Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: short- and long-term outcomes

Artificial intelligence-assisted diagnosis of early gastric cancer: present practice and future prospects

Gastric cancer (GC) occupies the first few places in the world among tumors in terms of incidence and mortality, causing serious harm to human health, and at the same time, its treatment greatly consumes the health care resources of all countries in the world. The diagnosis of GC is usually based on histopathologic examination, and it is very important to be able to detect and identify cancerous lesions at an early stage, but some endoscopists' lack of diagnostic experience and fatigue at work lead to a certain rate of under diagnosis. The rapid and striking development of Artificial intelligence (AI) has helped to enhance the ability to extract abnormal information from endoscopic images to some extent, and more and more researchers are applying AI technology to the diagnosis of GC. This initiative has not only improved the detection rate of early gastric cancer (EGC), but also significantly improved the survival rate of patients after treatment. This article reviews the results of various AI-assisted diagnoses of EGC in recent years, including the identification of EGC, the determination of differentiation type and invasion depth, and the identification of borders. Although AI has a better application prospect in the early diagnosis of ECG, there are still major challenges, and the prospects and limitations of AI application need to be further discussed.

Management Strategy of Non-curative ESD in Gastric Cancer: Curative Criteria, and the Critical Building Block for Determining Beyond It

Endoscopic submucosal dissection is performed in cases of early gastric cancer, where the risk of lymph node metastasis (LNM) is expected to be negligible, and 12%-21% of these patients are deemed to have undergone non-curative resections based on pathological criteria. In such cases, decisions regarding additional treatments must be made to maximize curability, depending on the anticipated LNM risk. Well-established risk factors for LNM include lymphatic invasion, vascular invasion, deep submucosal invasion, positive vertical margins, and larger tumor size. When pathological factors associated with a clear LNM risk, such as lymphatic or deep submucosal invasion, are present, additional gastrectomy with lymph node dissection should be considered. Conversely, in cases involving only a positive horizontal margin, additional endoscopic treatment may be an effective therapeutic option as opposed to gastrectomy because of the negligible risk of LNM despite the potential risk of residual tumors. Endoscopic resection is particularly advantageous for determining complete resection. In addition to pathological curability, patient-specific factors, such as age and comorbidities, must be considered. Several retrospective cohort studies have shown that the cause of mortality among patients placed only on observation without additional treatment after non-curative resection is generally related to underlying conditions irrelevant to gastric cancer. Thus, it is crucial to assess both GC-specific mortality and all-cause mortality to finalize treatment decisions that help minimize such mortality. Therefore, new treatment algorithms that integrate pathological curability with patient-specific factors must be developed.

Endoscopic Submucosal Dissection for Early Gastric Cancer Exceeding Expanded Criteria-Long-Term Outcomes from the German ESD Registry

Background and aims: Endoscopic submucosal dissection (ESD) has become a standard treatment for early gastric cancer (EGC), often fulfilling guideline criteria (GC) or expanded criteria (EC). When lesions exceed the EC, surgical resection is recommended. However, a subgroup of these patients are not treated surgically. The aim of this study was to investigate the long-term follow-up of patients after ESD for EGC outside the EC (out of indication; OI). Methods: Patients who were included in the prospective German ESD registry were analyzed when ESD was performed for EGC. Patients were stratified in three groups according to histopathological features (GC, EC and OI). The results were evaluated in terms of patient characteristics, procedure characteristics and follow-up data. Results: Over a 48-month period, 195 patients from 14 German centers were included. In total, 71 lesions (36.4%) met the guideline criteria, 70 lesions (35.9%) corresponded to the expanded criteria and 54 lesions (27.7%) turned out to be OI. The R0 resection rate was significantly higher for the GC and EC groups than for the OI group (94.4% vs. 84.3% vs. 55.6%, p < 0.001). Additional surgery was not performed in 72% (39/54) of patients in the OI group. During a mean follow-up of 37 months, overall survival showed no significant difference between the EC and OI groups when endoscopic follow-up was performed without additional surgery (p = 0.064). Conclusions: The results show that a good long-term survival can be achieved after ESD for patients with OI lesions without additional surgery. The treatment decision has to be made on an individual basis, taking the patient's comorbidities and the risk of surgical resection into account.

Long-term outcomes of endoscopic submucosal dissection for undifferentiated type early gastric cancer over 2 cm with R0 resection

BACKGROUND

Endoscopic submucosal dissection (ESD) for over 2 cm in size undifferentiated type (UD type) early gastric cancer (EGC) confined to the mucosa is not only challenging, but also long-term outcomes are not well known.

AIM

To evaluate the long-term outcomes of ESD done for UD type EGCs confined to the mucosa over 2 cm in size and compare the results with those where the lesions were less than 2 cm.

METHODS

143 patients with UD type EGC confirmed on histology after ESD at a tertiary hospital were reviewed. Cases with synchronous and metachronous lesions and a case with emergency surgery after ESD were excluded. A total of 137 cases were enrolled. 79 cases who underwent R0 resection were divided into 2 cm or less (group A) and over 2 cm (group B) in size.

RESULTS

Among 79 patients who underwent R0 resection, the number in group A and B were 51 and 28, respectively. The mean follow-up period (SD) was 79.71 ± 45.42 months. There was a local recurrence in group A (1/51, 2%) and group B (1/28, 3.6%) respectively. This patient in group A underwent surgery while the patient in group B underwent repeated ESD with no further recurrences in both patients. There was no regional lymph node metastasis, distant metastasis, and deaths in both groups. With R0 resection strategy for ESD on lesions over 2 cm, 20.4% (28/137) of patients were able to avoid surgery compared with expanded indication.

CONCLUSION

If R0 resection is achieved by ESD, UD type EGCs over 2 cm also showed good and similar clinical outcomes as compared to lesions less than 2 cm when followed for over 5 years. With R0 resection strategy, several patients can avoid surgery.

Verrucous gastritis-like lesion in intramucosal Helicobacter pylori-uninfected signet ring cell carcinoma with poorly differentiated adenocarcinoma

In Japan, accessible Helicobacter pylori (Hp) eradication therapy is associated with an increase in the prevalence of gastric cancers (GCs) in Hp uninfected stomachs. Signet ring cell carcinoma (SRCC) is the most common of these GCs. Intramucosal SRCC with poorly differentiated adenocarcinoma (PDA) occurring in Hp uninfected gastric mucosa is rare; furthermore, many Hp uninfected pure SRCCs exhibit discoloration and flat or slightly depressed lesions, and morphological elevation is relatively rare. We report a case of intramucosal SRCC with PDA with an elevated, verrucous gastritis-like lesion in a 57-year-old male patient. In the present case, the PDA area showed dense tumor cell growth and coexisting desmoplastic and fibrotic reactions. Histopathology and immunohistochemical staining identified extensive fibromuscular obliteration with smooth muscle bundles extending from the muscularis mucosa into the lamina propria. The patient underwent curative endoscopic submucosal dissection. The reporting and analysis of such rare cases may lead to a better understanding of the characteristics of advanced Hp uninfected GCs.

