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

Poor agreement between biopsies and endoscopic submucosal dissection specimens of Esophageal and Gastric Epithelial Lesions in a western setting

BACKGROUND

Endoscopic forceps biopsy is the primary method for obtaining mucosal tissues, but can lead to false negatives.

AIMS

To assess the agreement between endoscopic biopsies and submucosal dissection specimens in esophageal and gastric epithelial lesions and to identify factors associated.

METHODS

Cross-sectional study using data from the Spanish national multicenter endoscopic submucosal dissection register. Patients, lesions and technical characteristics were prospectively collected. Prognostic factors for discrepancies were analyzed.

RESULTS

604 endoscopic submucosal dissection with previous biopsies were performed between January 2016 and December 2023 across 32 centers. 48.7% presented disagreement between biopsies and endoscopic submucosal dissection; specifically, 40.4% were underestimated by endoscopic biopsy. Carcinoma was detected in 270 endoscopic submucosal dissection specimens, with 54.8% not suspected on the initial biopsy. The carcinomas already diagnosed with the biopsy presented more submucosal and lymphovascular invasion. Notably, a larger lesion (≥ 22 mm) was a significant predictor for histological upstaging.

CONCLUSIONS

The high rate of disagreement between endoscopic forceps biopsy and endoscopic submucosal dissection highlights biopsies limitations in accurately diagnosing esophageal and gastric epithelial lesions. In this setting, endoscopic submucosal dissection should be used not only as a treatment option, but also as a valuable diagnostic tool.

Development and validation of a predictive model for the pathological upgrading of gastric low-grade intraepithelial neoplasia

BACKGROUND

The discrepancy between endoscopic biopsy pathology and the overall pathology of gastric low-grade intraepithelial neoplasia (LGIN) presents challenges in developing diagnostic and treatment protocols.

AIM

To develop a risk prediction model for the pathological upgrading of gastric LGIN to aid clinical diagnosis and treatment.

METHODS

We retrospectively analyzed data from patients newly diagnosed with gastric LGIN who underwent complete endoscopic resection within 6 months at the First Medical Center of Chinese People's Liberation Army General Hospital between January 2008 and December 2023. A risk prediction model for the pathological progression of gastric LGIN was constructed and evaluated for accuracy and clinical applicability.

RESULTS

A total of 171 patients were included in this study: 93 patients with high-grade intraepithelial neoplasia or early gastric cancer and 78 with LGIN. The logistic stepwise regression model demonstrated a sensitivity and specificity of 0.868 and 0.800, respectively, while the least absolute shrinkage and selection operator (LASSO) regression model showed sensitivity and specificity values of 0.842 and 0.840, respectively. The area under the curve (AUC) for the logistic model was 0.896, slightly lower than the AUC of 0.904 for the LASSO model. Internal validation with 30% of the data yielded AUC scores of 0.908 for the logistic model and 0.905 for the LASSO model. The LASSO model provided greater utility in clinical decision-making.

CONCLUSION

A risk prediction model for the pathological upgrading of gastric LGIN based on white-light and magnifying endoscopic features can accurately and effectively guide clinical diagnosis and treatment.

Comparison of Effective Imaging Modalities for Detecting Gastric Neoplasms: A Randomized 3-Arm Phase II Trial

INTRODUCTION

The early detection of gastric neoplasms (GNs) leads to favorable treatment outcomes. The latest endoscopic system, EVIS X1, includes third-generation narrow-band imaging (3G-NBI), texture and color enhancement imaging (TXI), and high-definition white-light imaging (WLI). Therefore, this randomized phase II trial aimed to identify the most promising imaging modality for GN detection using 3G-NBI and TXI.

