Risk of lymph node metastasis in early gastric cancer and indications for endoscopic resection: is it worth applying the east rules to the west?

Risk assessment of lymph node metastasis in early gastric cancer patients with vagus nerve-preserving gastrectomy: A multiple centers potential analysis in China

BACKGROUND

Vagus nerve-preserving gastrectomy is gaining popularity for early gastric cancer treatment. This study assesses vagus nerve-preserving gastrectomy's perioperative safety and impact on postoperative quality of life, and explores vagus nerve-associated lymph node metastasis to create a risk model for enhanced therapy.

METHODS

Clinicopathologic data from 1,210 early gastric cancer patients across 11 Chinese centers were analyzed, and the data of 800 patients with follow-up information and 48 patients who underwent vagus nerve-preserving gastrectomy for validation were collected. Propensity score matching was applied to the analysis of perioperative safety and quality of life in vagus nerve-preserving gastrectomy patients. A 6-point risk assessment model was devised and validated to evaluate the risk of vagus nerve-associated lymph node metastasis after vagus nerve-preserving gastrectomy in early gastric cancer patients.

RESULTS

Vagus nerve-preserving gastrectomy patients had shorter postoperative stays, quicker drainage cessation, and fewer incidences of diarrhea, acid reflux, and postoperative gallstones. Additionally, key independent risk factors for vagus nerve-associated lymph node metastasis included tumor size, differentiation type, invasion depth, and lymphatic vessel invasion. Using these factors, a 6-point risk assessment model was established. The values of the area under the receiver operating characteristic curve for the model were 0.796, 0.806, 0.808, and 0.829 in the training cohort, internal validation cohort, external validation cohort, and vagus nerve-preserving gastrectomy cohort, respectively. The model effectively differentiated between high- and low-risk groups in terms of postoperative survival.

CONCLUSIONS

Vagus nerve-preserving gastrectomy can improve the patients' postoperative quality of life and ensure safety in the perioperative period. The vagus nerve-associated lymph node metastasis risk assessment model is a crucial tool in guiding the selection of optimal surgical procedures and treatment strategies for early gastric cancer patients.

Endoscopic resection versus gastrectomy for clinical T1a gastric adenocarcinoma: Predictors of nodal upstaging

BACKGROUND

Endoscopic resection is increasingly favored as a first-line curative treatment over surgery for early gastric cancer with minimal risk of lymph node metastasis. Our objective is to identify factors that may guide the treatment decision between endoscopic resection and gastrectomy in early gastric cancer.

METHODS

A retrospective analysis of the National Cancer Database from 2010 to 2021 for patients with cT1aN0M0 gastric adenocarcinoma was performed comparing endoscopic resection versus gastrectomy. Our main outcomes of interest were overall survival and lymph node upstaging. Multivariate logistic regression and Cox proportional hazards models were used.

RESULTS

A total of 2,177 patients were identified; 1,007 (46.3%) had endoscopic resection and 1,170 (53.7%) had gastrectomy. On average, endoscopic resection patients were more likely to be male (72.6% vs 61.1%, P < .01), older (69.7 ± 10.9 vs 65.4 ± 13.1 years, P < .01), and non-Hispanic White (80.3% vs 67%, P < .01). Compared with gastrectomy, tumors undergoing endoscopic resection were smaller, lower grade, more often in the cardia, and had lower rates of lymphovascular invasion and signet morphology. Endoscopic resection resulted in higher margin positivity (15.3% vs 4.6%, P < .01), but both approaches had similar survival (log-rank P = .24). There was a pathologic lymph node upstaging rate of 15.6% in gastrectomy. Factors predicting lymph node upstaging included larger tumor size (odds ratio: 1.01, 95% confidence interval: 1.01-1.02), poor differentiation (odds ratio: 2.65, 95% confidence interval: 1.15-6.09), lymphovascular invasion (odds ratio: 13.15, 95% confidence interval: 7.86-22.01), and positive margins (odds ratio: 5.85, 95% confidence interval: 2.30-14.87). Although signet morphology did not predict lymph node upstaging, it predicted having those aforementioned high-risk features for lymph node upstaging (odds ratio: 12.02, 95% confidence interval: 4.60-31.39).

