Is the recent WHO histological classification for gastric cancer helpful for application to endoscopic resection?

Clinical Features of Gastric Signet Ring Cell Cancer: Results from a Systematic Review and Meta-Analysis

BACKGROUND

Conflicting results about the prognostic relevance of signet ring cell histology in gastric cancer have been reported. We aimed to perform a meta-analysis focusing on the clinicopathological features and prognosis of this subgroup of cancer compared with other histologies.

METHODS

A systematic literature search in the PubMed database was conducted, including all publications up to 1 October 2021. A meta-analysis comparing the results of the studies was performed.

RESULTS

A total of 2062 studies referring to gastric cancer with signet ring cell histology were identified, of which 262 studies reported on its relationship with clinical information. Of these, 74 were suitable to be included in the meta-analysis. A slightly lower risk of developing nodal metastases in signet ring cell tumours compared to other histotypes was found (especially to undifferentiated/poorly differentiated/mucinous and mixed histotypes); the lower risk was more evident in early and slightly increased in advanced gastric cancer. Survival tended to be better in early stage signet ring cell cancer compared to other histotypes; no differences were shown in advanced stages, and survival was poorer in metastatic patients. In the subgroup analysis, survival in signet ring cell cancer was slightly worse compared to non-signet ring cell cancer and differentiated/well-to-moderately differentiated adenocarcinoma.

CONCLUSIONS

Most of the conflicting results in signet ring cell gastric cancer literature could be derived from the lack of standardisation in their classification and the comparison with the different subtypes of gastric cancer. There is a critical need to strive for a standardised classification system for gastric cancer, fostering clarity and coherence in the forthcoming research and clinical applications.

Prognostic Performance of Three Lymph-Node Staging Systems on Gastric Signet-Ring-Cell Carcinoma

BACKGROUND

The lymph-node staging system can predict the prognosis of gastric signet-ring-cell carcinoma (SRCC). However, there are significant differences in lymph-node status between early SRCC and advanced SRCC. Additionally, the optimal system for early and advanced SRCC remains unknown.

METHODS

This study retrospectively analyzed 693 SRCC patients who underwent radical resection in the Department of Gastrointestinal Surgery, Harbin Medical University Cancer Hospital. The predicted performance of three lymph-node staging systems, including pN staging, lymph-node metastasis rate (LNR), and log odds of positive lymph nodes (LODDS), was compared using the receiver characteristic operating curve (ROC) and c-index. The Kaplan-Meier method and the log-rank test analyzed the overall survival of patients. The Cox risk regression model identified independent risk factors associated with patient outcomes. The nomogram was made by R studio.

RESULTS

The 693 SRCC included 165 early SRCC and 528 advanced SRCC. ROC showed that LODDS had better predictive performance than pN and LNR in predicting prognosis regardless of early or advanced SRCC. LODDS can be used to predict the prognosis of early and advanced SRCC and was an independent risk factor associated with patient outcomes (p = 0.002, p < 0.001). Furthermore, the nomogram constructed by LODDS and clinicopathological features had good predictive performance.

CONCLUSIONS

LODDS showed clear prognostic superiority over both pN and LNR in early and advanced SRCC.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Diffuse-type Gastric Cancer

Gastric cancer is the most prevalent malignant tumor in Korea. Histologically, it is often classified into intestinal-type and diffuse-type. Intestinal-type gastric cancer is known to occur mainly from chronic gastritis caused by Helicobacter pylori (H. pylori) through atrophic gastritis and intestinal metaplasia, a precancerous change of the mucosa, whereas diffuse-type gastric cancer is caused by H. pylori infection, wherein active inflammation of the gastric mucosa occurs without precancerous changes in the mucosa. Compared with intestinal-type gastric cancer, it occurs at a young age, there is no difference in male to female ratio, or tends to occur more in women, and is more aggressive than intestinal-type gastric cancer. Intestinal-type gastric cancer is predominant in East Asian populations such as Koreans and Japanese, whereas diffuse-type gastric cancer has more uniform geographic distribution. In the present manuscript, I have reviewed diffuse-type gastric cancer, distinct from intestinal-type gastric cancer.

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.