METHODS

Patients with scheduled surveillance endoscopy after a history of esophageal cancer or GN or preoperative endoscopy for known esophageal cancer or GN were randomly assigned to the 3G-NBI, TXI, or WLI groups. Endoscopic observations were performed to detect new GN lesions, and all suspected lesions were biopsied. The primary endpoint was the GN detection rate during primary observation. Secondary endpoints were the rate of missed GNs, early gastric cancer detection rate, and positive predictive value for a GN diagnosis. The decision rule had a higher GN detection rate between 3G-NBI and TXI, outperforming WLI by >1.0%.

RESULTS

Finally, 901 patients were enrolled and assigned to the 3G-NBI, TXI, and WLI groups (300, 300, and 301 patients, respectively). GN detection rates in the 3G-NBI, TXI, and WLI groups were 7.3, 5.0, and 5.6%, respectively. The rates of missed GNs were 1.0, 0.7, and 1.0%, the detection rates of early gastric cancer were 5.7, 4.0, and 5.6%, and the positive predictive values for the diagnosis of GN were 36.5, 21.3, and 36.8% in the 3G-NBI, TXI, and WLI groups, respectively.

DISCUSSION

Compared with TXI and WLI, 3G-NBI is a more promising modality for GN detection.

Risk factors for pathological upgrading and noncurative resection in patients with gastric mucosal lesions after endoscopic submucosal dissection

BACKGROUND

The pathological results obtained from endoscopic forceps biopsy (EFB) do not always align with the findings of postoperative endoscopic submucosal dissection (ESD). Furthermore, as ESD becomes more widespread, the number of noncurative endoscopic cases increases; thus, an accurate preoperative diagnosis and an appropriate treatment method are crucial. The purpose of this study was to explore the risk factors for postoperative pathological upgrading and noncurative resection and to gather experience in clinical and pathological diagnosis.

METHODS

From March 2016 to November 2023, 292 ESD specimens were collected from 262 patients with gastric mucosal lesions. Clinicopathological information, the coincidence rate of pathological diagnosis between EFB and ESD specimens, and risk factors related to noncurative resection were analyzed retrospectively.

RESULTS

The overall upgraded pathological diagnosis rate between EFB and ESD was 26.4%. The independent predictors for the upgraded group included proximal stomach lesions, lesion size > 2 cm, surface ulceration, and surface nodules. Twenty of the 235 early gastric cancer (EGC) patients underwent noncurative ESD resection. Multivariate analysis showed that undifferentiated carcinoma and tumor infiltration into the submucosa were significantly associated with noncurative resection.

CONCLUSION

Biopsy cannot fully represent the lesions of gastric intraepithelial neoplasia (GIN). When a suspected epithelial dysplasia is suspected, a careful endoscopic examination should be conducted to evaluate the lesion site, size, and surface characteristics to ensure an accurate diagnosis. Noncurative endoscopic resection is associated with undifferentiated carcinoma and submucosal infiltration. Clinicians must be familiar with these predictive factors for noncurative resection and select the appropriate treatment for their patients.

The long-term outcome and risk factors of histologic discrepancy between forceps biopsies and endoscopic resections in early gastric cancer: An observational study

Although endoscopic forceps biopsy is the gold standard for early gastric cancer (EGC) diagnosis, the method can cause endoscopic resection of specimens and histological discrepancies. This study aims to examine the risk factors for histological discrepancies in EGC and long-term clinical outcomes. This retrospective study included patients diagnosed with differentiated-type EGC using forceps biopsy. Patients without histological discrepancies and with undifferentiated types in endoscopic resection histology were categorized into the concordant and discordant groups, respectively. Clinical characteristics and long-term outcomes related to histological discrepancies were analyzed. A total of 957 lesions from 936 patients were enrolled. An overall discrepancy rate of 8.7% was confirmed, with an undifferentiated-type discrepancy of 5.5%. The discordant group showed a higher tendency for lesions to be located in the upper third region, to have whitish discoloration, and to undergo a greater number of biopsies compared with the concordant group. Multivariate analysis confirmed that lesion location in the upper third region (odds ratio [OR]: 2.125; 95% confidence interval [CI]: 1.032-5.277; P = .041) and whitish surface discoloration (OR: 13.615; 95% CI: 6.028-28.728; P = .001) were significantly correlated with histologic discrepancy. Compared with the concordant group, the discordant group had a lower curative resection rate, but no differences were observed in complications, local recurrence, or survival rates. Upper third location and whitish discoloration were risk factors for the histologic discrepancy between differentiated and undifferentiated types in patients with EGC. For curative resections performed in patients with EGC and histologic discrepancies and without additional treatment, careful follow-up is possible.

