Mixed-histologic-type submucosal invasive gastric cancer as a risk factor for lymph node metastasis: feasibility of endoscopic submucosal dissection

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.

Clinical Outcome of Endoscopic Submucosal Dissection for Papillary Type Early Gastric Cancer: A Multicenter Study

Background/Aims

Papillary adenocarcinoma is classified to differentiated-type gastric cancer and is indicated for endoscopic submucosal dissection. However, due to its rare nature, there are limited studies on it. The purpose of this study was to determine the outcome of endoscopic submucosal dissection in patients with papillary-type early gastric cancer and to find the risk factors of lymph node metastasis.

Methods

Patients diagnosed with papillary-type early gastric cancer at eight medical centers, who underwent endoscopic submucosal dissection or surgical treatment, were retrospectively reviewed. The clinical results and long-term outcomes of post-endoscopic submucosal dissection were evaluated, and the risk factors of lymph node metastasis in the surgery group were analyzed.

Results

One-hundred and seventy-six patients with papillary-type early gastric cancer were enrolled: 44.9% (n=79) in the surgery group and 55.1% (n=97) in the endoscopic submucosal dissection group. As a result of endoscopic submucosal dissection, the en bloc resection and curative resection rates were 91.8% and 86.6%, respectively. The procedure-related complication rate was 4.1%, and local recurrence occurred in 3.1% of patients. Submucosal invasion (odds ratio, 3.735; 95% confidence interval, 1.026 to 12.177; p=0.047) and lymphovascular invasion (odds ratio, 7.636; 95% confidence interval, 1.730 to 22.857; p=0.004) were the risk factors of lymph node metastasis in papillary-type early gastric cancer patients.

Conclusions

The clinical results of endoscopic submucosal dissection in papillary-type early gastric cancer were relatively favorable, and endoscopic submucosal dissection is considered safe if appropriate indications are confirmed by considering the risk of lymph node metastasis.

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.

Clinical outcomes and risk factors of non-curative endoscopic submucosal dissection for early gastric cancer: a retrospective multicenter study in Zhejiang, China

Background

Endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) does not always lead to curative resection. Risk factors of lymph node metastasis (LNM)/local cancer residue after non-curative ESD for EGC have not been fully elucidated. We therefore aimed to clarify them and evaluate whether the "eCura system" is reliable for the risk stratification of LNM after non-curative ESD.

Methods

We conducted a multicenter retrospective study at seven institutions in Zhejiang, China, on 128 patients who underwent non-curative ESD for EGC. We divided the patients into two groups according to their therapeutic regimen after non-curative ESD. We analyzed the risk factors for LNM, local cancer residue, cancer recurrence, and cancer-specific mortality. Furthermore, we compared the outcomes in each risk category after applying the "eCura system".

Results

Among 68 patients undergoing additional surgery, LNM was found in three (4.41%) patients, while local cancer residue was found in eight (11.76%) patients. Multivariate analysis showed that upper third location and deep submucosal invasion were independent risk factors of LNM and local cancer residue. Among 60 patients who underwent simple follow-up, local cancer recurrence was found in four (6.67%) patients and cancer-specific mortality was found in one (1.67%) patient. There were no independent risk factors of cancer recurrence and cancer-specific mortality in our study. During the follow-up period, 5-year overall survival (OS) and disease-free survival (DFS) were 93.8% and 88.9%, respectively. Additionally, LNM and cancer recurrence were significantly associated with the eCura scoring system (p = 0.044 and p = 0.017, respectively), while local cancer residue and cancer-specific mortality were not (p = 0.478 and p = 0.131, respectively).

Conclusion

Clinicians should be aware of the risk factors for the prognosis of patients with non-curative ESD to determine subsequent treatment. Through the application of the "eCura system", additional surgery should be performed in patients with intermediate/high risk of LNM.

The Clinicopathological Features of Mixed Carcinoma in 7,215 Patients with Gastric Cancer in a Tertiary Hospital in South Korea

Background/Aims

There are few reports regarding mixed carcinoma, defined as a mixture of glandular and poorly cohesive components, in patients with gastric cancer (GC). The aim of this study was to evaluate the proportion and characteristics of mixed carcinoma in GC patients.

Methods

A total of 7,215 patients diagnosed with GC at Seoul National University Bundang Hospital were enrolled from March 2011 to February 2020. GC was divided into four groups (well-moderately differentiated GC, poorly differentiated GC, poorly cohesive carcinoma, and mixed carcinoma). The proportion of each GC type and the clinicopathological features were analyzed and divided into early GC and advanced GC.

Results

The proportion of mixed carcinoma was 10.9% (n=787). In early GC, submucosal invasion was the most common in poorly differentiated (53.7%), and mixed carcinoma ranked second (41.1%). Mixed carcinoma showed the highest proportion of lymph node metastasis in early GC (23.0%) and advanced GC (78.3%). In advanced GC, the rate of distant metastasis was 3.6% and 3.9% in well-moderately differentiated GC and mixed carcinoma, respectively, lower than that in poorly differentiated GC (6.4%) and poorly cohesive carcinoma (5.7%), without statistical significance.

Conclusions

Mixed carcinoma was associated with lymph node metastasis compared to other histological GC subtypes. And it showed relatively common submucosal invasion in early GC, but the rates of venous invasion and distant metastasis were lower in advanced GC. Further research is needed to uncover the mechanism underlying these characteristics of mixed carcinoma (Trial registration number: NCT04973631).

Clinicopathological features of endoscopically treated early gastric cancer with lymphovascular infiltration

PURPOSE

Lymphovascular infiltration (LVI) may play a critical role in radicality and prognostic assessment of early gastric cancer (EGC). However, risk factors for LVI in endoscopically resected EGC remain unknown. This study evaluated the clinicopathological characteristics and prognoses of patients who underwent endoscopic resection of EGC to identify potential risk factors of LVI.

METHODS

A cross-sectional study of patients who received gastric endoscopic submucosal dissection between February 1, 2012, and December 31, 2019, at two institutions was conducted. Among 1,462 lesions, 943 met the criteria for radical treatment considering features other than LVI and were included. The lesions were classified based on the presence of LVI. The clinicopathological characteristics of the two groups were compared.

RESULTS

LVI was detected in 17 lesions (1.8%). The positivity rates of LVI were 0.7% (7/903) for intramucosal cancer and 25% (10/40) for submucosally invasive cancer. The LVI positivity rate was significantly higher for mixed-type cancer (lesions containing differentiated and undifferentiated-type carcinoma) than for non-mixed-type cancer (35.3 vs. 2.8%; P < 0.001) and for submucosally invasive cancer than for intramucosal cancer (58.8 vs. 3.2%; P < 0.001). In the multivariate logistic regression analysis, independent risk factors for LVI were mixed-type cancer (odds ratio; 95% confidence interval: 23.9; 5.0-115; P < 0.001) and submucosal invasion (58.7; 16.0-215; P < 0.001).

CONCLUSIONS

Mixed-type cancer and submucosal invasion were risk factors for LVI in endoscopically resected EGC. These factors may play a critical role in the radicality and prognostic assessment of EGC.