Chinese national clinical practice guidelines on the prevention, diagnosis, and treatment of early gastric cancer

BACKGROUND

Gastric cancer is one of the most common malignant tumors in the digestive system in China. Few comprehensive practice guidelines for early gastric cancer in China are currently available. Therefore, we created the Chinese national clinical practice guideline for the prevention, diagnosis, and treatment of early gastric cancer.

METHODS

This clinical practice guideline (CPG) was developed in accordance with the World Health Organization's recommended process and with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) in assessing evidence quality. We used the Evidence to Decision framework to formulate clinical recommendations to minimize bias and increase transparency in the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and the Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guidelines to ensure completeness and transparency of the CPG.

RESULTS

This CPG contains 40 recommendations regarding the prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer based on available clinical studies and guidelines. We provide recommendations for the timing of Helicobacter pylori eradication, screening populations for early gastric cancer, indications for endoscopic resection and surgical gastrectomy, follow-up interval after treatment, and other recommendations.

CONCLUSIONS

This CPG can lead to optimum care for patients and populations by providing up-to-date medical information. We intend this CPG for widespread adoption to increase the standard of prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer; thereby, contributing to improving national health care and patient quality of life.

Feasibility for the application of expanded endoscopic resection criteria in mucosal undifferentiated gastric cancer

BACKGROUND & AIM

The indication of endoscopic submucosal dissection (ESD) for mucosal undifferentiated early gastric cancer (EGC) remains controversial because of risk of lymph node metastasis (LNM). The aim of this study was to identify risk factors for lymph node metastasis (LNM) in mucosal undifferentiated EGC, and further to confirm feasibility of the ESD for the treatment of mucosal undifferentiated EGC.

METHODS

We retrospectively reviewed data of patients who underwent surgical resection with lymph node dissection of T1a stage primary gastric adenocarcinoma at three medical centers between 2012 and 2022. We evaluated the frequency of lymph node metastasis and the associated risk factors, as well as the lymph node metastasis rate in the expanded indication of mucosal undifferentiated EGC.

RESULTS

A total of 100 surgically treated patients with mucosal undifferentiated EGC were enrolled. LNM was irrelevant to the age, tumor size, location, and macroscopic type (all P > 0.05), while it was significantly associated with lymphovascular invasion (LVI, P ＜0.001). And logistic regression analysis showed that the LVI was the only significant risk factors for LNM (OR: 0.34, 95%CI: 0.06-0.204; P ＜0.001). Of 44 mucosal undifferentiated EGC patients satisfying the expanded indication of ESD, 3 patients (6.8%) showed LN metastasis, all of them with undifferentiated cancer without ulceration, less than 2.0 cm in size.

CONCLUSIONS

Because LNM is present in mucosal undifferentiated EGC patients who satisfied the expanded indication of ESD, ESD cannot be considered a better choice than surgery for all undifferentiated EGC patients. LVI was significant risk factors for LNM in patients with mucosal undifferentiated EGC.

Diagnostic accuracy of frozen section biopsy for early gastric cancer extent during endoscopic submucosal dissection: a prospective study

BACKGROUND

Accurate diagnosis of the lateral extent of early gastric cancer during endoscopic submucosal dissection (ESD) is crucial to achieve negative resection margins. Similar to intraoperative consultation with a frozen section in surgery, rapid frozen section diagnosis with endoscopic forceps biopsy may be useful in assessing tumor margins during ESD. This study aimed to evaluate the diagnostic accuracy of frozen section biopsy.

METHODS

We prospectively enrolled 32 patients undergoing ESD for early gastric cancer. Biopsy samples for the frozen sections were randomly collected from fresh resected ESD specimens before formalin fixation. Two different pathologists independently diagnosed 130 frozen sections as "neoplasia," "negative for neoplasia," or "indefinite for neoplasia," and the frozen section diagnosis was compared with the final pathological results of the ESD specimens.

RESULTS

Among the 130 frozen sections, 35 were from cancerous areas, and 95 were from non-cancerous areas. The diagnostic accuracies of the frozen section biopsies by the two pathologists were 98.5 and 94.6%, respectively. Cohen's kappa coefficient of diagnoses by the two pathologists was 0.851 (95% confidence interval: 0.837-0.864). Incorrect diagnoses resulted from freezing artifacts, a small volume of tissue, inflammation, the presence of well-differentiated adenocarcinoma with mild nuclear atypia, and/or tissue damage during ESD.

CONCLUSIONS

Pathological diagnosis of frozen section biopsy is reliable and can be applied as a rapid frozen section diagnosis for evaluating the lateral margins of early gastric cancer during ESD.

Risk of lymph node metastasis in early gastric cancer for a Western population

INTRODUCTION

Endoscopic resection (ER) of early gastric cancer (EGC) is increasingly used in Eastern countries due to their low rates of lymph node metastasis (LNM); however, there is a paucity of evidence in Western countries. We investigated LNM and its effect on overall survival (OS) in Western patients with EGC.

METHODS

Patients diagnosed with T1 gastric cancer between 2000 and 2017 were retrospectively evaluated. Univariate Kaplan-Meier, multivariate logistic and Cox-regression models were used to assess the associations between clinical characteristics, LNM, and OS.

RESULTS

Among 86 patients, median age was 68 years and 72% were male. Node positivity was 30%. Two percent of patients met the classical guidelines for ER and all were node-negative, while 16% met expanded criteria of which 14% were node-positive. T1b disease (odds ratio [OR] 41.2 [95% confidence interval [CI] 1.62-1048], p = 0.02) and lymphovascular/perineural invasion (OR 18.0 [95% CI 2.41-134], p = 0.01) were predictive of node positivity. The 5-year OS for node-negative and node-positive patients was 84% and 53% (p = 0.004), respectively.

CONCLUSIONS

The risk of LNM in Western patients with EGC is higher; therefore, generalizability of the expanded criteria for ER should be interpreted with caution.

Long-term outcomes of additional surgery versus non-gastrectomy treatment for early gastric cancer after non-curative endoscopic submucosal dissection: a meta-analysis

BACKGROUND

Endoscopic resection is increasingly used in the treatment for early gastric cancer (EGC); however, about 15% of endoscopic submucosal dissection (ESD) cases report non-curative resection. The efficacy of different remedial interventions after non-curative ESD for EGC remains controversial. This meta-analysis aimed to compare the long-term outcomes of additional surgery and non-gastrectomy treatment for EGC patients who underwent non-curative ESD.

