Long-term outcomes after endoscopic submucosal dissection for differentiated-type early gastric cancer that fulfilled expanded indication criteria: A prospective cohort study

A machine learning model for predicting the lymph node metastasis of early gastric cancer not meeting the endoscopic curability criteria

BACKGROUND

We developed a machine learning (ML) model to predict the risk of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) who did not meet the existing Japanese endoscopic curability criteria and compared its performance with that of the most common clinical risk scoring system, the eCura system.

METHODS

We used data from 4,042 consecutive patients with EGC from 21 institutions who underwent endoscopic submucosal dissection (ESD) and/or surgery between 2010 and 2021. All resected EGCs were histologically confirmed not to satisfy the current Japanese endoscopic curability criteria. Of all patients, 3,506 constituted the training cohort to develop the neural network-based ML model, and 536 constituted the validation cohort. The performance of our ML model, as measured by the area under the receiver operating characteristic curve (AUC), was compared with that of the eCura system in the validation cohort.

RESULTS

LNM rates were 14% (503/3,506) and 7% (39/536) in the training and validation cohorts, respectively. The ML model identified patients with LNM with an AUC of 0.83 (95% confidence interval, 0.76-0.89) in the validation cohort, while the eCura system identified patients with LNM with an AUC of 0.77 (95% confidence interval, 0.70-0.85) (P = 0.006, DeLong's test).

CONCLUSIONS

Our ML model performed better than the eCura system for predicting LNM risk in patients with EGC who did not meet the existing Japanese endoscopic curability criteria. We developed a neural network-based machine learning model that predicts the risk of lymph node metastasis in patients with early gastric cancer who did not meet the endoscopic curability criteria.

Long-term outcome of regional cooperation pathway after endoscopic submucosal dissection for early detection of new gastric cancer

OBJECTIVES

The Cancer Control Act requires the maintenance of regional cooperation pathways (RCP) for cancer treatment. In 2008, we started RCP for early detection of new gastric cancer after endoscopic submucosal dissection (ESD). In gastric cancer treatment, RCP after surgical resection had been widely used, but little is known about RCP after ESD. This study aimed to evaluate the effectiveness of RCP after ESD.

METHODS

This study included 465 patients on whom our RCP was implemented from 2008 to 2018. A regional family physician performed surveillance endoscopy at 3 months and 1 year after ESD and annually thereafter. We retrospectively evaluated the cumulative incidence and treatment outcomes of new gastric cancer and compared them with previous reports.

RESULTS

During a median follow-up period of 70.5 months (3-120 months), 58 patients developed new gastric cancers, and metachronous gastric cancer was detected in 55 patients more than 1 year after ESD. The 5-year cumulative incidence rate was 9.8%. Three patients did not want treatment. Among the remaining 55 patients, the initial treatment was ESD in 51 and surgical resection in 4. Eventually, 50 patients (48 in the ESD group and 2 in the surgical resection group) fulfilled the pathologic criteria for curative ESD. There were no deaths due to gastric cancer.

CONCLUSION

Our study was the first to reveal the incidence of new gastric cancer after ESD using RCP. Most lesions were cured with ESD, and no patients died of gastric cancer. Therefore, we consider RCPs to be an option for surveillance after ESD.

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.

Diagnostic performance of deep-learning-based virtual chromoendoscopy in gastric neoplasms

BACKGROUNDS

Cycle-consistent generative adversarial network (CycleGAN) is a deep neural network model that performs image-to-image translations. We generated virtual indigo carmine (IC) chromoendoscopy images of gastric neoplasms using CycleGAN and compared their diagnostic performance with that of white light endoscopy (WLE).

METHODS

WLE and IC images of 176 patients with gastric neoplasms who underwent endoscopic resection were obtained. We used 1,633 images (911 WLE and 722 IC) of 146 cases in the training dataset to develop virtual IC images using CycleGAN. The remaining 30 WLE images were translated into 30 virtual IC images using the trained CycleGAN and used for validation. The lesion borders were evaluated by 118 endoscopists from 22 institutions using the 60 paired virtual IC and WLE images. The lesion area concordance rate and successful whole-lesion diagnosis were compared.