Gastric Cancer: Correlation of Histologic Type with Commonly Used Prognostic Variables

Background: Gastric cancer is one of the most common cancers among Iranian men and women. Objectives: The aim here was to investigate different histopathologic types and features of this cancer in association with selected prognostic variables. Methods: A retrospective cross-sectional study was performed to reevaluate the pathologic samples of 100 cases of gastric cancer referred to Shohadaye Tajrish Hospital, Tehran, Iran from 2017 to 2022. Results: We evaluated 100 cases of gastric cancer in this study. They had a mean age of 62.4 ± 13.44 years old (range 28 - 84 years) and were mostly men (n = 66, 66 %). On histopathologic evaluation, tubular carcinoma was the most common type (n = 45, 45%). We found a statistically significant correlation between the histologic type and perineural invasion (P-value = 0.024), lymphovascular invasion (P-value < 0.001), tumoral involvement of surgical margin (P-value = 0.012 ), infiltration depth of the primary tumor (pT) (P-value = 0.049) , number of metastatic lymph nodes (pN) (P-value = < 0.001) , tumor location in the antrum (P-value=0.033) and body (P-value = 0.013) , and tumor size (P-value = 0.002 and P-value = 0.031 in small and large size groups respectively). Conclusions: According to the findings, histologic type of gastric cancer correlates with perineural invasion, lymphovascular invasion, tumoral involvement of the surgical margin, pT, pN, and tumor location and size.

Clinicopathological characteristics of early gastric cancer with different level of undifferentiated component and nomogram to predict lymph node metastasis

Background

Few studies showed that mixed type early gastric cancer (EGC) relates to higher risk of lymph node metastasis. We aimed to explore the clinicopathological feature of GC according to different proportions of undifferentiated components (PUC) and develop a nomogram to predict status of lymph node metastasis (LNM) in EGC lesions.

Methods

Clinicopathological data of the 4,375 patients who underwent surgically resection for gastric cancer in our center were retrospectively evaluated and finally 626 cases were included. We classified mixed type lesions into five groups (M1:0% < PUC ≤ 20%, M2:20%<PUC ≤ 40%, M3:40%<PUC ≤ 60%, M4:60%<PUC ≤ 80%, M5:80%<PUC < 100%). Lesions with 0% PUC were classified as pure differentiated group (PD) and lesions with 100% PUC were classified as pure undifferentiated group (PUD).

Results

Compared with PD, LNM rate was higher in group M4 and group M5 (p < 0.05 after Bonferroni correction). Differences of tumor size, presence of lymphovascular invasion (LVI), perineural invasion and invasion depth also exist between groups. No statistical difference of LNM rate was found in cases who met the absolute endoscopic submucosal dissection (ESD) indications for EGC patients. Multivariate analysis revealed that tumor size over 2 cm, submucosa invasion to SM2, presence of LVI and PUC level M4 significantly predicted LNM in EGC. With the AUC of 0.899(P < 0.05), the nomogram exhibited a good discrimination. Internal validation by Hosmer-Lemeshow test showed a good fitting effect in model (P > 0.05).

Conclusion

PUC level should be considered as one of the predicting risk factors of LNM in EGC. A nomogram that predicts the risk of LNM in EGC was developed.

Endoscopic Resection of Undifferentiated Early Gastric Cancer

Endoscopic resection (ER) is widely performed for early gastric cancer (EGC) with a negligible risk of lymph node metastasis (LNM) in Eastern Asian countries. In particular, endoscopic submucosal dissection (ESD) leads to a high en bloc resection rate, enabling accurate pathological evaluation. As undifferentiated EGC (UD-EGC) is known to result in a higher incidence of LNM and infiltrative growth than differentiated EGC (D-EGC), the indications for ER are limited compared with those for D-EGC. Previously, clinical staging as intramucosal UD-EGC ≤2 cm, without ulceration, was presented as 'weakly recommended' or 'expanded indications' for ER in the guidelines of the United States, Europe, Korea, and Japan. Based on promising long-term outcomes from a prospective multicenter study by the Japan Clinical Oncology Group (JCOG) 1009/1010, the status of this indication has expanded and is now considered 'absolute indications' in the latest Japanese guidelines published in 2021. In this study, which comprised 275 patients with UD-EGC (cT1a, ≤2 cm, without ulceration) treated with ESD, the 5-year overall survival (OS) was 99.3% (95% confidence interval, 97.1%-99.8%), which was higher than the threshold 5-year OS (89.9%). Currently, the levels of evidence grades and recommendations for ER of UD-EGC differ among Japan, Korea, and Western countries. Therefore, a further discussion is warranted to generalize the indications for ER of UD-EGC in countries besides Japan.

A Standardized Pathology Report for Gastric Cancer: 2nd Edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

A standardized pathology report for gastric cancer: 2nd edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Applicability of endoscopic submucosal dissection for patients with early gastric cancer beyond the expanded indication for endoscopic submucosal dissection

BACKGROUND

Endoscopic submucosal dissection (ESD) application for patients with tumors beyond the expanded indication for ESD is inconclusive. This study aimed to identify the preoperative clinical features that can be curatively treated with ESD in patients with early gastric cancer (EGC) beyond the indication of ESD.

METHODS

From 2006 to 2016, 673 patients who underwent gastrectomy for EGC beyond the expanded indication for ESD based on preoperative assessments were retrospectively reviewed. We identified tumors curatively resected by ESD based on the postoperative pathologic findings. We also analyzed the clinical and pre-treatment features to determine the risk factors associated with curative resection of ESD.

RESULTS

39% of the patients (263/673) who had undergone gastrectomy had tumors of endoscopic curability A or B (eCuraA/B) that could be treated by ESD alone. In multivariate analysis, tumor size ≤ 10 mm (OR 0.240; 95% CI = 0.12-0.46), no ulceration (OR 0.500; 95% CI = 0.29-0.87), differentiated histology (OR 0.599; 95% CI = 0.43-0.84), and location in the distal two-thirds of the stomach (OR 0.499; 95% CI = 0.28-0.88) in pre-treatment assessment were identified as independent predictors of eCuraA/B. Considering the risk factors, 63.6% (7/11)/61.3% (19/31) of patients with a differentiated/undifferentiated tumor size ≤ 10 mm located in distal two-third of the stomach without ulceration were deemed as eCuraA/B.

CONCLUSIONS

This study suggests that patients with EGC indicated for surgery can be treated by ESD by adding tumor locations in the indication for ESD. Thus, ESD can be applied for patients with a tumor size ≤ 10 mm located in the lower/middle stomach without ulceration.

The Percentage of Signet Ring Cells Is Inversely Related to Aggressive Behavior and Poor Prognosis in Mixed-Type Gastric Cancer

BACKGROUND AND OBJECTIVES

Only recently the percentage of signet ring cells (SRCs) in gastric cancer (GC) has been proposed as an independent predictor of survival. High amounts of SRCs have been related to lower recurrence and mortality rates, better prognosis, and favorable clinicopathological features in a poorly cohesive histotype. It is not known what the effect of SRC percentage in mixed-type GC is. We investigate the role of SRCs as a prognostic marker in mixed-histotype GC.

METHODS

A retrospective analysis was performed through a prospectively maintained database of patients with diagnosed "mixed-type" gastric carcinoma, defined according to 2019 WHO classification. These patients underwent surgery between 1995 and 2016, and their tissue samples were stored in a tissue bank. All slides were analyzed, and patients were divided into three groups according to the percentage of SRCs: "Group 1" (displaying ≤10% of SRCs), "Group 2" (displaying <90% but >10% of SRCs), and "Group 3" (displaying ≥90% of SRCs). We compared clinical and pathological features as well as prognostic factors between the different groups.

