Magnifying chromoendoscopic findings of early gastric cancer and gastric adenoma

Chinese consensus on prevention of colorectal neoplasia (2021, Shanghai)

Most patients with colorectal cancer (CRC) were diagnosed in advanced stage and the prognosis is poor. Therefore, early detection and prevention of CRC are very important. As with other cancers, there is also the tertiary prevention for CRC. The primary prevention is etiological prevention, which is mainly the treatment of adenoma or inflammation for preventing the development into cancer. The secondary prevention is the early diagnosis and early treatment for avoiding progressing to advanced cancer. The tertiary prevention belongs to the broad category of prevention, mainly for advanced CRC, through surgical treatment and postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, immunotherapy for preventing tumor recurrence or metastasis. This consensus is based on the recent domestic and international consensus guidelines and the latest progress of international researches in the past five years. This consensus opinion seminar was hosted by the Chinese Society of Gastroenterology and Cancer Collaboration Group of Chinese Society of Gastroenterology, and was organized by the Division of Gastroenterology and Hepatology & Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University. The consensus opinion contains 60 statement clauses, the standard and basis of the evidence-based medicine grade and voting grade of the statement strictly complied with the relevant international regulations and practice.

Advances in the Aetiology & Endoscopic Detection and Management of Early Gastric Cancer

Simple Summary

Gastric adenocarcinoma has remained a highly lethal disease. Awareness and recognition of preneoplastic conditions (including gastric atrophy and intestinal metaplasia) using high-resolution white-light endoscopy as well as chromoendoscopy is therefore essential. Helicobacter pylori, a class I carcinogen, remains the main contributor to the development of sporadic distal gastric neoplasia. Management of early gastric neoplasia with endoscopic resections should be in line with standard indications. A multidisciplinary approach to any case of an early gastric neoplasia is imperative. Hereditary forms of gastric cancer require a tailored approach and individua-lized surveillance.

Abstract

The mortality rates of gastric carcinoma remain high, despite the progress in research and development in disease mechanisms and treatment. Therefore, recognition of gastric precancerous lesions and early neoplasia is crucial. Two subtypes of sporadic gastric cancer have been recognized: cardia subtype and non-cardia (distal) subtype, the latter being more frequent and largely associated with infection of Helicobacter pylori, a class I carcinogen. Helicobacter pylori initiates the widely accepted Correa cascade, describing a stepwise progression through precursor lesions from chronic inflammation to gastric atrophy, gastric intestinal metaplasia and neoplasia. Our knowledge on He-licobacter pylori is still limited, and multiple questions in the context of its contribution to the pathogenesis of gastric neoplasia are yet to be answered. Awareness and recognition of gastric atrophy and intestinal metaplasia on high-definition white-light endoscopy, image-enhanced endoscopy and magnification endoscopy, in combination with histology from the biopsies taken accurately according to the protocol, are crucial to guiding the management. Standard indications for endoscopic resections (endoscopic mucosal resection and endoscopic submucosal dissection) of gastric dysplasia and intestinal type of gastric carcinoma have been recommended by multiple societies. Endoscopic evaluation and surveillance should be offered to individuals with an inherited predisposition to gastric carcinoma.

Endoscopic Advances for Gastric Neoplasia Detection

This article explores advances in endoscopic neoplasia detection with supporting clinical evidence and future aims. The ability to detect early gastric neoplastic lesions amenable to curative endoscopic submucosal dissection provides the opportunity to decrease gastric cancer mortality rates. Newer imaging techniques offer enhanced views of mucosal and microvascular structures and show promise in differentiating benign from malignant lesions and improving targeted biopsies. Conventional chromoendoscopy is well studied and validated. Narrow band imaging demonstrates superiority over magnified white light. Autofluorescence imaging, i-scan, flexible spectral imaging color enhancement, and bright image enhanced endoscopy show promise but insufficient evidence to change current clinical practice.

Chromoendoscopy: role in modern endoscopic imaging

Detection of early gastrointestinal tract malignancy can be challenging on white light endoscopy especially as lesions can be subtle and inconspicuous. With the advent of electronic chromoendoscopy technologies, lesions which have already been detected can be quickly and "conveniently" characterised. This review will discuss some of the indications and modern applications of chromoendoscopy in various conditions including Barrett's oesophagus, oesophageal squamous cell carcinoma, early gastric cancer, inflammatory bowel disease and neoplastic colonic lesions. In carefully selected situations, chromoendoscopy could still be a useful adjunct to white light endoscopy in day-to-day clinical practice.

