Quality assurance in pathology in colorectal cancer screening and diagnosis—European recommendations

How to "pick up" colorectal serrated lesions and polyps in daily histopathology practice: From terminologies to diagnostic pitfalls

Over the last decade, our knowledge of colorectal serrated polyps and lesions has significantly improved due to numerous studies on this group of precursor lesions. Serrated lesions were misleading as benign before 2010, but they are currently reclassified as precancerous lesions that contribute to 30% of colorectal cancer through the serrated neoplasia pathway. The World Health Organization updated the classification for serrated lesions and polyps of the colon and rectum in 2019, which is more concise and applicable in daily practice. The responsible authors prescribe that “colorectal serrated lesions and polyps are characterized by a serrated (sawtooth or stellate) architecture of the epithelium.” From a clinical standpoint, sessile serrated lesion (SSL) and SSL with dysplasia (SSLD) are the two most significant entities. Despite these advancements, the precise diagnosis of SSL and SSLD based mainly on histopathology remains challenging due to various difficulties. This review describes the nomenclature and the terminology of colorectal serrated polyps and lesions and highlights the diagnostic criteria and obstacles encountered in the histopathological diagnosis of SSL and SSLD.

International consensus on the management of large (≥20 mm) colorectal laterally spreading tumors: World Endoscopy Organization Delphi study

OBJECTIVES

There have been significant advances in the management of large (≥20 mm) laterally spreading tumors (LSTs) or nonpedunculated colorectal polyps; however, there is a lack of clear consensus on the management of these lesions with significant geographic variability especially between Eastern and Western paradigms. We aimed to provide an international consensus to better guide management and attempt to homogenize practices.

METHODS

Two experts in interventional endoscopy spearheaded an evidence-based Delphi study on behalf of the World Endoscopy Organization Colorectal Cancer Screening Committee. A steering committee comprising six members devised 51 statements, and 43 experts from 18 countries on six continents participated in a three-round voting process. The Grading of Recommendations, Assessment, Development and Evaluations tool was used to assess evidence quality and recommendation strength. Consensus was defined as ≥80% agreement (strongly agree or agree) on a 5-point Likert scale.

RESULTS

Forty-two statements reached consensus after three rounds of voting. Recommendations included: three statements on training and competency; 10 statements on preresection evaluation, including optical diagnosis, classification, and staging of LSTs; 14 statements on endoscopic resection indications and technique, including statements on en bloc and piecemeal resection decision-making; seven statements on postresection evaluation; and eight statements on postresection care.

CONCLUSIONS

An international expert consensus based on the current available evidence has been developed to guide the evaluation, resection, and follow-up of LSTs. This may provide guiding principles for the global management of these lesions and standardize current practices.

Refining Risk Criteria May Substantially Reduce Unnecessary Additional Surgeries after Local Resection of T1 Colorectal Cancer

BACKGROUND

The low positive predictive value for lymph node metastases (LNM) of common practice risk criteria (CPRC) in T1 colorectal carcinoma (CRC) leads to manyunnecessary additional surgeries following local resection. This study aimed to identify criteria that may improve on the CPRC.

METHODS

Logistic regression analysis was performed to determine the association of diverse variables with LNM or 'poor outcome' (LNM and/or distant metastases and/or recurrence) in a single center T1 CRC cohort. The diagnostic capacity of the set of variables obtained was compared with that of the CPRC.

RESULTS

The study comprised 161 cases. Poorly differentiated clusters (PDC) and tumor budding grade > 1 (TB > 1) were the only independent variables associated with LNM. The area under the curve (AUC) for these criteria was 0.808 (CI 95% 0.717-0.880) compared to 0.582 (CI 95% 0.479-0.680) for CPRC. TB > 1 and lymphovascular invasion (LVI) were independently associated with 'poor outcome', with an AUC of 0.801 (CI 95% 0.731-0.859), while the AUC for CPRC was 0.691 (CI 95% 0.603-0.752). TB > 1, combined either with PDC or LVI, would reduce false positives between 41.5% and 45% without significantly increasing false negatives.

CONCLUSIONS

Indicating additional surgery in T1 CRC only when either TB > 1, PDC, or LVI are present could reduce unnecessary surgeries significantly.

Are the width, length, depth, and area of submucosal invasion predictive of lymph node metastasis in pT1 colorectal cancer?

PURPOSE

Submucosa-limited (pathological T1, pT1) colorectal cancers (CRCs) pose a continuing challenge in the choice of treatment options, which range from local excision to radical surgery. The aim of this study was to evaluate the morphometric and morphologic risk factors associated with regional lymph node metastasis (LNM) in pT1 CRC.

METHODS

We performed a histological review of patients who underwent oncological resection between 2016 and 2022. Tumor grade, budding, poorly differentiated clusters (PDCs), cancer gland rupture, lymphovascular invasion (LVI), and presence of deep submucosal invasion (DSI), as well as width, length, total area, and area of DSI, were evaluated as potential risk factors for LNM.

RESULTS

A total of 264 cases of colon and rectal carcinomas with invasion into the submucosal layer (pT1) were identified. LNM was found in 46 of the 264 cases (17.4%). All morphometric parameters, as well as DSI (P=0.330), showed no significant association with LNM. High grade adenocarcinoma (P=0.050), budding (P=0.056), and PDCs (P<0.001) were associated with LNM. In the multivariate analysis, LVI presence remained the only significant independent risk factor (odds ratio, 15.7; 95% confidence interval, 8.5-94.9; P<0.001).

CONCLUSION

The DSI of T1 CRC, as well as other morphometric parameters of submucosal tumor spread, held no predictive value in terms of LNM. LVI was the only independent risk factor of LNM.

Endoscopic full-thickness resection versus endoscopic submucosal dissection for challenging colorectal lesions: a randomized trial

BACKGROUND AND AIMS

The optimal endoscopic resection method of challenging colorectal lesions (ie, adenomatous recurrences, nongranular laterally spreading tumors [LST-NGs], lesions without lifting sign <30 mm) is still under debate. The aim of this study was to directly compare endoscopic submucosal dissection (ESD) and endoscopic full-thickness resection (EFTR) for the resection of challenging colorectal lesions in a randomized trial.

METHODS

A multicenter, prospective, randomized study was performed in 4 Italian referral centers. Consecutive patients referred for endoscopic resection of challenging lesions were randomly assigned to undergo EFTR or ESD. Primary outcomes were complete (R0) resection and en bloc resection of lesions. Technical success, procedure time, procedure speed, area of the resected specimen, adverse event rate, and local recurrence rate at 6 months were also compared.

RESULTS

Overall, 90 patients were included in the study, equally representing the 3 challenging lesion types. Age and sex were comparable in the 2 groups. En bloc resection was obtained in 95.5% of the EFTR group and in 93.3% of the ESD group. R0 resection rate was comparable in the 2 groups (EFTR vs ESD, 42 [93.3%] vs 36 [80%]; P = .06). The EFTR group exhibited a significantly shorter total procedure time (25.6 ± 10.6 minutes vs 76.7 ± 26.4 minutes, P ≤ .01), as well as overall procedure speed (16.8 ± 11.8 mm2/min vs 11.9 ± 9.2 mm2/min, P = .03). The EFTR group had a significantly smaller mean lesion size (21.6 ± 8.3 mm vs 28.7 ± 7.7 mm, P ≤ .01). Adverse events were reported less frequently in patients in the EFTR group (4.44% vs 15.5%, P = .04).

CONCLUSIONS

EFTR is comparable to ESD in the treatment of challenging colorectal lesions in terms of safety and efficacy. EFTR is considerably faster than ESD in the treatment of nonlifting lesions and adenoma recurrences. (Clinical trial registration number: NCT05502276.).

Trends in pathology diagnoses during 10 years of a colorectal cancer screening programme

AIMS

We report pathology findings from the first 10 years of the faecal-occult blood-based Northern Ireland Bowel Cancer Screening Programme, presenting summary data and trends in pathology diagnoses and clinicopathological features of screen-detected cancers.

METHODS AND RESULTS

Data were analysed from a comprehensive polyp-level pathology database representing all endoscopy specimens from programme inception in 2010 until 2021. A total of 9800 individuals underwent 13 472 endoscopy procedures, yielding 25 967 pathology specimens and 32 119 diagnoses. Index specimen diagnoses (4.1%) and index colonoscopies (10.4%) yielded a diagnosis of colorectal cancer, representing 1045 cancers from 1020 individuals (25 with synchronous cancers). A further 13 index cancers were identified via computed tomography colonography; 65.3% of cancer diagnoses were in males; 41.7% were stage I, 23.1% stage II, 25.8% stage III and 1.8% stage IV (7.6% unstaged). Of 233 pT1 cancers diagnosed within local excision specimens, 79 (33.9%) had completion surgery. Ten-year trends showed a steady decline in the proportion of index colonoscopies that yielded a diagnosis of cancer (14.7% in year 1; 4.8% in year 11) or advanced colorectal polyp. There was a strong upward trend in diagnoses of sessile serrated lesions, which overtook hyperplastic polyps in proportions of total index diagnoses by the end of the study time-frame (8.7% compared to 8.5%).