RESULTS

Among 164 enrolled patients, 68.9% were male and 31.1% were female (p = 0.612). The mean (±SD) age at diagnosis was 71.4 ± 9.6 years. Ninety-eight (59.7%) patients were classified as "Group 1", 66 (40.3%) as "Group 2", and none as "Group 3". Five-year overall survival was remarkably higher in Group 2 (73.8%) in comparison to Group 1 (35.4%), p < 0.001. Mortality risk was three times higher in patients with ≤10% SRC pattern compared to those with >10% [HR 2.70 (95% CI 1.72-4.24)]. After adjusting according to potential confounding factors, SRC percentage was still an independent predictor of survival.

CONCLUSIONS

The proportion of SRCs is inversely related to aggressive behavior and poor prognosis in mixed-type GCs, highlighting the role of SRC amount as an independent predictor of survival.

Relationship between histological mixed-type early gastric cancer and lymph node metastasis: A systematic review and meta-analysis

The clinicopathological features of early gastric cancer (EGC) with mixed-type histology (differentiated and undifferentiated) are incompletely understood, and the capacity of endoscopic submucosal dissection (ESD) to treat mixed-type cancer remains controversial. This systematic review analyzed the rate of lymph node metastasis (LNM) in mixed-type EGC. We gathered articles published up to February 21, 2021, that analyzed the relationship between LNM and mixed-type EGC from Embase, PubMed, and Web of Science. The primary outcome was the LNM rate associated with different histological types of EGC, and the secondary outcomes were the odds ratios (ORs) for LNM risk factors among EGC patients. From the 24 studies included in this meta-analysis, the overall rate of LNM in predominantly differentiated mixed-type (MD) EGC was 12%, whereas the LNM rate in predominantly undifferentiated mixed-type (MU) EGC was 22%. We further divided these studies into 2 groups according to the depth of invasion. In mixed-type mucosal EGC, the pooled LNM rate was 15%; in submucosal EGC, the rate was 33% for MU, which was higher than the rates for pure types (pure differentiated type, 13%; pure undifferentiated type, 21%; p<0.05). The LNM rate of MD was 20%, it was higher than those of the pure differentiated type and nearly the same as pure undifferentiated type. Other pooled statistics showed that submucosal invasion, pure undifferentiated EGC, and mixed-type EGC were independent risk factors for LNM. This meta-analysis showed that MD submucosal EGC has a high rate of LNM and is highly correlated with LNM; thus, the management of MD EGC as purely differentiated EGC according to the indications for ESD is inappropriate, and the mixed type should be added as a parameter in these indications.

Undifferentiated-predominant mixed-type early gastric cancer is more aggressive than pure undifferentiated type: a systematic review and meta-analysis

BACKGROUND

Studies have shown that differentiated-predominant mixed-type early gastric cancer (EGC) is more aggressive than pure differentiated-type EGC. However, the biological behaviour of undifferentiated-predominant mixed-type (MU) EGC and pure undifferentiated-type (PU) EGC are controversial. This study was conducted to compare the biological behaviour of MU EGC and PU EGC.

METHODS

A systematic review and meta-analysis of observational studies was conducted using literature published through PubMed and Embase from inception to 9 November 2021. Inclusion criteria were: (1) a direct or indirect comparison of MU and PU; (2) patients with EGC; (3) a specified outcome of lymph node metastasis (LNM), lymphovascular invasion, submucosal invasion and/or ulcer findings; and (4) the primary lesion was obtained. The literature search, data extraction and quality assessment were performed by two independent reviewers. The meta-analysis was conducted with a random-effect model using the Mantel-Haenszel method.

RESULTS

Twelve publications with 5644 patients were included. Patients with MU EGC had significantly higher risk of LNM (OR 2.28; 95% CI 1.72 to 3.03) and submucosal invasion (OR 2.19; 95% CI 1.90 to 2.52) compared with patients with PU EGC. No difference was found between patients with MU and PU EGC with respect to lymphovascular invasion risk (OR 1.81; 95% CI 0.84 to 3.87). After stratifying the data according to depth of tumour invasion, a significantly higher risk for LNM was associated with intramucosal MU EGC (OR 2.56; 95% CI 1.66 to 3.95) and submucosal MU EGC (OR 2.63; 95% CI 2.06 to 3.06). Submucosal MU EGC also had a significantly higher risk of lymphovascular invasion (OR 2.40; 95% CI 1.79 to 3.21) compared with submucosal PU EGC.

DISCUSSION

Patients with MU EGC had an increased risk of submucosal invasion and LNM compared with patients with PU EGC . MU patients with submucosal EGC also had an increased lymphovascular invasion risk compared with PU patients. Therefore, attention should be focused on the clinical management of patients with MU EGC.

Gastric mucin phenotype indicates aggressive biological behaviour in early differentiated gastric adenocarcinomas following endoscopic treatment

Background

The distribution of mucin phenotypes and their relationship with clinicopathological features in early differentiated gastric adenocarcinomas in a Chinese cohort are unknown. We aimed to investigate mucin phenotypes and analyse the relationship between mucin phenotypes and clinicopathological features, especially biological behaviours, in early differentiated gastric adenocarcinomas from endoscopic specimens in a Chinese cohort.

Methods

Immunohistochemical staining of CD10, MUC2, MUC5AC, and MUC6 was performed in 257 tissue samples from patients with early differentiated gastric adenocarcinomas. The tumour location, gross type, tumour size, histological type, depth of invasion, lymphovascular invasion, mucosal background and other clinicopathological parameters were evaluated. The relationship between mucin phenotypes and clinicopathological features was analysed with the chi-square test.

Results

The incidences of gastric, gastrointestinal, intestinal and null phenotypes were 21 %, 56 %, 20 and 3 %, respectively. The mucin phenotypes were related to histology classification (P < 0.05). The proportion of the gastric phenotype became greater during the transition from differentiated to undifferentiated (P < 0.05). Complete intestinal metaplasia was higher in the gastric and intestinal phenotypes than in the gastrointestinal phenotype (P < 0.05). Tumours with poorly differentiated adenocarcinoma were mainly of the gastric phenotype, which was significantly higher than that of purely differentiated tubular adenocarcinoma (P < 0.05), and the depth of invasion in the mixed type was deeper (P < 0.05). Neither recurrence nor metastasis was detected.

Conclusions

The mucin phenotype of early-differentiated gastric adenocarcinoma has clinical implications, and the gastric phenotype has aggressive biological behaviour in early differentiated gastric cancers, especially in those with poorly differentiated adenocarcinoma or papillary adenocarcinoma components.

Recurrence rate of intramucosal gastric cancer with positive vertical margin due to lesion damage during endoscopic submucosal dissection

BACKGROUND AND STUDY AIM

In principle, additional surgery is performed after endoscopic submucosal dissection for early gastric cancer if the vertical margin is positive, regardless of lesion damage. The recurrence rate of vertical margin-positive lesions due to lesion damage after endoscopic submucosal dissection is unknown, and unnecessary surgeries may be performed. In this study, we investigated whether there was a difference in the recurrence rate between vertical margin-positive lesions due to lesion damage and vertical margin-negative lesions.

PATIENTS AND METHODS

We included 1,294 intramucosal gastric cancer lesions that were resected by endoscopic submucosal dissection between January 2008 and December 2016, without additional surgery. The lesions were divided into the Damage and No damage groups based on vertical margin status. The Damage group had only one non-curative indication: a positive vertical margin due to lesion damage. The No damage group had no non curative indications. We compared the recurrence rate between the Damage and No damage groups.

