Treatment strategy for gastric non-invasive intraepithelial neoplasia diagnosed by endoscopic biopsy

Clinicopathological characteristics of gastric intraepithelial neoplasia: Analysis of 653 cases

BACKGROUND

The high mortality rate of gastric carcinoma (GC) is becoming a serious public concern around the world. Gastric intraepithelial neoplasia (GIN) is believed to be the pre-invasive lesions of GC. Therefore, this study aimed to investigate the clinicopathological characteristics of GIN and explore the risk factors for gastric precancerous lesions.

AIM

To analyze the clinical and pathological characteristics of GIN and identify its risk factors, so as to better guide the clinical diagnosis and treatment of GIN.

METHODS

A total of 653 Chinese patients undergoing diagnostic gastroscopy at a single center from June 2010 to October 2020 were included. The demographic, endoscopic, and pathological characteristics were collected to identify the risk factors associated with GIN.

RESULTS

There were 536 cases with low-grade gastric intraepithelial neoplasia (LGIN) (82.08%) and 117 cases with high-grade gastric intraepithelial neoplasia (HGIN) (17.92%). The gastric antrum was the most common location for GIN lesions (58.35%). The incidence of GIN lesions > 2 cm in the HGIN group (27/117, 23.08%) was twice as high as that of the LGIN group (56/536, 10.45%). The positive rate of atrophy and intestinal metaplasia improved as the age increased among patients 50-80 years old and > 60 years old, respectively. In addition, no statistical difference was observed in Helicobacter pylori infection rate between the LGIN and HGIN groups (P = 0.162).

CONCLUSION

Advanced age, lesion located at the antrum, lesion size > 1 cm, and presence of atrophy or intestinal metaplasia in the gastric mucosa are risk factors for HGIN. LGIN patients with these risk factors are more likely to develop into HGIN. H. pylori infection has no statistical correlations with LGIN and HGIN.

Clinical Outcomes of Endoscopic Resection for Low-Grade Dysplasia and High-Grade Dysplasia on Gastric Pretreatment Biopsy: Korea ESD Study Group

Background/Aims

Some cases of gastric low-grade dysplasia (LGD) and high-grade dysplasia (HGD) on forceps biopsy (FB) are diagnosed as gastric cancer (GC) after endoscopic resection (ER). This study aims to evaluate the clinical outcomes of ER for gastric LGD and HGD on pretreatment FB and to identify the factors that predict pathologic upstaging to GC.

Methods

Patients who underwent ER for LGD and HGD on pretreatment FB from March 2005 to February 2018 in 14 hospitals in South Korea were enrolled, and the patients’ medical records were reviewed retrospectively.

Results

This study included 2,150 cases of LGD and 1,534 cases of HGD diagnosed by pretreatment FB. In total, 589 of 2,150 LGDs (27.4%) were diagnosed as GC after ER. Helicobacterpylori infection, smoking history, tumor location in the lower third of the stomach, tumor size >10 mm, depressed lesion, and ulceration significantly predicted GC. A total of 1,115 out of 1,534 HGDs (72.7%) were diagnosed with GC after ER. Previous history of GC, H. pylori infection, smoking history, tumor location in the lower third of the stomach, tumor size >10 mm, depressed lesion, and ulceration were significantly associated with GC. As the number of risk factors predicting GC increased in both LGD and HGD on pretreatment FB, the rate of upstaging to GC after ER increased.

Conclusions

A substantial proportion of LGDs and HGDs on pretreatment FB were diagnosed as GC after ER. Accurate ER procedures such as endoscopic submucosal dissection should be recommended in cases of LGD and HGD with factors predicting pathologic upstaging to GC.

Role of magnifying endoscopy with narrow-band imaging in the diagnosis of noninvasive gastric neoplasia

Background and Aim

There are no globally approved, distinguishing criteria enabling the classification of gastric adenomas and intramucosal carcinomas for differential diagnosis of noninvasive neoplasia (NIN).