Gastric Intestinal Metaplasia: Real Culprit or Innocent Bystander as a Precancerous Condition for Gastric Cancer?

Gastric intestinal metaplasia (GIM), which denotes conversion of gastric mucosa into an intestinal phenotype, can occur in all regions of the stomach, including cardiac, fundic, and pyloric mucosa. Since the earliest description of GIM, its association with gastric cancer of the differentiated (intestinal) type has been a well-recognized concern. Many epidemiologic studies have confirmed GIM to be significantly associated with subsequent gastric cancer development. Helicobacter pylori, the principal etiologic factor for gastric cancer, plays the most important role in predisposing to GIM. Although the role of GIM in the stepwise progression model of gastric carcinogenesis (the so-called "Correa cascade") has come into question recently, we review the scientific evidence that strongly supports this long-standing model and propose a new progression model that builds on the Correa cascade. Eradication of H pylori is the most important method for preventing gastric cancer globally, but the effect of eradication on established GIM, is limited, if any. Endoscopic surveillance for GIM may, therefore, be necessary, especially when there is extensive corpus GIM. Recent advances in image-enhanced endoscopy with integrated artificial intelligence have facilitated the identification of GIM and neoplastic lesions, which will impact preventive strategies in the near future.

A Prediction Model Based on the Risk Factors Associated with Pathological Upgrading in Patients with Early-Stage Gastric Neoplasms Diagnosed by Endoscopic Forceps Biopsy

Background/Aims

The discrepancies between the diagnosis of preoperative endoscopic forceps biopsy (EFB) and endoscopic submucosal dissection (ESD) in patients with early gastric neoplasm (EGN) exist objectively. Among them, pathological upgrading directly influences the accuracy and appropriateness of clinical decisions. The aims of this study were to investigate the risk factors for the discrepancies, with a particular focus on pathological upgrading and to establish a prediction model for estimating the risk of pathological upgrading after EFB.

Methods

We retrospectively collected the records of 978 patients who underwent ESD from December 1, 2017 to July 31, 2021 and who had a final histopathology determination of EGN. A nomogram to predict the risk of pathological upgrading was constructed after analyzing subgroup differences among the 901 lesions enrolled.

Results

The ratio of pathological upgrading was 510 of 953 (53.5%). Clinical, laboratorial and endoscopic characteristics were analyzed using univariable and binary multivariable logistic regression analyses. A nomogram was constructed by including age, history of chronic atrophic gastritis, symptoms of digestive system, blood high density lipoprotein concentration, macroscopic type, pathological diagnosis of EFB, uneven surface, remarkable redness, and lesion size. The C-statistics were 0.804 (95% confidence interval, 0.774 to 0.834) and 0.748 (95% confidence interval, 0.664 to 0.832) in the training and validation set, respectively. We also built an online webserver based on the proposed nomogram for convenient clinical use.

Conclusions

The clinical value of identifying the preoperative diagnosis of EGN lesions is limited when using EFB separately. We have developed a nomogram that can predict the probability of pathological upgrading with good calibration and discrimination value.