CONCLUSIONS

Over the first 10 years of a population colorectal cancer screening programme, 'real world' pathology data demonstrate success in the form of reduced diagnoses of cancer and advanced colorectal polyp with passage of successive screening rounds. Interesting trends with respect to serrated polyp diagnoses are also evident, probably related to pathologist and endoscopist behaviour.

Endoscopic Submucosal Dissection of Superficial Colorectal Neoplasms at "Challenging Sites" Using a Double-Balloon Endoluminal Interventional Platform: A Single-Center Study

BACKGROUND

Colonic endoscopic submucosal dissection (ESD) at "challenging sites" such as the cecum, ascending colon, and colonic flexures could be difficult even for expert endoscopists due to poor endoscope stability/maneuverability, steep angles, and thinner wall thickness. A double-balloon endoluminal intervention platform (EIP) has been introduced in the market to fasten and facilitate ESD, particularly when located at difficult sites. Here, we report our initial experience with an EIP comparing the outcomes of an EIP versus standard ESD (S-ESD) at "challenging sites".

MATERIALS AND METHODS

We retrospectively collected data on consecutive patients with colonic lesions located in the right colon and at flexures who underwent ESD in our tertiary referral center between March 2019 and May 2023. Endoscopic and clinical outcomes (technical success, en bloc resection rate, R0 resection rate, procedure time, time to reach the lesion, and adverse events) and 6-month follow-up outcomes were analyzed.

RESULTS

Overall, 139 consecutive patients with lesions located at these challenging sites were enrolled (EIP: 31 and S-ESD: 108). Demographic characteristics did not differ between groups. En bloc resection was achieved in 92.3% and 93.5% of patients, respectively, in the EIP and S-ESD groups. Both groups showed a comparable R0 resection rate (EIP vs. S-ESD: 92.3% vs. 97.2%). In patients undergoing EIP-assisted ESD, the total procedure time was shorter (96.1 [30.6] vs. 113.6 [42.3] minutes, p = 0.01), and the mean size of the resected lesions was smaller (46.2 ± 12.7 vs. 55.7 ± 17.6 mm, p = 0.003). The time to reach the lesion was significantly shorter in the EIP group (1.9 ± 0.3 vs. 8.2 ± 2.7 min, p ≤ 0.01). Procedure speed was comparable between groups (14.9 vs. 16.6 mm2/min, p = 0.29). Lower adverse events were observed in the EIP patients (3.8 vs. 10.2%, p = 0.31).

CONCLUSIONS

EIP allows results that do not differ from S-ESD in the resection of colorectal superficial neoplasms localized in "challenging sites" in terms of efficacy and safety. EIP reduces the time to reach the lesions and may more safely facilitate endoscopic resection.

Cap-assisted endoscopic mucosal resection as a salvage technique for challenging colorectal laterally spreading tumors

BACKGROUND

Cap-assisted endoscopic mucosal resection (EMR-c) has emerged as a potential alternative to standard piecemeal wide-field EMR (WF-EMR) for the resection of laterally spreading tumors (LSTs). However, clear indications for this technique are still lacking. Our objective was to investigate the performance of salvage EMR-c after WF-EMR failure in the resection of large colorectal LSTs.

METHODS

The data of consecutive patients undergoing WF-EMR for large colorectal LSTs (2015-2021) were analyzed in this single-center, retrospective, observational study. In the event of a WF-EMR failure, the procedure was switched to EMR-c in the same session. The efficacy of the two techniques was evaluated in terms of complete endoscopic resection, R0 resection, and recurrence rate. Safety was also assessed.

RESULTS

Overall, the data from 81 WF-EMRs were collected. Eighteen cases of WF-EMR failure were switched to EMR-c in the same session and complete endoscopic resection was achieved in 17/18 patients (94.4%). No statistically significant difference was observed between WF-EMR and salvage EMR-c in terms of macroscopic radicality (P = 0.40) and R0 resection (P = 0.12). However, recurrence was more common with EMR-c (44.4% vs. 23.5%; P = 0.05), as were adverse events, particularly intraprocedural bleeding (27.8% vs. 7.9%; P = 0.04).

CONCLUSION

EMR-c is an effective salvage technique for challenging colorectal LSTs following WF-EMR failure. Due to the elevated risk of adverse events associated with this procedure, careful patient selection, endoscopic expertise, and close follow-up are strongly recommended.

Recurrence rates after piecemeal endoscopic mucosal resection of large colorectal laterally spreading tumors

Background

Piecemeal endoscopic mucosal resection (pEMR) is routinely employed for large laterally spreading tumors (LSTs). Recurrence rates following pEMR are still unclear, especially when cap-assisted EMR (EMR-c) is performed. We assessed the recurrence rates and recurrence risk factors post-pEMR for large colorectal LSTs, including both wide-field EMR (WF-EMR) and EMR-c.

Methods

This was a single-center, retrospective study of consecutive patients who underwent pEMR for colorectal LSTs ≥20 mm at our institution between 2012 and 2020. Patients had a post-resection follow-up period of at least 3 months. A risk factor analysis was carried out using the Cox regression model.

Results

The analysis included 155 pEMR: 51 WF-EMR and 104 EMR-c, with a median lesion size of 30 (range: 20-80) mm and a median endoscopic follow up of 15 (range: 3-76) months. Overall, disease recurrence occurred in 29.0% of cases; there was no significant difference in recurrence rates between WF-EMR and EMR-c. Recurrent lesions were safely managed by endoscopic removal, and at risk analysis lesion size was the only significant risk factor for recurrence (mm; hazard ratio 1.03, 95% confidence interval 1.00-1.06, P=0.02).

Conclusions

Recurrence of large colorectal LSTs after pEMR occurs in 29% of cases. This rate is mainly dependent on lesion size, and the use of a cap during pEMR has no effect on recurrence. Prospective controlled trials are needed to validate these results.

Idiopathic pulmonary fibrosis and intestinal disorders: An observational study

BACKGROUND AND AIM

Idiopathic pulmonary fibrosis (IPF) is a chronic respiratory disease characterized by a progressive decline in lung function and a specific histopathologic pattern defined as usual interstitial pneumonia. Early diagnosis and new therapeutic protocols have contributed to a reduction in disease progression. Thus, some patients may develop extrapulmonary diseases including malignancies and chronic pathologies. The aim of this study was to investigate the frequency of intestinal disorders such as polyps, colorectal carcinoma (CRC), and chronic inflammatory bowel disease (IBD) in patients with IPF.

METHODS

From the database of 189 patients with IPF (148 males, 78.3 %; 41 females, 21.7 %) residing in the district of Modena, we identified 44 patients (36 males, 81.8 %; 8 females, 18.2 %) with a histologically confirmed intestinal disease.

RESULTS

Intestinal polyps were detected in 41 cases (93.2 %), of which 4 were associated with CRC and 1 with IBD; 1 patient had only CRC (2.3 %), and 2 patients had only IBD (4.5 %). Both males and females developed bowel disease, but males seemed to have a higher number of polyps and high-grade adenomas with a predisposition to malignant transformation.

CONCLUSIONS

As patients with IPF may present with intestinal diseases that can evolve into malignancies in some cases, they should undergo appropriate follow-up and targeted colorectal screening. Thus, colorectal pathologies should not take a back seat. These preliminary results encourage further research to select suitable patients for specific diagnostic and therapeutic procedures in order to prolong survival and improve the quality of life.

Systematic review of shared decision-making in guidelines about colorectal cancer screening

INTRODUCTION

We aimed to systematically evaluate quality of shared decision-making (SDM) in colorectal cancer (CRC) screening clinical practice guidelines (CPGs) and consensus statements (CSs).

METHODS

Search for CRC screening guidances was from 2010 to November 2021 in EMBASE, Web of Science, MEDLINE, Scopus and CDSR, and the World Wide Web. Three independent reviewers and an arbitrator rated the quality of each guidance using a SDM quality assessment tool (maximum score: 31). Reviewer agreement was 0.88.

RESULTS

SDM appeared in 41/83 (49.4%) CPGs and 9/19 (47.4%) CSs. None met all the quality criteria, and 51.0% (52/102) failed to meet any quality items. Overall compliance was low (mean 1.63, IQR 0-2). Quality was better in guidances published after 2015 (mean 1, IQR 0-3 vs. mean 0.5, IQR 0-1.5; p = 0.048) and when the term SDM was specifically reported (mean 4.5, IQR 2.5-4.5 vs. mean 0.5, IQR 0-1.5; p < 0.001). CPGs underpinned by systematic reviews showed better SDM quality than consensus (mean 1, IQR 0-3 vs. mean 0, IQR 0-2, p = 0.040).