RESULTS

The recurrence rates of the Damage and No damage groups were 0% (0/23; 95% confidence interval: 0-14.8%) and 0% (0/1,271; 95% confidence interval: 0-0.003%), respectively, with no statistically significant difference.

CONCLUSIONS

In intramucosal gastric cancer, the recurrence rate of vertical margin-positive lesions due to lesion damage was 0%, which did not differ from that of vertical margin-negative lesions with curative resection. Follow-up, instead of additional surgery, may be an option for patients with non-curative resection when the only non-curative indication is a positive vertical margin due to lesion damage.

Mixed histology poses a greater risk for noncurative endoscopic resection in early gastric cancers regardless of the predominant histologic types

OBJECTIVES

Clinicopathologic characteristics and treatment outcomes of mixed-histological-type (MT) early gastric cancers (EGCs) treated with endoscopic submucosal dissection (ESD) have not been sufficiently elucidated. We aimed to clarify them in comparison with pure-histological-type EGCs.

METHODS

We used 3022 consecutive EGCs in 2281 patients treated with ESD from our prospectively maintained database. Cases were stratified into four groups according to the final diagnosis of the resected specimen are as follows: 2780 pure differentiated-type (DT), 127 DT-predominant MT (D-MT), 87 pure undifferentiated-type (UDT), and 28 UDT-predominant MT (U-MT). Clinicopathologic characteristics and treatment outcome were compared between pure DT and D-MT, and between pure UDT and U-MT separately. Risk factors for deep submucosal invasion, lymphovascular invasion, and a final diagnosis of MT were identified using multivariate analysis.

RESULTS

Both D-MT (41.7 vs. 92.0%; P < 0.0001) and U-MT (35.7 vs. 75.9%; P = 0.0002) showed a significantly lower curative resection rate than their pure histologic counterparts. Multivariate analysis revealed that MT was an independent risk factor for deep submucosal (OR 6.55; 95% CI, 4.18-10.14) and lymphovascular (OR 4.74; 95% CI, 2.72-8.29) invasion. Preoperative biopsy results that did not show well-differentiated tubular adenocarcinoma (OR 28.2; 95% CI, 18.9-42.9) were an independent risk factor for a final diagnosis of MT.

CONCLUSIONS

MT poses a greater risk for noncurative resection regardless of the predominant histologic types, reflecting more aggressive malignant potential. Although a biopsy examination rarely shows MT, clinicians should consider the possibility of MT when a biopsy examination does not show well-differentiated tubular adenocarcinoma.

Risk-Scoring System for Prediction of Non-Curative Endoscopic Submucosal Dissection Requiring Additional Gastrectomy in Patients with Early Gastric Cancer

Purpose

When patients with early gastric cancer (EGC) undergo non-curative endoscopic submucosal dissection requiring gastrectomy (NC-ESD-RG), additional medical resources and expenses are required for surgery. To reduce this burden, predictive model for NC-ESD-RG is required.

Materials and Methods

Data from 2,997 patients undergoing ESD for 3,127 forceps biopsy-proven differentiated-type EGCs (2,345 and 782 in training and validation sets, respectively) were reviewed. Using the training set, the logistic stepwise regression analysis determined the independent predictors of NC-ESD-RG (NC-ESD other than cases with lateral resection margin involvement or piecemeal resection as the only non-curative factor). Using these predictors, a risk-scoring system for predicting NC-ESD-RG was developed. Performance of the predictive model was examined internally with the validation set.

Results

Rate of NC-ESD-RG was 17.3%. Independent pre-ESD predictors for NC-ESD-RG included moderately differentiated or papillary EGC, large tumor size, proximal tumor location, lesion at greater curvature, elevated or depressed morphology, and presence of ulcers. A risk-score was assigned to each predictor of NC-ESD-RG. The area under the receiver operating characteristic curve for predicting NC-ESD-RG was 0.672 in both training and validation sets. A risk-score of 5 points was the optimal cut-off value for predicting NC-ESD-RG, and the overall accuracy was 72.7%. As the total risk score increased, the predicted risk for NC-ESD-RG increased from 3.8% to 72.6%.

Conclusions

We developed and validated a risk-scoring system for predicting NC-ESD-RG based on pre-ESD variables. Our risk-scoring system can facilitate informed consent and decision-making for preoperative treatment selection between ESD and surgery in patients with EGC.

Histopathological validation of magnifying endoscopy for diagnosis of mixed-histological-type early gastric cancer

BACKGROUND

The undifferentiated-type (UDT) component profoundly affects the clinical course of early gastric cancers (EGCs). However, an accurate preoperative diagnosis of the histological types is unsatisfactory. To date, few studies have investigated whether the UDT component within mixed-histological-type (MT) EGCs can be recognized preoperatively.

AIM

To clarify the histopathological characteristics of the endoscopically-resected MT EGCs for investigating whether the UDT component could be recognized preoperatively.

METHODS

This was a single-center retrospective study. First, we attempted to clarify the histopathological characteristics of the endoscopically-resected MT EGCs with emphasis on the UDT component. Histopathological examination investigated each lesion’s UDT component: (1) Whole mucosal layer occupation of the UDT component; (2) UDT component exposure to the surface of the mucosa; and (3) existence of a clear border between the differentiated-type and UDT components. Then, preoperative endoscopic images with magnifying endoscopy with narrow-band imaging (ME-NBI) were examined to identify whether the endoscopic UDT component finding was recognizable within the area where it was present in the histopathological examination. The preoperative biopsy results and comparative relationships between endoscopic and histopathological findings were also examined.

RESULTS

In the histopathological examination, the whole mucosal layer occupation of the UDT component and exposure of the UDT component to the mucosal surface were observed in 67.3% (33/49) and 79.6% (39/49) of samples, respectively. A clear distinction of the border between the differentiated-type and UDT components could not be drawn in 65.3% (32/49) of MT lesions. In the endoscopic examination, the preoperative endoscopic images showed that only 24.5% (12/49) of MT EGCs revealed the UDT component within the area where it was present histopathologically. Histopathological UDT predominance was the single significant factor associated with the presence of the endoscopic UDT component finding (61.5% vs 11.1%, P = 0.0009). Only 26.5% (13/49) of the lesions were diagnosed from the pretreatment biopsy as having a UDT component. Combined results of the pretreatment biopsy and ME-NBI showed the preoperative presence of the UDT component in 40.8% (20/49) of MT EGCs.

CONCLUSION

Recognition of a UDT component within MT EGCs is difficult even when pretreatment biopsy and ME-NBI are combined. Endoscopic resection plays a significant role in both treatment and diagnosis.