METHODS

All relevant studies published up to October 2021 were systematically searched in the PubMed, Web of Science, and Embase databases. The medical subject headings terms "early gastric cancer," "gastrectomy," "endoscopic submucosal dissection," and their related free keywords were used to search relevant articles without restrictions on regions, publication types, or languages. The Newcastle-Ottawa Quality Assessment Scale was used to evaluate the quality of the included studies. Odds ratios (ORs) with 95% confidence intervals (CIs) of 5-year overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS) and hazard ratios (HRs) with 95% CIs of OS were calculated using a random- or fixed-effects model.

RESULTS

This meta-analysis included 17 retrospective cohort studies with 5880 patients, of whom 3167 underwent additional surgery and 2713 underwent non-gastrectomy. We found that patients receiving additional gastrectomy had better 5-year OS (OR = 3.63, 95% CI = 3.05-4.31), DSS (OR = 3.22, 95% CI = 2.22-4.66), and DFS (OR = 4.39, 95% CI = 1.78-10.82) outcomes than those receiving non-gastrectomy treatments. The pooled HR also showed that gastrectomy following non-curative ESD significantly improved OS (HR = 0.40, 95% CI = 0.33-0.48). In addition, elderly patients benefited from additional surgery in consideration of the 5-year OS (HR = 0.54, 95% CI = 0.41-0.72).

CONCLUSIONS

Compared with non-gastrectomy treatments, additional surgery offered better long-term survival outcomes for patients with EGC who underwent non-curative ESD.

Feasibility of same-day discharge following endoscopic submucosal dissection for esophageal or gastric early cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) is an established technique for the treatment of early gastrointestinal neoplasia. Generally, multi-day (M-D) admission is required for patients undergoing ESD due to potential complications.

AIM

To evaluate the feasibility of a same-day (S-D) discharge strategy for ESD of the esophagus or stomach.

METHODS

The data of patients who underwent esophageal or gastric ESD were retrospectively collected from January 2018 to December 2021 at Peking University Cancer Hospital. The propensity score matching (PSM) method was applied to balance the unevenly distributed patient baseline characteristics between the S-D and M-D groups. Intraoperative and postoperative parameters were compared between the matched groups.

RESULTS

Among the 479 patients reviewed, 470 patients, including 91 in the S-D group and 379 in the M-D group, fulfilled the inclusion and exclusion criteria. Following PSM, 78 patients in each group were paired using the 1:1 nearest available score match algorithm. No significant difference was found between groups with respect to intraoperative and postprocedural major adverse events (AEs). Tumor size, complete resection rate, and procedural duration were comparable between the groups. The S-D group demonstrated a significantly shorter length of hospital stay (P < 0.001) and lower overall medical expenses (P < 0.001) compared with the M-D group.

CONCLUSION

The S-D discharge strategy may be feasible and effective for esophagogastric ESD, and the procedural-related AEs can be managed successfully.

Endoscopic submucosal dissection for early signet ring cell gastric cancer: A systematic review and meta-analysis

BACKGROUND

The use of endoscopic submucosal dissection (ESD) for treating early signet ring cell carcinoma (SRC) is controversial due to the risk of lymph node metastasis.

AIM

To carry out a meta-analysis to evaluate ESD for therapeutic efficacy and safety in early signet ring cell gastric cancer.

METHODS

The PubMed, Web of Science, Cochrane Library, and EMBASE databases were used to search for relevant studies evaluating the therapeutic efficacy and safety of ESD in SRC. The rates of recurrence, complete resection, incomplete resection, curative resection, en bloc resection, and adverse events were extracted and analyzed. The methodological quality of the enrolled studies was assessed using the Newcastle-Ottawa Scale. Publication bias was evaluated by the Egger’s test. Institutional review board approval and written consent were not needed for this report.

RESULTS

This meta-analysis enrolled seven studies with 653 participants undergoing ESD treatment for early SRC. The overall recurrence rate was 0.010 [95% confidence interval (CI): 0.000-0.040, Z = 1.422, P = 0.155]. The total lymphovascular invasion rate was 0.038 (95%CI: 0.007-0.088, Z = 3.026, P = 0.002). The total en bloc resection rate was estimated at 0.984 (95%CI: 0.925-1.000, Z = 19.463, P = 0.000). The total complete and incomplete resection rates were estimated at 0.785 (95%CI: 0.596-0.928, Z = 9.789, P = 0.000) and 0.188 (95%CI: 0.016-0.468, Z = 2.531, P = 0.011), respectively. The total procedure-associated gastric hemorrhage and perforation rates were estimated at 0.026 (95%CI: 0.005-0.061, Z = 3.006 P = 0.003) and 0.004 (95%CI: 0.000-0.028, Z = 0.938, P = 0.348), respectively. The curative resection, vertical margin invasion, and lateral margin invasion rates were 72.1% (145/341), 2.3% (8/348), and 34.45% (41/119), respectively.

CONCLUSION

ESD constitutes a promising therapeutic approach for early undifferentiated SRC gastric cancer. However, further improvements are required for increasing its treatment efficacy and reducing adverse outcomes.

Long-term outcomes of endoscopic submucosal dissection and surgery for undifferentiated intramucosal gastric cancer regardless of size

BACKGROUND

The clinical outcomes of endoscopic submucosal dissection (ESD) for undifferentiated (UD) intramucosal early gastric cancer (EGC) compared with those of surgery, regardless of lesion size, are not well known. Furthermore, there is a concern regarding the treatment plan before and after ESD in cases of UD intramucosal EGC within expanded indications.

AIM

To evaluate clinical outcomes of ESD compared with those of surgery in UD intramucosal EGC patients regardless of tumor size.

METHODS

We enrolled patients with UD intramucosal EGC after ESD with complete resection or surgery from January 2005 to August 2020 who met the within or beyond expanded indications with lesion size > 2 cm (the only non-curative factor). Overall, 123 and 562 patients underwent ESD and surgery, respectively. After propensity-score matching, clinical and long-term outcomes, i.e., recurrence-free survival (RFS) and overall survival (OS), were analyzed. The multivariable Cox proportional hazard model with treatment modality and ESD indication was used to evaluate the recurrence risk.

RESULTS

After matching, 119 patients each were finally enrolled in the ESD and surgery groups. The median length of hospital stay was shorter in the ESD group than surgery group (4.0 vs 9.0 days, P < 0.001). Four cases of recurrence after ESD were local recurrences, all of which occurred within 1 year. Total recurrence was seven (5.9%) and two (1.7%) in the ESD and surgery groups, respectively. No difference was observed between the two groups with respect to OS (P = 0.948). However, the ESD group had inferior RFS compared with the surgery group (P = 0.031). ESD was associated with the risk of recurrence after initial treatment in all enrolled patients (hazard ratio, 5.2; 95% confidence interval: 1.0-25.8, P = 0.045).