CONCLUSION

SDM quality was suboptimal and mentioned in less than half of the guidances, and recommendations were scarce. Guideline developers should incorporate evidence-based SDM recommendations in guidances to underpin the translation of evidence into practice.

Pitfalls in the reporting of neoplastic and pseudo neoplastic lesions in the colon and rectum

INTRODUCTION

Colonic biopsies comprise large portion of pathologists' daily work. Within various pathological entities, there are histological ranges and variations. Unawareness of all of these variabilities might lead to misdiagnosis by an inexperienced pathologist and, accordingly, to mismanagement.

Efficacy and safety of endoscopic resection techniques of large colorectal lesions: experience of a referral center in Italy

BACKGROUND

Endoscopic mucosal resection and submucosal dissection (ESD) are treatments of choice for superficial neoplastic colorectal lesions. Only a few studies have compared these techniques.

AIM

To compare the efficacy and safety of endoscopic piecemeal mucosal resection (EPMR), ESD and hybrid-endoscopic submucosal dissection (H-ESD) of large colorectal lesions in a Western endoscopic center.

METHODS

This is a retrospective analysis on a prospective medical database of consecutive colorectal superficial lesions larger than 20 mm, resected by EPMR, ESD or H-ESD collected from 2015 to 2019.

RESULTS

Two hundred twenty-nine colorectal lesions were included. All lesions were completely endoscopically resected, 65.9% by EPMR, 19.7% by ESD and 14.4% by H-ESD. Endoscopic control after the index procedure was available for 86.5% patients. Among these patients, 80% had a second follow-up colonoscopy. The overall recurrence rate was 13.2, 0 and 6.1% for EPMR, ESD and H-ESD respectively, with a significant difference between EPMR and ESD. All recurrences were endoscopically treated during follow-up procedures. Risk of complications was not significantly different between the three groups.

CONCLUSIONS

EPMR, ESD and H-ESD are effective and safe procedures. Recurrence rate in EPMR was higher but can be managed endoscopically with high success rates. EPMR is faster and technically simpler so should be considered a potential first-line therapy for colorectal superficial neoplastic lesions.

Endoscopic full-thickness resection of polyps involving the appendiceal orifice: a multicenter international experience

BACKGROUND

Endoscopic resection of lesions involving the appendiceal orifice remains a challenge. We aimed to report outcomes with the full-thickness resection device (FTRD) for the resection of appendiceal lesions and identify factors associated with the occurrence of appendicitis.

METHODS

This was a retrospective study at 18 tertiary-care centers (USA 12, Canada 1, Europe 5) between November 2016 and August 2020. Consecutive patients who underwent resection of an appendiceal orifice lesion using the FTRD were included. The primary outcome was the rate of R0 resection in neoplastic lesions, defined as negative lateral and deep margins on post-resection histologic evaluation. Secondary outcomes included the rates of: technical success (en bloc resection), clinical success (technical success without need for further surgical intervention), post-resection appendicitis, and polyp recurrence.

RESULTS

66 patients (32 women; mean age 64) underwent resection of colonic lesions involving the appendiceal orifice (mean [standard deviation] size, 14.5 (6.2) mm), with 40 (61 %) being deep, extending into the appendiceal lumen. Technical success was achieved in 59/66 patients (89 %), of which, 56 were found to be neoplastic lesions on post-resection pathology. Clinical success was achieved in 53/66 (80 %). R0 resection was achieved in 52/56 (93 %). Of the 58 patients in whom EFTR was completed who had no prior history of appendectomy, appendicitis was reported in 10 (17 %), with six (60 %) requiring surgical appendectomy. Follow-up colonoscopy was completed in 41 patients, with evidence of recurrence in five (12 %).

CONCLUSIONS

The FTRD is a promising non-surgical alternative for resecting appendiceal lesions, but appendicitis occurs in 1/6 cases.

Artificial intelligence-assisted colonoscopy: A review of current state of practice and research

Colonoscopy is an effective screening procedure in colorectal cancer prevention programs; however, colonoscopy practice can vary in terms of lesion detection, classification, and removal. Artificial intelligence (AI)-assisted decision support systems for endoscopy is an area of rapid research and development. The systems promise improved detection, classification, screening, and surveillance for colorectal polyps and cancer. Several recently developed applications for AI-assisted colonoscopy have shown promising results for the detection and classification of colorectal polyps and adenomas. However, their value for real-time application in clinical practice has yet to be determined owing to limitations in the design, validation, and testing of AI models under real-life clinical conditions. Despite these current limitations, ambitious attempts to expand the technology further by developing more complex systems capable of assisting and supporting the endoscopist throughout the entire colonoscopy examination, including polypectomy procedures, are at the concept stage. However, further work is required to address the barriers and challenges of AI integration into broader colonoscopy practice, to navigate the approval process from regulatory organizations and societies, and to support physicians and patients on their journey to accepting the technology by providing strong evidence of its accuracy and safety. This article takes a closer look at the current state of AI integration into the field of colonoscopy and offers suggestions for future research.

Surgical rather than endoscopic resection of early-stage colorectal cancers promotes excessive imaging surveillance

BACKGROUND AND AIMS

Imaging surveillance after curative resection of colorectal cancer (CRC) is debated, particularly in cases of early-stage CRC. The aim of this study was to retrospectively analyze whether and how patients with screened stage 0 and stage 1 CRC were monitored by imaging.

METHODS

A cohort of patients with stage 0 (intramucosal) or stage 1 (T1N0) CRC detected from 2003 to 2015 through the French national screening programme was included. All imaging findings were recorded. Statistical analyses were performed for the entire cohort (n = 450) and separately for the two groups (stage 0 n = 268, stage 1 n = 182). Factors associated with imaging surveillance, including the patient's referring gastroenterologist, were determined by logistic regression.

RESULTS

A total of 450 patients were followed up for 6.6 ± 3.9 years. Imaging surveillance was performed for 159 (35.3%), more often for those with stage 1 (66.5%) than stage 0 (14.2%) tumours (p < 0.0001). Within the stage 1 group, 17 of the 47 patients (36.2%) treated by local (endoscopic or surgical transanal) resection alone were followed up by imaging monitoring. Factors significantly associated with surveillance in the entire cohort were the gastroenterologist assigned to the patient (p < 0.0001) and surgical vs endoscopic resection (OR = 39.0, p < 0.0001). The histological risk of lymph node metastasis was not significantly associated with imaging monitoring for stage 1 patients. Of the 5 patients who developed distant metastasis during follow-up, one was diagnosed through imaging surveillance.

CONCLUSION

This study demonstrates excessive imaging surveillance for early-stage cancers. The use of surgical over endoscopic tumour resection could promote unnecessary surveillance.

CAD systems for colorectal cancer from WSI are still not ready for clinical acceptance

Most oncological cases can be detected by imaging techniques, but diagnosis is based on pathological assessment of tissue samples. In recent years, the pathology field has evolved to a digital era where tissue samples are digitised and evaluated on screen. As a result, digital pathology opened up many research opportunities, allowing the development of more advanced image processing techniques, as well as artificial intelligence (AI) methodologies. Nevertheless, despite colorectal cancer (CRC) being the second deadliest cancer type worldwide, with increasing incidence rates, the application of AI for CRC diagnosis, particularly on whole-slide images (WSI), is still a young field. In this review, we analyse some relevant works published on this particular task and highlight the limitations that hinder the application of these works in clinical practice. We also empirically investigate the feasibility of using weakly annotated datasets to support the development of computer-aided diagnosis systems for CRC from WSI. Our study underscores the need for large datasets in this field and the use of an appropriate learning methodology to gain the most benefit from partially annotated datasets. The CRC WSI dataset used in this study, containing 1,133 colorectal biopsy and polypectomy samples, is available upon reasonable request.

The histomorphological and molecular landscape of colorectal adenomas and serrated lesions

The 2019 WHO classification of digestive system tumors significantly reformed the classificatory definition of serrated lesions of the colorectal mucosa and added new essential diagnostic criteria for both conventional adenomas and hereditary gastrointestinal polyposis syndromes. Histopathological examination of colorectal adenocarcinoma precursors lesions represents an important segment of daily clinical practice in a pathology department and is essential for the implementation of current colorectal adenocarcinoma secondary prevention strategies. This overview will focus on a schematic histopathological and molecular classification of precursor lesions arising within colorectal mucosa.

Variability in Synoptic Reporting of Colorectal Cancer pT4a Category and Lymphovascular Invasion

CONTEXT.—

Serosal involvement (pT4a category) and lymphovascular invasion have prognostic significance in colorectal carcinoma, but are subject to interobserver variation in assessment.