The updated WHO classification of digestive system tumours-gastric adenocarcinoma and dysplasia

The fifth edition of the World Health Organization (WHO) classification of digestive system tumours was published in 2019. The classification of invasive carcinoma is basically the same as in the fourth edition, but the description of each histological type has been updated, and some rare subtypes such as micropapillary carcinoma, gastric adenocarcinoma of the fundic gland type and undifferentiated carcinoma have been added and explained. Although this classification did not provide specific numerical criteria for the diagnosis of signet-ring cell carcinoma in poorly cohesive carcinoma, an additional study defined signet-ring cell carcinoma as having more than 90% signet-ring cells. The molecular classification of gastric cancer (Epstein-Barr virus-positive type, microsatellite instability type, genomically stable type, chromosomally unstable type) was additionally introduced. Many pages in the present classification have been devoted to precancerous lesions, and this article focuses on foveolar-type adenoma/dysplasia.

Subepithelial spread of early gastric cancer is common and extends more than expected

BACKGROUNDS

The clinical significance of subepithelial (SE) spread from early gastric cancer (EGC) is poorly understood. Thus, we evaluated the proportion and extent of SE spread from EGC, as well as related risk factors.

METHODS

We reviewed medical records and pathological specimens from patients with EGC who underwent surgery or endoscopic resection between January 2016 and December 2016 at Chungnam National University Hospital.

RESULTS

A total of 404 patients were reviewed and SE spread was identified for 142 patients (35.1%). The presence of SE spread was associated with gender, histological type, location, endoscopic appearance, color change, presence of lymphovascular invasion, and invasion depth. Multivariable analysis revealed that SE spread was only independently associated with histological type. The distance of SE spread was significantly different between histological types, and the maximum distance was 17 mm.

CONCLUSION

More than 30% of our patients with EGC had SE spread, which could reach up to 17 mm. Given the proportion of SE spread in these cases, a wider resection margin may be safe during endoscopic resection or surgery.

Prognosis and Biological Behavior of Gastric Signet-Ring Cell Carcinoma Better or Worse: A Meta-Analysis

BACKGROUND

The clinical pathology of gastric signet-ring cell carcinoma (SRC) is still unclear. This meta-analysis was performed to evaluate the difference in biological behavior and prognosis between SRC and non-signet ring cell carcinoma (NSRC).

METHODS

A total of 58 eligible studies were analyzed using RevMan and other auxiliary software. Biological behaviors were compared based on odds ratio (OR) and mean difference (MD). Hazards ratio (HR) was calculated for prognosis based on Kaplan-Meier curves.

RESULTS

Totally, 28,946 SRC patients were compared with 81,917 NSRC patients. Compared with NSRC patients, lower male: female ratio (OR = 0.53, P < 0.01), younger age (MD = -4.89, P < 0.01), more middle location (OR = 1.64, P < 0.01), more depressed type at early stage (OR = 1.31, P < 0.05), higher incidence of Borrmann type IV (OR = 1.96, P < 0.01), less lymph node metastasis at early stage (OR = 0.78, P < 0.05), better prognosis at early stage (HR = 0.59, P < 0.01), and worse prognosis at advanced stage (HR = 1.19, P < 0.01) were associated with SRC patients.

CONCLUSION

The prognosis of SRC at early stage is better than other types of gastric cancer, while that of SRC at advanced stage is relatively poorer.

Difference Between Signet Ring Cell Gastric Cancers and Non-Signet Ring Cell Gastric Cancers: A Systematic Review and Meta-Analysis

Background: There is controversy about the characteristics and prognostic implications of signet ring cell gastric cancers and non-signet ring cell gastric cancers.

Objective: This study aims to evaluate clinicopathological characteristics and prognoses of signet ring cell carcinoma (SRCC) and non-signet ring cell carcinoma (NSRCC) of stomach.

Methods: Studies compared between SRCC and NSRCC of the stomach after gastrectomy and published before September 1st, 2020, in the PubMed, Cochrane, and Embase databases, were identified systematically.