Methods

Next‐generation sequencing of 50 cancer‐related genes was undertaken on 68 pathologically diagnosed microdissected gastric neoplasms (25 adenomas, 27 intramucosal carcinomas, and 16 submucosal carcinomas) obtained during endoscopic submucosal dissection. Findings from magnifying endoscopy with narrow‐band imaging (M‐NBI) of 52 NINs (the 25 adenomas and 27 intramucosal carcinomas) were compared with these data.

Results

Among all 68 neoplasms, the most frequently mutated genes were APC (76% in adenoma, 11.1% in intramucosal carcinoma, and 0% in submucosal carcinoma; P < 0.001) and TP53 in intramucosal and submucosal carcinomas (8% in adenoma, 48.1% in intramucosal carcinoma, and 75% in submucosal carcinoma; P < 0.001). Dividing the NIN neoplasms into five groups according to their mutational status (A1: APC mutation, A2: APC + α mutation, B: APC + TP53 mutation, C: TP53 mutation, D: no mutation in either APC or TP53) resulted in almost identical diagnoses by pathology and M‐NBI for groups A1 (12/13, 92%), C (12/13, 92%), and D (16/17, 94%) but not for groups A2 (3/7, 43%) or B (0/2, 0%). This finding implies that NINs with the APC + α mutation have carcinoma‐like endoscopic features despite most being judged as adenomas by pathology.

Conclusion

A diagnosis of NINs by pathology or M‐NBI in the subset of gastric tumors classified by cancer‐related mutations is not completely identical, suggesting the possible additional role of M‐NBI in diagnosing NINs. Further studies are needed to confirm this.

Vonoprazan vs proton pump inhibitors in treating post-endoscopic submucosal dissection ulcers and preventing bleeding: A meta-analysis of randomized controlled trials and observational studies

BACKGROUND

Vonoprazan is a potassium-competitive acid blocker (P-CAB) that is frequently used in Japan for Helicobacter pylori (H. pylori) eradication, treatment of gastroesophageal reflux disease, and treatment of post endoscopic submucosal dissection (ESD) complications. We sought to determine if vonoprazan was superior to proton pump inhibitors (PPIs) for treating ESD-induced ulcers (as assessed by ulcer healing and shrinkage ratios) and preventing delayed bleeding over various treatment durations (2, 4, and 8 weeks).

METHODS

We collected randomized controlled trials (RCTs) and observational studies that discussed the effectiveness of vonoprazan and PPIs on ESD-induced ulcers and bleeding from PubMed, Cochrane Library, ClinicalTrials.gov, and Google Scholar. Studies were selected according to pre-established eligibility criteria and data were extracted separately by 2 researchers with double-check. We used the Cochrane risk of bias tool to assess RCTs and the Newcastle-Ottawa Quality Assessment Scale to assess observational studies. Meta-analyses, based on the random-effects model, were conducted to compare differences in ulcer shrinkage ratios (%) and odds ratios (ORs) for ulcer healing and delayed bleeding. Publication bias was evaluated using funnel plots and Egger regression test. Heterogeneity was assessed using I statistics. A sensitivity analysis was conducted to check the robustness of results. The evidential quality of the findings was assessed using the GRADE profiler.

RESULTS

Thirteen studies were included in this meta-analysis. The OR effect sizes of vonoprazan relative to PPIs for ulcer healing were 1.33 (P = .13) with a 95% CI (0.33-3.21) at 4 weeks and 1.48 (P = .09) with a 95% CI (0.81-5.20) at 8 weeks. The overall effect size for the shrinkage ratio was 12.24% (P = .16) with a 95% CI (-4.96-29.44) at 2 weeks. The effect size of its subgroup of H. pylori-positive patients was 19.51% (P < .001) with a 95% CI (11.91-27.12). The overall OR for the occurrence of delayed bleeding was 0.66 (P = .26) with a 95% CI (0.32-1.35). After excluding combination drug studies, the overall ORs between vonoprazan and PPIs on ulcer healing and delayed bleeding were 1.44 and 0.76, respectively.