Narrow band imaging for head and neck malignancies: Lessons learned from mistakes

BACKGROUND

The accuracy of white light endoscopy in combination with narrow band imaging (WLE + NBI) for diagnosis of squamous cell carcinoma (SCC) does not reach 100%. We evaluated the characteristics of the false-negative and false-positive cases.

METHODS

Five hundred thirty lesions of the upper airways were evaluated. The WLE was followed by NBI examination before performing a biopsy.

RESULTS

The false-negative lesions (7.36%) were represented by submucosal and non-SCC tumors. Among the 25 non-SCC tumors, 72% did not show any suspicious vascular pattern under NBI. The false-positive lesions (6.04%) were mainly represented by postradiotherapy mucosal changes, ulcers, and infections. Regarding papillomas, NBI accuracy reached 95.32%, although cases with dysplasia were difficult to distinguish from SCC.

CONCLUSION

The WLE + NBI improved diagnostic accuracy, but not all lesions were ideally evaluated with current defined patterns. An accurate anamnesis is mandatory, because, in some cases, it may be more relevant than the NBI pattern.

Endoluminal Diagnosis of Early Gastric Cancer and Its Precursors: Bridging the Gap Between Endoscopy and Pathology

Although dye-based and image-enhanced endoscopic techniques have revolutionized endoscopic diagnosis, conventional white light endoscopy still plays an important role in the diagnosis of early gastric cancer (EGC) during routine endoscopy. Chromoendoscopy reveals morphological characteristics of the mucosal lesions by enhancing mucosal contrast, while narrow-band imaging (NBI) facilitates detailed evaluation of the vascular architecture and surface features. Positive diagnostic findings of EGC on white light imaging and indigo carmine chromoendoscopy are a sharply demarcated lesion and irregularity in surface morphology or color. Magnifying NBI further improves diagnostic accuracy of white light imaging and chromoendoscopy. We review our approach to the endoscopic diagnosis of (pre-)malignant lesions in the stomach and discuss in detail novel endoscopic microvascular architectural patterns which further leverage diagnostic biopsy yield. We expect that further improvement of endoscopic techniques and correlative studies will close the gap between endoscopy and pathology.

Diagnosis and therapies for gastric non-invasive neoplasia

There has been a great discrepancy of pathological diagnosis for gastric non-invasive neoplasia/dysplasia between Japanese and western pathologists. In Japan, lesions that most western pathologists diagnose as dysplasia are often considered adenocarcinoma based on nuclear and structural atypia regardless of the presence of invasion. In the Vienna classification, gastric non-invasive intraepithelial neoplasia (NIN) were divided into low grade and high grade (including intra-mucosal cancer of Japanese criteria). The diagnosis by both endoscopy and pathology of biopsy specimen is difficult. Recent advances of diagnostic modality such as magnified endoscopy and imaged enhanced endoscopy is expected to improve the diagnostic yield for NIN. There are two treatment strategies for NIN, observation and diagnostic therapy by endoscopic resection (ER). ER is acceptable because of its less invasiveness and high local control rate, on the other hand, cancer-developing rate of low-grade NIN is reported to be low. Therefore there is controversy for the treatment of gastric NIN. Prospective study based on unified pathological definition is required in the future.

Early stage signet ring cell carcinoma of the colon examined by magnifying endoscopy with narrow-band imaging: a case report

Background

Signet ring cell carcinoma of the colon and rectum is rare, and most cases are detected at an advanced stage. We present a case of primary signet ring cell carcinoma detected at an early stage by magnifying endoscopy with narrow-band imaging (NBI) and crystal violet staining.