Results: A total of 2,865 studies were screened, and 36 studies were included, with 19,174 patients in the SRCC group and 55,942 patients in the NSRCC group. SRCC patients were younger in age (P < 0.001), less likely to be male patients (P < 0.001), more afflicted with upper third lesions (P < 0.001), and presenting with more Borrmann type IV tumors (P = 0.005) than NSRCC patients. Lymph nodes metastasis was similar between SRCC and NSRCC patients with advanced tumor stage (OR: 0.86, 95% CI: 0.671.10, P = 0.23), but lower in the SRCC than NSRCC patients with early tumor stage (OR: 0.73; 95% CI: 0.560.98, P = 0.02). SRCC patients had comparable survival outcomes with NSRCC patients for early gastric cancers (HR: 1.05, 95% CI: 0.651.68, P < 0.001) but had significantly poor prognosis for patients with advanced tumor stage (HR: 1.50, 95% CI: 1.281.76, P < 0.001).

Conclusions: Signet ring cell carcinomas of the stomach are an increasingly common histopathological subtype of gastric cancers. These kinds of patients tend to be younger in age and more often female. Although, signet ring cell gastric cancer is a negative prognostic factor for patients with advanced stage. The difference is that for early stage of signet ring cell gastric cancers, it has low lymph nodes metastasis rate and comparable prognosis with non-signet ring cell cancers.

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.

Comparable rates of lymph node metastasis and survival between diffuse type and intestinal type early gastric cancer patients: a large population-based study

BACKGROUND AND AIMS

Limited evidence and contradictory results exist regarding the impact of Lauren type, namely diffuse and intestinal types, of lymph node metastasis (LNM) and prognosis for early gastric cancer (EGC). We aimed to compare LNM and prognosis between diffuse and intestinal type EGCs using comprehensive statistical analysis.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify all patients with surgically resected, histologically diagnosed, intestinal or diffuse type EGC. Multivariate logistic regression, multivariate Cox regression, multivariate competing risk model, and propensity score matching were used to analyze association the Lauren type and LNM or prognosis.

RESULTS

We identified 5593 EGCs from the SEER database, including 4376 intestinal types and 1217 diffuse types. No positive association was found between LNM and Lauren type (odds ratio, .93; 95% confidence interval [CI], .70-1.24; P = .62) after adjustment for other risk factors. Moreover, diffuse-type EGCs showed a similar prognosis to intestinal type EGCs in both multivariate Cox regression (HR [hazard ratio], .95; 95% CI, .77-1.18; P = .66) and the multivariate competing risk model (subdistribution HR [SHR], .99; 95% CI, .80-1.22; P = .926). Propensity score matching was used, and 733 diffuse types were matched with 733 intestinal types. We did not find any association between the Lauren type and LNM (odds ratio, .98; 95% CI, .71-1.37; P = .934) or prognosis in the univariate Cox regression (HR, .98; 95% CI, .76-1.26; P = .893) and univariate competing risk model (SHR, .98; 95% CI, .76-1.26; P = .893).

CONCLUSIONS

Diffuse-type EGC may have a comparable risk of LNM and prognosis to intestinal-type EGC. Nevertheless, these results should be carefully interpreted with caution when choosing endoscopic resection instead of surgery, because the treatment choice for EGC depends on the risk of lymphovascular invasion rather than LNM rate or prognosis.

Low expression levels of plasma miR-141 are associated with susceptibility to gastric cancer

MicroRNAs (miRNAs/miRs) offer great potential as biomarkers for the early detection and prognosis of cancer, and the discovery of miRNAs associated with gastric cancer is required. In the present study, the differences in the plasma expression levels of miR-141 between patients with gastric cancer and healthy controls, and the role of miR-141 in gastric cancer cell oncogenesis were investigated. A follow-up study of 164 patients with gastric cancer who underwent tumor resection was conducted, and comparisons with healthy control subjects were drawn. To investigate the biological functions of miR-141, a series of in vitro and in vivo assays were conducted, including proliferation, wound-healing and Transwell assays, and a xenograft tumor model. The results demonstrated that miR-141 expression was significantly decreased in tumor tissues compared with in healthy tissues (P<0.05). Kaplan-Meier analysis revealed improved survival benefits with increased miR-141 expression (as determined using the log-rank test, P<0.001), and multivariate Cox regression analysis revealed that patients with decreased expression levels of miR-141 carried a greater risk of death (hazard ratio=2.352; 95% CI=1.379-4.012; P=0.002). The downregulation of miR-141 was also associated with WHO staging, particularly for lymph node and distant metastasis. Exogenous overexpression of miR-141 significantly inhibited the proliferative and migratory abilities of the gastric cancer cell line BGC-823. In vivo studies also demonstrated that exogenous overexpression of miR-141 in BGC-823 cells markedly reduced tumor growth in nude mice. The present study revealed that increased miR-141 expression may be a positive prognostic factor, which may be clinically beneficial in patients with gastric cancer.

