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

Development and application of deep learning-based diagnostics for pathologic diagnosis of gastric endoscopic submucosal dissection specimens

BACKGROUND

Accurate diagnosis of ESD specimens is crucial for managing early gastric cancer. Identifying tumor areas in serially sectioned ESD specimens requires experience and is time-consuming. This study aimed to develop and evaluate a deep learning model for diagnosing ESD specimens.

METHODS

Whole-slide images of 366 ESD specimens of adenocarcinoma were analyzed, with 2257 annotated regions of interest (tumor and muscularis mucosa) and 83,839 patch images. The development set was divided into training and internal validation sets. Tissue segmentation performance was evaluated using the internal validation set. A detection algorithm for tumor and submucosal invasion at the whole-slide image level was developed, and its performance was evaluated using a test set.

RESULTS

The model achieved Dice coefficients of 0.85 and 0.79 for segmentation of tumor and muscularis mucosa, respectively. In the test set, the diagnostic performance of tumor detection, measured by the AUROC, was 0.995, with a specificity of 1.000 and a sensitivity of 0.947. For detecting submucosal invasion, the model achieved an AUROC of 0.981, with a specificity of 0.956 and a sensitivity of 0.907. Pathologists' performance in diagnosing ESD specimens was evaluated with and without assistance from the deep learning model, and the model significantly reduced the mean diagnosis time (747 s without assistance vs. 478 s with assistance, P < 0.001).

CONCLUSION

The deep learning model demonstrated satisfactory performance in tissue segmentation and high accuracy in detecting tumors and submucosal invasion. This model can potentially serve as a screening tool in the histopathological diagnosis of ESD specimens.

Risk Factors of Lymph Node Metastasis and Prognosis in 891 Chinese Patients With Submucosal Early Gastric Carcinoma, Emphasizing Differences Between Gastric Cardiac and Noncardiac Origins

Differences in risk factors (RF) of lymph node metastasis (LNM) and prognosis between submucosal early gastric cardiac (SEGCC) and noncardiac (SEGNCC) carcinomas remain unclear. In this study, we investigated and compared RF of LNM and prognosis in 891 patients with radical gastrectomy for SEGCC (n=217) or SEGNCC (n=674). Compared with SEGNCC, SEGCC displayed significantly higher proportion of elderly patients (70 y or above), the elevated macroscopic type, well/moderately differentiated tubular and low-grade papillary adenocarcinomas, as well as low-grade tumor budding, but lower prevalence of the depressed macroscopic type, poorly differentiated tubular adenocarcinoma, mixed adenocarcinoma, poorly cohesive carcinoma, lymphovascular invasion (LVI), perineural invasion, and high-grade tumor budding. By univariate analysis, significant RF for LNM of the cohort included female sex, poor differentiation, SM2 invasion, LVI, intermediate-grade and high-grade tumor budding, whereas tumor size, histology type, and perineural invasion were the significant RF for LNM in SEGNCC. By multivariate analysis, significant independent RF for LNM included female sex and LVI in SEGCC but were female sex, mixed adenocarcinoma, LVI, and high-grade tumor budding in SEGNCC. The 5-year overall survival was significantly worse in SEGCC than in SEGNCC for patients with LNM, but not for those without. For overall survival, LNM was the only significant independent RF in SEGCC, whereas age 70 years or above and LNM were independent RF in SEGNCC. The results of our study provided the clinicopathologic evidence for individualized clinical management strategies for these 2 groups of patients and suggested different pathogenesis mechanisms between SEGCC and SEGNCC.

A simplified algorithm to evaluate the risk of submucosal invasive cancer in large (≥20 mm) nonpedunculated colonic polyps

BACKGROUND

Recognition of submucosal invasive cancer (SMIC) in large (≥20 mm) nonpedunculated colonic polyps (LNPCPs) informs selection of the optimal resection strategy. LNPCP location, morphology, and size influence the risk of SMIC; however, currently no meaningful application of this information has simplified the process to make it accessible and broadly applicable. We developed a decision-making algorithm to simplify the identification of LNPCP subtypes with increased risk of potential SMIC.

METHODS

Patients referred for LNPCP resection from September 2008 to November 2022 were enrolled. LNPCPs with SMIC were identified from endoscopic resection specimens, lesion biopsies, or surgical outcomes. Decision tree analysis of lesion characteristics identified in multivariable analysis was used to create a hierarchical classification of SMIC prevalence.