Tumor heterogeneity and carcinoma in resected specimens of gastric low-grade dysplasia: A retrospective single center study

Lesions diagnosed as gastric low-grade dysplasia (LGD) may be pathologically upgraded to early gastric cancer (EGC) or high-grade dysplasia (HGD) after endoscopic resection (ER). In this study, we investigated the risk factors for pathological upgrades after ER and assessed the reason for these upgrades by retrospectively analyzing ER data between January 1999 and December 2019. We enrolled patients with LGD confirmed by forceps biopsy; the patients were classified into pathologically concordant (LGD) and upgraded (HGD and EGC) groups according to the pathology of their resected specimen. To determine the risk factors for upgrade, we compared the endoscopic findings of the concordant and upgraded groups via 1:1 matched case-control design. To find the reasons for discordance, all upgraded cases were pathologically re-evaluated. Among 1,643 cases of LGD, pathological upgrades were observed in 423 (25.7%) resected specimens and EGC was found in 111 (6.7%) lesions. After matching the upgraded and concordant cases, lesion sizes exceeding 1.5 cm (odds ratio (OR): 1.8; 95% CI: 1.1-3.0), mucosal nodularity (OR: 10.8; 95% CI: 5.6-21.0), heterogeneous color (OR: 3.0; 95% CI: 1.7-5.3), presence of erosion (OR: 2.7; 95% CI: 1.8-5.3), and open-type gastric atrophy (OR: 2.9; 95% CI: 1.7-4.9) were noted to be significantly associated with upgraded pathology to EGC. Among the EGC cases, 99 (89.2%) were found to have pre-existing dysplasia. In conclusion, endoscopic evaluations should be performed because of possible pathological upgrades and co-existence of carcinomas in LGDs, especially when they exhibit surface nodularity, erosion, heterogeneous color, and large size.

Discrepancy Between Forceps Biopsy and Resection in Colorectal Polyps: A 1686 Paired Screening-Therapeutic Colonoscopic Finding

Purpose

To identify pathology discrepancy between forceps biopsies and polypectomy specimens in colorectal polyps, as well as the reliability of biopsy-based treatment strategy.

Methods

All endoscopic polypectomy cases with forceps biopsies performed within 6 months were included in the study. The biopsies were compared with polypectomy specimens in terms of concordance of histological diagnosis. A logistic regression model was used to investigate the independent predictors of upgrade in histological diagnosis compared with concordance in histological diagnosis.

Results

A total of 1686 paired screening-therapeutic colonoscopies and 1739 paired biopsy-polypectomy specimens were enrolled in the study. The grade of dysplasia in 84.5% of biopsy specimens were concordant to polypectomy specimens, but this proportion decreased to 75.4% when the specimens were classified using tubular or villousness structure. 10.1% and 5.4% of biopsy specimens were upgraded and downgraded in assessing grade of dysplasia, respectively, while 14.3% and 10.3% of biopsy specimens were upgraded and downgraded in assessing tubular or villousness structure, respectively. In subgroup analysis stratified by size of polyps, 9.0% and 10.6% of biopsies obtained from polyps smaller than 10 mm were upgraded in assessing dysplasia and tubular or villousness structure, respectively. This proportion increased to 10.7% and 21.3%, respectively, in biopsies obtained from polyps larger than 10 mm. Larger size of polyps and pedunculated polyps were associated with a higher incidence of upgrade in histological diagnosis. Nearly 25% of biopsy specimens with high-grade dysplasia were identified as adenocarcinoma in polypectomy specimens.

Conclusion

The concordance between biopsy and polypectomy specimens is not adequate. The biopsy-based treatment strategy is not reliable and should not be considered as an indicator for further treatment, particularly in large or pedunculated polyps.