CONCLUSION

In the real-world analysis of early gastric cancer treatment, endoscopic resection alone achieved similar survival to gastrectomy for cT1aN0M0 early gastric cancer. Despite these early gastric cancer staged as cN0, approximately 15% of gastrectomy patients had lymph node upstaging. We found tumor size, grade, margin positivity, and particularly lymphovascular invasion to be important clinical predictors of pathologic lymph node upstaging that should be considered in early gastric cancer treatment decision-making.

Nomogram for pre-procedural prediction of lymph node metastasis in patients with submucosal early gastric cancer

BACKGROUND

The treatment of early gastric cancer (EGC) is contingent upon the status of lymph node metastasis (LNM). Accurate preoperative prediction of LNM is critical for reducing unnecessary surgeries. This study seeks to evaluate the risk factors for LNM in submucosal EGC and develop a predictive model to optimize therapeutic decision-making.

METHODS

A retrospective analysis was performed on clinical data from 389 patients with T1b-stage EGC who underwent radical gastrectomy. Univariate and multivariate analyses were conducted to identify independent risk factors, followed by the development of a nomogram to predict LNM. The model's efficacy was validated through receiver operating characteristic curves, calibration curves, and decision curve analysis.

RESULTS

Of the 389 patients, 77 had LNM. Logistic regression analysis identified gender, CA199 levels, tumor location, degree of differentiation, presence of ulcers, and lymph node enlargement on CT as independent risk factors for LNM. A nomogram was constructed to assess the risk of LNM, demonstrating strong predictive accuracy with an area under the curve of 0.82 in the training set and 0.74 in the validation set, along with good sensitivity and positive predictive value.

CONCLUSIONS

This study presents a reliable preoperative nomogram to estimate the likelihood of LNM in submucosal EGC, providing valuable guidance for determining the most effective treatment strategies for patients.

Nomograms of risk prediction and prognosis for the T1-T2 stage gastric cancer with lymph node metastasis: a population-based study

Background and aims

Lymph node metastasis plays a crucial role in determining the appropriate treatment approach for patients with gastric cancer (GC), particularly those in the T1-T2 stage. Currently available diagnostic strategies for GC with lymph nodes have limited accuracy. The present research aimed to create and validate diagnostic and prognostic nomograms specifically tailored for the T1-T2 stage GC patients with LNM.

Methods

We derived clinicopathological characteristics of patients diagnosed with GC from the Surveillance, Epidemiology, and End Results (SEER) database. We utilized univariate and multivariate logistic analyses to examine the risk factors linked with the occurrence of lymph node metastasis (LNM) in GC patients within the T1-T2 stage. Furthermore, the prognostic factors related to the T1-T2 stage GC patients with LNM were explored by univariate and multivariate cox analyses. Two nomograms were built by the risk factors screened above.

Results

Ultimately, our study included 5,350 patients with T1-T2 stage GC. After identifying age, T stage, tumor size, primary site, grade, and histological type as risk factors for the LNM occurrence, we successfully developed a diagnostic nomogram utilizing these variables. Age, T stage, M stage, tumor size, primary site, grade, radiation, surgery, and chemotherapy were all independent prognostic factors that related to the T1 - T2 GC patients with LNM. The results of the AUC, calibration curve and decision curve analysis (DCA) showed excellent calibration performance and clinical applicability of the two nomograms. The Kaplan-Meier (K-M) curves clearly demonstrated a notable distinction in overall survival between low-risk and high-risk groups, highlighting the prognostic significance of the nomogram.

Conclusion

The establishment and validation of the two nomograms for T1-T2 GC patients with LNM were successful, serving as valuable tools for clinical decision-making and the formulation of personalized treatment approaches.