RESULTS

2451 LNPCPs were analyzed: 1289 (52.6%) were flat, 1043 (42.6%) nodular, and 118 (4.8%) depressed. SMIC was confirmed in 273 of the LNPCPs (11.1%). It was associated with depressed and nodular vs. flat morphology (odds ratios [ORs] 35.7 [95%CI 22.6-56.5] and 3.5 [95%CI 2.6-4.9], respectively; P<0.001); rectosigmoid vs. proximal location (OR 3.2 [95%CI 2.5-4.1]; P<0.001); nongranular vs. granular appearance (OR 2.4 [95%CI 1.9-3.1]; P<0.001); and size (OR 1.12 per 10-mm increase [95%CI 1.05-1.19]; P<0.001). Decision tree analysis targeting SMIC identified eight terminal nodes: SMIC prevalence was 62% in depressed LNPCPs, 19% in nodular rectosigmoid LNPCPs, and 20% in nodular proximal colon nongranular LNPCPs.

CONCLUSIONS

This decision-making algorithm simplifies identification of LNPCPs with an increased risk of potential SMIC. When combined with surface optical evaluation, it facilitates accurate lesion characterization and resection choices.

Histopathological Assessment of the Endoscopic Resection Specimen

Background

Endoscopic resection for early neoplastic lesions of the gastrointestinal tract is nowadays the accepted and feasible method also in non-tertiary reference centers. The main clinical advantage is the preserved quality of life compared to larger surgical procedures.

Summary

Clinical colleagues need to have basic knowledge of factors that may influence the outcome of histopathology. This article discusses issues connected to the histopathological work-up of endoscopic resection specimens within in the gastrointestinal tract.

Key Messages

Besides the clinical technical prerequisites, standardized histopathology is the key element of the pathology laboratory work-up of endoscopic resection specimens. Overdiagnoses of reactive lesions as low-grade neoplasia lead to incomparable study data and although criteria to overcome this situation exist, they are not accepted worldwide, calling for further efforts in harmonization.

Hybrid resection versus conventional resection for laterally spreading lesions of the papilla

BACKGROUND AND AIMS

Although conventional hot snare resection (CR) of laterally spreading lesions of the major papilla (LSL-Ps) is effective, it can be associated with delayed bleeding in upward of 25% of cases. Given the excellent safety profile of cold snare polypectomy in the colorectum, we investigated the efficacy and safety of a novel hybrid resection (HR) technique for LSL-P management, consisting of hot snare papillectomy plus cold snare resection of the laterally spreading component.

METHODS

A prospective cohort of patients underwent HR in a tertiary referral center over 60 months until December 2022. This cohort was compared with a historical cohort of patients who underwent CR at the same institution over 120 months until August 2017. The primary outcomes were recurrence and bleeding.

RESULTS

Twenty patients underwent HR (14 female; mean age 65.2 ± 12.2 years). Median lesion size was 30 mm (interquartile range, 25.0-47.5 mm). Recurrent or residual adenoma (RRA) was greater with HR (58.8% [n = 10] vs 29.8% [n = 14]; P = .034). The odds ratio for recurrence was 3.6 times (95% CI, 1.2-11.0) higher with HR (P = .027). RRA was multifocal in 4 (40%) and had a composite RRA volume >10 mm in 7 (70%). The median number of procedures required to treat RRA was higher with HR (4 vs 1, P = .002). There was no difference between CR and HR for intraprocedural bleeding (41.1% [n = 23] vs 25% [n = 5]; P = .587) or delayed bleeding (25.0% vs 10.0%, P = .211). There were no perforations.

CONCLUSIONS

The novel HR technique for LSL-P management is associated with a high rate of RRA that is recalcitrant to treatment, without mitigating the risk of intraprocedural or delayed bleeding. Therefore, CR should remain the mainstay management option for treating patients with an LSL-P. (Clinical trial registration number: NCT02306603.).

Essentials of macroscopic evaluation of specimens from gastrointestinal tract

An astute macroscopic examination, coupled with correlating the gross findings with clinical indication and operative notes along with judicious, yet all pertinent sectioning for pathological examination is crucial for an accurate histopathological diagnosis, eventually leading to optimal patient care. This succinct review highlights the general concepts that lay the foundation of evaluating and grossing specimens from the luminal gastrointestinal (GI) tract. We also discuss the gross evaluation and sectioning of small therapeutic resections, along with a systematic approach and rationale when grossing and submitting histological sections from larger oncological resections from the luminal GI tract. Selected site-specific considerations, for example, grossing treated rectal and oesophageal cancers or taking sections from mucinous tumours of the appendix, among others, are also discussed.

Endoscopic resection of large anastomotic polyps is safe and effective

BACKGROUND

Large (≥20mm) adenomatous anastomotic polyps (LAAPs) are uncommon. Data pertaining to their prevalence, characteristics, and the efficacy of endoscopic resection (ER) are absent. A safe and effective strategy for ER would reduce morbidity and healthcare costs.

METHODS

Large nonpedunculated colorectal polyps of ≥20mm (LNPCPs) referred for ER were prospectively studied. Multiple data points were recorded including anastomotic location, polyp morphology, resection modality, complications, and technical success.