CONCLUSION

Although OS was similar between the two groups, surveillance endoscopy was important for the ESD than for the surgery group because RFS was inferior and local recurrence was an issue.

Comparison of Gene Expression Profiles of Signet Ring Cell Carcinoma and Poorly Cohesive Carcinoma in Early Gastric Cancer

Introduction:

Although signet ring cell carcinoma (SRC) is a subtype of poorly cohesive carcinoma (PC), the differences in the biological behavior between the 2 morphologically similar carcinomas have not been fully studied. Therefore, we performed transcriptome analysis to evaluate the differences of genetic expressions between SRC and PC.

Methods:

The study group consisted of patients with SRC or PC pathology from patients with early gastric cancer (EGC) whose depth of invasion was localized in the mucosal layer. A total of 18 patients were enrolled. The patients were divided into 3 groups based on their histologic type and lymph node (LN) status. Group 1 consisted of patients with PC and positive LN metastasis, Group 2 consisted of patients with PC without LN metastasis, and Group 3 consisted of patients with SRC without LN metastasis. Transcriptome analysis was performed using the nCounter PanCancer Progression Panel Kit.

Results:

The expression of 77 genes in Group 1 was altered compared to that in normal tissues. The expression of 49 and 13 genes in Groups 2 and 3, respectively, was altered when compared to that in normal tissues. Groups 1 and 2 showed similar genetic expressions. However, Group 3 showed numerous differences in gene expression including Roundabout4 (Robo4) compared to the other groups, especially Group 1.

Conclusion:

Our data suggest that gene expression patterns were different between SRC and PC and expression of ROBO4 may play an important role in the prognosis of SRC and PC type of EGC.

Risk Factors of Lymph Node Metastasis and Its Prognostic Significance in Early Gastric Cancer: A Multicenter Study

Background

Early gastric cancer (EGC) is invasive gastric cancer that invades no deeper than the submucosa, regardless of lymph node metastasis (LNM). It is mainly treated by surgery. Recently, the resection range of EGC has been minimized, but cancer recurrence and overall survival in some patients should be given high status. LNM is an important indicator of prognosis and treatment in gastric cancer. The law of the number and location of metastatic lymph nodes in EGC is not yet clear. Therefore, we aimed to identify the risk factors of LNM in radically resected EGC and guide treatment.

Methods

The clinicopathological factors of 611 patients with EGC were retrospectively analyzed in six hospitals between January 2010 and December 2016. The relationship between clinicopathological factors and LNM, as well as their prognostic significance, were analyzed by univariate and multivariate analyses.

Results

The rate of LNM was 20.0% in the 611 EGC patients. The depth of invasion, differentiation type, tumor diameter, morphological ulceration, and lymphovascular invasion were independent risk factors for LNM (P<0.05) by logistic regression analysis. Tumor location in the proximal third of the stomach and morphological ulceration were significant factors for group 2 LNM. Moreover, the 5-year survival rate was 94.9% for patients with no positive nodes, 88.5% for patients with 1-2 positive nodes, 64.3% for patients with 3-6 positive nodes, and 41.8% for patients with >6 metastatic nodes. Interestingly, the 7-year risk of relapse diminished for patients with no LNM or retrieved no less than 15 lymph nodes.

Conclusions

Fifteen lymph node dissection and D2 radical operation are the surgical options in case of high risk factors for LNM. Extended lymph node dissection (D2+) is recommended for morphological ulceration or disease located in the proximal third of the stomach due to their high rate of group 2 LNM. Furthermore, LNM is a significant prognostic factor of EGC. Moreover, lymph nodes can also play a significant role in the chemotherapeutic and radiotherapy approach for non-surgical patients with EGC.

Diagnostic Ability of Magnifying Narrow-Band Imaging for the Extent of Early Gastric Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Accurate delineation of tumor margin is essential for complete resection of early gastric cancer (EGC). The objective of this study is to assess the performance of magnifying endoscopy with narrow-band imaging (ME-NBI) for the accurate demarcation of EGC margins.

METHODS

We searched PubMed, EMBASE, Web of Science, and Cochrane Library databases up to March 2020 to identify eligible studies. The diagnostic accuracy of ME-NBI for EGC margins was calculated, and subgroup analyses were performed based on tumor size, depth of tumor invasion, tumor-occupied site, macroscopic type, histological type, Helicobacter pylori (H. pylori), and endoscopists' experience. Besides, we also evaluated the negative and positive resection rates of the horizontal margin (HM) of EGC after endoscopic submucosal dissection (ESD) and surgery.

RESULTS

Ten studies comprising 1018 lesions were eligible in the databases. The diagnostic accuracy of ME-NBI for the demarcation of EGC margins was 92.4% (95% confidence interval (CI): 86.7%-96.8%). According to ME-NBI subgroup analyses, the rate of accurate evaluation of EGC margins was not associated with H. pylori infection status, tumor size, depth of tumor invasion, tumor-occupied site, macroscopic type, histological type, and endoscopists' experience, and no statistical differences were found in subgroup analyses. Moreover, the negative and positive resection rates of HM after ESD and surgery were 97.4% (95% CI: 92.1%-100%) and 2.6% (95% CI: 0.02%-7.9%), respectively.

CONCLUSIONS

ME-NBI enables a reliable delineation of the extent of EGC.

Establishing Machine Learning Models to Predict Curative Resection in Early Gastric Cancer with Undifferentiated Histology: Development and Usability Study

BACKGROUND

Undifferentiated type of early gastric cancer (U-EGC) is included among the expanded indications of endoscopic submucosal dissection (ESD); however, the rate of curative resection remains unsatisfactory. Endoscopists predict the probability of curative resection by considering the size and shape of the lesion and whether ulcers are present or not. The location of the lesion, indicating the likely technical difficulty, is also considered.

OBJECTIVE

The aim of this study was to establish machine learning (ML) models to better predict the possibility of curative resection in U-EGC prior to ESD.

METHODS

A nationwide cohort of 2703 U-EGCs treated by ESD or surgery were adopted for the training and internal validation cohorts. Separately, an independent data set of the Korean ESD registry (n=275) and an Asan medical center data set (n=127) treated by ESD were chosen for external validation. Eighteen ML classifiers were selected to establish prediction models of curative resection with the following variables: age; sex; location, size, and shape of the lesion; and whether ulcers were present or not.