Surgical outcomes and long-term survival of laparoscopic distal gastrectomy at high-volume centers in Korea and China: a two-centered retrospective analysis

PURPOSE

Laparoscopic distal gastrectomy is now widely used in East Asia and worldwide with different preferences and outcomes. This study aimed to compare the short- and long-term outcomes and preferences between two high-volume gastric cancer centers in Korea and China.

METHODS

Patients who underwent laparoscopic-assisted distal gastrectomy (LADG) and totally laparoscopic distal gastrectomy (TLDG) for gastric cancer from Seoul National University Hospital (SNUH) and the First Affiliated Hospital of Nanjing Medical University (NMUH) from 2017 to 2020 were enrolled in this study.

RESULTS

A total of 1166 SNUH cases and 847 NMUH cases enrolled in this study. The overall complication rate of SNUH (14.49%) did not differ from that of NMUH after LADG or TLDG (12.28%). The anastomosis-related complications rate (2.74%) did not show a significant difference with that of NMUH (2.01%) either. The median postoperative hospital stay for SNUH (7,(7,10)) was shorter than that for NMUH (8,(7,9)). The 5-year overall survival (OS) rate of SNUH was not significantly different from that of NMUH.

CONCLUSION

There was no significant difference in the overall complication rate, anastomosis-related complication rate, resected lymph nodes, and 5- year overall survival rate between SNUH and NMUH except for the postoperative stay. Both the LADG and TLDG achieved satisfactory short- and long-term outcomes when performed by surgeons with adequate experience.

The Effect of Systemic Immune-Inflammatory Index (SII) and Prognostic Nutritional Index (PNI) in Early Gastric Cancer

Background

In recent years, the systemic immune-inflammatory index (SII) and prognostic nutritional index (PNI) have been considered potential predictors of survival outcomes in various solid tumors, including gastric cancer. However, there is a notable lack of research focusing on their prognostic implications specifically in the early stage of gastric cancer. This study aims to investigate the prognostic indicators of early gastric cancer (EGC), including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), SII, PNI, and lymph node metastasis (LNM).

Methods

In this retrospective analysis, we examined 490 patients diagnosed with EGC (pT1Nx). The peripheral blood indices of interest were SII, PNI, PLR, and NLR. The receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were used to determine optimal cutoff values and prognostic efficacy for each parameter. Additionally, Kaplan-Meier survival curves and multivariate Cox regression models were utilized to delineate independent prognostic factors.

Results

The optimal cutoff values for SII and PNI were determined as 613.05 and 42.21, respectively. Patients in the low SII (SII-L) group demonstrated significantly higher 5-year Disease-Free Survival (DFS) and Overall Survival (OS) rates of 94.7% and 96.2%, compared to the high SII (SII-H) group (DFS: 78.7%; OS: 81.9%), with both differences proving statistically significant (P < 0.001, P < 0.001). Similarly, patients in the high PNI (PNI-H) group showed superior 5-year DFS (93.3%) and OS rates (95.1%) versus the low PNI (PNI-L) group (DFS: 71.4%; OS: 74.3%), also demonstrating statistical significance (P < 0.001, P < 0.001). Multivariate analysis identified SII, PNI, and LNM as independent prognostic factors for EGC. A combined analysis of SII, PNI, and LNM yielded a C-index of 0.723 (P = 0.008).

Conclusion

SII, PNI, and LNM are effective markers for predicting the survival outcomes of patients undergoing radical gastrectomy for EGC.

Advances in Endoscopic Resection

This article provides an overview of recent advances in endoscopic resection techniques. It includes the brief overview of endoscopic submucosal dissection, regional differences in ESD indications, innovation of ESD techniques, and expansion to full-thickness resection. The article covers cold snare polypectomy for small polyps with tips, underwater endoscopic mucosal resection (U-EMR) for sessile lesions with tips and expanding role of U-EMR, and the key assistive techniques for ESD that have improved the safety and efficacy. Furthermore, it discusses the emerging field of endoscopic full-thickness resection including device-assisted and freehand exposure techniques.