OBJECTIVES.—

To provide the first large-scale assessment of interobserver variability in pT4a category and lymphovascular invasion reporting in real-world practice and to explore the impact of information from guidelines on variability in reporting these features.

DESIGN.—

Analysis of 1555 consecutive synoptic reports of colorectal carcinoma was performed using multivariate logistic regression. Interobserver variability before and after the presentation of guideline information was assessed using an image-based survey.

RESULTS.—

Significant differences in the odds of reporting pT4a versus pT3 category, detecting lymphovascular invasion of any type, and detecting large vessel invasion were identified among hospital sites and for individual pathologists compared with the median pathologist at the same site. Consistent with these results, interobserver agreement was only moderate in the image-based survey regarding T4a staging and lymphovascular invasion (all κ ≤ 0.57). The provision of information from guidelines did not tend to increase interobserver agreement in the survey, though responses in favor of using an elastic stain increased following recommendations for their use. However, when observers were provided with elastic-stained images, interobserver agreement remained only moderate (κ = 0.55).

CONCLUSIONS.—

Real-world reporting of pT4a category and lymphovascular invasion shows substantial variability at both local and regional levels. Our study underscores the need to address these features in quality initiatives, and provides a novel method through which existing synoptic data can be harnessed to monitor reporting patterns and provide individualized feedback.

From Mixed Hyperplastic/Adenomatous Polyp to Sessile Serrated Lesion: A Long and Winding Road for Long and Winding Crypts

CONTEXT.—

During the past 3 decades, numerous articles in the literature have offered terminology, diagnostic criteria, and consensus recommendations regarding the entity currently referred to by the World Health Organization as sessile serrated lesion. Given the many names and various, variably reproducible diagnostic criteria ascribed to sessile serrated lesion, confusion persists for many pathologists and gastroenterologists regarding the diagnosis. This distinction is important, as sessile serrated lesion can progress to malignancy, unlike its main differential diagnosis, hyperplastic polyp. Research studies have shed light on the characteristic architecture and morphology, immunohistochemical patterns, and molecular alterations of sessile serrated lesion, and multiple consensus meetings around the globe have developed their criteria and nomenclature, often clashing or mixing terms.

OBJECTIVE.—

To provide a narrative review from the entity's early description to our current understanding.

DATA SOURCES.—

The existing scientific and clinical literature, published texts, medical society recommendations, and specialty consensus guidelines.

CONCLUSIONS.—

The current World Health Organization criteria are a distillation of this scientific process, but terminology is still a point of contention worldwide.

Management of T1 colorectal cancers detected at screening colonoscopy: A study from the French national screening programme

AIM

The main aim of this study was to examine the management strategies that were used and to determine the outcomes (survival and recurrence rate) of screen-detected T1-CRC.

METHODS

Medical records from 207 patients with T1-CRC diagnosed through the French national screening programme in one district from 2003 to 2015 were analysed. The 5-year overall, CRC-specific and CRC-free survival were calculated for the whole cohort and for the 3 groups treated by endoscopic resection (ER) alone, ER followed by subsequent surgery (ERSS), and primary surgery (PS).

RESULTS

Of the 207 patients, 81 (39%) underwent PS, and 126 (61%) underwent primary ER, of whom 82 (64%) underwent subsequent surgery. The 5-year overall and cancer-specific survival rates were 95.5% (95% CI, 90.8; 97.9) and 98.8% (95% CI, 95.4; 99.7%), respectively. Long-term cancer-specific mortality and recurrence crude rates were 2.4% and 5.6%, respectively. The 5-year CRC-free survival rate was 96.1% (95% CI, 91.8; 98.1%) and did not differ amongst the 3 groups (ER alone, ERSS and PS).

CONCLUSION

This study demonstrates the good prognosis of screen-detected T1-CRC, regardless of the treatment strategy used. But, there is a room to improve the screening programme quality with regard to the management of screen-detected CRC.

Poorly differentiated clusters in colorectal cancer: a current review and implications for future practice

Poorly differentiated clusters (PDC), defined as small groups of ≥5 tumour cells without glandular differentiation, have gained recent attention as a promising prognostic factor in colorectal cancer (CRC). Numerous studies have shown PDC to be significantly associated with other adverse histopathological features and worse clinical outcomes. PDC may hold particular promise in stage II colon cancer, where risk stratification plays a critical role in patient selection for adjuvant chemotherapy. In addition, emerging evidence suggests that PDC can predict lymph node metastasis in endoscopically resected pT1 CRC, potentially helping the selection of patients for oncological resection. In 'head-to-head' comparisons, PDC grade has consistently outperformed conventional histological grading systems both in terms of risk stratification and reproducibility. With a number of large-scale studies now available, this review evaluates the evidence regarding the prognostic significance of PDC, considers its relationship with other emerging invasive front prognostic markers (such as tumour budding and stroma type), assesses its 'practice readiness', addressing issues such as interobserver reproducibility, scoring methodologies and special histological subtypes (e.g. micropapillary and mucinous carcinoma), and draws attention to ongoing challenges and areas in need of further study. Finally, emerging data on the role of PDC in non-colorectal cancers are briefly considered.

Neo-adjuvant chemotherapy alone for the locally advanced rectal cancer: a systematic review

Neo-adjuvant chemoradiation (NA-CRT) is the standard of management for the locally advanced rectal cancer (LARC), achieving very low rates of local recurrence (LR). However, NA-CRT fails to control distant recurrence and improve survival, whilst it is associated with increased postoperative morbidity and increased acute and late toxicity. In recent years, neo-adjuvant chemotherapy (NACTx) appears in the literature as an alternative to NA-CRT in patients with LARC. In the present study, the authors review all current evidence on the specific subject. Following a systematic search of the literature, 25 studies were identified reporting on short- or long-term outcomes of NACTx for LARC. Seventeen studies were prospective or retrospective series, and 8 comparative. Of the comparative studies, one was a randomized control trial (RCT) comparing NACTx to NA-CRT and to the combination of NACTx/NA-CRT, and another a non-randomized study comparing NACTx to NA-CRT. Chemotherapeutic regimens were 5-fluoropyrimidine and oxaliplatin based. In some of them, irinotecan or/and bevacizumab was added. A pooled analysis showed that NACTx is associated with a mean anastomotic leak rate of 6.8%. In the RCT, postoperative morbidity and overall toxicity was significantly less in the NACTx group. Mean T downstaging (ypStage 0-I) was 49.6%, mean N downstaging 69.6% and mean pathologic complete response (pCR) 10.7%. The RCT showed an inferior pCR rate after NACTx than after NA-CRT, but similar rates of T downstaging. Mean LR was 8.6% and mean distant recurrence 17.2%. Satisfactory survival rates are reported by several studies. NACTx seems to be an alternative to NA-CRT for patients with LARC, associated with low anastomotic leak, adequate tumour downstaging, low LR and rather high survival rates. Further data deriving from high-quality studies are necessary to assess safety and efficacy of NACTx as a substitute to NA-CRT, for at least a subset of patients with LARC.

Pathological assessment of endoscopic resections of the gastrointestinal tract: a comprehensive clinicopathologic review

Endoscopic resection (ER) allows optimal staging with potential cure of early-stage luminal malignancies while maintaining organ preservation. ER and surgery are non-competing but complementary therapeutic options. In addition, histological examination of ER specimens can either confirm or refine the pre-procedure diagnosis. ER is used for the treatment of Barrett's related early carcinomas and dysplasias, early-esophageal squamous cell carcinomas and dysplasias, early gastric carcinomas and dysplasia, as well as low-risk submucosal invasive carcinomas (LR-SMIC) and, large laterally spreading adenomas of the colon. For invasive lesions, histological risk factors predict risk of lymph node metastasis and residual disease at the ER site. Important pathological risk factors predictive of lymph node metastasis are depth of tumor invasion, poor differentiation, and lymphovascular invasion. Complete resection with negative margins is critical to avoid local recurrences. For non-invasive lesions, complete resection is curative. Therefore, a systematic approach for handling and assessing ER specimens is recommended to evaluate all above key prognostic features appropriately. Correct handling starts with pinning the specimen before fixation, meticulous macroscopic assessment with orientation of appropriate margins, systematic sectioning, and microscopic assessment of the entire specimen. Microscopic examination should be thorough for accurate assessment of all pathological risk factors and margin assessment. Site-specific issues such as duplication of muscularis mucosa of the esophagus, challenges of assessing ampullectomy specimens and site-specific differences of staging of early carcinomas throughout the gastrointestinal tract (GI) tract should be given special consideration. Finally, a standard, comprehensive pathology report that allows optimal staging with potential cure of early-stage malignancies or better stratification and guidance for additional treatment should be provided.