Risk factors for the histologic discrepancy of gastric adenomatous lesions and long-term outcome

Although endoscopic forceps biopsies (EFB) have a significant role in diagnosing gastric adenoma, there are still discrepancies between EFBs and finalized pathology results.Therefore, the objective of this study was to find the risk factors that cause this discrepancy and to analyze the effects of this discrepancy on the long-term outcome.In this study patients that had received endoscopic resection due to low-grade gastric adenoma diagnosis from EFB between January of 2011 and January of 2018 at the Chungnam National University Hospital were retrospectively analyzed. According to whether there was histological discrepancy the cumulative incidence of the metachronous lesions were analyzed.A total of 745 lesions diagnosed as low-grade gastric adenoma at EFB were enrolled, and the final pathology results were confirmed to be non-neoplastic (n = 19), low-grade adenoma (n = 614), High-grade adenoma (n = 63), and carcinoma (n = 49), and with the exception of non-neoplastic lesion, the results confirmed 84.6% (n = 614) for the concordant group and 15.4% (n = 112) for the discordant. The results of the multivariate analysis confirmed that depressed lesion (odds ratio [OR]: 2.056; 95% confidence interval [CI]: 1.130-3.451; P = .011), erythema (OR: 2.546; 95% CI: 1.604-4.030; P = .004), and a size >1.5 cm (OR: 1.903; 95% CI: 1.102-3.172; P = .018) were risk factors for discrepancy. The results also confirmed that for the average observation period of (SD) 39.12 (12.31) months, the cumulative incidence of metachronous neoplasm had a higher significance (P = 0.001) in the discordant group when compared to that of the concordant group.The factors related to the histologic discrepancy of low-grade gastric adenoma were depressed lesion, erythema and size >1.5 cm. In the groups with histological discrepancy, the cumulative incidence of the metachronous neoplasm was significantly higher and therefore closer observation of such patients after performing endoscopic resection is necessary.

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.

Multiple metabolic parameters and visual assessment of 18F-FDG uptake heterogeneity of PET/CT in advanced gastric cancer and primary gastric lymphoma

PURPOSE

Advanced gastric cancer (AGC) and primary gastric lymphoma (PGL) are the two most common malignant tumors of the stomach. Conventional imaging examinations have difficulty distinguishing the two. This study explored the values of multiple parameters and visual assessment of ¹⁸F-fluorodeoxyglucose(¹⁸F-FDG) uptake heterogeneity of positron emission tomography/computed tomography(PET/CT) for differentiating between AGC and PGL.

METHODS

This retrospective study included 70 AGC and 26 PGL patients, all of whom had undergone ¹⁸F-FDG PET/CT before treatment. We analyzed the differences between AGC and PGL in the distribution of metastatic lesions and multiple metabolic parameters, including the maximum standardized uptake value (SUVmax), SUVmax/maximal thickness(THKmax), metabolic tumor volume and total lesion glycolysis (TLG). In addition, ¹⁸F-FDG uptake heterogeneity was visually assessed using a visual scoring method and a method of measuring SUVmax differences (SUVmax-d).

RESULTS

The most common metastasis of AGC patients were liver, bone, peritoneal and proximal lymph nodes; PGL patients had fewer peritoneal metastases and lymph node metastasis could appeared to be "skip metastasis." The metabolic parameters-SUVmax, SUVmax/THKmax and TLG-were higher in patients who had PGL, especially in diffuse large B-cell lymphoma (DLBCL). In the visual assessment of ¹⁸F-FDG uptake heterogeneity, the measurements of SUVmax-d in PGL were significantly higher than in AGC. Receiver operating characteristics curve analysis suggested that SUVmax has the highest comprehensive diagnostic efficiency due to having the highest value of area under the curve and the highest accuracy (77.2%).

CONCLUSION

¹⁸F-FDG PET/CT had a high diagnostic efficiency for discrimination of AGC and PGL, especially between DLBCL and other pathological subtypes. Visual assessment used to evaluate ¹⁸F-FDG uptake heterogeneity could help to distinguish the two types of tumors. In addition, our innovative method of measuring the heterogeneity of ¹⁸F-FDG uptake-namely, SUVmax-d-could contribute to identification of the two tumor types and should have its significance clarified by future studies.