RESULTS

The lesion area concordance rate based on the pathological diagnosis in virtual IC was lower than in WLE (44.1% vs. 48.5%, p < 0.01). The successful whole-lesion diagnosis was higher in the virtual IC than in WLE images; however, the difference was insignificant (28.2% vs. 26.4%, p = 0.11). Conversely, subgroup analyses revealed a significantly higher diagnosis in virtual IC than in WLE for depressed morphology (41.9% vs. 36.9%, p = 0.02), differentiated histology (27.6% vs. 24.8%, p = 0.02), smaller lesion size (42.3% vs. 38.3%, p = 0.01), and assessed by expert endoscopists (27.3% vs. 23.6%, p = 0.03).

CONCLUSIONS

The diagnostic ability of virtual IC was higher for some lesions, but not completely superior to that of WLE. Adjustments are required to improve the imaging system's performance.

Comparison of Prognosis and Metachronous Gastric Tumor Rates After Endoscopic Submucosal Dissection Between Gastric Neoplasm of Fundic Gland Type Neoplasms and Conventional Gastric Adenocarcinoma

INTRODUCTION

Gastric neoplasm of the fundic gland type (GNFG) is a tumor with a good prognosis. However, since it has not been compared with conventional gastric adenocarcinoma (CGA), it is unknown whether it has a good prognosis or requires surveillance after treatment. The purpose of this study was to determine the prognosis and metachronous gastric tumor rates compared with those of CGA.

METHODS

We conducted a single-center, retrospective, matched-cohort study using our database from January 2010 to December 2021. We extracted GNFG data from the endoscopic submucosal dissection (ESD) database and matched patients with conventional early gastric cancer as controls in a 1:4 ratio by age and sex. GNFG and CGA were compared for the overall survival (OS), disease-specific survival, progression-free survival, and metachronous gastric tumor rates.

RESULTS

Overall, 43 lesions were GNFG and 164 CGAs were matched. There were three deaths in the GNFG group and 11 deaths in the CGA group. There was no significant difference in the OS between the two groups (P=0.81). The five-year OS rates for the GNFG and CGA groups were 90.9% and 92.9%, respectively. No disease-specific deaths or recurrences were observed in either group. There was no significant difference in the cumulative metachronous gastric tumor rate between the two groups (P=0.17). The cumulative five-year metachronous gastric tumor rates for the GNFG and CGA groups were 6.6% and 2.5%, respectively.

CONCLUSIONS

The prognosis for GNFG is good, however, not better than that for CGA. The metachronous gastric tumor rate after ESD in GNFG was not lower than that in CGA. Therefore, after ESD, GNFG may need to be managed in the same way as CGA.

Editorial article to: Animal experimental study on magnetic anchor technique-assisted endoscopic submucosal dissection of early gastric cancer

In this editorial we comment on the article published in the recent issue of the World Journal of Gastrointestinal Endoscopy 2023; 15 (11): 634-680. Gastric cancer (GC) remains the fifth most common malignancy and the fourth leading cause of cancer-related death worldwide. The overall prevalence of GC has declined, although that of proximal GC has increased over time. Thus, a significant proportion of GC cases and deaths can be avoided if preventive interventions are taken. Early GC (EGC) is defined as GC confined to the mucosa or submucosa. Endoscopic resection is considered the most appropriate treatment for precancerous gastrointestinal lesions improving patient quality of life, with reduced rates of complications, shorter hospitalization period, and lower costs when compared to surgical resection. Endoscopic mucosal resection (EMR) and endoscopic sub-mucosal dissection (ESD) are representative endoscopic treatments for EGC and precancerous gastric lesions. Standard EMR implies injection of a saline solution into the sub-mucosal space, followed by excision of the lesion using a snare. Complete resection rates vary depending on the size and severity of the lesion. When using conventional EMR methods for lesions less than 1 cm in size, the complete resection rate is approximately 60%, whereas for lesions larger than 2 cm, the complete resection rate is low (20%-30%). ESD can be used to remove tumors exceeding 2 cm in diameter and lesions associated with ulcers or submucosal fibrosis. Compared with EMR, ESD has higher en bloc resection rates (90.2% vs 51.7%), higher complete resection rates (82.1 vs 42.2%), and lower recurrence rates (0.65% vs 6.05%). Thus, innovative techniques have been introduced.