RESULTS

Among the 18 models, the extreme gradient boosting classifier showed the best performance (internal validation accuracy 93.4%, 95% CI 90.4%-96.4%; precision 92.6%, 95% CI 89.5%-95.7%; recall 99.0%, 95% CI 97.8%-99.9%; and F1 score 95.7%, 95% CI 93.3%-98.1%). Attempts at external validation showed substantial accuracy (first external validation 81.5%, 95% CI 76.9%-86.1% and second external validation 89.8%, 95% CI 84.5%-95.1%). Lesion size was the most important feature in each explainable artificial intelligence analysis.

CONCLUSIONS

We established an ML model capable of accurately predicting the curative resection of U-EGC before ESD by considering the morphological and ecological characteristics of the lesions.

Long-term outcomes of endoscopic resection followed by additional surgery after non-curative resection in undifferentiated-type early gastric cancer: a nationwide multi-center study

BACKGROUND

Undifferentiated-type early gastric cancer (UD EGC) shows lower curative resection rates after endoscopic submucosal dissection (ESD). Additional surgery is recommended after non-curative resection. We evaluated the long-term outcomes of ESD followed by additional surgery after non-curative resection in UD EGC compared to those for surgery as initial treatment.

METHODS

We reviewed 1139 UD EGC patients who underwent ESD at 18 hospitals and 1956 patients who underwent surgery at two hospitals between February 2005 and May 2015. We enrolled 636 patients with non-curative ESD and 1429 surgery subjects beyond the curative ESD criteria. Among them, 133 patients with additional surgery after ESD (ESD + OP group) and 252 patients without additional surgery (ESD-only group) were matched 1:1 using propensity scores to patients with surgery as initial treatment (surgery group). Overall survival (OS) and recurrence-free survival (RFS) were compared.

RESULTS

Signet ring cell carcinoma and poorly differentiated adenocarcinoma (PDA) were observed in 939 and 1126 cases, respectively. OS was significantly longer in the surgery group than in the ESD + OP group, especially for PDA. However, RFS was shorter in the ESD-only group than those in the ESD + OP and surgery groups. RFS did not differ significantly between the ESD + OP and surgery groups. Compared to the surgery group, the ESD-only and ESD + OP groups had an overall hazard ratio for RFS of 3.58 (95% confidence interval 1.44-8.88) and 0.46 (0.10-2.20), respectively.

CONCLUSIONS

ESD followed by additional surgery after non-curative resection showed comparable cancer-specific outcomes to initial surgery in UD EGC.

Clinico-pathologic determinants of non-e-curative outcome following en-bloc endoscopic submucosal dissection in patients with early gastric neoplasia

Background

Endoscopic submucosal dissection (ESD) is gaining enormous popularity in the treatment of early gastric cancers (EGCs) in many institutions across the world. However, appropriate selection of candidates for endoscopic resection is crucial to sufficiently mitigate non-e-curative (NEC) resection. This study aims at identifying the various clinico-pathologic factors that independently predict the NEC outcome and depth of submucosal invasion following ESD procedure in patients with EGC.

Methods

Multiple logistic regression analysis was applied to investigate factors that independently predict both non-curability phenomenon and the level of submucosal invasion in patients with early gastric neoplasia. Statistical Packages for the Social Sciences version 23 was used for analysis.

Results

A total of 153 patients (162 EGC lesions) underwent en-bloc ESD after which the rate of complete resection and non-e-curative outcome were 95% and 22.2%, correspondingly. Multivariate analysis depicted that tumor location in the upper two third of stomach (odds ratio [OR], 5.46; 95% confidence interval [95% CI], 1.65–18.12; p = 0.006), tumor size > 2 cm (OR, 7.63; 95% CI, 2.29–25.42; p = 0.001), histologically undifferentiated tumor (OR, 15.54; 95% CI, 1.65–146.22; p = 0.001), and tumors with 0-IIa/0-IIc or their mixed variants with predominant 0-IIa/0-IIc (OR, 9.77; 95% CI, 1.23–77.65; p = 0.031) were all independent predictors of NEC resection for early gastric tumors. Additionally, location in the upper two third of the stomach (OR, 8.88; 95% CI, 2.90–27.17; p < 0.001), ulcerated lesions (OR, 3.70; 95% CI, 1.15–11.90; p = 0.028), lesions with > 2 cm (OR, 2.94; 95% CI, 1.08–8.02; p = 0.036) and those with poor differentiation (OR, 6.51; 95% CI, 2.23–18.98; p = 0.001) were found to have significant association with submucosal invasion.

Conclusions

Tumors located in the upper two third of the stomach having a larger size (> 2 cm), poor histo-differentiation and a gross type of 0-IIa/0-IIc or their mixed variants with predominant 0-IIa/0-IIc were significantly associated with a risk of NEC after ESD procedure. Thus, early gastric tumors displaying these features need to be handled carefully during endoscopic resection. Our findings may shed light on the pre-procedural detection of clinicopathologic factors that determine non-e-curability in patients with EGC.

Prognostic factors for ESD of early gastric cancers: a systematic review and meta-analysis

Background and study aims  Gastric neoplasms are one of the leading types of cancer in the world and early detection is essential to improve prognosis. Endoscopy is the gold-standard diagnostic procedure and allows adequate treatment in selected cases. Endoscopic submucosal dissection (ESD) has been reported to safely address most early gastric cancers (EGCs), with high curability rates. However, data on prognostic factors related to ESDs of EGCs are conflicting. Therefore, we aimed to systematically review the available literature and to perform a meta-analysis to identify the relevant prognostic factors in this context. Methods  We performed this study according to PRISMA guidelines. Comparative studies assessing the relationship between curative resection or long-term curability rates and relevant prognostic factors were selected. Prognostic factors were demographic data, lesion features (location, morphology of the lesion, size, and depth of invasion), histological findings, Helycobacter pylori (HP) infection, presence of gastric a atrophy and body mass index (BMI). Finally, we also evaluated risk factors related to metachronous gastric neoplasm. Results  The initial search retrieved 2829 records among which 46 studies were included for systematic review and meta-analysis. The total sample comprised 28366 patients and 29282 lesions. Regarding curative resection, pooled data showed no significant influence of sex [odds ratio (OR): 1.15 (0,97, 1.36) P  = 0.10 I 2  = 47 %] , age [OR: 1.00 (0.61, 1.64) P  = 1.00 I 2  = 58 %], posterior vs non-posterior location [OR: 1.35 (0.81, 2.27) P  = 0.25 I 2  = 84 %], depressed vs von-depressed macroscopic type[OR: 1.21 (0.99, 1.49) P  = 0.07 I 2  = 0 %], non-upper vs upper location [OR: 1.41 (0.93, 2.14) P  = 0.10 I 2  = 77 %] and BMI [OR: 0.84 (0.57; 1.26) P  = 0.41 I 2  = 0 %]. Differentiated neoplasms presented greater chance of cure compare to undifferentiated [OR: 0.10 (0.07, 0.15) P  < 0.00001 I 2  = 0 %]. Ulcerated lesions had lower curative rates compared to non-ulcerated [OR: 3.92 (2.81, 5.47) P  < 0.00001 I 2  = 44 %]. Lesions smaller than 20 mm had greater chance of curative resection [OR: 3.94 (3.25, 4.78) P  < 0.00001 I 2  = 38 %]. Bleeding during procedure had lower curative rates compared to non-bleeding [OR: 2.13 (1.56, 2.93) P  < 0.0001 I 2  = 0 %]. Concerning long-term cure, female gender [OR 1.62 (1.33, 1.97) P  < 0.00001 I 2  = 0 %] and the mucosal over SM1 cancers were protective factors [OR: 0.08 (0.02, 0.39) P  = 0.002 I 2  = 86 %]. Gastric atrophy [OR: 0.60 (0.45, 0.81) P  = 0.0006 I 2  = 42 %] and the pepsinogen I/pepsinogen II ratio [OR 2.29 (1.47, 3.57) P  = 0.0002 I 2  = 0 %] were risk factors to metachronous gastric neoplasm. Conclusions  Ulcerated lesions, histology, bleeding and size > 20 mm are prognostic factors concerning curative resection. Regarding long-term cure, female gender and mucosal over SM1 cancer are predictive factors. Gastric atrophy and the pepsinogen ratio are risk factors for metachronous gastric neoplasm.