Feedback from artificial intelligence improved the learning of junior endoscopists on histology prediction of gastric lesions

Background and study aims  Artificial intelligence (AI)-assisted image classification has been shown to have high accuracy on endoscopic diagnosis. We evaluated the potential effects of use of an AI-assisted image classifier on training of junior endoscopists for histological prediction of gastric lesions. Methods  An AI image classifier was built on a convolutional neural network with five convolutional layers and three fully connected layers A Resnet backbone was trained by 2,000 non-magnified endoscopic gastric images. The independent validation set consisted of another 1,000 endoscopic images from 100 gastric lesions. The first part of the validation set was reviewed by six junior endoscopists and the prediction of AI was then disclosed to three of them (Group A) while the remaining three (Group B) were not provided this information. All endoscopists reviewed the second part of the validation set independently. Results  The overall accuracy of AI was 91.0 % (95 % CI: 89.2-92.7 %) with 97.1 % sensitivity (95 % CI: 95.6-98.7%), 85.9 % specificity (95 % CI: 83.0-88.4 %) and 0.91 area under the ROC (AUROC) (95 % CI: 0.89-0.93). AI was superior to all junior endoscopists in accuracy and AUROC in both validation sets. The performance of Group A endoscopists but not Group B endoscopists improved on the second validation set (accuracy 69.3 % to 74.7 %; P  = 0.003). Conclusion  The trained AI image classifier can accurately predict presence of neoplastic component of gastric lesions. Feedback from the AI image classifier can also hasten the learning curve of junior endoscopists in predicting histology of gastric lesions.

Identifying high-risk individuals for gastric cancer surveillance from western and eastern perspectives: Lessons to learn and possibility to develop an integrated approach for daily practice

Current evidence shows that individuals with gastric dysplasia, severe and extensive gastric atrophy, extensive gastric intestinal metaplasia and the incomplete subtype of intestinal metaplasia are at high risk for gastric cancer (GC) development. There are several approaches to identifying these subjects, including noninvasive methods, esophagogastroduodenoscopy and histology. The main approach in Western countries is histology-based while that in Eastern countries with a high prevalence of GC is endoscopy-based. Regarding asymptomatic individuals, the key issues in selecting applicable approaches are the ability to reduce GC mortality and the cost-effectiveness of the approach. At present, population-based screening programs have only been applied in a few Asian countries with a high risk of GC. Pre-endoscopic risk assessment based on demographic and clinical features, such as ethnicity, age, gender, smoking and Helicobacter pylori status, is helpful for identifying subjects with high pre-test probability for a possibly cost-effective approach, especially in intermediate- and low-risk countries. Regarding symptomatic patients with indications for esophagogastroduodenoscopy, the importance of opportunistic screening should be emphasized. The combination of endoscopic and histological approaches should always be considered as endoscopy provides a real-time assessment of the patient's risk level. In addition, imaging enhanced endoscopy (IEE) has been shown to facilitate targeted biopsies resulting in better correlation between endoscopic and histological findings. Currently, the use of IEE is recommended for endoscopic examinations, and the Operative Link for Gastric Intestinal Metaplasia or Operative Link on Gastritis Assessment grading systems are recommended for histological examinations whenever available. However, resource limitations are an important barrier in many regions worldwide. Thus, for an approach to be applicable in real-life practice, it should be not only evidence-based but also resource-sensitive. In this review, we discuss the current understanding and approaches to identifying high-risk individuals from western and eastern perspectives, as well as the possibility of an integrated, resource-sensitive approach.

Clinical outcomes of endoscopic treatment for gastric epithelial neoplasm in remnant stomach after distal gastrectomy

BACKGROUNDS/AIM

We aimed to evaluate the feasibility of endoscopic treatment for gastric epithelial neoplasm in the remnant stomach after distal gastrectomy and compared the clinical outcomes by tumor location and endoscopic treatment modality.