Curative criteria for endoscopic treatment of gastric cancer

Endoscopic treatment, particularly endoscopic submucosal dissection, has become the primary treatment for early gastric cancer. A comprehensive optical assessment, including white light endoscopy, image-enhanced endoscopy, and magnification, are the cornerstones for clinical staging and determining the resectability of lesions. This paper discusses factors that influence the indication for endoscopic resection and the likelihood of achieving a curative resection. Our review stresses the critical need for interpreting the histopathological report in accordance with clinical guidelines and the imperative of tailoring decisions based on the patients' and lesions' characteristics and preferences. Moreover, we offer guidance on managing complex scenarios, such as those involving non-curative resection. Finally, we identify future research avenues, including the role of artificial intelligence in estimating the depth of invasion and the urgent need to refine predictive scores for lymph node metastasis and metachronous lesions.

Risk assessment of metachronous gastric cancer after endoscopic submucosal dissection based on endoscopic intestinal metaplasia

Background and Aim

The incidence of metachronous gastric cancer (MGC) after endoscopic treatment for early gastric cancer (EGC) is high, but a method of risk assessment for MGC based on endoscopic findings has not been established. In this study, we focused on endoscopic intestinal metaplasia (IM) and investigated the risk for MGC after endoscopic submucosal dissection (ESD) for EGC.

Methods

This retrospective observational study involved patients who underwent curative ESD for EGC from April 2015 to January 2021. We assessed endoscopic IM using the pretreatment endoscopic examination images. The severity of endoscopic IM was classified into four levels: 0 (none), 1 (mild), 2 (moderate), and 3 (severe). Four different gastric areas were evaluated. We divided the patients into a low-score group and a high-score group, and compared the cumulative incidence of MGC.

Results

In total, 156 patients who met the inclusion criteria were followed up for at least 12 months after ESD, and MGC developed in 14 patients during a mean period oof 41.5 months. The endoscopic IM scores in the lesser curvature of the antrum, lesser curvature of the corpus, and greater curvature of the corpus were higher in patients with MGC than in those without MGC. In the corpus, the 5-year cumulative incidence of MGC was significantly higher in the high-score group than in the low-score group (29.8% vs 10.0%, P = 0.004).

Conclusion

The severity of endoscopic corpus IM was associated with MGC. Thus, patients with severe corpus IM at the time of ESD require careful examination and intensive follow-up.

Endoscopic resection of early gastric cancer

Endoscopic resection (ER) is an effective treatment for early gastric cancer (EGC) without metastases. Existing endoscopic mucosal resection (EMR) is easy to perform, has few complications, and can be applied when the lesion size is small. However, en bloc and complete resection rates vary depending on the size and severity of the lesion. EMR using the cap-mounted panendoscopic method and EMR after circumferential preamputation of the lesion are useful in the treatment of EGC. However, completely oversized lesions (≥2 cm) and lesions associated with ulcers or submucosal fibrosis are more likely to fail resection. Endoscopic submucosal dissection has been widely used to resect tumors larger than 2 cm in diameter and has a higher acceptable complication rate and en bloc and complete resection rates than EMR. ER for EGC is superior to surgical resection in terms of improving patient quality of life. Additionally, compared to surgery, emergency rooms have a lower rate of treatment-related complications, shorter hospital stays, and lower costs. Accordingly, the indications for ER are expanding in the field of therapeutic endoscopy. Long-term outcomes regarding recurrence are excellent in both absolute and extended criteria for ER in EGC. Close surveillance should be performed after ER to detect early metachronous gastric cancer and precancerous lesions that can be treated with ER. Follow-up gastroscopy and abdominopelvic computed tomography scans every 6 to 12 months are recommended for patients who undergo curative ER for EGC on absolute or extended criteria.