RESULTS

Over 7 years until November 2022, 2629 lesions were referred. Of these, 10 (0.4%) were LAAPs (median size 35 mm [interquartile range (IQR) 30-40mm]). All LAAPs were removed by piecemeal endoscopic mucosal resection (EMR), most (n=9; 90%) in combination with cold-forceps avulsion with adjuvant snare-tip soft coagulation (CAST). On comparison of the LAAP group with the conventional LNPCP group, CAST was more commonly used (90% vs. 9%; P<0.001) and deep mural injury (DMI) type II was more frequent (40% vs. 11%, P=0.003); however, significant DMI (III-V) did not occur. At 6 month (IQR 5.25-6 months) surveillance, there was no recurrence in any of the 10 cases. There were no serious adverse events.

CONCLUSIONS

LAAPs present unique challenges owing to their location overlying an anastomosis. Despite these challenges they can be safely and effectively managed endoscopically without recurrence at endoscopic follow-up.

Lensless single-fiber ghost imaging

We demonstrate lensless single-fiber ghost imaging, which allows illumination and collection using a single optical fiber without a transmission-type system. Speckle patterns with relative coincidence degrees of 0.14 were formed by image reconstruction using improved differential ghost imaging. Employing fiber with a diameter of 105 µm, we achieved a spatial resolution of 0.05 mm in an observing area of 9m m 2, at a working distance of 10 mm. Compared to a conventional neuroendoscope at a power density of 94m W/c m 2, our imaging could be realized by extremely weak illumination at a laser power density of 0.10m W/c m 2. Using our lensless single-fiber ghost imaging, with 30,000 speckle patterns and implementing a diffuser, we attained an average coincidence degree of 0.45.

Safety and feasibility of same-day discharge after endoscopic submucosal dissection: a Western multicenter prospective cohort study

BACKGROUND AND AIMS

Recent Western studies support the safety and efficacy of endoscopic submucosal dissection (ESD) for lesions throughout the GI tract. Although admission for observation after ESD is standard in Asia, a more selective approach may optimize resource utilization. We aimed to evaluate the safety and feasibility of same-day discharge (SDD) after ESD and factors associated with admission.

METHODS

This was a post hoc analysis of a multicenter, prospective cohort of patients undergoing ESD (2016-2021). The primary end points were safety of SDD and factors associated with post-ESD admission.

RESULTS

Of 831 patients (median age, 67 years; 57% male) undergoing 831 ESDs (240 performed in the esophagus, 126 in the stomach, and 465 in the colorectum; median lesion size, 44 mm), 588 (71%) were SDD versus 243 (29%) admissions. Delayed bleeding and perforation occurred in 12 (2%) and 4 (.7%) of SDD patients, respectively; only 1 (.2%) required surgery. Of the 243 admissions, 223 (92%) were discharged after ≤24 hours of observation. Interestingly, larger lesion size (>44 mm) was not associated with higher admission rate (odds ratio [OR], .5; 95% confidence interval [CI], .3-.8; P = .001). Lesions in the upper GI tract versus colon (OR, 1.7; 95% CI, 1.1-2.6; P = .01), invasive cancer (OR, 1.9; 95% CI, 1.2-3.1; P = .01), and adverse events (OR, 2.7; 95% CI, 1.5-4.8; P = .001) were independent factors for admission. Admissions were more likely performed by endoscopists with ESD volume <50 cases (OR, 2.1; 95% CI, 1.3-3.3; P = .001) with procedure time >75 minutes (OR, 13.5; 95% CI, 8.5-21.3; P < .0001).

CONCLUSIONS

SDD after ESD can be safe and feasible. Patients with invasive cancer, lesions in the upper GI tract, longer procedure times, or procedures performed by low-volume ESD endoscopists are more likely to be admitted postprocedure. Risk stratification of patients for SDD after ESD should help optimize resource utilization and enhance ESD uptake in the West. (Clinical trial registration number: NCT02989818.).

Measuring the Submucosal Depth of Invasion in Endoscopic Mucosal Resections for Barrett-associated Adenocarcinoma: Practical Issues and Relevance for the Decision for Esophagectomy

CONTEXT.—

Endoscopic mucosal resection (EMR) has made it possible for Barrett esophagus patients with superficial cancers to be treated without esophagectomy. Recent guidelines recommend measuring depth of invasion (DOI) in submucosal cancers based on reports that in low-risk cancers, submucosal invasion 500 μm or less is associated with low nodal metastasis rates. However, pathologists face challenges in reproducibly measuring DOI.

OBJECTIVE.—

To determine how often DOI measurements could impact treatment and to evaluate reproducibility in measuring submucosal DOI in EMR specimens.

DESIGN.—

Consecutive adenocarcinoma EMR cases were identified, including cases of "low histologic risk" submucosal cancer, as follows: those with negative deep margins, no high-grade histology (G3), and no lymphovascular invasion. Submucosal DOI was measured by 7 pathologists according to guidelines.