Sentinel Node Navigation Surgery for Early Gastric Cancer: A Narrative Review

Early gastric cancer (EGC) refers to malignant tumor lesions that are limited to the mucosa and submucosa layers, regardless of the presence of lymph node metastasis. Typically, EGC has a low rate of perigastric lymph node metastasis, and long-term survival outcomes are good after radical surgical treatment. The primary objective of surgical treatment for EGC is to achieve functional preservation while ensuring a radical cure. Sentinel node navigation surgery (SNNS) is a surgical technique used in the treatment of EGC. This approach achieves functional preservation by limiting lymph node dissection and performing restrictive gastrectomy guided by intraoperative negative sentinel node (SN) biopsy. Despite the apparent improvement in the detection rate of SN with the emergence of various tracing dyes and laparoscopic fluorescence systems, the oncological safety of SNNS remains a controversial research topic. SNNS, as a true form of stomach preservation surgery that enhances the quality of life, has become a topic of interest in the EGC field. In recent years, scholars from Japan and South Korea have conducted extensive research on the feasibility and safety of SNNS in the treatment of EGC. This article aims to provide reference choices for surgeons treating EGC by reviewing relevant research on SNNS for EGC in recent years.

Clinicopathologic factors correlated with lymph node metastasis in gastric cancer: a retrospective cohort study involving 5606 patients

BACKGROUND

The identification of risk factors associated with lymph node metastasis (LNM) in gastric cancer will establish a crucial foundation for the implementation of endoscopic operation and multidisciplinary treatment programs.

METHODS

A total of 5606 patients with gastric cancer with comprehensive clinicopathologic data were enrolled through systematic searching and rigorous screening. Of the 5606 patients, 1438 were diagnosed with early gastric cancer (EGC), which would be used for further analysis. Subsequently, univariate and multivariate logistic regression analyses were performed to identify the risk factors.

RESULTS

The rates of LNM in T1a, T1b, T2, T3, T4a, and T4b stage gastric cancer were 7.0%, 19.4%, 48.4%, 77.1%, 83.8%, and 89.6%, respectively. Female (odds ratio [OR], 1.559; P = .032), lower tumor location (OR, 1.773; P = .023), tumor size of >2 cm (OR, 2.007; P < .001), mixed (OR, 2.371; P = .001) and undifferentiated histologic types (OR, 2.952; P < .001), T1b stage (OR, 2.041; P < .001), presence of ulceration (OR, 1.758; P = .027), and lymphovascular invasion (OR, 5.722; P < .001) were identified as independent risk factors for LNM in EGC. A nomogram was constructed using appropriate predictors to preoperatively predict the risk of LNM in patients with EGC.

CONCLUSION

This study identified the clinicopathologic factors associated with LNM in patients with EGC and developed a prediction model, thereby facilitating the integration of diverse treatment modalities in managing patients with EGC.

Analysis of lymph node metastasis and survival prognosis in early gastric cancer patients: A retrospective study

BACKGROUND

Early gastric cancer (EGC) is a common malignant tumor of the digestive system, and its lymph node metastasis and survival prognosis have been concerning. By retrospectively analyzing the clinical data of EGC patients, we can better understand the status of lymph node metastasis and its impact on survival and prognosis.

AIM

To evaluate the prognosis of EGC patients and the factors that affect lymph node metastasis.

METHODS

The clinicopathological data of 1011 patients with EGC admitted to our hospital between January 2015 and December 2023 were collected in a retrospective cohort study. There were 561 males and 450 females. The mean age was 58 ± 11 years. The patient underwent radical gastrectomy. The status of lymph node metastasis in each group was determined according to the pathological examination results of surgical specimens. The outcomes were as follows: (1) Lymph node metastasis in EGC patients; (2) Analysis of influencing factors of lymph node metastasis in EGC; and (3) Analysis of prognostic factors in patients with EGC. Normally distributed measurement data are expressed as mean ± SD, and a t test was used for comparisons between groups. The data are expressed as absolute numbers or percentages, and the chi-square test was used for comparisons between groups. Rank data were compared using a nonparametric rank sum test. A log-rank test and a logistic regression model were used for univariate analysis. A logistic stepwise regression model and a Cox stepwise regression model were used for multivariate analysis. The Kaplan-Meier method was used to calculate the survival rate and construct survival curves. A log-rank test was used for survival analysis.