Clinical and endoscopic features of metachronous gastric cancer with possible lymph node metastasis after endoscopic submucosal dissection and Helicobacter pylori eradication

BACKGROUND

Several studies have reported the metachronous gastric cancers (MGCs) with possible lymph node metastasis (LNM) after endoscopic submucosal dissection (ESD) and Helicobacter pylori (H. pylori) eradication in which a curative ESD had not been achieved. There have been no published reports of evaluations of the features of patients with MGC with possible LNM after ESD and H. pylori eradication.

METHODS

We identified 264 patients with 369 MGCs after H. pylori eradication among the 4354 patients with 5059 early gastric cancers (EGCs) who underwent ESD between 1999 and 2017 and divided them into two groups: patients with MGCs with possible LNM (Group I) and patients with MGCs undergone curative ESD (Group II). We retrospectively compared the features of patients with MGCs and patients with EGCs at index ESD in the two groups.

RESULT

Group I consisted of 20 patients with 21 MGCs, and Group II consisted of 244 patients with 348 MGCs. Group I lesions were significantly more common in the posterior wall than in the lesser curvature (odds ratio [OR] = 3.97; 95% confidence intervals [CI] 1.20-13.10). Development of Group I was significantly more common in patients with a body mass index (BMI) < 19.0 kg/m2 than in patients with a BMI ≥ 19.0 kg/m2 at index ESD (OR = 4.44; 95% CI 1.30-15.20).

CONCLUSIONS

During surveillance endoscopy after gastric ESD and H. pylori eradication, the posterior wall should be carefully examined to detect MGCs early. Lower BMI may be associated with the development of MGCs with possible LNM.

Endoscopic Resection of Early Gastric Cancer and Pre-Malignant Gastric Lesions

Early gastric cancer comprises gastric malignancies that are confined to the mucosa or submucosa, irrespective of lymph node metastasis. Endoscopic resection is currently pivotal for the management of such early lesions, and it is the recommended treatment for tumors presenting a very low risk of lymph node metastasis. In general, these lesions consist of two groups of differentiated mucosal adenocarcinomas: non-ulcerated lesions (regardless of their size) and small ulcerated lesions. Endoscopic submucosal dissection is the technique of choice in most cases. This procedure has high rates of complete histological resection while maintaining gastric anatomy and its functions, resulting in fewer adverse events than surgery and having a lesser impact on patient-reported quality of life. Nonetheless, approximately 20% of resected lesions do not fulfill curative criteria and demand further treatment, highlighting the importance of patient selection. Additionally, the preservation of the stomach results in a moderate risk of metachronous lesions, which underlines the need for surveillance. We review the current evidence regarding the endoscopic treatment of early gastric cancer, including the short-and long-term results and management after resection.

Systemic immune-inflammation index in predicting non-curative resection of endoscopic submucosal dissection in patients with early gastric cancer

BACKGROUND AND PURPOSE

Although endoscopic submucosal dissection (ESD) is considered standard treatment for early gastric cancer (EGC), patients with non-curative resection (NCR) of ESD may still require gastrectomy. The systemic immune-inflammation index (SII) showed great potential in predicting the prognosis of gastric cancer patients. This study aims to investigate the predictive validity of SII of NCR in EGC patients.

METHODS

We reviewed data from EGC patients who underwent ESD in the past. The relationship between SII and clinicopathologic features was investigated. We used Receiver operating characteristic curves to compare the predictive values of NCR between SII and other inflammation indices. Binary logistic analysis was used to identify independent risk factors for NCR. These factors were then used to construct a predictive nomogram.