METHODS

We reviewed the data of patients who underwent endoscopic treatment for gastric epithelial neoplasms in the remnant stomach after distal gastrectomy between January 1996 and August 2013. The treatments included endoscopic resection or argon plasma coagulation.

RESULTS

Herein, 107 patients (median age, 65.1 years; 92 men) encompassing 117 cases of gastric neoplasms in the remnant stomach after distal gastrectomy were endoscopically treated. Forty of these lesions were located at anastomotic sites; they were treated with endoscopic resection in 29 cases (72.5%) and argon plasma coagulation in 11 cases (27.5%). For 77 lesions located on the non-anastomotic site, endoscopic resection was performed in 68 cases (88.4%) and argon plasma coagulation was performed in nine cases (11.7%; p = 0.031). The mean endoscopic resection duration was significantly longer in the anastomotic site group than in the non-anastomotic site group (43.6 vs. 26.3 min, p = 0.018). Recurrence was observed in five (12.8%) patients in the former and in one (1.3%) in the latter (p = 0.015); all the patients were successfully retreated with endoscopic resection or APC.

CONCLUSIONS

Endoscopic treatment for gastric epithelial neoplasm in a remnant stomach after distal gastrectomy is effective and safe. However, closely monitoring for recurrence should be conducted, particularly when the tumor is located at the anastomotic site.

Calcium Carbonate Nanoparticles Can Activate the Epithelial⁻Mesenchymal Transition in an Experimental Gastric Cancer Model

Previously, we have shown the possibility of intramucosal gastric carcinoma induction by the intragastric administration of a mixture of formaldehyde and hydrogen peroxide in rats. In this study, we report a sizable increase in carcinogenic properties of the mixture when a suspension containing calcium carbonate nanoparticles was added to it. This technique allowed us to reduce both the number of the carcinogen administrations from twelve to two and the time to the cancer induction from six to four months. Although the induced tumors were represented by the intramucosal carcinomas, they were characterized by the extensive invasion of individual tumor cells and their clusters into the muscle layer and serosa as well as into the omentum and blood vessels. Considering that the invasive tumor cells were positive for vimentin, Snail and TGF-β2, we concluded that their invasion was the result of the activation of epithelial⁻mesenchymal transition (EMT) mechanisms. Thus, taking into account the data obtained, it can be assumed that under the conditions of inflammation or carcinogenesis, the calcium carbonate nanoparticles may affect the activation of EMT mechanisms.

Risk factors associated with histological upgrade of gastric low-grade dysplasia on pretreatment biopsy

OBJECTIVES

Histological discrepancies between biopsy and resection specimens are common. In this study, we aimed to analyze the risk factors predicting histological upgrade or downgrade of biopsy-diagnosed gastric low-grade dysplasia (LGD).

METHODS

The medical records of patients with 104 biopsy-diagnosed gastric LGD from January 2011 to December 2017 were collected. The association of endoscopic characteristics with histological discrepancies between the biopsy and resection specimens was analyzed. The risk factors for histological upgrade were studied using the multivariate analysis.

RESULTS

Among the 104 lesions, 88 were removed by endoscopic resection and 16 were monitored. The upgrade and downgrade rates of the pathological diagnosis were 48.9% and 12.5%, respectively. Lesion size >20 mm, surface redness and positive results in magnifying endoscopy with narrow band imaging (ME-NBI) were risk factors for histological upgrade. Compared with the negative ME-NBI group, the positive ME-NBI group had a higher upgrade rate (56.8% vs 7.1%) but a lower downgrade rate (2.7% vs 64.3%). In addition, 11 of the 16 the gastric LGD with negative ME-NBI findings were monitored, and all 11 lesions regressed to gastritis during follow-up.

CONCLUSIONS

Endoscopic resection should be recommended in cases of LGD showing surface redness, with a lesion size of >20 mm or positive ME-NBI result, whereas regular follow-up may be an option for LGD with negative ME-NBI result.