RESULTS.—

Of 213 cancer EMR cases, 46 were submucosa invasive and 6 cases were low histologic risk submucosal cancers for which measurement could impact decision-making. Of these low histologic risk cases, 3 were categorized as superficial, indicating that measurement would be a clinically actionable decision point in only 1.4% of adenocarcinoma EMRs. Interobserver agreement for in-depth categorization between 7 pathologists was moderate (κ = 0.42), and the range of measurements spanned the 500-μm relevant threshold in 40 of 55 measured samples (72.7%).

CONCLUSIONS.—

While therapeutic decisions would rarely have depended on DOI measurements alone in our cohort, interobserver variability raises concerns about their use as a sole factor on which to offer patients conservative therapy. Responsibly reporting and clinically using submucosal DOI measurements will require practical experience troubleshooting common histologic artifacts, as well as multidisciplinary awareness of the impact of variable specimen-handling practices.

Academy of Medicine, Singapore clinical guideline on endoscopic surveillance and management of gastric premalignant lesions

Gastric cancer (GC) has a good prognosis, if detected at an early stage. The intestinal subtype of GC follows a stepwise progression to carcinoma, which is treatable with early detection and intervention using high-quality endoscopy. Premalignant lesions and gastric epithelial polyps are commonly encountered in clinical practice. Surveillance of patients with premalignant gastric lesions may aid in early diagnosis of GC, and thus improve chances of survival. An expert professional workgroup was formed to summarise the current evidence and provide recommendations on the management of patients with gastric premalignant lesions in Singapore. Twenty-five recommendations were made to address screening and surveillance, strategies for detection and management of gastric premalignant lesions, management of gastric epithelial polyps, and pathological reporting of gastric premalignant lesions.

Effect of endoscopic submucosal dissection on histologic diagnosis in Barrett's esophagus visible neoplasia

BACKGROUND AND AIMS

Data are limited on the role of endoscopic submucosal dissection (ESD) as a potential diagnostic and staging tool in Barrett's esophagus (BE) neoplasia. We aimed to evaluate the frequency and factors associated with change of histologic diagnosis by ESD compared with pre-ESD histology.

METHODS

This was a multicenter, prospective cohort study of patients who underwent ESD for BE visible neoplasia. A change in histologic diagnosis was defined as "upstaged" or "downstaged" if the ESD specimen had a higher or lower degree, respectively, of dysplasia or neoplasia when compared with pre-ESD specimens.

RESULTS

Two hundred five patients (median age, 69 years; 81% men) with BE visible neoplasia underwent ESD from 2016 to 2021. Baseline histology was obtained using forceps (n = 182) or EMR (n = 23). ESD changed the histologic diagnosis in 55.1% of cases (113/205), of which 68.1% were upstaged and 31.9% downstaged. The frequency of change in diagnosis after ESD was similar whether baseline histology was obtained using forceps (55.5%) or EMR (52.2%) (P = .83). In aggregate, 23.9% of cases (49/205) were upstaged to invasive cancer on ESD histopathology. On multivariate analysis, lesions in the distal esophagus and gastroesophageal junction (odds ratio, 2.1; 95 confidence interval, 1.1-3.9; P = .02) and prior radiofrequency ablation (odds ratio, 2.5; 95% confidence interval, 1.2-5.5; P = .02) were predictors of change in histologic diagnosis.

CONCLUSIONS

ESD led to a change of diagnosis in more than half of patients with BE visible neoplasia. Selective ESD can serve as a potential diagnostic and staging tool, particularly in those with suspected invasive disease. (Clinical trial registration number: NCT02989818.).

Malignant colon polyps: predicting lymph node metastasis following endoscopic excision

AIM

The risk of lymph node metastasis (LNM) of malignant colon polyps (MCPs) is partly estimated by histologic features of the sampled polyp. However, the routinely available histologic data is limited to tumor grade and status of lymphovascular invasion (LVI).

METHODS

The NCDB for colon cancer 2004-2018 was utilized. Patients with pT1Nx adenocarcinoma arising in a polyp and undergoing partial colectomy with ≥ 12 retrieved nodes were selected. NCDB 2004-2017 was used as a training cohort to develop two scoring systems based on a multivariable regression for predictors of LNM including clinical characteristics, grade, and LVI: a nomogram scoring system (NSS) and a simplified scoring system (SSS). These models were internally validated using NCDB 2018 to calculate precision metrics for each model.

RESULTS

Six thousand sixty-nine patients were selected in the training cohort. 64.5% of MCPs were in the sigmoid, and LNM rate was 11.2%. Multivariable regression identified younger age, females, hindgut location, higher grade, and LVI as significant predictors of LNM. LNM risk was 1.2% when all unfavorable predictors were absent and exceeded 10% when NSS > 70 or SSS ≥ 3. In the 2018 validation cohort, 723 patients were scored per NSS and SSS, and the negative predictive value for both was 96%.