Undifferentiated-type predominant mixed-type early gastric cancer is a significant risk factor for requiring additional surgeries after endoscopic submucosal dissection

We aimed to clarify the differences in therapeutic outcomes of patients with pure undifferentiated-type and mixed undifferentiated-type cancers who underwent endoscopic submucosal dissection (ESD), and whether pre-treatment diagnosis of mixed undifferentiated-type cancer is associated with requiring additional surgery after ESD. Patients subjected to ESD as initial treatment between May 2005 and March 2017 were enrolled. There were 277 undifferentiated-type cancers (265 patients). Histologically, 258 lesions were pure-type and 19 were mixed-type. We compared therapeutic outcomes and pre-treatment factors (tumour diameter, tumour depth, ulcerative findings, tumour location, and the macroscopic, and histological type of the biopsy specimen) between pure-type and mixed-type lesions, and between cases not requiring additional surgeries and cases requiring additional surgeries. Tumour diameter >20 mm, submucosal invasion, and the presence of ulcerative findings made pre-treatment diagnosis more difficult for mixed-type than for pure-type lesions. In cases requiring additional surgery, pre-treatment diagnosis of mixed-type lesions was significantly more likely than pre-treatment diagnosis of pure-type lesions. For mixed-type lesions, pre-treatment histological diagnosis and careful consideration are necessary to determine indications for ESD to avoid additional surgery after ESD.

Poorly differentiated is more significant than signet ring cell component for lymph node metastasis in mixed-type early gastric cancer: a retrospective study from a large-volume hospital

Objective

The purpose of this study was to explore the role of different undifferentiated components in the lymph node metastasis (LNM) of early mixed gastric cancer.

Methods

A total of 1596 patients with EGC who underwent gastrectomy were divided into four types: pure differentiated (PD), pure poorly differentiated (Poorly D), pure signet ring cell carcinoma (SRC), and mixed. Mixed type was classified into four subtypes: differentiated-predominant type mixed with poorly differentiated component (MD-P), poorly differentiated-predominant type mixed with differentiated component (MP-D), differentiated-predominant type mixed with SRC component (MD-S), and poorly differentiated-predominant type mixed with SRC component (MP-S). We analyzed the clinicopathological differences between all types and the rates of LNM of patients fulfilling endoscopic submucosal dissection (ESD) criteria.

Results

LNM was more common in mixed (21.9%) than in PD (7.5%, P < 0.001) or SRC (11.3%, P < 0.001). When analyzed the subgroups of mixed type, LNM was more frequent in MD-P (15.4%) than in PD (7.5%, P = 0.003). LNM in MD-S (7.4%, P = 1.000) was not higher than in PD. MP-S (24.5%) showed a higher rate of LNM than SRC (11.3%, P < 0.001) rather than Poorly-D (22.7%, P = 0.681). For lesions satisfying ESD criteria, MD-S (0%, P = 1.000), and MD-P (5.9%, P = 0.12) did not have higher rates of LNM than PD (1.4%).

Conclusion

The presence of poorly differentiated component but not SRC increases the LNM rate of mixed type. ESD is recommended for the treatment of MD-S and MD-P consistent with ESD criteria.

Favorable Long-Term Outcomes of Endoscopic Submucosal Dissection for Differentiated-Type-Predominant Early Gastric Cancer with Histological Heterogeneity

It remains unclear whether endoscopic submucosal dissection (ESD) can be indicated for differentiated-type-predominant early gastric cancer mixed with a minor undifferentiated component (EGC with histological heterogeneity (HH)). Here, we reviewed and compared clinicopathologic characteristics and long-term outcomes of ESD of 257 patients with EGC-HH and those of 2386 patients with pure differentiated-type EGC (PuD-EGC). After ESD, EGC-HH was managed in the same way as PuD-EGC. EGC-HHs were significantly associated with larger tumor size, more frequent submucosal invasion, and lymphovascular invasion compared to PuD-EGCs. Despite these aggressive features of EGC-HH, no local recurrence or gastric cancer-related death occurred during a median of 58 months of follow up after ESD for EGC-HH, if curative resection was achieved. After curative ESD for EGC-HH, six patients had metachronous recurrence (5.0%) and one patient underwent extragastric recurrence in a regional lymph node (0.8%). All these recurrence cases were curatively treated with ESD or gastrectomy. For patients with EGC-HH, five-year overall survival and recurrence-free survival rates after curative ESD were 97.0% and 94.8%, respectively, which were comparable to those of patients with PuD-EGC. In conclusion, ESD showed favorable long-term outcomes after curative resection and may be an acceptable treatment option for EGC-HH meeting curative endoscopic resection criteria.

Lesion-Based Convolutional Neural Network in Diagnosis of Early Gastric Cancer

Diagnosis and evaluation of early gastric cancer (EGC) using endoscopic images is significantly important; however, it has some limitations. In several studies, the application of convolutional neural network (CNN) greatly enhanced the effectiveness of endoscopy. To maximize clinical usefulness, it is important to determine the optimal method of applying CNN for each organ and disease. Lesion�-based CNN is a type of deep learning model designed to learn the entire lesion from endoscopic images. This review describes the application of lesion-based CNN technology in diagnosis of EGC.

Feasibility of further expansion of the indications for endoscopic submucosal dissection in undifferentiated-type early gastric cancer

BACKGROUND

Based on Japanese guidelines for endoscopic submucosal dissection (ESD) in undifferentiated-type early gastric cancer (UD-EGC), UD-predominant mixed-type (M-UD) EGC is considered high risk for lymph node metastasis (LNM). However, differences in LNM risk between pure UD (P-UD) and M-UD remain unclear. This study assessed risk factors for LNM considering differences between P-UD and M-UD and identified pathological features related to the lowest LNM risk.

METHODS

This single-center, retrospective study included 1425 patients with UD-EGC treated with surgical resection between April 2005 and May 2017. We divided patients into those with and without LNM and compared background characteristics and post-operative pathological results between groups. Patients were further stratified based on depth, tumor diameter, ulcerative findings, lymphatic invasion, vascular invasion, and histological type to clarify post-operative pathological features associated with the lowest LNM risk.

RESULTS

When comparing background characteristics and post-operative pathological results, multivariate analysis showed that, in patients with LNM, tumor diameters were significantly larger, and there were higher rates of submucosal invasion, lymphatic invasion, and M-UD histological type. In patients with absence of ulcerative findings, absence of lymphatic invasion, and absence of vascular invasion, no LNM occurred among those with intramucosal P-UD tumor diameters of 1-40 mm (1-20 mm: 95% confidence interval [CI], 0-5.5%; 21-40 mm: 95% CI, 0-6.1%).

CONCLUSIONS

Intramucosal P-UD EGC patients with absence of ulcerative findings, absence of lymphatic invasion, absence of vascular invasion, and tumor diameters of ≤ 40 mm did not show LNM. We suggest expanding indications for ESD to include these patients.

Outcomes of endoscopic submucosal dissection for intestinal-type adenocarcinoma with anastomosing glands of the stomach

BACKGROUND AND AIM

Gastric intestinal-type adenocarcinoma with anastomosing glands (IAAG) is characterized by architectural abnormality with frequent anastomosing glands and low-grade cytologic atypia. Clinicopathologic features and long-term outcomes of endoscopic submucosal dissection (ESD) for IAAG remain unclear.

METHODS

This study included 2828 patients who underwent ESD for early gastric cancers (EGCs) (78 IAAGs [2.6%] and 2893 well-differentiated [WD] or moderately differentiated [MD] EGCs [97.4%]). Clinicopathologic features and short-term and long-term outcomes of ESD for IAAG were reviewed and compared with those for WD or MD EGCs.