Case presentation

A 73-year-old man visited our hospital for screening colonoscopy. Six years previously, he had undergone endoscopic submucosal dissection (ESD) for early gastric cancer. The pathological diagnosis was a well-differentiated adenocarcinoma, invading into the mucosa without lymphovascular invasion. Colonoscopy revealed a flat elevated lesion with a slightly depressed area, 20 mm in diameter, in the cecum. Further, magnifying endoscopy with NBI revealed that the surface pattern was slightly irregular and microvessels had a regular diameter and distribution in the margin of the lesion, but in the central part of the lesion, irregularity in the tumor surface pattern and form as well as in the diameter and distribution of microvessels was noted. Additionally, due to mucus, avascular areas were also observed. Magnifying endoscopy combined with 0.05 % crystal violet staining showed IIIL and V_I pit patterns in the margin of the lesion, and a V_I pit pattern in the central part of the lesion; however, due to mucus exudate, this finding could not be established with certainty. The lesion was successfully removed en bloc using ESD without complications. The tumor was composed mainly of signet ring cell carcinoma, partially mixed with moderately differentiated (tub2) and well-differentiated (tub1) adenocarcinomas. The tumor cells infiltrated 250 μm into the submucosal layer and involved lymphatic vessels. Therefore, the patient underwent an additional laparoscopic ileocecal resection, and the resected specimen revealed no residual carcinoma or lymph node metastasis.

Conclusion

In this case report, we present a case of primary signet ring cell carcinoma detected at an early stage and identified by magnifying endoscopy with NBI and crystal violet staining.

Dense-type crypt opening seen on magnifying endoscopy with narrow-band imaging is a feature of gastric adenoma

BACKGROUND

Magnifying endoscopy with narrow-band imaging (ME-NBI) can visualize crypt openings (CO) as slit-like structures in gastric epithelial neoplasia. Visualization of numerous CO is characteristic of low-grade adenoma (LGA). The aim of the present study was to investigate whether visualization of CO by ME-NBI is useful for discriminating between LGA and early gastric cancer (EGC).

PATIENTS AND METHODS

Fifty-one superficial elevated-type gastric neoplasias (10 LGA and 41 EGC) were retrospectively evaluated. The presence of CO and the number of CO were evaluated in endoscopic photos obtained at high-power endoscopic magnification by ME-NBI. The optimal cut-off value for the number of CO visualized to discriminate between LGA and EGC was determined by receiver operating characteristic curve analysis.

RESULTS

The mean number of CO visualized was significantly larger in the LGA group than in the EGC group (31.2, 95% confidence interval [CI] 16.3-46.1 vs 6.3, 95% CI 3.6-9.0; P < 0.001). When the cut-off for the number of CO visualized was set at 20, the sensitivity, specificity, and accuracy of dense-type CO for discriminating between LGA and EGC were 90.0%, 87.8%, and 88.2%, respectively.

CONCLUSION

Determining the number of CO visualized in superficial elevated-type gastric neoplasias by ME-NBI appears to be a useful method for discriminating between LGA and EGC.

Endocytoscopic findings of lymphomas of the stomach

BACKGROUND

The gastric lesions of various lymphomas were observed at the cellular level using endocytoscopy.

METHODS

Endocytoscopy and magnifying endoscopy with narrow band imaging (NBI) were performed in 17 patients with lymphomas of the stomach. The lesions consisted of 7 with low-grade mucosa-associated lymphoid tissue (MALT), 5 with gastric involvement by adult T-cell leukemia/lymphoma (ATLL), 4 with diffuse large B-cell lymphoma (DLBCL), and 1 with peripheral T-cell lymphoma.

RESULTS

On conventional endoscopy, 9 were classified as having superficial spreading type, 7 were mass-forming type, and 1 was diffuse infiltrating type. Anti-H. pylori treatment was given in the 7 MALT lymphoma cases. NBI magnification endoscopy invariably showed dilatation or ballooning and destruction of gastric pits and elongation and distortion in microvessels. Endocytoscopy showed mucosal aggregation of interstitial cellular elements in almost all gastric lymphoma cases. The nuclear diversity in size and configuration was exclusively seen in gastric lymphomas other than MALT lymphoma, whereas the nuclei of MALT lymphoma cells were regular and small to moderate in size. Inter-glandular infiltration by lymphomatous cell elements was frequently observed in MALT lymphoma and DLBCL, but it was uncommon in peripheral gastric T-cell malignancies. Endocytoscopy could identify the disease-specific histology, the lymphoepithelial origin, as inter-glandular infiltration of cellular components in MALT lymphoma and the possibly related DLBCL cases. Complete regression (CR) was observed in 2 of the 7 MALT lymphoma patients. In the 2 patients with CR who underwent repeat endocytoscopy, the ultra-high magnification abnormalities returned to normal, while they were unchanged in those without tumor regression.