CONCLUSION

Estimating LNM risk in MCPs by applying clinical characteristics along with limited histologic data can help inform decision-making when considering formal oncologic resection. The NSS and SSS demonstrated comparable predictability of LNM among pT1Nx MCPs. The models require external validation and may be strengthened by incorporating additional endoscopic and pathologic characteristics.

Significant variation in histopathological assessment of endoscopic resections for Barrett's neoplasia suggests need for consensus reporting: propositions for improvement

Endoscopic resection (ER) is an important diagnostic step in management of patients with early Barrett's esophagus (BE) neoplasia. Based on ER specimens, an accurate histological diagnosis can be made, which guides further treatment. Based on depth of tumor invasion, differentiation grade, lymphovascular invasion, and margin status, the risk of lymph node metastases and local recurrence is judged to be low enough to justify endoscopic management, or high enough to warrant invasive surgical esophagectomy. Adequate assessment of these histological risk factors is therefore of the utmost importance. Aim of this study was to assess pathologist concordance on these histological features on ER specimens and evaluate causes of discrepancy. Of 62 challenging ER cases, one representative H&E slide and matching desmin and endothelial marker were digitalized and independently assessed by 13 dedicated GI pathologists from 8 Dutch BE expert centers, using an online assessment module. For each histological feature, concordance and discordance were calculated. Clinically relevant discordances were observed for all criteria. Grouping depth of invasion categories according to expanded endoscopic treatment criteria (T1a and T1sm1 vs. T1sm2/3), ≥1 pathologist was discrepant in 21% of cases, increasing to 45% when grouping diagnoses according to the traditional T1a versus T1b classification. For differentiation grade, lymphovascular invasion, and margin status, discordances were substantial with 27%, 42%, and 32% of cases having ≥1 discrepant pathologist, respectively. In conclusion, histological assessment of ER specimens of early BE cancer by dedicated GI pathologists shows significant discordances for all relevant histological features. We present propositions to improve definitions of diagnostic criteria.

AGA Clinical Practice Update on Surveillance After Pathologically Curative Endoscopic Submucosal Dissection of Early Gastrointestinal Neoplasia in the United States: Commentary

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update was to review the available evidence and provide expert advice regarding surveillance using endoscopy and other relevant modalities after removal of dysplastic lesions and early gastrointestinal cancers with endoscopic submucosal dissection deemed to be pathologically curative. This Clinical Practice Update was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. This expert commentary incorporates important as well as recently published studies in this field, and it reflects the experiences of the authors, who are advanced endoscopists with high-level expertise in performing endoscopic submucosal dissection to treat dysplasia and early cancers in the luminal gastrointestinal tract.

Clinicopathologic correlations of superficial esophageal adenocarcinoma in endoscopic submucosal dissection specimens

Background

Endoscopic submucosal dissection (ESD) is a novel endoscopic treatment for early esophageal adenocarcinoma (EAC). The western pathologists’ experience with ESD specimens remains limited. This study aimed to correlate histopathologic features of Barrett’s esophagus (BE)-associated adenocarcinoma in ESD resections with clinical outcomes to determine whether they aid future management decisions.

Methods

We retrospectively evaluated 49 consecutive ESD resection specimens from 42 patients with BE-associated adenocarcinoma (24 intramucosal and 18 submucosal EAC) at a single tertiary referral center. Pathologic evaluation included presence of dysplasia, invasive adenocarcinoma, peritumoral inflammation, desmoplasia, lymphovascular and perineural invasion; tumor differentiation, depth of invasion, morphology, and budding; and margin status for dysplasia or carcinoma. Follow up data included endoscopic biopsies in 35 patients and pathology reports of esophagectomies in 11 patients. Poor outcomes were defined as recurrence or residual invasive adenocarcinoma at esophagectomy, metastasis on imaging, or R1 resection in patients undergoing ESD for tumor debulking.

Results

Two patients (8%) with intramucosal adenocarcinoma and 9 patients (50%) with submucosal adenocarcinoma had poor outcomes. Histopathologic features associated with poor outcomes included poor differentiation, lymphovascular invasion, submucosal invasion > 500 μm, tumor budding, and tubuloinfiltrative histologic pattern. Four patients had positive deep margin away from the deepest tumor invasion and did not show residual tumor on follow up.

Conclusions

Our results validated European Society of Gastroenterology (ESGE) guidelines of high-risk pathologic features for additional therapy in esophageal adenocarcinoma and identified tumor budding frequently in association with other high-risk features. Positive deep margin distant from deepest tumor invasion could be procedural and warrants endoscopic correlation for management.