RESULTS

Analysis of influencing factors of lymph node metastasis in EGC. The results of the multifactor analysis showed that tumor length and diameter, tumor site, tumor invasion depth, vascular thrombus, and tumor differentiation degree were independent influencing factors for lymph node metastasis in patients with EGC (odds ratios = 1.80, 1.49, 2.65, 5.76, and 0.60; 95%CI: 1.29-2.50, 1.11-2.00, 1.81-3.88, 3.87-8.59, and 0.48-0.76, respectively; P < 0.05). Analysis of prognostic factors in patients with EGC. All 1011 patients with EGC were followed up for 43 (0-13) months. The 3-year overall survival rate was 97.32%. Multivariate analysis revealed that age > 60 years and lymph node metastasis were independent risk factors for prognosis in patients with EGC (hazard ratio = 9.50, 2.20; 95%CI: 3.31-27.29, 1.00-4.87; P < 0.05). Further analysis revealed that the 3-year overall survival rates of gastric cancer patients aged > 60 years and ≤ 60 years were 99.37% and 94.66%, respectively, and the difference was statistically significant (P < 0.05). The 3-year overall survival rates of patients with and without lymph node metastasis were 95.42% and 97.92%, respectively, and the difference was statistically significant (P < 0.05).

CONCLUSION

The lymph node metastasis rate of EGC patients was 23.64%. Tumor length, tumor site, tumor infiltration depth, vascular cancer thrombin, and tumor differentiation degree were found to be independent factors affecting lymph node metastasis in EGC patients. Age > 60 years and lymph node metastasis are independent risk factors for EGC prognosis.

Risk Factors for Lymph Node Metastasis in a Western Series of Patients with Distal Early Gastric Cancer

Background: Assessment of potential lymph node metastasis is mandatory in the appropriate treatment of early gastric cancers. This study analysed factors associated with lymph node metastasis to identify differences between node-negative and node-positive patients and between T1a and T1b cancers. Methods: The clinicopathological features of 129 early gastric cancer patients who had undergone radical gastrectomy were analysed to identify predictive factors for lymph node metastasis. Results: Lymph node metastasis was detected in 76 (59.0%) patients. Node-positive patients were younger (58.1 ± 11.3 years) than those without metastasis (61.9 ± 9.6 years, p = 0.02). Greater tumour sizes were observed in patients with lymph node metastasis (3.6 ± 1.0 cm) compared to node-negative patients (1.9 ± 0.5 cm, p = 0.00001). Depressed form, ulceration, diffuse histological type, and undifferentiated lesions were more frequent in node-positive patients than in the node-negative group. Tumour size > 3.0 cm showed a correlation with lymph node metastasis in both T1a (p = 0.0001) and T1b (p = 0.006) cancer. The male sex (p = 0.006) had a significant correlation with lymph node metastasis in T1a cancer. Depressed appearance (p = 0.02), ulceration (p = 0.03), differentiation (p = 0.0001), diffuse type (p = 0.0002), and lower third location (p = 0.005) were associated with lymph node metastasis in T1b cancer. Conclusions: Tumour size > 3 cm, undifferentiated lesions, ulceration, diffuse type, lower third location, and submucosal invasion are risk factors for lymph node metastasis in early gastric cancer.

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.

A nomogram based on platelet-to-lymphocyte ratio for predicting lymph node metastasis in patients with early gastric cancer

Background

Preoperative assessment of the presence of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) remains difficult. We aimed to develop a practical prediction model based on preoperative pathological data and inflammatory or nutrition-related indicators.

Methods

This study retrospectively analyzed the clinicopathological characteristics of 1,061 patients with EGC who were randomly divided into the training set and validation set at a ratio of 7:3. In the training set, we introduced the least absolute selection and shrinkage operator (LASSO) algorithm and multivariate logistic regression to identify independent risk factors and construct the nomogram. Both internal validation and external validation were performed by the area under the receiver operating characteristic curve (AUC), C-index, calibration curve, and decision curve analysis (DCA).