Combination of endoscopic submucosal dissection and laparoscopic sentinel lymph node dissection in early mucinous gastric cancer: Role of lymph node metastasis

BACKGROUND

Recent evidence showed that combining endoscopic submucosal dissection (ESD) and laparoscopic sentinel lymph node dissection may avoid unnecessary gastrectomy in treating early mucinous gastric cancer (EMGC) patients with risks of positive lymph node metastasis (pLNM).

AIM

To explore the predictive factors for pLNM in EMGC, and to optimize the clinical application of combing ESD and sentinel lymph node dissection in a proper subgroup of patients with EMGC.

METHODS

Thirty-one patients with EMGC who had undergone gastrectomy with lymph node dissection were consecutively enrolled from January 1988 to December 2016. Univariate and multivariate logistic regression analyses were used to estimate the association between the rates of pLNM and clinicopathological factors, providing odds ratio (OR) with 95% confidence interval. And the association between the number of predictors and the pLNM rate was also investigated.

RESULTS

Depth of invasion (OR = 7.342, 1.127-33.256, P = 0.039), tumor diameter (OR = 9.158, 1.348-29.133, P = 0.044), and lymphatic vessel involvement (OR = 27.749, 1.821-33.143, P = 0.019) turned out to be significant and might be the independent risk factors for predicating pLNM in the multivariate analysis. For patients with 1, 2, and 3 risk factors, the pLNM rates were 9.1%, 33.3%, and 75.0%, respectively. pLNM was not detected in seven patients without any of these risk factors.

CONCLUSION

ESD might serve as a safe and sufficient treatment for intramucosal EMGC if tumor size ≤ 2 cm, and when lymphatic vessel involvement is absent by postoperative histological examination. Combining ESD and sentinel lymph node dissection could be recommended as a safe and effective treatment for EMGC patients with a potential risk of pLNM.

Long-term outcomes of endoscopic submucosal dissection versus surgery for treating early gastric cancer of undifferentiated-type

Application of endoscopic submucosal dissection (ESD) for treating undifferentiated-type early gastric cancers (EGCs) remains controversial. Therefore, we aimed to compare long-term outcomes of ESD with those of surgery for patients with undifferentiated-type EGCs by a retrospective study.We retrospectively reviewed data of patients who underwent curative ESD or gastrectomy for undifferentiated-type EGCs between 2010 and 2017. Gastric cancers were undifferentiated-type adenocarcinoma without ulceration confined to the mucosal layer and 2 cm or smaller in size. Demographics, complications, recurrence cancer rates, and survival data were collected and compared.Forty patients who underwent curative ESD and 52 patients who underwent surgery were included. The median follow-up duration was 74.6 months. There was no significant difference of metachronous gastric cancer rate (5.0% vs 3.8%, P = .75) or total cancer recurrence rate (10.0% vs 3.8%, P = .33) between the 2 groups. The 5-year overall survival, disease-free survival, recurrence-free survival rates did not significantly differ between the 2 groups (P = .72, .26, .27 respectively). There were no gastric cancer-related deaths in either group.Long-term outcomes after curative ESD for undifferentiated-type EGCs that met the expanded indication were comparable to that achieved with surgery. ESD without additional surgery is an acceptable choice to treat undifferentiated-type EGCs that meet the curative criteria.

Subepithelial Spread of Early Gastric Signet Ring Cell Carcinoma: How Far They Can Reach?

INTRODUCTION

Although signet ring cell carcinoma (SRC) is a poorly differentiated cancer subtype, recent studies suggest that endoscopic resection can be applied in small, mucosal early gastric SRC. However, other studies report frequent positive lines at the lateral resection margin after endoscopic treatment. Subepithelial spread beneath normal mucosa can exist in SRC, and such lesions may be the cause of positive margins after endoscopic resection. Thus, we conducted a retrospective study in order to evaluate the significance of subepithelial spread in early gastric SRC.

METHOD

Medical records of early gastric SRC patients who underwent surgery or endoscopic resection from January 2011 to December 2016 at a single tertiary hospital (Daejeon, South Korea) were reviewed to examine subepithelial spread and clinical datum. Two expert pathologists reviewed all pathologic specimens, and only patients showing a pure SRC component were included.

RESULTS

Eighty-six patients were initially enrolled, and subepithelial spread existed in 62 patients (72.1%). The mean distance of subepithelial spread was 1,132.1 µm, and the maximal distance was 6,000 μm. Only discoloration was significantly associated with the presence of a subepithelial spread (p < 0.05, χ2 test, and logistic regression test). Distance of subepithelial spread did not correlate with total lesion size.

CONCLUSION

Subepithelial spread of early gastric SRC occurs frequently and can reach up to 6 mm. Lesion discoloration may be associated with the presence of subepithelial spread. Our results suggest that careful decision of the margin is needed when performing endoscopic resection of early gastric SRC.

The relationship between the number of examined lymph nodes and the efficacy of chemotherapy for gastric cancer

BACKGROUND

The purpose of this research was to investigate the relationship between the number of examined lymph nodes (eLNs) and the prognosis.

METHODS

A retrospective examination of reports and studies carried out at two institutions was conducted. According to TNM stages, the relationship between the number of eLNs and the prognosis was analyzed.