Analysis of the Diagnostic Effect of EUS-RTE on Giant Cystic Tumours of the Oesophagus Based on Cluster Analysis

This paper presents an in-depth analysis and study of the diagnostic effectiveness of EUS-RTE in giant cystic tumours of the oesophagus utilizing cluster analysis. A new form of interval data expression was designed based on the cluster analysis algorithm, as well as a new way of updating the cluster radius and cluster centre. Feature triads are defined, eliminating the need to access all historical data at the time of update. It also prevents the case of overfusion of clusters and outputting only one cluster. If there exist a very low number of clusters, the newly merged clusters are reclustered according to the density clustering method for the internal data objects based on the cluster segmentation so that the data objects in the same cluster have a high similarity as possible. All accumulated electronic files of oesophageal cancer cases were collected and comprehensively organized, and all clinical data of 129 eligible cases with a total of 356 consultations were screened in strict accordance with inclusion and exclusion criteria. A database of oesophageal cancer cases was established using Visual FoxPro software, and frequency distribution, cluster analysis, association rule, and chi-square test were used to focus on mining the association between symptoms, disease mechanisms, prescriptions, and medications. The results were analysed and summarized. Overall, the therapeutic efficacy and safety of the three groups of treatment modalities for gastric mesenchymal tumours were positive, and the preoperative endoscopic treatment modalities should be selected based on the EUS-RTE characteristics of the tumour, the site, and the operator's skill level in a comprehensive manner.

Evolving management of colorectal polyps

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

Human telomerase reverse transcriptase (hTERT) synergistic with Sp1 upregulate Gli1 expression and increase gastric cancer invasion and metastasis

Abnormal expression of human telomerase reverse transcriptase (hTERT) has been widely identified in tumors, but the relevant mechanism is not well known. This study aims to investigate the role and mechanism of hTERT in gastric cancer metastasis. Gastric cancer and adjacent non-tumor tissues were collected and the expression levels of hTERT and Gli1 were detected by immunohistochemistry. The results demonstrated that hTERT and Gli1 expression levels in gastric cancer tissue were significantly higher than adjacent non-tumor tissues. Western blot and quantitative real-time PCR were used to an identified expression of the related protein in BGC-823 and SGC-7901 cells. The interactions between hTERT and Sp1 were tested by co-immunoprecipitation experiments. Chromatin immunoprecipitation was performed to confirm that Sp1 and hTERT could bind to the Gli1 promoter. Chromatin reimmunoprecipitation assay further demonstrated that both hTERT and Sp1 bind to the Sp1 site of the Gli1 promoter. Moreover, the hTERT, Sp1, and Gli1 were upregulate was verified in human gastric cancer tissues. These results showed that the expression levels of hTERT in GC tissues were strongly closed to the depth of invasion, lymph node metastasis, TNM (tumor, node, metastasis) stage, and distant metastasis. By combining Sp1 and Gli1 promoter, hTERT upregulated Gli1 expression and promoted invasion and metastasis of GC cells. Overall, these data provide a new molecular mechanism of hTERT to promotes gastric cancer progression. Targeting the hTERT/Sp1/Gli1 axis may represent a new therapeutic strategy.

Measuring depth of invasion of submucosa - invasive adenocarcinoma in oesophageal endoscopic specimens: how good are we?☆

AIMS

Emerging data support that submucosa-invasive (pT1b) esophageal adenocarcinomas are cured via endoscopic resection, provided that invasion measures ≤500 μm, they lack other histological features predictive of nodal metastasis and have negative margins. Hence, pathologists' measurement of the depth of submucosal invasion in endoscopic resections may dictate further management (i.e. endoscopic follow-up versus oesophagectomy). In this study, we assessed the interobserver agreement in measuring the depth of submucosal invasion in oesophageal endoscopic resections.

METHODS AND RESULTS

Six subspecialised gastrointestinal (GI) pathologists from five academic centres independently measured the depth of submucosal invasion in μm from the deepest muscularis mucosae on 37 oesophageal endoscopic resection slides (round 1 scoring). A consensus meeting with a systematic approach for measuring and discussion of pitfalls was undertaken and remeasuring (round 2 scoring) was conducted. Interobserver agreement was assessed by the intraclass correlation coefficient (ICC) and Cohen's kappa statistics. A lack of agreement was seen among the six reviewers with a poor ICC for both rounds: 1 [0.40, 95% confidence interval (CI) = 0.26-0.56] and 2 (0.49, 95% CI = 0.34-0.63). When measurements were categorised as < or >500 μm, the overall agreement among the six reviewers was only fair for both rounds: 1 (kappa = 0.37, 95% CI = 0.22-0.53) and 2 (kappa = 0.29, 95% CI = 0.12-0.46).

CONCLUSIONS

Our study shows a lack of agreement among gastrointestinal pathologists in measuring the depth of submucosal invasion in oesophageal endoscopic resections despite formulating a consensus approach for scoring. If important management decisions continue to be based upon this parameter, more reproducible and concrete guidelines are needed.