CONCLUSIONS

On endocytoscopy, intra-glandular aggregation of cellular components was invariably identified in lymphomas of the stomach. Nuclear regularity in size and configuration may indicate the cytological grade, differentiating the indolent low-grade from aggressive lymphoproliferative diseases. The inter-glandular infiltration seen on endocytoscopy can indicate the lymphoepithelial lesions seen in MALT lymphoma and related DLBCL. Endocytoscopy would be applicable for virtual histopathological diagnosis of different lymphoproliferative disorders and their clinical assessment during ongoing endoscopy.

Magnified and enhanced computed virtual chromoendoscopy in gastric neoplasia: A feasibility study

AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia.

METHODS: Patients with superficial lesions no larger than 1.0 cm found during high definition endoscopy were included. Those with advanced or obviously protruded or depressed lesions, lesions larger than 1.0 cm and/or lesions which were not amenable to observation by zoom function were excluded. The endoscopist was required to give the real-time descriptions of surface pit patterns of the lesions, based on surface pattern classification of enhanced magnification endoscopy. According to previous reports, types I-III represent non-neoplastic lesions, and types IV-V represent neoplastic lesions. Diagnosis with M i-scan and biopsy was performed before histopathological diagnosis. Magnified images of gastric lesions with and without enhancement were collected for further analysis. The diagnostic yield of real-time M i-scan and effects on magnification image quality by tone enhancement (TE), surface enhancement (SE) and color enhancement (CE) were calculated. The selected images were sent to another endoscopist. The endoscopist rated the image quality of each lesion at 3 levels. Ratings of image quality were based on visualization of pit pattern, vessel and demarcation line.

RESULTS: One hundred and eighty-three patients were recruited. Five patients were excluded for advanced gastric lesions, 1 patient was excluded for poor preparation and 2 patients were excluded for superficial lesions larger than 1.0 cm; 132 patients were excluded for no lesions found by high definition endoscopy. In the end, 43 patients with 43 lesions were included. Histopathology revealed 10 inflammation, 14 atrophy, 10 metaplasia, 1 low grade dysplasia (LGD), 5 high grade dysplasia (HGD) and 3 cancers. For 7 lesions classified into type I, histopathology revealed 6 atrophy and 1 metaplasia; for 10 lesions classified into type II, histopathology revealed 2 inflammation, 7 atrophy and 1 metaplasia; for 10 lesions classified into type III, histopathology revealed 1 inflammation, 8 metaplasia and 1 LGD; for 9 lesions classified into type IV, histopathology revealed 4 inflammation, 1 atrophy and 4 HGD; for 7 lesions classified into type V, histopathology revealed 3 inflammation, 1 HGD and 3 cancers. A total of 172 still images, including 43 images by white light (MWL) and 129 images by M i-scan (43 with TE, 43 with SE and 43 with CE), were selected and sent to the endoscopist who did the analysis. General image quality of M i-scan with TE and SE was significantly better than that of MWL (TE, 4.55 ± 1.07; SE, 4.30 ± 1.02; MWL, 3.25 ± 0.99; P < 0.001). Visualization of pit pattern was significantly improved by M i-scan with SE (1.93 ± 0.25 vs 1.50 ± 0.50, P < 0.001). Microvessel visualization was significantly improved by M i-scan with TE (1.23 ± 0.78 vs 0.76 ± 0.73, P < 0.001). Demarcation line visualization was improved by M i-scan with both TE and SE (TE, 1.75 ± 0.52; SE, 1.56 ± 0.59; MWL, 0.98 ± 0.44; P < 0.001). M i-scan with CE did not show any significant improvements of image quality in general or in the 3 key parameters. Although M i-scan with TE and SE slightly increased the diagnostic yield of MWL, there was no significant difference (P > 0.1).

CONCLUSION: Although digital enhancement improves the image quality of magnification endoscopy, its value in improving the diagnostic yield seems to be limited.

Novel serine/threonine kinase 11 gene mutations in Peutz-Jeghers syndrome patients and endoscopic management

AIM: To explore mutations in serine/threonine kinase 11 (STK11) gene in Peutz-Jeghers syndrome (PJS) with gastrointestinal (GI) hamartomatous polyps.