RESULTS

The 5-year disease-specific survival (DSS) of all enrolled patients was 66.3%. A multivariate analysis showed the type of gastrectomy, histologic type, perineural invasion, pT stage, pN stage, chemotherapy and eLNs to be independent prognostic markers. Additionally, with the exception of patients with stage I disease, the 5-year DSS of patients who had < 25 eLNs removed had a higher risk of having a worst prognosis compared to patients who had ≥ 25 eLNs removed. Through this study, a hypothetical TNM staging system was obtained for predicting the prognosis according to the number of eLNs. Chemotherapy was able to improve the prognosis of patients with stage III and < 25 eLNs in stage II.

CONCLUSIONS

Extended lymphadenectomy with a new goal of dissecting 25 LNs for the evaluation of stage II-III cancer cases is recommended. Our hypothetical TNM staging system may be able to stratify the risk more accurately compared to the current AJCC 8th system. Chemotherapy can improve the prognosis in advanced gastric cancer, but its benefit may be affected by the surgical quality.

Possible indication of endoscopic resection in undifferentiated early gastric cancer

Endoscopic resection for early gastric cancer (EGC) without lymph node metastasis may be a valuable treatment option. To date, endoscopic resection for undifferentiated EGC is being investigated. We evaluated the risk of lymph node metastasis in undifferentiated EGC by examining the preoperative endoscopic findings and operated pathologic specimen. The medical records of patients who underwent surgical resection because of undifferentiated EGC between November 2008 and December 2015 were reviewed retrospectively. The risk factors associated with lymph node metastasis and the lymph node metastasis rate in the expanded indication of undifferentiated EGC were evaluated. A total of 376 patients with undifferentiated EGC (233 signet ring cell type and 143 poorly differentiated type) were analyzed. Lymph node metastasis was found in 9.8% of the patients. Among the patients who met the expanded criteria (59 patients), only one patient had lymph node metastasis (signet ring cell type without ulceration and 15 mm in size). The risk factors associated with lymph node metastasis were lesion size >20 mm (OR 3.013), scar deformity (OR 2.248), surface depression (OR 2.360), submucosal invasion (OR 3.427), and lymphovascular invasion (OR 6.296). Before endoscopic resection of undifferentiated EGC, careful selection of patients should be considered. The undifferentiated EGC with size ≥15 mm, scar deformity, surface depression, submucosal invasion, and lymphovascular invasion should be considered surgical resection instead of endoscopic resection.

Gastric endoscopic submucosal dissection: a systematic review and meta-analysis on risk factors for poor short-term outcomes

OBJECTIVE

Endoscopic submucosal dissection (ESD) is now established as the first option to manage early gastric neoplasms, but its efficacy may vary according to diverse factors. We aimed to systematically identify risk factors for poor short-term outcomes of gastric ESD with the purpose to improve patients' selection and management.

METHODS

Three online databases (MEDLINE, ISI Web of Knowledge and Scopus) were searched (last search on June 2018) for poor outcomes of gastric ESD (deep submucosal invasion, piecemeal/incomplete resection, noncurative resection and local recurrence).

RESULTS

One hundred five studies were included referring to 52.126 ESDs. Undifferentiated histology and upper location (vs lower) were associated with submucosal invasion [odds ratio (OR) = 2.42 [95% confidence interval (CI), 1.62-3.61] and OR = 3.20 (1.04-9.86), respectively] and deep submucosal invasion [OR = 2.98 (2.02-4.39) and OR = 2.35 (1.45-3.81), respectively]. Lesion size greater than 30 mm and ulceration were associated with piecemeal resection [OR = 2.78 (1.17-6.60) and OR = 2.76 (1.23, 6.20), respectively]. Lesion size greater than 30 mm, ulceration, upper location and fibrosis were risk factors for incomplete resection [OR = 3.83 (2.68-5.49), OR = 4.06 (1.62-10.16), OR = 3.71 (2.49-5.54) and OR = 4.46 (1.66-11.96), respectively]. A noncurative resection was more often observed for lesions located in the upper third of the stomach [OR = 1.49 (1.24-1.79)], depressed morphology [OR = 1.49 (1.04-2.12)] and those outside standard criteria [OR = 3.56 (2.31-5.48)]. Older age was significantly linked with local recurrence rates [OR = 3.08 (1.13-5.02)].

CONCLUSION

Several risk factors influence poor efficacy short-term outcomes of gastric ESD that may be used to inform both patients and health providers about the expected efficacy.

Common Locations of Gastric Cancer: Review of Research from the Endoscopic Submucosal Dissection Era

Detection of early-stage gastric cancer improves the prognosis of patients. Endoscopic submucosal dissection (ESD) is a curative and stomach-preserving treatment for early gastric cancer (EGC) associated with a low risk of lymph node metastasis. However, several studies have reported missed diagnosis of gastric cancer. Therefore, endoscopists are required to learn accurate diagnostic skills to eliminate endoscopic blind spots. A systematic screening protocol to map the entire stomach without blind spots reduces the risk of missed lesions. Knowledge of the features of EGC or dysplasia is essential to identify suspicious lesion. Information of the common sites of occurrence of EGC can also enable a detailed endoscopic examination to improve detection rates. Previous reports investigating the location of gastric cancers resected by ESD or surgery showed that the antrum and lesser curvature of stomach were predominantly affected. Helicobacter pylori-induced atrophic changes advance from the antrum to the corpus along the lesser curvature, predominantly affecting these areas. Gastric cancers in the antrum and the lower corpus are also commonly missed during screening examination. Therefore, a careful examination of the lower third stomach is warranted to avoid missing synchronous and metachronous gastric lesions. Knowledge of the location of EGC enables accurate endoscopic examination and detection of EGC in early stage.

A suitable marking method to achieve lateral margin negative in endoscopic submucosal dissection for undifferentiated-type early gastric cancer

Background and study aims  Delineating undifferentiated-type early gastric cancer (UD-type EGC) from noncancerous areas is difficult. Therefore, the lateral margin negative (LM-) resection rate of endoscopic submucosal dissection (ESD) is lower for UD-type EGC than for differentiated-type EGC. This study aimed to retrospectively evaluate the effectiveness of the marking methods with circumferential biopsies in ESD for UD-type EGC. Patients and methods  We analyzed the clinical outcomes of ESD in 127 patients with UD-type EGC between April 2013 and 2017. We performed diagnostic delineation of cancerous areas using magnifying endoscopy with narrow-band imaging, and four or more circumferential biopsies approximately 5 mm apart from the estimated lesion border were obtained to confirm noncancerous areas. The markings were placed on the circumferential biopsy scars, and a mucosal incision line was made outside the markings. Results  Median size of the tumors and ESD specimens was 12 and 35 mm, respectively. En-bloc resection rate was 100 % (127/127), and LM- and curative resection rates were 97.6 % (124/127) and 80.3 % (102/127), respectively. Circumferential biopsy in preoperative esophagogastroduodenoscopy has successfully identified the misdiagnosis of cancerous areas of four patients (3.2 %), with three (2.4%) achieving LM- resection. LM + resection was pathologically identified in three patients (2.4 %), with all undergoing non-curative resection due to > 20-mm tumor. The proportion of patients with the shortest distance ≥ 5 mm from the lesion edge to the specimen edge was 88.2 % (112/127). Conclusion  Our marking methods with circumferential biopsies may reduce LM + resections in ESD for UD-type EGC.