Malignant Colorectal Polyp Pathology: Are We Getting Sufficient Information to Make Decisions?

The College of American Pathologists has published guidelines for malignant colorectal polyp pathology reports that list histopathological features that are "core elements" and "optional." Lack of element reporting may result in inaccurate tumor risk stratification.This study aimed to perform a population-based assessment of pathology reporting for T1 colorectal cancers and determine the completeness of reporting for core and optional histopathological elements.This is a retrospective cohort study.This study reviews the pathology reports of endoscopically resected malignant colorectal polyps in Alberta, Canada between 2014 and 2016.Individuals aged 18 years or older with T1 colorectal polyps were selected.Histopathological elements were dichotomized into core and optional. Malignant polyps were classified as high risk or low risk for lymph node metastases and local intraluminal recurrence. Addendum reports were compared with first reports.After applying exclusion criteria, 431 polyps were analyzed. The mean age of patients was 65.5 years; 59.4% were male. Histological grade, deep margin, and lymphovascular invasion were reported in 82.4%, 86.8% and 75.6%; all 3 were reported in only 66.4%. Tumor budding (not in the 2016 guidelines) was reported in 14.4%. One hundred ninety polyps (44.1%) were high risk. Thirty-seven polyps (8.3%) had an addendum report. Following the addendum, 1 polyp was downgraded to low risk, and 9 polyps were upgraded to high risk.The main limitation of the study is its retrospective nature. The decision making surrounding treatment for T1 cancers is complex, and factors other than histopathological tumor features may have been part of treatment decisions.There is a high rate of incomplete reporting of core and optional elements for malignant colorectal polyp pathology reports in Alberta. Several variables used by colorectal surgeons for decision making, such as tumor budding and depth of submucosal invasion, are not considered core elements and are infrequently reported. A pathology review by a second pathologist often results in a change in risk stratification. See Video Abstract at http://links.lww.com/DCR/B98. PATOLOGÍA DEL PÓLIPO COLORRECTAL MALIGNO: ¿ESTAMOS OBTENIENDO INFORMACIÓN SUFICIENTE PARA TOMAR DECISIONES?: El Colegio de Patólogos Americanos publico pautas para informes de patología de pólipos colorrectales malignos que enumeran características histopatológicas como "elementos centrales" y "opcionales". La falta de información elemental puede resultar en una estratificación de riesgo tumoral imprecisa.Valoración basada en una población de los informes de patología para los cánceres colorrectales T1 y determinar la precisión de los informes en cuanto los elementos histopatológicos centrales y opcionales.Estudio de cohorte retrospectivo.Este estudio revisa los informes de patología de pólipos colorrectales malignos resecados endoscópicamente en Alberta, Canadá, entre 2014 y 2016.personas mayores de 18 años con pólipos colorrectales T1.Los elementos histopatológicos se dicotomizaron entre elementales y opcionales. Pólipos malignos se clasificaron como de alto riesgo o bajo riesgo de metástasis en los ganglios linfáticos y recurrencia intraluminal local. Los informes enmendados se compararon con los informes originales.Después de aplicar los criterios de exclusión, se analizaron 431 pólipos. La edad media fue 65.5 años, con 59.4% masculinos. El grado histológico, el margen profundo y la invasión linfovascular se informaron confirmaron en 82.4%, 86.8% y 75.6% respectivamente; las tres características se demostraron en solo 66.4%. Un patrón tumoral en ciernes se reporto en 14.4-una característica que no se usaba en las guías de 2016. Ciento noventa pólipos (44.1%) eran de alto riesgo. Treinta y siete pólipos (8.3%) requirieron de un informe enmendado. Aplicación de los nuevos criterios resulto en que 1 pólipo se redujo a bajo riesgo y 9 pólipos se actualizaron como a alto riesgo.La principal limitación del estudio es el diseño retrospectivo. La toma de decisiones en torno al tratamiento de los cánceres T1 es compleja y otros factores además de las características histopatológicas del tumor pueden haber sido parte de las decisiones terapéuticas.Hay una alta tasa de informes incompletos de elementos centrales y opcionales para informes de patología de pólipos colorrectales malignos en Alberta. Algunas variables utilizadas por los cirujanos colorrectales para la toma de decisiones, como el patrón tumoral en ciernes y la profundidad de la invasión submucosa, no se consideran elementos centrales y se informan con poca frecuencia. Una revisión de patología realizada por un segundo patólogo a menudo resulta en un cambio en la estratificación del riesgo. Consulte Video Resumen en http://links.lww.com/DCR/B98. (Traducción-Dr. Adrian E. Ortega).

Colorectal epithelial neoplasm associated with gut-associated lymphoid tissue

BACKGROUND

Colorectal epithelial neoplasm extending into the submucosal gut-associated lymphoid tissue (GALT) can cause difficulties in the differential diagnosis. Regarding GALT-associated epithelial neoplasms, a few studies favor the term "GALT carcinoma" while other studies have mentioned the term "GALT-associated pseudoinvasion/epithelial misplacement (PEM)".

METHODS

The clinicopathologic characteristics of 11 cases of colorectal epithelial neoplasm associated with submucosal GALT diagnosed via endoscopic submucosal dissection were studied.

RESULTS

Eight cases (72.7%) were in males. The median age was 59 years, and age ranged from 53 to 73. All cases had a submucosal tumor component more compatible with GALT-associated PEM. Eight cases (72.7%) were located in the right colon. Ten cases (90.9%) had a non-protruding endoscopic appearance. Nine cases (81.8%) showed continuity between the submucosal and surface adenomatous components. Nine cases showed (81.8%) focal defects or discontinuation of the muscularis mucosae adjacent to the submucosal GALT. No case showed hemosiderin deposits in the submucosa or desmoplastic reaction. No case showed single tumor cells or small clusters of tumor cells in the submucosal GALT. Seven cases (63.6%) showed goblet cells in the submucosa. No cases showed oncocytic columnar cells lining submucosal glands.

CONCLUSIONS

Our experience suggests that pathologists should be aware of the differential diagnosis of GALT-associated submucosal extension by colorectal adenomatous neoplasm. Further studies are needed to validate classification of GALT-associated epithelial neoplasms.

IBD-Associated Dysplastic Lesions Show More Chromosomal Instability Than Sporadic Adenomas

BACKGROUND

Patients with longstanding inflammatory bowel disease (IBD; ie, ulcerative colitis and Crohn's disease) have an increased risk of colorectal cancer (CRC). Due to ongoing inflammation, IBD-associated dysplastic lesions can develop. These lesions have an increased risk to progress to cancer compared with sporadic adenomas, which are also found in these patients. Differentiating between these 2 types of dysplasia remains challenging, both clinically and histologically, while treatment strategies may differ. Therefore, the aim of this study was to investigate molecular alterations associated with colorectal dysplasia to cancer progression in IBD and evaluate to what extent these alterations differ from sporadic adenomas.

METHODS

DNA copy number aberrations and mutation analyses of 48 genes were performed by next-generation sequencing in 43 IBD-associated dysplastic lesions, 30 of which were dysplastic and 13 of which were cancers. Results were compared with existing DNA copy number and mutation data from 118 sporadic adenomas and 24 sporadic cancers.

RESULTS

Inflammatory bowel disease-associated dysplastic lesions harbor patterns of DNA copy number aberrations comparable to carcinomas, which are rare in sporadic adenomas. TP53 mutation was the most frequent mutation observed in IBD-associated dysplastic lesions and in cancers. FBXW7 was mutated significantly more often in IBD-associated dysplastic lesions than in sporadic adenomas.

CONCLUSIONS

Inflammatory bowel disease-associated dysplastic lesions show more DNA copy number aberrations than sporadic adenomas. TP53 and FBXW7 mutations appear to be involved in the development of IBD-associated dysplastic lesions and cancer. These findings indicate that IBD-associated dysplastic lesions are more genomically unstable, possibly reflecting a faster progression toward cancer.

Current Management of Malignant Colorectal Polyps Across a Regional United Kingdom Cancer Network

BACKGROUND

The incidence of malignant colorectal polyps has increased secondary to the greater use of diagnostic colonoscopy and introduction of screening programs. Faced with the dilemma of whether major resection is required or whether polypectomy has been sufficient treatment, the clinician relies on high- and low-risk histological parameters to guide decision-making.

OBJECTIVE

The purpose of this study was to review current practice and evaluate multidisciplinary team decision-making across a United Kingdom Regional Cancer Network to establish the efficacy of previously set guidance from the Association of Coloproctology of Great Britain and Ireland (2013).

DESIGN

This was a retrospective cohort study.

SETTINGS

The study was conducted at a United Kingdom Regional Cancer Network composed of 4 separate National Health Service Hospital Trusts, covering an overall population of 1.5 million.