METHODS: Six Japanese PJS patients in 3 families were enrolled in this study. Each of the cases had hamartomatous polyposis in the gastrointestinal tract, including the small intestine, along with mucocutaneous hyperpigmentation. Narrow-band imaging (NBI)-magnification endoscopy was employed to detect microvascular and microsurface irregularities in the GI lesions. NBI magnification findings could be classified into three groups (type A, type B, or type C). Endoscopic polypectomy was performed using double-balloon enteroscopy or colonoscopy. Genomic DNA was extracted from a whole blood sample from each subject. All of the coding exons of STK11 gene, its boundary regions, and the promoter region containing the polymorphic regions were amplified by polymerase chain reaction, and direct sequencing was performed to assess the germline mutations.

RESULTS: NBI-magnification endoscopic observation could detect the abnormalities in microvessels and microsurface structures of GI polyps. Overall, we found 5 cases of type A and one case without the examination for the gastric polyps, while there were 4 cases of type B and 2 case of type A for the colorectal polyps. Seventy-nine small-bowel and 115 colorectal polyps over 27 sessions for each were resected endoscopically without significant complications. The only delayed complication included the occurrence of bleeding in a case, and this was successfully managed with hemoclips. Resected polyps contained no malignant components. Based on mutation analysis, all 3 cases in Family I exhibited the +658C>T nonsense mutation in exon 5, which resulted in the production of a truncated protein (Q220X). In Family II, a case had -252C>A and -193C>A in the promoter region. In Family III, a case was found to have the +1062C>G (F342L) mutation in exon 8.

CONCLUSION: We found two novel mutations of STK11 in association with PJS. Endoscopic polypectomy of GI polyps in PJS patients appears to be useful to prevent emergency laparotomies and reduce the cancer risk.

Fluorescence-based surface magnifying chromoendoscopy and optical coherence tomography endoscope

A side-viewing, 2.3-mm diameter, surface magnifying chromoendoscopy-optical coherence tomography (SMC-OCT) endoscope has been designed for simultaneous, nondestructive surface fluorescence visualization and cross-sectional imaging. We apply this endoscope to in vivo examination of the mouse colon. A 30,000 element fiber bundle is combined with single mode fibers, for SMC and OCT imaging, respectively. The distal optics consist of a gradient-index lens and spacer to provide a 1× magnification at a working distance of 1.58 mm in air, necessary to image the sample through a 0.23-mm thick outer glass envelope, and an aluminized right-angle prism fixed to the distal end of the gradient-index lens assembly. The resulting 1∶1 imaging system is capable of 3.9-µm lateral and 2.3-µm axial resolution in the OCT channel, and 125-lp/mm resolution across a 0.70-mm field of view in the SMC channel. The endoscope can perform high contrast crypt visualization, molecular imaging, and cross-sectional imaging of colon microstructure.

Flexible spectral imaging color enhancement (FICE) is useful to discriminate among non-neoplastic lesion, adenoma, and cancer of stomach

BACKGROUND

Studies regarding the discrimination of non-neoplastic lesion, adenoma, and cancer of the stomach using magnifying endoscopy with flexible spectral imaging color enhancement system (FIME) in each different channel of that system have not yet been reported.

AIMS

To ascertain the usefulness of FIME discriminating among the three kinds of gastric lesions.

METHODS

When finding a lesion to be a possible neoplasm using conventional endoscopy, the examiner discriminated among the three kinds of gastric lesions by observing the pit pattern on the lesion using magnifying endoscopy with white light (WLME) and then recorded the image. The procedure was repeated three more times with FIME with channel 0, 2, and 4. The four recorded images per lesion were then given to four raters for discriminating among the three kinds of gastric lesions.

RESULTS

The proportion of agreement and the degree of agreement between endoscopic and pathological diagnosis (AEP) by WLME were 0.85 and 0.76, respectively, and those by FIME were 0.91 and 0.86, respectively. All AEPs from discriminations with FIME was higher than that with WLME. AEPs from the discriminations with FIME with channel 4 were higher than those with FIME with channel 0 or 2. The degree of interobserver agreement among the results of the four raters was 0.42 for WLME and 0.50-0.59 for FIME with each of the three different channels.

CONCLUSIONS

FICE is useful in discriminating among non-neoplastic lesions, adenoma, and cancer of the stomach, and channel 4 of the FICE is better than channel 0 and 2 for the discriminations.