Strategy for Curative Endoscopic Resection of Undifferentiated-Type Early Gastric Cancer

Endoscopic resection (ER) of undifferentiated-type early gastric cancer (UD-EGC) has a lower curative resection (CR) rate than differentiated-type EGC. However, if UD-EGC is curatively resected using ER, long-term outcomes can be favorable. Thus, the strategy for CR by ER is important in UD-EGC. To achieve CR in UD-EGC, biological behaviors including tumor growth patterns must be considered. This review aims to describe what is important for curative ER of UD-EGC.

Predictive factors for lymph node metastasis and defining a subgroup treatable for laparoscopic lymph node dissection after endoscopic submucosal dissection in poorly differentiated early gastric cancer

AIM

To investigate the predictive factors of lymph node metastasis (LNM) in poorly differentiated early gastric cancer (EGC); to guide the individual application of a combination of endoscopic submucosal dissection (ESD) and laparoscopic lymph node dissection (LLND) in a suitable subgroup of patients with poorly differentiated EGC.

METHODS

We retrospectively analyzed 138 patients with poorly differentiated EGC who underwent gastrectomy with lymphadenectomy between January 1990 and December 2015. The association between the clinicopathological factors and the presence of LNM was retrospectively analyzed by univariate and multivariate logistic regression analyses. Odds ratios (OR) with 95% confidence interval (95%CI) were calculated. We further examined the relationship between the positive number of the significant predictive factors and the LNM rate.

RESULTS

The tumor diameter (OR = 13.438, 95%CI: 1.773-25.673, P = 0.029), lymphatic vessel involvement (LVI) (OR = 38.521, 95%CI: 1.975-68.212, P = 0.015) and depth of invasion (OR = 14.981, 95%CI: 1.617-52.844, P = 0.024) were found to be independent risk factors for LNM by multivariate analysis. For the 138 patients diagnosed with poorly differentiated EGC, 21 (15.2%) had LNM. For patients with one, two and three of the risk factors, the LNM rates were 7.7%, 47.6% and 64.3%, respectively. LNM was not found in 77 patients that did not have one or more of the three risk factors.

CONCLUSION

ESD might be sufficient treatment for intramucosal poorly differentiated EGC if the tumor is less than or equal to 2 cm in size and when LVI is absent upon postoperative histological examination. ESD with LLND may lead to the elimination of unnecessary gastrectomy in poorly differentiated EGC.

Screening for gastric cancer with magnetically controlled capsule gastroscopy in asymptomatic individuals

BACKGROUND AND AIMS

Gastric cancer (GC) is the fourth most common cancer and the fourth leading cause of cancer death worldwide. In some Asian countries, screening EGD has greatly improved the survival rate. However, patients' discomfort and the need for sedation may limit adherence to screening programs. Previous studies have shown good tolerance and good agreement of magnetically controlled capsule gastroscopy (MCCG) with EGD. This study was designed to assess the application of MCCG in GC detection in an asymptomatic population.

METHODS

In this observational cohort study, 3182 asymptomatic individuals undergoing MCCG in 99 participating medical examination centers from April to December 2016 were enrolled. Patients with ulcers and suspected malignancies were referred for gastroscopy and biopsy. The detection rate of GC and focal lesions were used to explore the application of MCCG in asymptomatic individuals.

RESULTS

Seven patients (0.22%) were diagnosed with GC among the enrolled 3182 individuals, accounting for 0.74% (7/948) in patients over 50 years. No gender disparity was observed. EGD and biopsy confirmed adenocarcinoma in all cases of suspected malignancy. Benign polyps, gastric ulcers, and submucosal tumors were found in 10.4%, 4.9%, and 3.6% of patients, respectively. There was a trend for the prevalence of focal lesions to increase with age. MCCG examination proved to be safe.

CONCLUSIONS

MCCG can detect cancer and benign lesions and is safe and clinically feasible in a large population. Studies of its role in a screening program should be considered.

Differential analysis of lymph node metastasis in histological mixed-type early gastric carcinoma in the mucosa and submucosa

AIM

To investigate the relationship between histological mixed-type of early gastric cancer (EGC) in the mucosa and submucosa and lymph node metastasis (LNM).

METHODS

This study included 298 patients who underwent gastrectomy for EGC between 2005 and 2012. Enrolled lesions were divided into groups of pure differentiated (pure D), pure undifferentiated (pure U), and mixed-type according to the proportion of the differentiated and undifferentiated components observed under a microscope. We reviewed the clinicopathological features, including age, sex, location, size, gross type, lymphovascular invasion, ulceration, and LNM, among the three groups. Furthermore, we evaluated the predictors of LNM in the mucosa-confined EGC.

RESULTS

Of the 298 patients, 165 (55.4%) had mucosa-confined EGC and 133 (44.6%) had submucosa-invasive EGC. Only 13 (7.9%) cases of mucosa-confined EGC and 30 (22.6%) cases of submucosa-invasive EGC were observed to have LNM. The submucosal invasion (OR = 4.58, 95%CI: 1.23-16.97, P = 0.023), pure U type (OR = 4.97, 95%CI: 1.21-20.39, P = 0.026), and mixed-type (OR = 5.84, 95%CI: 1.05-32.61, P = 0.044) were independent risk factors for LNM in EGC. The rate of LNM in mucosa-confined EGC was higher in the mixed-type group (P = 0.012) and pure U group (P = 0.010) than in the pure D group, but no significant difference was found between the mixed-type group and pure U group (P = 0.739). Similarly, the rate of LNM in the submucosa-invasive EGC was higher in the mixed-type (P = 0.012) and pure U group (P = 0.009) than in the pure D group but was not significantly different between the mixed-type and pure U group (P = 0.375). Multivariate logistic analysis showed that only female sex (OR = 5.83, 95%CI: 1.64-20.70, P = 0.028) and presence of lymphovascular invasion (OR = 13.18, 95%CI: 1.39-125.30, P = 0.020) were independent risk factors for LNM in mucosa-confined EGC, while histological type was not an independent risk factor for LNM in mucosa-confined EGC (P = 0.106).

CONCLUSION

For mucosal EGC, histological mixed-type is not an independent risk factor for LNM and could be managed in the same way as the undifferentiated type.