Results

LNM occurred in 162 of 1,061 patients, and the rate of LNM was 15.27%. In the training set, four variables proved to be independent risk factors (p < 0.05) and were incorporated into the final model, including depth of invasion, tumor size, degree of differentiation, and platelet-to-lymphocyte ratio (PLR). The AUC values were 0.775 and 0.792 for the training and validation groups, respectively. Both calibration curves showed great consistency in the predictive and actual values. The Hosmer-Lemeshow (H-L) test was carried out in two cohorts, showing excellent performance with p-value >0.05 (0.684422, 0.7403046). Decision curve analysis demonstrated a good clinical benefit in the respective set.

Conclusion

We established a preoperative nomogram including depth of invasion, tumor size, degree of differentiation, and PLR to predict LNM in EGC patients and achieved a good performance.

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.

Predictive factors of lymphatic metastasis and evaluation of the Japanese treatment guidelines for endoscopic resection of early gastric cancer in a high-volume center in Perú

Purpose

This study aimed to identify the predictive factors of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) and to evaluate the applicability of the Japanese treatment guidelines for endoscopic resection in the western population.

Methods

Five hundred-one patients with pathological diagnoses of EGC were included. Univariate and multivariate analyses were conducted to identify the predictive factors of LNM. EGC patients were distributed according to the indications for endoscopic resection of the Eastern guidelines. The incidence of LNM was evaluated in each group.

Results

From 501 patients with EGC, 96 (19.2%) presented LNM. In 279 patients with tumors with submucosal infiltration (T1b), 83 (30%) patients had LNM. Among 219 patients who presented tumors > 3 cm, 63 (29%) patients had LNM. Thirty-one percent of patients with ulcerated tumors presented LMN (33 out of 105). In 76 patients and 24 patients with lymphovascular and perineural invasion, the percentage of LMN was 84% and 87%, respectively. In the multivariate analysis, a tumor diameter >3 cm, submucosal invasion, lymphovascular, and perineural invasion were independent predictors of LMN in EGC. No patient with differentiated, non-ulcerated mucosal tumors presented LNM regardless of tumor size. Three of 17 patients (18%) with differentiated, ulcerated mucosal tumors and ≤ 3 cm presented LNM. No LNM was evidenced in patients with undifferentiated mucosal tumors and ≤ 2 cm.

Conclusions

The presence of LNM in Western EGC patients was independently related to larger tumors (>3 cm), submucosal invasion, lymphovascular and perineural invasion. The Japanese absolute indications for EMR are safe in the Western population. Likewise, Western patients with differentiated, non-ulcerated mucosal tumors, and larger than 2 cm are susceptible to endoscopic resection. Patients with undifferentiated mucosal tumors smaller than 2 cm presented encouraging results and ESD could be recommended only for selected cases.

A retrospective analysis based on multiple machine learning models to predict lymph node metastasis in early gastric cancer

Background

Endoscopic submucosal dissection has become the primary option of treatment for early gastric cancer. However, lymph node metastasis may lead to poor prognosis. We analyzed factors related to lymph node metastasis in EGC patients, and we developed a construction prediction model with machine learning using data from a retrospective series.

Methods

Two independent cohorts’ series were evaluated including 305 patients with EGC from China as cohort I and 35 patients from Spain as cohort II. Five classifiers obtained from machine learning were selected to establish a robust prediction model for lymph node metastasis in EGC.

Results

The clinical variables such as invasion depth, histologic type, ulceration, tumor location, tumor size, Lauren classification, and age were selected to establish the five prediction models: linear support vector classifier (Linear SVC), logistic regression model, extreme gradient boosting model (XGBoost), light gradient boosting machine model (LightGBM), and Gaussian process classification model. Interestingly, all prediction models of cohort I showed accuracy between 70 and 81%. Furthermore, the prediction models of the cohort II exhibited accuracy between 48 and 82%. The areas under curve (AUC) of the five models between cohort I and cohort II were between 0.736 and 0.830.