PATIENTS

All patients with malignant colorectal polyps who presented to the colorectal multidisciplinary team over a 3-year period (April 1, 2012 to April 1, 2015) were included.

MAIN OUTCOME MEASURES

Rate of residual disease after major resection, recurrence of cancer after polypectomy and surveillance alone, reporting of histological features, adherence to endoscopic surveillance guidelines, and outcomes of surveillance cross-sectional imaging were measured.

RESULTS

A total of 173 patients (median age = 69 y) with a malignant colorectal polyp were identified during the study period, with a median of 2.7 years of follow-up. Thirty-seven patients (21.4%) underwent primary surgical resection with a residual disease rate of 43% (16/37). The remaining 136 patients (76.8%) were managed conservatively with recurrence in 6 cases (4.4%). Endoscopic follow-up at 3 months occurred in 61% of cases. Histological reporting was varied, with tumor differentiation and resection margin being reported in 84% of cases and lymphovascular invasion and depth of invasion in 71% and 59% of cases, respectively.

LIMITATIONS

This was an observational retrospective study.

CONCLUSIONS

The residual disease rate in patients treated surgically was higher than previously reported (43.2%). Incidence of recurrence in patients treated conservatively was low (4.4%). Areas of improvements have been identified in adherence to endoscopic follow-up, histopathological reporting, and potential overuse of radiological surveillance. See Video Abstract at http://links.lww.com/DCR/B47. MANEJO ACTUAL DE PÓLIPOS COLORRECTALES MALIGNOS A TRAVÉS DE UNA RED REGIONAL DE CÁNCER DEL REINO UNIDO: La incidencia de pólipos colorrectales malignos ha aumentado secundariamente al mayor uso de la colonoscopia diagnóstica y a la introducción de programas de detección. Ante el dilema de si se requiere una resección mayor o si la polipectomía ha sido un tratamiento suficiente, el médico se basa en parámetros histológicos de alto y bajo riesgo, para guiarse en la toma de decisiones.Revisar la práctica actual y evaluar la toma de decisiones, del equipo multidisciplinario de una red regional de cáncer del Reino Unido, para establecer la eficacia de las recomendaciones previamente establecidas, por la Asociación de Coloproctología de la Gran Bretaña e Irlanda (2013).Estudio de cohorte retrospectivo.Red Regional del Cáncer del Reino Unido, que comprende cuatro Fideicomisos Hospitalarios del Servicio Nacional de Salud y que cubren una población general de 1,5 millones de personas.Todos los pacientes con pólipos colorrectales malignos presentados al equipo colorrectal multidisciplinario durante un período de 3 años (01/04/2012-01/04/2015).Tasa de enfermedad residual después de una resección mayor, recurrencia de cáncer después de polipectomía y vigilancia sola, informe de características histológicas, adherencia a directrices de vigilancia endoscópica y resultados de la vigilancia de la imagen transversal.Se identificaron un total de 173 pacientes (mediana de edad de 69 años) con pólipo colorrectal maligno durante el período de estudio, con una mediana de seguimiento de 2.7 años. 37 pacientes (21,4%) fueron sometidos a resección quirúrgica primaria con tasa de enfermedad residual del 43% (16/37). Los 136 pacientes restantes (76.8%) fueron manejados conservadoramente, con recurrencia en 6 casos (4.4%). El seguimiento endoscópico a los 3 meses, ocurrió en el 61% de los casos. El reporte histológico varió con la diferenciación tumoral. El margen de resección se informó en el 84% de los casos. La invasión linfovascular y la profundidad de la invasión fue del 71% y 59% de los casos.Estudio observacional retrospectivo.La tasa de enfermedad residual en pacientes tratados quirúrgicamente, fue más alta que la reportada previamente (43.2%). La incidencia de recurrencia en pacientes tratados de forma conservadora fue baja (4,4%). Se han identificado áreas de mejoras en cumplimiento del seguimiento endoscópico, informe histopatológico y el posible uso excesivo de la vigilancia radiológica. Vea el Resumen del Video en http://links.lww.com/DCR/B47.

Role of Endoscopic Resection Versus Surgical Resection in Management of Malignant Colon Polyps: a National Cancer Database Analysis

BACKGROUND

Endoscopic resection (polypectomy) or surgery, are the main approaches in management of malignant colon polyps. There are very few large population-based studies comparing outcomes between the two.

METHODS

Using the National Cancer Database, we identified patients ≥ 18 years with the first diagnosis of T1N0M0 malignant polyp from 2004 to 2015. Patients with a positive resection margin were excluded. Outcomes were compared between those who had surgery versus those who had polypectomy. Overall survival was compared using Kaplan-Meier curves. Multivariate Cox proportional hazards analysis was performed to generate hazard ratios, adjusted for patient, demographic, and tumor factors.

RESULTS

A total of 31,062 patients met the inclusion criteria, out of which 2593 (8.3%) underwent polypectomy alone and 28,469 (91.7%) had surgery. Overall survival was significantly better in the surgical group compared with the polypectomy group. One-year and 5-year survival for surgery were 95.8% and 86.1% respectively compared with 94.2% and 80.6% for polypectomy (p < .0001). Hazard ratio for surgery after adjusting for various clinical-, demographic-, and tumor-level factors was 0.53 (p < .0001).

CONCLUSION

Our study is the largest population-based analysis of patients with T1N0M0 malignant colon polyps. Overall survival was higher in patients who underwent surgery compared with polypectomy. This remained consistent even after adjusting for multiple patient and tumor factors between the two groups.

Endoscopic full-thickness resection of duodenal lesions (with video)

BACKGROUND AND AIM

The endoscopic treatment of non-lifting or submucosal duodenal lesions is associated with a high risk of incomplete resection and adverse events. Clip-assisted endoscopic full-thickness resection (EFTR) is a new approach for en bloc removal of neoplastic lesions in the GI tract. The aim of this study was to investigate its efficacy and safety in the duodenum.

MATERIALS AND METHODS

We retrospectively collected all consecutive patients with duodenal lesions who underwent EFTR with OTSC (Ovesco Endoscopy, Tübingen, Germany) or the new full-thickness resection device (FTRD; Ovesco Endoscopy, Tübingen, Germany). Complete resection rate was defined as histologically-verified R0 resection. Main endoscopic and clinical outcomes (technical success, rate of EFTR, adverse events) were systematically assessed at 3 and 6 months.

RESULTS

Between May 2017 and January 2019, 10 patients with duodenal lesions underwent EFTR (5 non-lifting adenomas, 2 adenomas recurrence/relapse and 3 subepithelial tumours). Technical success was overall achieved in 8/10 cases (80%). The two FTRD failed cases were completed with snare resection. The complete full-thickness resection rate was achieved in 8/10 (80%), while in two cases it was limited to mucosal or submucosal layer. R0 resection rate was achieved in 8/10 (80%) patients. The mean procedure time was 75 min (range 53-120 min). There were no major adverse events. At 3 and 6-month follow-up, no recurrence was observed.

CONCLUSIONS

Clip-assisted EFTR is a feasible and effective technique for en bloc resection of "difficult" superficial neoplasia and submucosal lesions in the duodenum, representing another technique that must be part of the endoscopist's armamentarium.

Virtual Chromoendoscopy With FICE for the Classification of Polypoid and Nonpolypoid Raised Lesions in Ulcerative Colitis

GOALS

The aim of this study was to analyze the performance of Fuji Intelligent Color Enhancement (FICE) using the classification of Kudo in the differentiation of neoplastic and non-neoplastic raised lesions in ulcerative colitis (UC).

BACKGROUND

The Kudo classification of mucosal pit patterns is an aid for the differential diagnosis of colorectal polyps in the general population, but no systematic studies are available for all forms of raised lesions in UC.

STUDY

All raised, polypoid and nonpolypoid, lesions found during consecutive surveillance colonoscopies with FICE for long-standing UC were included. In the primary prospective analysis, the Kudo classification was used to predict the histology by FICE. In a post hoc analysis, further endoscopic markers were also explored.

RESULTS

Two hundred and five lesions (mean size, 8 mm; range, 2 to 30 mm) from 59 patients (mean age, 56 y; range, 21 to 79 y) were analyzed. Twenty-three neoplastic (11%), 18 hyperplastic (9%), and 164 inflammatory (80%) lesions were found. Thirty-one lesions (15%), none of which were neoplastic, were unclassifiable according to Kudo. After logistic regression, a strong negative association resulted between endoscopic activity and neoplasia, whereas the presence of a fibrin cap was significantly associated with endoscopic activity. Using FICE, the sensitivity, specificity, and positive and negative likelihood ratios of the Kudo classification were 91%, 76%, 3.8, and 0.12, respectively. The corresponding values by adding the fibrin cap as a marker of inflammation were 91%, 93%, 13, and 0.10, respectively.