RESULTS

SII was associated with larger tumor size, male gender, older age, submucosal invasion, and a greater risk of NCR. SII showed better predictivity of NCR than platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR). SII [odds ratio (OR) = 1.003, P = 0.001], NLR (OR = 1.520, P = 0.029), PLR (OR = 1.009, P = 0.010), upper stomach tumors (OR = 16.393, P < 0.001), poorly differentiated type (OR = 29.754, P < 0.001), ulceration (OR = 4.814, P = 0.001), and submucosal invasion (OR = 48.91, P < 0.001) were independent risk factors for NCR. The nomogram model based on these factors exhibited superior concordance and accuracy.

CONCLUSION

SII could be considered a simple and effective predictor of NCR of ESD in EGC patients.

Long-term Survival After Endoscopic Resection For Gastric Cancer: Real-world Evidence From a Multicenter Prospective Cohort

BACKGROUND & AIMS

We aimed to clarify the long-term outcomes of endoscopic resection (ER) for early gastric cancers (EGCs) based on pathological curability in a multicenter prospective cohort study.

METHODS

We analyzed the long-term outcomes of 9054 patients with 10,021 EGCs undergoing ER between July 2010 and June 2012. Primary endpoint was the 5-year overall survival (OS). The hazard ratio for all-cause mortality was calculated using the Cox proportional hazards model. We also compared the 5-year OS with the expected one calculated for the surgically resected patients with EGC. If the lower limit of the 95% confidence interval (CI) of the 5-year OS exceeded the expected 5-year OS minus a margin of 5% (threshold 5-year OS), ER was considered to be effective. Pathological curability was categorized into en bloc resection, negative margins, and negative lymphovascular invasion: differentiated-type, pT1a, ulcer negative, ≤2 cm (Category A1); differentiated-type, pT1a, ulcer negative, >2 cm or ulcer positive, ≤3 cm (Category A2); undifferentiated-type, pT1a, ulcer negative, ≤2 cm (Category A3); differentiated-type, pT1b (SM1), ≤3 cm (Category B); or noncurative resections (Category C).

RESULTS

Overall, the 5-year OS was 89.0% (95% CI, 88.3%-89.6%). In a multivariate analysis, no significant differences were observed when the hazard ratio of Categories A2, A3, and B were compared with that of A1. In all the pathological curability categories, the lower limit of the 95% CI for the 5-year OS exceeded the threshold 5-year OS.

CONCLUSION

ER can be recommended as a standard treatment for patients with EGCs fulfilling Category A2, A3, and B, as well as A1 (UMIN Clinical Trial Registry, UMIN000005871).

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.

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.

Construction and analysis of an ulcer risk prediction model after endoscopic submucosal dissection for early gastric cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) has been widely used in the treatment of early gastric cancer (EGC). A personalized and effective prediction method for ESD with EGC is urgently needed.

AIM

To construct a risk prediction model for ulcers after ESD for EGC based on LASSO regression.

METHODS

A total of 196 patients with EGC who received ESD treatment were prospectively selected as the research subjects and followed up for one month. They were divided into an ulcer group and a non-ulcer group according to whether ulcers occurred. The general data, pathology, and endoscopic characteristics of the groups were compared, and the best risk predictor subsets were screened by LASSO regression and tenfold cross-validation. Multivariate logistic regression was applied to analyze the risk factors for ulcers after ESD in patients with EGC. A receiver operating characteristic (ROC) curve was used to estimate the predictive model performance.

RESULTS

One month after the operation, no patient was lost to follow-up. The incidence of ulcers was 20.41% (40/196) (ulcer group), and the incidence of no ulcers was 79.59% (156/196) (non-ulcer group). There were statistically significant differences in the course of disease, Helicobacter pylori infection history, smoking history, tumor number, clopidogrel medication history, lesion diameter, infiltration depth, convergent folds, and mucosal discoloration between the groups. Gray's medication history, lesion diameter, convergent folds, and mucosal discoloration, which were the 4 nonzero regression coefficients, were screened by LASSO regression analysis. Further multivariate logistic analysis showed that lesion diameter [Odds ratios (OR) = 30.490, 95%CI: 8.584-108.294], convergent folds (OR = 3.860, 95%CI: 1.060-14.055), mucosal discoloration (OR = 3.191, 95%CI: 1.016-10.021), and history of clopidogrel (OR = 3.554, 95%CI: 1.009-12.515) were independent risk factors for ulcers after ESD in patients with EGC (P < 0.05). The ROC curve showed that the area under the curve of the risk prediction model for ulcers after ESD in patients with EGC was 0.944 (95%CI: 0.902-0.972).