RESULTS

Gastric IAAGs were larger and more likely to be confined to the lamina propria than WD or MD EGCs. Histological heterogeneity, flat or depressed lesion and lateral resection margin (LRM) involvement were observed with significantly higher frequencies in IAAGs than in WD or MD EGCs. En bloc with R0 resection and curative resection rates of IAAGs were 79.5% and 73.1%, respectively, and both were significantly lower than those of WD or MD EGCs (93.8% and 82.9%). LRM involvement accounted for 57.1% of the non-curative resection cases in gastric IAAGs. Half of IAAGs with LRM involvement had a crawling pattern at tumor periphery. Among patients undergoing curative ESD for IAAG, no recurrences occurred during a median 52 months of follow-up. No lymph node metastasis was found in any of IAAG patients undergoing additional surgery after ESD.

CONCLUSIONS

Gastric IAAGs have distinct clinicopathologic features from WD or MD EGCs. Given the favorable long-term outcomes after curative resection, ESD can be indicated for early gastric IAAGs.

Endoscopic Submucosal Dissection of Early Gastric Cancer with Mixed-Type Histology: A Systematic Review

BACKGROUND

Endoscopic submucosal dissection (ESD) criteria are histologically categorized by early gastric cancer (EGC) with differentiated- and undifferentiated-type histology. However, EGC is histologically heterogenous and there have been no separate criteria for EGC with mixed-type histology [EGC-MH; differentiated-type predominant EGC mixed with an undifferentiated component (EGC-MD) or undifferentiated-type predominant EGC mixed with a differentiated component (EGC-MU)]. Moreover, therapeutic outcomes of ESD for EGC-MH have not been clearly described.

AIM

This study aimed to evaluate the feasibility of ESD for EGC-MH.

METHODS

We searched core databases for specific inclusion factors: patients with EGC-MH, intervention of ESD, and at least one of the following outcomes: rate of en bloc, complete, curative resection, recurrence, procedure-related adverse event, lymphovascular invasion (LVI), or lymph node metastasis (LNM) that enabled evaluation of feasibility of ESD.

RESULTS

A total of eight (systematic review) and four studies (meta-analysis) were included. There was no robustness in age, location, or morphology of EGC-MH. Moderately differentiated adenocarcinoma was frequent in pre-ESD biopsy. EGC-MH showed larger size, deeper invasion, and higher rates of LVI/LNM than pure-type EGC. Total en bloc, complete resection, and curative resection rates were 94.6% (95% confidence interval 86.6-97.9%), 77.8% (57.9-89.9%), and 55.1% (50.4-59.6%), respectively. There was no LNM or extra-gastric recurrence after ESD if the EGC-MD met the curative resection criteria. However, the EGC-MD itself was a risk factor for non-curative resection. (Margin positivity was the most common reason.) CONCLUSIONS: Although ESD seems to be technically feasible, inaccurate prediction of lateral or vertical margin leads to lower curative resection rate. Application of more strict indication is needed for EGC-MH.

Endoscopic management of patients with early gastric cancer before and after endoscopic resection: A review

With the wide application of endoscopic resection for early gastric cancer (EGC) by not only Asian endoscopists but also those from Western countries, reviews on standardized treatment processes before and after endoscopic resection are nevertheless lacking. In this article we provide a narrative review of studies on the selection of appropriate EGC for endoscopic resection and the follow-up strategies for those with histologically confirmed EGC after endoscopic resection. EGC should be comprehensively assessed before endoscopic resection, including its exact margin, invasive depth and risk of lymph node metastasis (LNM). While the curative resection status of EGC may be evaluated after endoscopic resection based on the newly developed eCura system, although this needs to be further verified. Surveillance with endoscopy and computed tomography scan is necessary for patients with an EGC level A or B. An additional endoscopic resection is recommended for patients with a level-C1 EGC. For patients with a level-C2 EGC, close follow-up is suggested for low-risk tumors of level C2 and additional surgery for those at high risks. Further postoperative strategy is suggested based on comprehensive assessment of the risk of LNM, patient's quality of life and wishes.

The Role of an Undifferentiated Component in Submucosal Invasion and Submucosal Invasion Depth After Endoscopic Submucosal Dissection for Early Gastric Cancer

BACKGROUND/AIMS

The role of an undifferentiated component in submucosal invasion and submucosal invasion depth (SID) for lymph node metastasis (LNM) of early gastric cancer (EGC) with deep submucosal invasion (SID ≥500 μm from the muscularis mucosa) after endoscopic submucosal dissection (ESD) has not been fully understood. This study aimed to clarify the risk factors (RFs), including these factors, for LNM in such patients.

METHODS

We enrolled 513 patients who underwent radical surgery after ESD for EGC with deep submucosal invasion. We evaluated RFs for LNM, including an undifferentiated component in submucosal invasion and the SID, which was subdivided into 500-999, 1,000-1,499, 1,500-1,999, and ≥2,000 µm.

RESULTS

LNM was detected in 7.6% of patients. Multivariate analysis revealed that an undifferentiated component in submucosal invasion (OR 2.22), in addition to tumor size >30 mm (OR 2.51) and lymphatic invasion (OR 3.07), were the independent RFs for LNM. However, the SID was not significantly associated with LNM.

CONCLUSION

An undifferentiated component in submucosal invasion was one of the RFs for LNM, in contrast to SID, in patients who underwent ESD for EGC with deep submucosal invasion. This insight would be helpful in managing such patients.

Risk Factors for Lymph Node Metastasis in Undifferentiated-Type Gastric Carcinoma

Undifferentiated-type carcinoma has a high incidence of lymph node metastasis. The independent risk factors for lymph node metastasis in undifferentiated-type carcinoma are invasion depth, tumor size, lymphovascular invasion, and presence of ulcer. In the cases that meet the curative resection criteria, no lymph node metastasis was observed in the Japanese studies, but some metastases were observed in Korean studies. After performing curative endoscopic submucosal dissection, the survival rate is similar to that of gastrectomy. The discrepancy between endoscopy and pathology is high in undifferentiated-type carcinoma. The tumor size in endoscopy is a significant risk factor for non-curative resection, and when the tumor size is small, the non-curative resection rate is significantly reduced. Lymphovascular invasion can be assessed in pathologic examination and D2-40 stain is helpful. The presence of ulcer should be determined by pathology, but ulcer's omission in pathology report makes the analysis difficult. Undifferentiatedtype carcinomas with differentiated-type components show higher lymph node metastasis rate than that of pure undifferentiatedtype carcinomas. The lymph node metastasis rate of signet ring cell type is lower than that of other undifferentiated-type carcinomas and is similar to differentiated-type carcinomas. The application of these additional histologic findings may improve the indication of endoscopic submucosal dissection.

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

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

Consensus on the pathological definition and classification of poorly cohesive gastric carcinoma

BACKGROUND AND AIMS

Clinicopathological characteristics of gastric cancer (GC) are changing, especially in the West with a decreasing incidence of distal, intestinal-type tumours and the corresponding increasing proportion of tumours with Laurén diffuse or WHO poorly cohesive (PC) including signet ring cell (SRC) histology. To accurately assess the behaviour and the prognosis of these GC subtypes, the standardization of pathological definitions is needed.

METHODS

A multidisciplinary expert team belonging to the European Chapter of International Gastric Cancer Association (IGCA) identified 11 topics on pathological classifications used for PC and SRC GC. The topics were debated during a dedicated Workshop held in Verona in March 2017. Then, through a Delphi method, consensus statements for each topic were elaborated.