CONCLUSION

During the first 2 weeks of treatment, vonoprazan was more effective than PPIs for treating H. pylori-positive patients with ESD-induced gastric ulcers.

Vonoprazan versus proton pump inhibitors in treating post-endoscopic submucosal dissection ulcers and preventing bleeding: Protocol for meta-analysis of randomized controlled trials and observational studies

BACKGROUND

Vonoprazan is a potassium-competitive acid blocker (P-CAB). It is often used in Japan for Helicobacter pylori (H pylori) eradication, gastroesophageal reflux disease, and endoscopic submucosal dissection (ESD) ulcers and bleeding. This meta-analysis aims to evaluate whether vonoprazan has better therapeutic effect on ESD-induced ulcers and bleeding than proton pump inhibitors (PPIs) at different length of treatment periods (2, 4, and 8 weeks).

METHODS

This meta-analysis will include both randomized controlled trials (RCTs) and observational studies discussing the effectiveness of vonoprazan and PPIs on ESD-induced ulcers and bleeding. Information of studies will be collected from PubMed, Cochrane Library, ClinicalTrials.gov, and Google Scholar. Studies will be selected according to the eligibility criteria and data will be extracted by 2 people and compared with each other to keep in consistency. Cochrane risk of bias tool will be used to assess RCTs and the Newcastle-Ottawa Quality Assessment Scale will be used to assess the observational studies. Meta-analysis based on the random-effects model will be conducted to compare the differences of ulcers' shrinkage ratios (%) and the odds ratios (OR) of scars' stages and delayed bleeding. Publication bias will be evaluated using funnel plots and Egger's regression test. Heterogeneity will be assessed with the I statistics. Sensitivity analysis will be conducted on follow-up periods. The evidential quality of the findings will be assessed with the Grading of Recommendations Assessment Development and Evaluation (GRADE) profiler.

DISCUSSION

The findings of the present systematic review will be critical for physicians, patients, and policymakers regarding the use of vonoprazan in ESD-induced ulcers.

STUDY REGISTRATION

PROSPERO registration number: CRD42018116855.

Incidence of gastric adenocarcinoma among lesions diagnosed as low-grade adenoma/dysplasia on endoscopic biopsy: A multicenter, prospective, observational study

BACKGROUND AND AIM

Differentiation between gastric adenocarcinoma and low-grade adenoma/dysplasia (LGA) on endoscopic forceps biopsy is difficult. We aim to clarify the incidence of carcinoma in specimens, obtained by endoscopic resection (ER), from cases that had been diagnosed as LGA (Vienna category 3) on endoscopic biopsy.

METHODS

In this multicenter, prospective, observational study, patients with gastric adenoma (Vienna category 3 or 4.1) diagnosed on endoscopic forceps biopsy were enrolled. All the specimens were subjected to histopathological central review. Primary endpoint was the incidence of carcinoma (Vienna category 4.2 or over) among the biopsy-proven gastric LGA. Secondary endpoints were the histological findings of resected specimens, clinicopathological features of carcinoma, and short-term outcomes of all ER cases.

RESULTS

Ninety-five patients with 104 lesions diagnosed as gastric adenoma were enrolled. After central review of the biopsy specimens, 47 lesions were diagnosed as LGA and seven lesions (15%) as adenocarcinoma (95% confidence interval, 7.6-28%). Carcinoma was detected in lesions that had a minimum size of 6 mm; the incidence of carcinoma was higher in the larger lesions. There was a histological discrepancy between biopsy and ER material in more than 60% of the cases.

CONCLUSIONS

A substantial proportion of biopsy-proven gastric LGA specimens were diagnosed as adenocarcinoma after ER. This indicated histological discrepancy between biopsy-proven gastric LGA and histology of the resected material.