CONCLUSIONS

FICE can help to predict the histology of raised lesions in UC. A new classification of pit patterns, based on inflammatory markers, should be developed in the setting of UC to improve the diagnostic performance.

Colo-rectal endoscopic full-thickness resection (EFTR) with the over-the-scope device (FTRD®): A multicenter Italian experience

BACKGROUND AND AIM

Endoscopic full-thickness resection(EFTR) with FTRD^® in colo-rectum may be useful for several indications.The aim was to assess its efficacy and safety.

MATERIAL AND METHODS

In this retrospective multicenter study 114 patients were screened; 110 (61M/49F, mean age 68 ± 11 years, range 20-90) underwent EFTR using FTRD^®. Indications were:residual/recurrent adenoma (39), incomplete resection at histology (R1 resection) (26), non-lifting lesion (12), adenoma involving the appendix (2) or diverticulum (2), subepithelial lesions(10), suspected T1 carcinoma (16), diagnostic resection (3). Technical success (TS: lesion reached and resected), R0 resection (negative lateral and deep margins),EFTR rate(all layers documented in the specimen) and safety have been evaluated.

RESULTS

TS was achieved in 94.4% of cases. EFTR was achieved in 91% with lateral and deep R0 resection in 90% and 92%. Mean size of specimens was 20 mm (range 6-42). In residual/recurrent adenomas, final analysis revealed: low-risk T1 (11), adenoma with low-grade dysplasia (LGD) (24) and high-grade dysplasia (HGD) (3), scar tissue (1). Histology reports of R1 resections were: adenoma with LGD (6), with HGD (1), low-risk (6) and high-risk (1) T1, scar tissue (12). Non-lifting lesions were diagnosed as: adenoma with HGD (3), low-risk (7) and high risk (2) T1. Adverse clinical events occurred in 12 patients (11%),while adverse technical events in11%. Three-months follow-up was available in 100 cases and residual disease was evident in only seven patients.

CONCLUSIONS

EFTR using FTRD^® seems to be a feasible, effective and safe technique for treating selected colo-rectal lesions. Comparative prospective studies are needed to confirm these promising results.

World Endoscopy Organization Consensus Statements on Post-Colonoscopy and Post-Imaging Colorectal Cancer

BACKGROUND & AIMS

Colonoscopy examination does not always detect colorectal cancer (CRC)- some patients develop CRC after negative findings from an examination. When this occurs before the next recommended examination, it is called interval cancer. From a colonoscopy quality assurance perspective, that term is too restrictive, so the term post-colonoscopy colorectal cancer (PCCRC) was created in 2010. However, PCCRC definitions and methods for calculating rates vary among studies, making it impossible to compare results. We aimed to standardize the terminology, identification, analysis, and reporting of PCCRCs and CRCs detected after other whole-colon imaging evaluations (post-imaging colorectal cancers [PICRCs]).

METHODS

A 20-member international team of gastroenterologists, pathologists, and epidemiologists; a radiologist; and a non-medical professional met to formulate a series of recommendations, standardize definitions and categories (to align with interval cancer terminology), develop an algorithm to determine most-plausible etiologies, and develop standardized methodology to calculate rates of PCCRC and PICRC. The team followed the Appraisal of Guidelines for Research and Evaluation II tool. A literature review provided 401 articles to support proposed statements; evidence was rated using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. The statements were voted on anonymously by team members, using a modified Delphi approach.

RESULTS

The team produced 21 statements that provide comprehensive guidance on PCCRCs and PICRCs. The statements present standardized definitions and terms, as well as methods for qualitative review, determination of etiology, calculation of PCCRC rates, and non-colonoscopic imaging of the colon.

CONCLUSIONS

A 20-member international team has provided standardized methods for analysis of etiologies of PCCRCs and PICRCs and defines its use as a quality indicator. The team provides recommendations for clinicians, organizations, researchers, policy makers, and patients.

Interval colorectal cancer: a challenging field in colorectal cancer

Accumulated evidence has shown that colonoscopy may not be a perfect tool in screening and reducing the incidence of the colorectal cancer (CRC), because interval CRC (I-CRC), a specific subgroup of CRCs, has been challenging the traditional detection technology in recent years. I-CRC is accounting for an increasing proportion in CRCs. However, the effective procedures to prevent and supervise I-CRC need to be explored. In this review, we summarized the incidence, causes, risk factors, characteristics and management of I-CRC. It would promote the awareness of the special value in the education and training for the gastroenterologists, which plays an important role in conquering CRC.

Genetic and epigenetic profiling of a solitary Peutz-Jeghers colon polyp

Colon polyps represent precursor lesions of colon cancers and their malignant potential varies according to histological subtype. A rare subtype of colon polyps is the Peutz–Jeghers (PJ) polyp. PJ polyps mostly occur in the context of Peutz–Jeghers syndrome, which is characterized by the development of multiple polyps in the intestinal tract and hyperpigmentation of oral mucosa and lips. Peutz–Jeghers is an autosomal dominant disorder caused by pathogenic variants of the serine threonine kinase STK11. PJ polyps very rarely occur outside of the syndrome and are then referred to as solitary PJ polyps. Contrary to the situation in Peutz–Jeghers, the genetic basis and the malignant potential of solitary PJ polyps are currently unknown. Here we describe a detailed and comprehensive genetic profile of a solitary PJ polyp. Pathological examination revealed a high tissue homogeneity with >80% epithelial cells. Whole-genome sequencing failed to identify any clonal mutations but demonstrated a significant number of subclonal mutations. No somatic or germline mutations were found at the STK11 locus, suggesting that solitary PJ polyps are genetically distinct from Peutz–Jeghers polyps. In addition, methylome analysis revealed global hypomethylation and CpG island hypermethylation, two features that have been described as hallmarks of the colorectal cancer epigenome. These results provide an example of a premalignant lesion that is defined by epigenetic, rather than genetic changes. Furthermore, our findings support the notion that solitary PJ polyps constitute neoplastic tissue with malignant potential that should be removed for cancer prevention.

Problematic Colorectal Polyps: Is It Cancer and What Do I Need to Do About It?

Two issues commonly arise for pathologists reporting adenomatous polyps of the colorectum. Particularly problematic within large sigmoid colonic adenomas is the distinction between benign misplacement of epithelium into the submucosa and invasive malignancy. This distinction requires careful morphologic evaluation of key discriminatory features, assisted only rarely by the application of selected adjunctive immunohistochemistry. Following a diagnosis of adenocarcinoma within a polypectomy or other local excision specimen, systematic assessment is required of features that may indicate the risk of residual local and/or nodal neoplastic disease and inform management decision-making regarding the need for further endoscopic or surgical intervention.

Endoscopic full-thickness resection of superficial colorectal neoplasms using a new over-the-scope clip system: A single-centre study

BACKGROUND AND AIM

Endoscopic full-thickness resection (EFTR) provides complete en-bloc resection with a histopathological evaluation of submucosal, muscular, and serosal layers. The aim of this study was to investigate the efficacy and safety of a novel over-the-scope device for colorectal EFTR.

MATERIAL AND METHODS

In this retrospective, observational, open-label case study, a total of 20 patients with superficial colorectal neoplasms, underwent EFTR using a new endoscopic full-thickness resection device (FTRD; Ovesco Endoscopy, Tübingen, Germany). Endoscopic treatment outcomes (technical success, rate of EFTR, adverse events) and early follow-up at three months, were analyzed.

RESULTS

We reported a 100% of technical success, defined as full-thickness resection. Among the R1 resections, histology was negative for neoplasm. Non-lifting adenomas had histology positive for adenocarcinoma: seven T1/G1/sm1; one T1/G1/sm2; one, who underwent a surgical resection, T1/G1/sm3. Mean size of the resected lesions was 26mm, ranging from 10 to 42mm. One (5%) patient developed abdominal pain, fever and leukocytosis and was treated conservatively with medical therapy. In all specimens, histological complete resection was confirmed.

CONCLUSIONS

EFTR is a feasible and effective technique that could become a valid alternative to EMR and ESD in the management of recurrent adenomas, no-lifting lesions and scars of R1 resections. However, prospective studies are needed to further evaluate the device and technique.