A Risk-Scoring Model for Predicting Lymph Node Metastasis in Early Gastric Cancer Patients: a Retrospective Study and External Validation

BACKGROUND

The possibility of lymph node metastasis (LNM) is critical to the assessment of the indication for endoscopic submucosal dissection. Thus, the aim of this study is to identify the risk factors for LNM and construct a risk-scoring model for patients with early gastric cancer to guide treatment.

METHODS

A retrospective examination of reports and studies carried out January 2000 and December 2014 was conducted. A risk-scoring model for predicting LNM was developed based on the data thus collected. In addition, the model is subject to verification and validation by three institutions.

RESULTS

Of the 1029 patients, 228 patients (22%) had LNM. Multivariate analysis showed that female, depressed type, undifferentiated type, submucosa, tumor size, and lymphovascular invasion were significantly associated with LNM. An 11-point risk-scoring model was used to predict LNM risk. An area under the receiver operating characteristic (AUROC) of the risk-scoring model was plotted using the development set and the AUROC of the model [0.76 (95% CI 0.73-0.80)] to predict LNM risk. After internal and external validation, the AUROC curve for predicting LNM was 0.77 (95% CI 0.68-0.86), 0.82 (95% CI 0.72-0.91), and 0.82 (95% CI 0.70-0.94), respectively.

CONCLUSIONS

A risk-scoring model for predicting LNM was developed and validated. It could help with personalized care for patients with EGC.

A Promising Method for Tumor Localization during Total Laparoscopic Distal Gastrectomy: Preoperative Endoscopic Clipping based on Negative Biopsy and Selective Intraoperative Radiography Findings

PURPOSE

Precise localization of tumors and creation of sufficient proximal resection margins are complicated processes during total laparoscopic distal gastrectomy (TLDG) for clinical T1/T2 gastric cancers. Various solutions to this problem have also yielded many disadvantages. In this study, we reviewed a preoperative endoscopic clipping method based on the results of negative biopsy and selective intraoperative radiography.

MATERIALS AND METHODS

A retrospective review of 345 consecutive patients who underwent TLDG and preoperative endoscopic clipping for tumor localization was conducted. During preoperative endoscopy, the endoscopists performed negative biopsies just 1-2 cm selectively above the tumor's upper limit. After confirming the biopsy results, endoscopic metal clips were applied just proximal to the negative biopsy site the day before surgery. Selective intraoperative tumor localization using portable abdominal radiography was performed only when we could not ensure a precise resection line.

RESULTS

Negative biopsy was performed in 244 patients. Larger tumor size (P=0.008) and more distally located tumors (P=0.052) were observed more frequently in the negative biopsy group than in the non-negative biopsy group. The non-negative biopsy group had significantly higher frequencies of differentiated tumor types than the negative biopsy group (P=0.003). Of the 244 patients who underwent negative biopsies, 6 had cancer cells in their biopsy specimens. We performed intraoperative radiography in 12 patients whose tumors had difficult-to-determine proximal margins. No tumors were found in the proximal resection margins of any patients.

CONCLUSIONS

Our tumor localization method is a promising and accurate method for securing a sufficient resection margin during TLDG.

Predictive factors for lymph node metastasis in early gastric cancer with signet ring cell histology: a meta-analysis

BACKGROUND

Less invasive surgery is widely used in the treatment of early gastric cancer; however, no definite guidelines exist regarding indications for less invasive surgery to treat early gastric cancer with signet ring cell histology. The aim of this study was to identify risk factors for lymph node metastasis (LNM) in early signet ring cell carcinoma (SRC). An extensive search of PubMed, Embase and the Cochrane library was performed for pertinent articles involving early SRC and LNM.

METHODS

Eligible data (gender, depth of invasion, lymphovascular invasion, size, ulceration, macroscopic type and location) were extracted from the included studies and systematically reviewed via a meta-analysis. Review Manager version 5.3 was used to perform the data processing. The Newcastle-Ottawa Scale was utilized to evaluate the quality of the included articles.