The importance of the concept and histological criteria of "intraepithelial squamous cell carcinoma" of the esophagus: in comparison between Western and Japanese criteria

BACKGROUND

There are differences in the histological diagnostic criteria for early stage gastrointestinal carcinoma between Western and Japanese pathologists. Western histological criteria of carcinoma are "presence of stromal invasion of neoplastic cells", while Japanese criteria are "the degree of cytological and structural abnormality of neoplastic cells, regardless of stromal invasion". The aim of the present study is to clarify and review the present status of the Western and Japanese histological criteria of early stage esophageal squamous cell carcinoma (SCC) and also to clarify their significance and accuracy.

METHODS

Twenty-nine Polish, German, and Japanese pathologists participated in this study. A total of 18 histological slides of biopsy, endoscopic submucosal dissection (ESD), and surgical resection of esophageal squamous lesions were diagnosed using a virtual slide system.

RESULTS

Most of noninvasive (intraepithelial) carcinomas diagnosed by Japanese pathologists were diagnosed as high- or low-grade dysplasia (intraepithelial neoplasia) or reactive atypia by the majority of Polish and German pathologists. Diagnoses of not only high-grade dysplasia but also low-grade dysplasia or reactive lesion by Western criteria were given for many biopsy specimens of cases in which the corresponding ESD or surgical specimens showed definite stromal invasion.

CONCLUSION

There still exist differences in the histological diagnostic criteria for early stage esophageal carcinoma between Western and Japanese pathologists. The Japanese diagnostic criteria could improve agreement of diagnoses between biopsy and resected specimens of esophageal SCC. Moreover, diagnostic approaches using Western criteria may cause delay in the early diagnosis and treatment of esophageal SCC.

Lentivirus-mediated inhibition of USP39 suppresses the growth of gastric cancer cells via PARP activation

Gastric cancer (GC) is the second most common cause of cancer-associated mortality worldwide. Ubiquitin-specific peptidase 39 (USP39) has important roles in mRNA processing and has been reported to be involved in the growth of breast cancer cells. However, the roles of USP39 in GC have remained to be investigated, which was the aim of the present study. A lentivirus expressing short hairpin RNA targeting USP39 was constructed and transfected into MGC80‑3 cells. Suppression of USP39 expression significantly decreased the proliferation and colony forming ability of MGC80‑3 cells as indicated by an MTT and a clonogenic assay, respectively. In addition, flow cytometric cell cycle analysis revealed that depression of USP39 induced G2/M‑phase arrest, while an intracellular signaling array showed that the cleavage of PARP at Asp214 was increased following USP39 knockdown. These results suggested that USP39 is involved in the proliferation of GCs and may be utilized as a molecular target for GC therapy.

Diagnosis and management of gastric dysplasia

Gastric dysplasia is a neoplastic lesion and a precursor of gastric cancer. The Padova, Vienna, and World Health Organization classifications were developed to overcome the discrepancies between Western and Japanese pathologic diagnoses and to provide a universally accepted classification of gastric epithelial neoplasia. At present, the natural history of gastric dysplasia is unclear. Much evidence suggests that patients with high-grade dysplasia are at high risk of progression to carcinoma or synchronous carcinoma. Therefore, endoscopic resection is required. Although patients with low-grade dysplasia have been reported to be at low risk of progression to carcinoma, due to the marked histologic discrepancies between forceps biopsy and endoscopic specimens, endoscopic resection for this lesion is recommended, particularly in the presence of other risk factors (large size; depressed gross type; surface erythema, unevenness, ulcer, or erosion; and tubulovillous or villous histology). Helicobacter pylori eradication in patients with dysplasia after endoscopic resection appear to reduce the incidence of metachronous lesions.