RESULTS

A consensus was reached on the need to classify gastric carcinoma according to the most recent edition of the WHO classification which is currently WHO 2010. Moreover, to standardize the definition of SRC carcinomas, the proposal that only WHO PC carcinomas with more than 90% poorly cohesive cells having signet ring cell morphology have to be classified as SRC carcinomas was made. All other PC non-SRC types have to be further subdivided into PC carcinomas with SRC component (< 90% but > 10% SRCs) and PC carcinomas not otherwise specified (< 10% SRCs).

CONCLUSION

The reported statements clarify some debated topics on pathological classifications used for PC and SRC GC. As such, this consensus classification would allow the generation of evidence on biological and prognostic differences between these GC subtypes.

The incidence of lymph node metastasis in submucosal early gastric cancer according to the expanded criteria: a systematic review

BACKGROUND

For successful endoscopic treatment of early gastric cancer (EGC), absolute criteria for a curative en bloc resection were initially established to include predominantly differentiated mucosal lesions ≤ 2 cm in diameter without ulceration. These indications were subsequently expanded to include larger, ulcerated, and predominantly undifferentiated mucosal lesions. In addition, differentiated type adenocarcinomas ≤ 3 cm with slight submucosal invasion of < 500 µm (pT1b1) are regarded as "curative" under the expanded criteria. However, data derived from studies of surgical specimens in patients with pT1b1 EGC have yielded varying rates of lymph node metastasis (LNM).

METHOD

A systemic review was conducted using the pooled analysis to calculate the incidence of LNM in pT1b1 EGC, and to investigate whether using a cut-off value of < 300 µm would decrease the risk of LNM in patients with submucosal EGC.

RESULTS

Nineteen articles were included. 1507 patients with pT1b1 EGC met the expanded indications. The incidence of LNM was 3% (45 out of 1507 patients). In a subgroup analysis of three studies, there was no significant difference in the LNM between pT1b EGC < 300 µm and < 500 µm [3/121(2.5%) vs. 5/180 (2.8%)] (OR 0.89, 95% CI 0.22-3.54).

CONCLUSION

Overall, expanding the indications for endoscopic resection of EGC to include lesions ≤ 3 cm T1b1 is associated with a potential risk of LNM of 3%. In countries outside of Japan, we found a slightly higher risk of LNM (4.0%). These estimates of LNM should be incorporated into decisions regarding further management of patients with EGC ≤ 3 cm who are found to have slight submucosal invasion (< 500 µm) in an ESD specimen. Standardization of specimen handling and histological evaluation is essential if the Japanese results of endoscopic treatment for EGC are to be successfully applied in other parts of the world.

Evaluation of Gastric Carcinomas Histological Patterns in Relation to Tumors Aggressiveness Parameters

Gastric carcinomas are frequent tumors with variable growth patterns that may interfere with the evaluation of histopathological prognostic parameters of the lesions. In this study we analyzed the incidence and statistical relation of histological growth patterns depending on the prognostic parameters of gastric carcinomas for 95 cases. Pure forms were present in 82.2% of cases, from which more frequent subtypes were low grade tubular carcinomas and poorly cohesive with signet-ring cells carcinomas. Mixed forms were present in 17.8% of cases, with the highest incidence of tumors containing well differentiated tubular carcinoma and poorly differentiated papillary carcinoma areas. Analysis of the identified types and subtypes in relation to the histological prognostic parameters indicated significant differences regarding the tumor stage, the mixed subtypes being more frequent in advanced stages. Although mixed subtypes were more commonly associated with vascular and perineural invasion, the aspects were statistically insignificant. Together with tumor stage, the lymphovascular and/or perineural invasion should be taken into consideration as prognostic indicators in the postoperative management of gastric cancer.

Mixed Histology Is a Risk Factor for Lymph Node Metastasis in Early Gastric Cancer

BACKGROUND

The risk factors of lymph node (LN) metastasis are important factors to consider in endoscopic submucosal dissection in early gastric cancer (EGC). The aim of the study was to identify the correlation between mixed histology and LN metastasis in EGC.

METHODS

A total of 1645 patients who underwent curative radical gastrectomy for EGC were divided into three groups (pure differentiated [pure D], mixed, and pure undifferentiated [pure UD]) according to histologic type. They were subsequently analyzed retrospectively for LN metastasis. The patients who had mixed histology between differentiated and undifferentiated tubular adenocarcinoma were defined as mixed group.

RESULTS

The pure UD group was significantly younger than the other groups. Tumor size was larger in the mixed group. LN metastasis occurred more frequently in the mixed group and the pure UD group than in the pure D group (pure D, mixed, and pure UD, 7.7%, 23.2%, and 10.8%, respectively; P < 0.001). A logistic regression analysis revealed that the independent risk factors for LN metastasis were large tumor size (odd ratio [OR], 1.308), submucosal invasion (OR, 3.565), lymphovascular invasion (OR, 9.755), and histologic types of mixed (OR, 2.360) and pure UD (OR, 1.657).

CONCLUSIONS

Mixed histology is an important risk factor for LN metastasis in EGC. Thus, radical gastrectomy should be considered in the cases of mixed-type histology after endoscopic resection.

A Rare Case of Lymph Node Metastasis from Early Gastric Cancer

Gastric cancers that fulfill the Japanese criteria for curative endoscopic resection show a low risk of lymph node (LN) metastasis. Here, we report a case of LN metastasis from early gastric cancer that fulfilled the curative criteria. A 74-year-old Japanese woman was referred to our hospital for treatment of early gastric cancer identified at the site of a hyperplastic polyp that had been diagnosed 10 years prior to presentation. Contrast-enhanced computed tomography did not show any lymphadenopathy and laparoscopy-assisted distal gastrectomy was performed. Histopathological examination revealed a predominantly moderately differentiated adenocarcinoma that measured 15 mm in size and was confined to the mucosa. However, a single metastatic regional LN was observed. A few cancer cells showed positive staining for alpha-fetoprotein. It should be noted that early gastric cancer can be accompanied by LN metastasis even if it fulfills the criteria for curative endoscopic resection.

Low risk of lymph node metastasis in 495 early gastric cardiac carcinomas: a multicenter clinicopathologic study of 2101 radical gastrectomies for early gastric carcinoma

Clinical decision-making on endoscopic vs. surgical resection of early gastric cardiac carcinoma remains challenging because of uncertainty on risk of lymph node metastasis. The aim of this multicenter study was to investigate risk factors of lymph node metastasis in early gastric cardiac carcinoma. Guided with the World Health Organization diagnostic criteria, we studied 2101 radical resections of early gastric carcinoma for risk factors associated with lymph node metastasis, including tumor location, gross pattern, size, histology type, differentiation, invasion depth, lymphovascular, and perineural invasion. We found that the risk of lymph node metastasis was significantly lower in early gastric cardiac carcinomas (6.7%, 33/495), compared with early gastric non-cardiac carcinomas (17.1%, 275/1606) (p < 0.0001). In early gastric cardiac carcinoma, no lymph node metastasis was identified in intramucosal carcinoma (0/193) and uncommon types of carcinomas (0/24), irrespective of the gross pattern, size, histologic type, differentiation, and invasion depth. Ulceration, size > 3 cm, and submucosal invasion were not significant independent risk factors for lymph node metastasis. In 33 early gastric cardiac carcinomas with lymph node metastasis, either lymphovascular invasion or poor differentiation was present in 16 (48.5%) cases and together in six cases. By multivariate analysis, independent risk factors of lymph node metastasis in early gastric cardiac carcinoma included lymphovascular invasion (Odds Ratio (OR): 7.6, 95% Confidence Interval (CI): 2.8-20.2) (p < 0.0001) and poor differentiation (OR: 6.0, 95% CI: 1.4-25.9) (p < 0.05). In conclusion, lymph node metastasis was not identified in early gastric cardiac intramucosal carcinoma and uncommon types of carcinoma. The risk of lymph node metastasis was also significantly lower in tumors with submucosal invasion, especially for cases without lymphovascular invasion or poor differentiation. These results lend support to the role of endoscopic therapy in the treatment of patients with early gastric cardiac carcinoma.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Endoscopic submucosal dissection for papillary adenocarcinoma of the stomach: is it really safe?