RESULTS

Fourteen studies were included in the final analysis. After meta-analysis, female gender, submucosal invasion, lymphovascular invasion and size >20 mm were associated with LNM in early SRC.

CONCLUSION

Four variables were identified as risk factors for LNM in early SRC. The significance of the results of the present study should be further confirmed in more early SRC patients for future clinical use.

Histologic purity of signet ring cell carcinoma is a favorable risk factor for lymph node metastasis in poorly cohesive, submucosa-invasive early gastric carcinoma

BACKGROUND

The prediction of biologic behavior of poorly cohesive early gastric carcinoma (EGC) is an important issue in the selection of the treatment modality. To elucidate the risk factors for lymph node metastasis (LNM) of poorly cohesive EGC, we focused on the histologic purity of the poorly cohesive component and evaluated the impact of this factor on LNM.

METHODS

We divided poorly cohesive EGC into (1) pure signet ring cell (SRC) carcinoma, which was defined as composed only of signet ring cells or poorly cohesive cells and (2) mixed SRC carcinoma, defined as poorly cohesive carcinoma with minor tubular components. We reviewed the clinicopathologic features, including age, sex, location, size, depth, lymphovascular invasion (LVI), LNM, ulceration, and intestinal metaplasia between the two groups in a large series of poorly cohesive, submucosa-invasive EGC (n = 317).

RESULTS

LNM was found in 58 cases (18.3 %). Mixed SRC carcinoma histologic type (p < 0.001), larger tumor size (more than 2 cm) (p = 0.012), and the presence of LVI (p < 0.001) were associated with LNM. Pure SRC carcinomas accounted for 56.2 % (178/317) of the cases. Fourteen pure SRC carcinomas (7.8 %) showed LNM, whereas 44 mixed SRC carcinomas (31.9 %) exhibited LNM (p < 0.001). On multivariate logistic regression, the presence of LVI (odds ratio 6.737; 95 % confidence interval 2.714-16.720; p < 0.001) and mixed SRC carcinoma histologic type (odds ratio 4.674; 95 % confidence interval 2.370-9.216; p < 0.001) were independent predictors of LNM in poorly cohesive, submucosa-invasive EGC.

CONCLUSIONS

The presence of a tubular component in SRC carcinoma was a risk factor for LNM in poorly cohesive, submucosa-invasive EGC. On the basis of this finding, we propose that the presence of a minor tubular component or the purity of the poorly cohesive/SRC carcinoma component should be reported in daily pathologic practice.

Clinicopathology of Early Gastric Carcinoma: An Update for Pathologists and Gastroenterologists

BACKGROUND

The WHO defines early gastric carcinoma (EGC) as invasive carcinoma up to the submucosal layer, regardless of nodal metastasis. The recent study results indicate that EGC varies in location, histology, nodal metastasis, and prognosis.

SUMMARY

The heterogeneity in EGC may be related to various types of epithelial stem cells. The most important stem cells include Lgr5+ cells at the base of a gastric unit in the antrum-pylorus-cardia, Mist1+ cells at the isthmus/Troy+ cells at the base in the corpus-fundus, and Sox2+ cells at the base in almost all regions. Dysregulation of these cells along with environmental factors transform stem cells in different regions into malignancy in genetically susceptible populations.

KEY MESSAGE

The 2 most vulnerable regions for EGC have been found along the lesser curvature: the cardia in elderly patients and antrum-angularis in mid-aged and elderly patients. Most hereditary early-onset gastric carcinomas are concentrated in the corpus-fundus of young women. By histology, the most common EGC type is tubular adenocarcinoma in many growth patterns, starting in the neck of a gastric unit. Worse prognosis has been found in early papillary, compared to tubular, adenocarcinoma, related to deeper penetration, more lymphovascular invasion, and more liver and nodal metastases. Contrary to the common belief, intramucosal signet ring cell carcinoma demonstrates low risk of nodal metastasis, comparable to early intestinal-type EGC.

PRACTICAL IMPLICATIONS

The overall risk for nodal metastasis in EGC is low but significant. It is urgent to organize multicenter studies on risk of nodal metastasis in EGC in order to establish more reliable clinical practice guidelines to treat EGC patients.