Progress in research of gastric intraepithelial neoplasia

Gastric carcinoma is one of the most common malignant tumors in the world, and the accurate diagnosis of precancerous lesions plays an important role in gastric cancer prevention. Intraepithelial neoplasia is a form of precancerous lesion of gastric cancer, and many efforts have been done to explore the relationship between gastric cancer and dysplasia. Recently, there has been much progress in the research of intraepithelial neoplasia, including genetic changes at the molecular level, the eradication of Helicobacter pylori (H. pylori), regular follow-up and endoscopic therapy. All of these will play an important role in clinical management of this condition. However, the etiological mechanism, influencing factors and malignant transformation of GIN are still unclear. Hence, further multi-center and long-term prospective studies are needed to solve these problems.

Endoscopic surveillance strategy after endoscopic resection for early gastric cancer

Early detection of early gastric cancer (EGC) is important to improve the prognosis of patients with gastric cancer. Recent advances in endoscopic modalities and treatment devices, such as image-enhanced endoscopy and high-frequency generators, may make endoscopic treatment, such as endoscopic submucosal dissection, a therapeutic option for gastric intraepithelial neoplasia. Consequently, short-term outcomes of endoscopic resection (ER) for EGC have improved. Therefore, surveillance with endoscopy after ER for EGC is becoming more important, but how to perform endoscopic surveillance after ER has not been established, even though the follow-up strategy for more advanced gastric cancer has been outlined. Therefore, a surveillance strategy for patients with EGC after ER is needed.

Enalapril inhibits nuclear factor-κB signaling in intestinal epithelial cells and peritoneal macrophages and attenuates experimental colitis in mice

AIMS

Enalapril, an angiotensin-converting enzyme (ACE) inhibitor, has pleiotropic effects such as anti-inflammatory effects. This study investigated the effect of enalapril on the nuclear factor-kappa B (NF-κB) pathway and on experimental colitis.

MAIN METHODS

The human intestinal epithelial cell (IEC) line COLO 205 and peritoneal macrophages from C57BL/6 wild-type mice and IL-10-deficient (IL-10(-/-)) mice were prepared and subsequently stimulated with lipopolysaccharide (LPS) alone or LPS plus enalapril. The effect of enalapril on NF-κB signaling was examined by western blotting to detect IκBα phosphorylation/degradation; an electrophoretic mobility shift assay (EMSA) to assess the DNA binding activity of NF-κB; and ELISAs to qualify IL-8, TNF-α, IL-6, and IL-12 production. In in vivo studies, dextran sulfate sodium (DSS)-induced acute colitis in wild-type mice and chronic colitis in IL-10(-/-) mice were treated with or without enalapril. Colitis was quantified by histologic scoring, and the phosphorylation of IκBα in the colonic mucosa was assessed using immunohistochemistry.

KEY FINDINGS

Enalapril significantly inhibited LPS-induced IκBα phosphorylation/degradation, NF-κB binding activity, and pro-inflammatory cytokine production in both IEC and peritoneal macrophages. The administration of enalapril significantly reduced the severity of colitis, as assessed based on histology in both murine colitis models. Furthermore, in colon tissue, the up-regulation of IκBα phosphorylation with colitis induction was attenuated in enalapril-treated mice.

SIGNIFICANCE

Enalapril may block the NF-κB signaling pathway, inhibit the activation of IECs and macrophages, and attenuate experimental murine colitis by down-regulating IκBα phosphorylation. These findings suggest that enalapril is a potential therapeutic agent for inflammatory bowel disease.

Early gastric cancer and dysplasia

Since the concept of early gastric cancer was first described in Japan in 1962, its treatment has evolved from curative surgical resection to endoscopic resection, initially with polypectomy to more recently with endoscopic submucosal dissection. As worldwide experience with these endoscopic techniques evolve and gain acceptance, studies have confirmed its comparable effectiveness with historical surgical outcomes in carefully selected patients. The criteria for endoscopic resection have expanded to offer more patients improved quality of life, avoiding the morbidity and mortality associated with surgery. This article summarizes the evolutional role of endoscopic and surgical therapy in early gastric cancer.