CONCLUSION

Clopidogrel medication history, lesion diameter, convergent folds, and mucosal discoloration can predict the occurrence of ulcers after ESD in patients with EGC.

Endoscopic Resection of Gastric Cancer

With improvements in the early detection of early gastric cancer (EGC) and advances in therapeutic techniques, endoscopic resection (ER) for EGC has become widely adopted in East Asian and Western countries. Endoscopic submucosal dissection has higher rates of en bloc, complete, and curative resections with lower rates of local recurrence than that of endoscopic mucosal resection. ER is a minimally invasive method with low morbidity that provides excellent outcomes. ER for EGC is a safe, effective method, preserving organ function and thus maintaining the patient's quality of life, and is recognized as the first-line treatment of EGC in selected patients.

Risk of Lymph Node Metastasis and Feasibility of Endoscopic Treatment in Ulcerative Early Gastric Cancer

BACKGROUND

When the risk of lymph node metastasis (LNM) is considered minimal in patients with early gastric cancer (EGC), endoscopic submucosal dissection (ESD) is an effective alternative to radical resection. This study aims to estimate the feasibility of ESD for EGC with ulceration.

PATIENTS AND METHODS

We retrospectively reviewed data from 691 patients who underwent gastrectomy for EGC with ulceration. Subsequently, a stratification system for lesions was created based on the expanded ESD criteria, and the associations between the subgroups and the rate of LNM were analyzed.

RESULTS

LNM was confirmed in 16.5% (114/691) of patients. Univariate analysis demonstrated that age, sex, tumor size, macroscopic features, depth of invasion, tumor differentiation, Lauren type, lymphovascular invasion (LVI), and perineural invasion were associated with LNM. Multivariate analysis showed that LVI [odds ratio (OR) = 16.761, P < 0.001], SM1 invasion (OR = 2.159, P = 0.028), and SM2 invasion (OR = 3.230, P < 0.001) were independent risk factors for LNM. LNM occurred in undifferentiated mucosal tumors, with ulceration being 1.7% (2/116) when the lesion was smaller than 20 mm. Further stratification revealed that among lesions < 30 mm in size, undifferentiated tumors with SM1 invasion had a higher rate of LNM and a lower disease-free survival rate than differentiated tumors with SM1 invasion and tumors limited to the mucosal layer.

CONCLUSIONS

Depth of invasion and LVI were strongly associated with LNM in ulcerative EGC. Endoscopic resection may be applicable for undifferentiated mucosal ulcerative EGC < 30 mm in size, and additional investigation is needed to evaluate its safety.

The Significance of Exosomal RNAs in the Development, Diagnosis, and Treatment of Gastric Cancer

Gastric cancer (GC) is one of the most common malignancies in the world. Exosomes, a subset of extracellular vesicles with an average diameter of 100 nm, contain and transfer a variety of functional macromolecules such as proteins, lipids, and nucleic acids. A large number of studies indicated that exosomes can play a significant role in the initiation and development of GC via facilitating intercellular communication between gastric cancer cells and microenvironment. Exosomal RNAs, one of the key functional cargos, are involved in the pathogenesis, development, and metastasis of GC. In addition, recent studies elucidated that exosomal RNAs may serve as diagnostic and prognostic biomarkers or therapeutic targets for GC. In this review, we summarized the function of exosomal RNA in the tumorigenesis, progression, diagnosis, and treatment of GC, which may further unveil the functions of exosome and promote the potentially diagnostic and therapeutic application of exosomes in GC.