Conclusions

Our results support that the machine learning method could be used to predict lymph node metastasis in early gastric cancer and perhaps provide another evaluation method to choose the suited treatment for patients.

Meta-analysis of the relationship between lymphovascular invasion and prognosis of patients with stage I gastric cancer

Lymphovascular invasion is considered to be a high-risk pathological feature after radical resection of gastric cancer, but the relationship between lymphovascular invasion and the prognosis of stage I gastric cancer is still controversial. Therefore, we used meta-analysis to systematically evaluate the relationship between lymphovascular invasion and the prognosis of stage I gastric cancer. Up to September 2, 2021, the databases of PubMed, EMBASE, Cochrane Library, CNKI, and Wanfang were searched. According to the inclusion and exclusion criteria, 2 researchers independently completed the screening of literature, extraction of data, and quality evaluation. Meta-analysis was performed using RevMan 5.4 software merged with HR and 95%CI. A total of 7508 patients with stage I gastric cancer were included in 9 studies, and the positive rate of lymphovascular invasion was 17%. Lymphovascular invasion was significantly associated with shorter overall survival (OS) (univariate: HR = 4.05, 95%CI: 1.91-8.58; multivariate: HR = 2.10, 95%CI: 1.37-3.22) and relapse-free survival (RFS) (univariate: HR = 4.79, 95%CI: 2.30-9.99; multiple: HR = 2.17, 95%CI: 1.56-3.00). This study indicates that lymphovascular invasion is an independent risk factor affecting the prognosis of patients with stage I gastric cancer, and can be used as a reference index for postoperative adjuvant therapy.

Early gastric cancer: A challenge in Western countries

Early gastric cancer (EGC) is an invasive carcinoma involving only the stomach mucosa or submucosa, independently of lymph node status. EGC represents over 50% of cases in Japan and in South Korea, whereas it accounts only for approximately 20% of all newly diagnosed gastric cancers in Western countries. The main classification systems of EGC are the Vienna histopathologic classification and the Paris endoscopic classification of polypoid and non-polypoid lesions. A careful endoscopic assessment is fundamental to establish the best treatment of EGC. Generally, EGCs are curable if the lesion is completely removed by endoscopic resection or surgery. Some types of EGC can be resected endoscopically; for others the most appropriate treatment is surgical resection and D2 lymphadenectomy, especially in Western countries. The favorable oncological prognosis, the extended lymphadenectomy and the reconstruction of the intestinal continuity that excludes the duodenum make the prophylactic cholecystectomy mandatory to avoid the onset of biliary complications.

Application of Machine Learning Algorithms to Predict Lymph Node Metastasis in Early Gastric Cancer

OBJECTIVE

This study aimed to establish the best early gastric cancer lymph node metastasis (LNM) prediction model through machine learning (ML) to better guide clinical diagnosis and treatment decisions.

METHODS

We screened gastric cancer patients with T1a and T1b stages from 2010 to 2015 in the Surveillance, Epidemiology and End Results (SEER) database and collected the clinicopathological data of patients with early gastric cancer who were treated with surgery at the Second Affiliated Hospital of Nanchang University from January 2014 to December 2016. At the same time, we applied 7 ML algorithms-the generalized linear model (GLM), RPART, random forest (RF), gradient boosting machine (GBM), support vector machine (SVM), regularized dual averaging (RDA), and the neural network (NNET)-and combined them with patient pathological information to develop the best prediction model for early gastric cancer lymph node metastasis. Among the SEER set, 80% were randomly selected to train the models, while the remaining 20% were used for testing. The data from the Second Affiliated Hospital were considered as the external verification set. Finally, we used the AUROC, F1-score value, sensitivity, and specificity to evaluate the performance of the model.

RESULTS

The tumour size, tumour grade, and depth of tumour invasion were independent risk factors for early gastric cancer LNM. Comprehensive comparison of the prediction model performance of the training set and test set showed that the RDA model had the best prediction performance (F1-score = 0.773; AUROC = 0.742). The AUROC of the external validation set was 0.73.

