whose biopsy was carried out by physicians who obtained targeted biopsies only and seven among those carried out by physicians who obtained step biopsies and targeted biopsies (P < 0.0001).

CONCLUSION

A considerable proportion of the respondents did not follow the guidelines when selecting patients for surveillance and carrying out SCS.

Surveillance strategies for colitis-associated cancer: state of the art and future perspectives

Colitis-associated cancer (CAC) represents a concrete risk of morbidity and mortality in patients with long lasting inflammatory bowel diseases. Surveillance colonoscopy is a rapidly evolving research field with profound changes from the traditional approach based on scheduled controls and random biopsy protocols. Areas covered: A literature search was performed using PubMed/Embase to review the latest evidence supporting the need for surveillance colonoscopy. By focusing on the most promising recent advances in this field, we provide a state-of-the-art overview of the current gold standards for the diagnosis and management of colitis-associated dysplasia. Expert commentary: Evidence-based and emerging data have questioned the efficacy and effectiveness of both standard surveillance colonoscopy and random biopsy protocols. The latest guidelines endorse early initiation of surveillance programs, risk-profiling assessment of colonoscopy intervals and standardized use of advanced imaging modalities to detect early dysplasia. Current trends clearly reveal increased attention to direct visualization and endoscopic management of visible dysplastic lesions, even in patients with longstanding colitis. Emerging technological advances in gastrointestinal endoscopy are expected to change the endoscopic surveillance protocols in the near future.