A Nomogram to Predict Adequate Lymph Node Recovery before Resection of Colorectal Cancer

Increased lymph node count (LNC) has been associated with prolonged survival in colorectal cancer (CRC), but the underlying mechanisms are still poorly understood. The study aims to identify new predictors and develop a preoperative nomogram for predicting the probability of adequate LNC (≥ 12). 501 eligible patients were retrospectively selected to identify clinical-pathological factors associated with LNC ≥ 12 through univariate and multivariate logistic regression analyses. The nomogram was built according to multivariate analyses of preoperative factors. Model performance was assessed with concordance index (c-index) and area under the receiver operating characteristic curve (AUC), followed by internal validation and calibration using 1000-resample bootstrapping. Clinical validity of the nomogram and LNC impact on stage migration were also evaluated. Multivariate analyses showed patient age, CA19-9, circulating lymphocytes, neutrophils, platelets, tumor diameter, histology and deposit significantly correlated with LNC (P < 0.05). The effects were marginal for CEA, anemia and CRC location (0.05 < P < 0.1). The multivariate analyses of preoperative factors suggested decreased age, CEA, CA19-9, neutrophils, proximal location, and increased platelets and diameter were significantly associated with increased probability of LNC ≥ 12 (P < 0.05). The nomogram achieved c-indexes of 0.75 and 0.73 before and after correction for overfitting. The AUC was 0.75 (95% CI, 0.70–0.79) and the clinically valid threshold probabilities were between 10% and 60% for the nomogram to predict LNC < 12. Additionally, increased probability of adequate LNC before surgery was associated with increased LNC and negative lymph nodes rather than increased positive lymph nodes, lymph node ratio, pN stages or AJCC stages. Collectively, the results indicate the LNC is multifactorial and irrelevant to stage migration. The significant correlations with preoperative circulating markers may provide new explanations for LNC-related survival advantage which is reflected by the implication of regional and systemic antitumor immune responses.

Narrow-band Imaging International Colorectal Endoscopic Classification to predict polyp histology: REDEFINE study (with videos)

BACKGROUND AND AIMS

The Narrow-band Imaging International Colorectal Endoscopic (NICE) Classification has been validated for differentiating hyperplastic from adenomatous polyps. This classification system was based on narrow-band imaging (NBI) technology, leaving uncertainty regarding its applicability to other systems. The aim of this study was to assess accuracy and reliability of histologic predictions for polyps <1 cm by applying the NICE classification to the Fujinon Spectral Imaging Color Enhancement (FICE) System.

METHODS

A video library of 55 polyps <1 cm histologically verified with FICE was prospectively created, including polyps that fulfilled inclusion criteria (morphology, size, histology) in consecutive colonoscopies. Six endoscopists with experience in electronic chromoendoscopy independently reviewed the polyp images, scored the polyps as adenomatous or hyperplastic, and assigned a level of confidence to the predictions. Twenty videos were reassessed at 6 months. The diagnostic performances of the endoscopists was calculated both combined and individually according to the histopathology of the polyps. A mixed-effect logistic regression model, in which polyps were considered as random effects, and polyp histology, confidence level, and readers were considered as fixed effects, was used. Results were expressed as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Of the 55 polyps (mean size 4.6 mm), 29 (53%) were adenomas, and 26 (47%) were hyperplastic. Across all the readers and observations, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the curve (AUC) were 77%, 75%, 88%, 75%, 77%, and 0.82, respectively. Individual rater accuracy ranged from 66% to 96%, being <90% in 5 of 6 cases. Overall, 68.5% of predictions (226/330) were made with high confidence, although there was high variability (Fleiss kappa, 0.15; 95% CI, 0.08-0.22). Sensitivity, specificity, PPV, NPV, accuracy, and AUC for predictions made with high confidence were 81%, 80.5%, 80%, 77%, 82%, and 0.88 being significantly more accurate as compared with a low confidence of diagnosis (OR 2.4; 95% CI, 1.2-4.7). Regarding the performance of the individual NICE criteria, the odds of adenoma detection were 3.4 (95% CI, 1.8-6.3) and 4.0 (95% CI, 2.1-7.5) by using surface and vessels patterns alone, as compared with the color criterion. Interrater and intrarater agreement with the NICE was only moderate (interrater: Fleiss kappa, 0.51; 95% CI, 0.44-0.56; intrarater: kappa, 0.40; 95% CI, 0.20-0.60).

CONCLUSIONS

The application of the NICE classification to FICE resulted in suboptimal accuracy and only moderate interobserver agreement.

A comparison of endoscopy versus pathology sizing of colorectal adenomas and potential implications for surveillance colonoscopy

BACKGROUND AND AIMS

The aim of this study was to compare endoscopy and pathology sizing in a large population-based series of colorectal adenomas and to evaluate the implications for patient stratification into surveillance colonoscopy.

METHODS

Endoscopy and pathology sizes available from intact adenomas removed at colonoscopies performed as part of the Northern Ireland Bowel Cancer Screening Programme, from 2010 to 2015, were included in this study. Chi-squared tests were applied to compare size categories in relation to clinicopathologic parameters and colonoscopy surveillance strata according to current American Gastroenterology Association and British Society of Gastroenterology guidelines.

RESULTS

A total of 2521 adenomas from 1467 individuals were included. There was a trend toward larger endoscopy than pathology sizing in 4 of the 5 study centers, but overall sizing concordance was good. Significantly greater clustering with sizing to the nearest 5 mm was evident in endoscopy versus pathology sizing (30% vs 19%, P < .001), which may result in lower accuracy. Applying a 10-mm cut-off relevant to guidelines on risk stratification, 7.3% of all adenomas and 28.3% of those 8 to 12 mm in size had discordant endoscopy and pathology size categorization. Depending on which guidelines are applied, 4.8% to 9.1% of individuals had differing risk stratification for surveillance recommendations, with the use of pathology sizing resulting in marginally fewer recommended surveillance colonoscopies.

CONCLUSIONS

Choice of pathology or endoscopy approaches to determine adenoma size will potentially influence surveillance colonoscopy follow-up in 4.8% to 9.1% of individuals. Pathology sizing appears more accurate than endoscopy sizing, and preferential use of pathology size would result in a small, but clinically important, decreased burden on surveillance colonoscopy demand. Careful endoscopy sizing is required for adenomas removed piecemeal.

Molecular pathological classification of colorectal cancer

Colorectal cancer (CRC) shows variable underlying molecular changes with two major mechanisms of genetic instability: chromosomal instability and microsatellite instability. This review aims to delineate the different pathways of colorectal carcinogenesis and provide an overview of the most recent advances in molecular pathological classification systems for colorectal cancer. Two molecular pathological classification systems for CRC have recently been proposed. Integrated molecular analysis by The Cancer Genome Atlas project is based on a wide-ranging genomic and transcriptomic characterisation study of CRC using array-based and sequencing technologies. This approach classified CRC into two major groups consistent with previous classification systems: (1) ∼16 % hypermutated cancers with either microsatellite instability (MSI) due to defective mismatch repair (∼13 %) or ultramutated cancers with DNA polymerase epsilon proofreading mutations (∼3 %); and (2) ∼84 % non-hypermutated, microsatellite stable (MSS) cancers with a high frequency of DNA somatic copy number alterations, which showed common mutations in APC, TP53, KRAS, SMAD4, and PIK3CA. The recent Consensus Molecular Subtypes (CMS) Consortium analysing CRC expression profiling data from multiple studies described four CMS groups: almost all hypermutated MSI cancers fell into the first category CMS1 (MSI-immune, 14 %) with the remaining MSS cancers subcategorised into three groups of CMS2 (canonical, 37 %), CMS3 (metabolic, 13 %) and CMS4 (mesenchymal, 23 %), with a residual unclassified group (mixed features, 13 %). Although further research is required to validate these two systems, they may be useful for clinical trial designs and future post-surgical adjuvant treatment decisions, particularly for tumours with aggressive features or predicted responsiveness to immune checkpoint blockade.

Clinical practice guidelines for the surgical treatment of rectal cancer: a consensus statement of the Hellenic Society of Medical Oncologists (HeSMO)

In rectal cancer management, accurate staging by magnetic resonance imaging, neo-adjuvant treatment with the use of radiotherapy, and total mesorectal excision have resulted in remarkable improvement in the oncological outcomes. However, there is substantial discrepancy in the therapeutic approach and failure to adhere to international guidelines among different Greek-Cypriot hospitals. The present guidelines aim to aid the multidisciplinary management of rectal cancer, considering both the local special characteristics of our healthcare system and the international relevant agreements (ESMO, EURECCA). Following background discussion and online communication sessions for feedback among the members of an executive team, a consensus rectal cancer management was obtained. Statements were subjected to the Delphi methodology voting system on two rounds to achieve further consensus by invited multidisciplinary international experts on colorectal cancer. Statements were considered of high, moderate or low consensus if they were voted by ≥80%, 60-80%, or <60%, respectively; those obtaining a low consensus level after both voting rounds were rejected. One hundred and two statements were developed and voted by 100 experts. The mean rate of abstention per statement was 12.5% (range: 2-45%). In the end of the process, all statements achieved a high consensus. Guidelines and algorithms of diagnosis and treatment were proposed. The importance of centralization, care by a multidisciplinary team, adherence to guidelines, and personalization is emphasized.