Fecal Enterotoxigenic Bacteroides fragilis-Peptostreptococcus stomatis-Parvimonas micra Biomarker for Noninvasive Diagnosis and Prognosis of Colorectal Laterally Spreading Tumor

Objective

Up to now, non-invasive diagnosis of laterally spreading tumor (LST) and prediction of adenoma recurrence after endoscopic resection of LSTs is inevitable. This study aimed to identify a microbial signature with clinical significance of diagnosing LSTs and predicting adenoma recurrence after LSTs colectomy.

Methods

We performed 16S rRNA sequencing in 24 mucosal samples, including 5 healthy controls (HC), 8 colorectal adenoma (CRA) patients, and 11 LST patients. The differentiating microbiota in fecal samples was quantified by qPCR in 475 cases with 113 HC, 208 CRA patients, 109 LST patients, and 45 colorectal cancer (CRC) patients. We identified differentially abundant taxa among cases and controls using linear discriminant analysis effect size analysis. ROC curve was used to evaluate diagnostic values of the bacterial candidates. Pairwise comparison of AUCs was performed by using the Delong's test. The Mantel-Haenszel hazard models were performed to determine the effects of microbial compositions on recurrence free survival.

Results

The microbial dysbiosis of LST was characterized by relative high abundance of the genus Lactobacillus-Streptococcus and the species enterotoxigenic Bacteroides fragilis (ETBF)-Peptostreptococcus stomatis (P. stomatis)-Parvimonas micra (P. micra). The abundance of ETBF, P. stomatis, and P. micra were steadily increasing in LST and CRC groups. P. stomatis behaved stronger value on diagnosing LST than the other two bacteria (AUC 0.887, 95% CI 0.842-0.931). The combination of P. stomatis, P. micra, and ETBF (AUC 0.922, 95% CI 0.887-0.958) revealed strongest diagnostic power with 88.7% sensitivity and 81.4% specificity. ETBF, P. stomatis, and P. micra were associated with malignant LST (P_P.stomatis = 0.0015, P_P.micra = 0.0255, P_ETBF = 0.0169) and the abundance of IL-6. The high abundance of P. stomatis was related to the adenoma recurrence after LST resection (HR = 3.88, P = 0.008).

Conclusions

Fecal microbiome signature (ETBF-P. stomatis-P. micra) can diagnose LSTs with high accuracy. ETBF, P. stomatis, and P. micra were related to malignant LST and P. stomatis exhibited high predictive value on the adenoma recurrence after resection of LSTs. The fecal microbiome signature of LST may provide a noninvasive alternative to early detect LST and predict the adenoma recurrence risk after resections of LSTs.

The modern management of Barrett's oesophagus and related neoplasia: role of pathology

Modern management of Barrett's oesophagus and related neoplasia essentially focuses upon surveillance to detect early low-risk neoplastic lesions and offering organ-preserving advanced endoscopic therapies, while traditional surgical treatments of oesophagectomy and lymph node clearance with or without chemoradiation are preserved only for high-risk and advanced carcinomas. With this evolution towards figless invasive therapy, the choice of therapy hinges upon the pathological assessment for risk stratifying patients into those with low risk for nodal metastasis who can continue with less invasive endoscopic therapies and others with high risk for nodal metastasis for which surgery or other forms of treatment are indicated. Detection and confirmation of neoplasia in the first instance depends upon endoscopic and pathological assessment. Endoscopic examination and biopsy sampling should be performed according to the recommended protocols, and endoscopic biopsy interpretation should be performed applying standard criteria using appropriate ancillary studies by histopathologists experienced in the pathology of Barrett's disease. Endoscopic resections (ERs) are both diagnostic and curative and should be performed by clinicians who are skilled with advanced endoscopic techniques. Proper preparation and handling of ERs are essential to assess histological parameters that dictate the curative nature of the procedure. Those parameters are adequacy of resection and risk of lymph node metastasis. The risk of lymph node metastasis is determined by depth invasion and presence of poor differentiation and lymphovascular invasion. Those adenocarcinomas with invasion up to muscularis mucosae (pT1a) and those with superficial submucosal invasion (pT1b) up to 500 µ with no poor differentiation and lymphovascular invasion and negative margins may be considered cured by endoscopic resections.