CONCLUSIONS

Tumour size, tumour grade, and depth of tumour invasion were independent risk factors for early gastric cancer LNM. ML predicted LNM risk more accurately, and the RDA model had the best predictive performance and could better guide clinical diagnosis and treatment decisions.

Higher Lymph Node Metastasis Rate and Poorer Prognosis of Intestinal-Type Gastric Cancer Compared to Diffuse-Type Gastric Cancer in Early-Onset Early-Stage Gastric Cancer: A Retrospective Study

Background: The incidence of early-onset gastric cancer (GC) that was diagnosed at <50 years is increasing, but there is a knowledge gap on early-onset early-stage GC (EEGC) that was defined as early-onset GC limited to the mucosa or submucosa. Therefore, we comprehensively analysed the clinical features based on Lauren type.

Methods: Logistic and Cox analyses were used to investigate risk factors for lymph node metastasis (LNM) and prognosis, respectively. Propensity score matching (PSM) was used to adjust confounding factors. Protein mass spectrometry analysis was used to explore the molecular mechanism of LNM.

Result: Our study included 581 patients with EEGC from the Surveillance, Epidemiology, and End Results (SEER) database and 226 patients with EEGC from our own centre. We identified intestinal type, T1b stage, and tumour size (>3 cm) as risk factors for LNM using SEER and our own data. We also found that the prognosis of patients with intestinal-type EEGC was poorer than patients with diffuse-type EEGC, and T1b stage and positive LNM were hazard factors for survival. After analysing the expression of proteins between positive and negative LNM in the intestinal or diffuse type, we found no similar proteins between these groups. The differentially expressed genes (DEGs) in the intestinal type functioned as epithelial cell signalling in Helicobacter pylori. The DEGs in the diffuse type functioned in the tricarboxylic acid cycle (TCA cycle) and oxidative phosphorylation.

Conclusion: For EEGC, our study was the first report to demonstrate that the intestinal type was a risk factor for LNM and survival compared to the diffuse type, and the oncogenic expression promoting the occurrence of LNM was different. These findings suggest that clinicians should pay more attention to intestinal-type EEGC than diffuse-type EEGC.

Establishment of a per oral endoscopic myotomy program at a rural tertiary care center

BACKGROUND

This study's purpose is to determine the application and effectiveness of a POEM program in the rural healthcare setting. Achalasia has a substantial impact on the lives of afflicted patients. Traditionally, a Heller myotomy with fundoplication has been the standard of care for treatment. In 2008, the first per oral endoscopic myotomy (POEM) was performed in Japan. Since 2017, our rural healthcare institution has performed approximately 60 POEMs.

METHODS

An IRB approved, single-institution retrospective review of patient outcomes after POEM was performed along with prospective analysis of post-operative surveys. An institutional cost analysis was also performed. Demographic and qualitative variables were measured and included PPI use, a Likert scale of 0-5 for progressively worsening symptoms of heartburn, dysphagia, and regurgitation. In addition, we included a Dysphagia Outcome and Severity Scale.

RESULTS

The number of myotomy operations increased from 4.5 per year to 28.8 per year after initiation of the POEM program. Mean Likert scale scores were 0.91, 0.73, and 1 for heartburn, dysphagia, and regurgitation, respectively. 72.5% percent of patients were satisfied with their present condition. 87.5% of patients reported minimal or no dysphagia on the Dysphagia Severity Scale. Intraoperative costs were $2477 for laparoscopic myotomy and $1650 for POEM. The capital expense of the equipment required to perform POEM was $110,232. Average contribution margin per case was $6024. The procedure pays off capital outlay upon completion of the 19th case.

CONCLUSIONS

This study shows that patients have excellent symptom control after POEM. When compared to the institution's laparoscopic myotomy volume, POEM far surpasses in terms of operative volume and monetary benefit. Examination of these data shows that a rural hospital can successfully employ a state-of-the-art intervention when there is a population in need and an infrastructure in place.