Multimodal Imaging Mass Spectrometry: Next Generation Molecular Mapping in Biology and Medicine

Imaging mass spectrometry has become a mature molecular mapping technology that is used for molecular discovery in many medical and biological systems. While powerful by itself, imaging mass spectrometry can be complemented by the addition of other orthogonal, chemically informative imaging technologies to maximize the information gained from a single experiment and enable deeper understanding of biological processes. Within this review, we describe MALDI, SIMS, and DESI imaging mass spectrometric technologies and how these have been integrated with other analytical modalities such as microscopy, transcriptomics, spectroscopy, and electrochemistry in a field termed multimodal imaging. We explore the future of this field and discuss forthcoming developments that will bring new insights to help unravel the molecular complexities of biological systems, from single cells to functional tissue structures and organs.

m6A Reader HNRNPA2B1 Promotes Esophageal Cancer Progression via Up-Regulation of ACLY and ACC1

N6-methyladenosine (m6A) modification is the most abundant modification on eukaryotic RNA. In recent years, lots of studies have reported that m6A modification and m6A RNA methylation regulators were involved in cancer progression. However, the m6A level and its regulators in esophageal cancer (ESCA) remain poorly understood. In this study, we analyzed the expression of m6A regulators using The Cancer Genome Atlas data and found 14 of 19 m6A regulators are significantly increased in ESCA samples. Then we performed a univariate Cox regression analysis and LASSO (least absolute shrinkage and selection operator) Cox regression model to investigate the prognostic role of m6A regulators in ESCA, and the results indicated that a two-gene prognostic signature including ALKBH5 and HNRNPA2B1 could predict overall survival of ESCA patients. Moreover, HNRNPA2B1 is higher expressed in high-risk scores subtype of ESCA, indicating that HNRNPA2B1 may be involved in ESCA development. Subsequently, we confirmed that the level of m6A and HNRNPA2B1 was significantly increased in ESCA. We also found that HNRNPA2B1 expression positively correlated with tumor diameter and lymphatic metastasis of ESCA. Moreover, functional study showed that knockdown of HNRNPA2B1 inhibited the proliferation, migration, and invasion of ESCA. Mechanistically, we found that knockdown of HNRNPA2B1 inhibited the expression of de novo fatty acid synthetic enzymes, ACLY and ACC1, and subsequently suppressed cellular lipid accumulation. In conclusion, our study provides critical clues to understand the role of m6A and its regulators in ESCA. Moreover, HNRNPA2B1 functions as an oncogenic factor in promoting ESCA progression via up-regulation of fatty acid synthesis enzymes ACLY and ACC1, and it may be a promising prognostic biomarker and therapeutic target for human ESCA.

Pathologic assessment of endoscopic resection specimens with superficial carcinoma of the esophagus: current practice and practical issues

Endoscopic resection (ER) has become the first-line therapy for early esophageal cancer and offers a treatment alternative to surgery, owing to less morbidity and better quality of life. ER techniques include endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). EMR is faster, simpler, and cheaper than ESD, but limited by its ability to resect lesions larger than 1.5 centimeters. Piecemeal EMR has limitations, including a high local recurrence rate and a suboptimal specimen for an accurate pathologic assessment. ESD, on the other hand, allows en bloc resections with negative (R0) margins, irrespective of lesion size, providing an excellent pathologic specimen, however, is technically challenging with a higher risk of complications. The evaluation of ER specimens in pathology varies slightly from institution to institution. Our review summarizes the current practices and issues in the pathologic assessment of esophageal ER specimens, which highlights the necessity of a systematic approach and standardization of both macroscopic and microscopic evaluation. There is a need for a comprehensive and standardized pathology report that will allow for uniform terminology for endoscopists, surgeons, and pathologists, which, in turn, will result in better treatment guidance.

Automatic detection of squamous cell carcinoma metastasis in esophageal lymph nodes using semantic segmentation

Esophageal squamous cell carcinoma (ESCC) is more prevalent than esophageal adenocarcinoma in Asia, especially in China, where more than half of ESCC cases occur worldwide. Many studies have reported that the automatic detection of lymph node metastasis using semantic segmentation shows good performance in breast cancer and other adenocarcinomas. However, the detection of squamous cell carcinoma metastasis in hematoxylin-eosin (H&E)-stained slides has never been reported. We collected a training set of 110 esophageal lymph node slides with metastasis and 132 lymph node slides without metastasis. An iPad-based annotation system was used to draw the contours of the cancer metastasis region. A DeepLab v3 model was trained to achieve the best fit with the training data. The learned model could estimate the probability of metastasis. To evaluate the effectiveness of the detection model of learned metastasis, we used another large cohort of clinical H&E-stained esophageal lymph node slides containing 795 esophageal lymph nodes from 154 esophageal cancer patients. The basic authenticity label for each slide was confirmed by experienced pathologists. After filtering isolated noise in the prediction, we obtained an accuracy of 94%. Furthermore, we applied the learned model to throat and lung lymph node squamous cell carcinoma metastases and achieved the following promising results: an accuracy of 96.7% in throat cancer and an accuracy of 90% in lung cancer. In this work, we organized an annotated dataset of H&E-stained esophageal lymph node and trained a deep neural network to detect lymph node metastasis in H&E-stained slides of squamous cell carcinoma automatically. Moreover, it is possible to use this model to detect lymph nodes metastasis in squamous cell carcinoma from other organs. This study directly demonstrates the potential for determining the localization of squamous cell carcinoma metastases in lymph node and assisting in pathological diagnosis.