BACKGROUND

Papillary adenocarcinoma of the stomach has been treated according to the same endoscopic submucosal dissection (ESD) indication criteria as other differentiated-type adenocarcinomas. We aimed to compare lymph node metastasis (LNM) in patients with early gastric cancer (EGC) with papillary adenocarcinoma (EGC-P) with that in patients with EGC with nonpapillary adenocarcinoma (EGC-NP) and to consider the potential limitation of current ESD indication criteria in the treatment of EGC-P.

METHODS

In total, 1583 patients who underwent gastrectomy for EGC from 2005 to 2014 were included. Clinicopathologic characteristics of 56 patients with EGC-P were compared with those of 1527 patients with EGC-NP. The safety of ESD was evaluated, by application of current ESD indication criteria to EGC-P.

RESULTS

The frequency of submucosal invasion was significantly higher in EGC-P than in both EGC-NP with differentiated-type histologic appearance and EGC-NP with undifferentiated-type histologic appearance (71.4% vs 50.8% and 37.6%, respectively). In addition, the frequency of LNM in EGC-P was 17.9%, higher than that in both EGC-NP with differentiated-type histologic appearance and EGC-NP with undifferentiated-type histologic appearance (9.7% and 11.1%, respectively). When the current ESD indication criteria were applied to the 56 patients with EGC-P, 17 patients met the current indications. Of these patients, two (11.8%) had LNM and three (17.6%) had lymphovascular invasion (LVI). When LNM and LVI were combined, one of seven patients (16.7%) meeting the absolute ESD indications and three of ten patients (30.0%) meeting the expanded ESD indications would not be cured after ESD.

CONCLUSIONS

The use of ESD should be more carefully applied in patients with EGC-P meeting the ESD indication criteria, especially the expanded indication criteria, after pretreatment workup compared with other differentiated-type adenocarcinomas, owing to the higher frequencies of submucosal invasion, LNM, and LVI in EGC-P.

Predictive factors to diagnosis undifferentiated early gastric cancer after endoscopic submucosal dissection

It is difficult to predict precisely whether the lesion corresponds to endoscopic resection indication. Furthermore, discrepancy may occur between endoscopic forceps biopsy (EFB) and finally resected specimen, which may be diagnosed as undifferentiated cancer and additional surgery may be required. Our study aimed to evaluate predictive factors to diagnose undifferentiated cancer after endoscopic submucosal dissection (ESD).Among the 532 patients diagnosed by ESD between January 2009 and December 2015, 557 early gastric cancer (EGC) cases were studied. Factors predicting diagnosis of undifferentiated cancer and clinical outcomes of the lesions were retrospectively analyzed.Among the 557 cases with EGC, 535 (96.1%) were diagnosed as differentiated cancer and 22 (3.9%) as the undifferentiated type with ESD. Tumor size was larger (mean size 20.67 vs 13.59 mm, P < .001) and age was lower (60.24 vs 64.50 years, P < .001) in the group with undifferentiated cancer. En bloc resection rate was similar (95.5% vs 95.9%, P = .886), but the complete resection rate was lower (72.7% vs 92.4%, P < .001) in the group with undifferentiated cancer. On multivariate analysis, tumor size ≥10 mm (OR = 11.340, P = .032), age <55 years (OR = 5.972, P = .004), surface redness (OR = 11.562, P = .024), and whitish discoloration (OR = 35.368, P < .001) were predominantly associated with undifferentiated cancer.Young age (<55 years), large tumor size (≥10 mm), surface redness, and whitish discoloration are predictors of undifferentiated cancer, and lesions with these features detected need to be treated cautiously.

Does the discrepancy in histologic differentiation between a forceps biopsy and an endoscopic specimen necessitate additional surgery in early gastric cancer?

AIM

To investigate the clinicopathological variables in early gastric cancer (EGC) patients in relation to differentiation discrepancy.

METHODS

The data of 265 specimens from 240 patients with EGC, who had undergone radical operation at Hallym University Sacred Heart Hospital from 2010 to 2015, were retrospectively analyzed. We evaluated clinical, endoscopic, and histopathological data according to histological discrepancy.

RESULTS

Clinically significant discrepancy rate showed the difference in differentiated type (well and moderately differentiated) and undifferentiated type (poorly differentiated and signet ring cell) between endoscopic biopsies and postoperative specimens was 9.4% (25/265). There were no differences in tumor location, size, gross pattern, and number of biopsies. Specimens having histological discrepancy showed more submucosal invasion (72.0% vs 49.6%, P = 0.033) and lymph node involvement (24.0% vs 7.9%, P = 0.009) than specimens having non-discrepancy. The rate of a positive epidermal growth factor receptor status was higher in specimens having discrepancy than in specimens having non-discrepancy (81.0% vs 55.4%, P = 0.035).

CONCLUSION

The discordance of histologic differentiation is associated with higher submucosal invasion and lymph node metastases in EGC. Patients have histological discrepancy may require additional surgical treatments.

Signet ring cell carcinoma of early gastric cancer, is endoscopic treatment really risky?

Signet ring cell carcinoma (SRC) is a poorly differentiated cancer of the stomach. Generally, poorly differentiated cancer is believed to show poor prognosis and aggressive behavior. Recently, however, there is debate on the aggressiveness of SRC in early gastric cancer (EGC). We therefore studied postoperation biopsies to investigate the aggressiveness of SRC in EGC.We reviewed medical records of patients with EGC who had surgery from January 2011 to December 2015 in a tertiary hospital in Daejeon, South Korea. We evaluated the histologic type, invasion depth, lymphovascular invasion (LVI), and lymph node (LN) metastasis.A total of 822 EGC lesions from 789 patients were studied. Approximately 498 differentiated cancer, 65 poorly differentiated cancer, 91 SRC, 26 poorly differentiated with SRC, 41 mixed type, 10 medullary carcinoma, and 91 poorly cohesive carcinoma other than SRC were included. LN metastasis was associated with the histologic type of EGC (P = .000). Nine percent of differentiated cancer, 21.5% of poorly differentiated cancer, 5.5% of SRC, 11.5% of poor differentiation with SRC, 26.8% of mixed type, 20% of medullary type, and 15.4% of poorly cohesive carcinoma other than SRC showed LN metastasis. The risk of SRC was not higher than well to moderated differentiated cancer (odds ratio [OR] = 0.842, P = .768). Risk of LVI was also similar with LN metastasis. Compared with differentiated cancer, OR of SRC was 1.969 (P = .172).Our results show that SRC is not more aggressive than differentiated cancer. SRC may be considered a candidate for endoscopic treatment.

Expansion of lymph node metastasis in mixed-type submucosal invasive gastric cancer

BACKGROUND/OBJECTIVE

Mixed-type early gastric cancer (differentiated and undifferentiated components) incurs a higher risk of lymph node metastasis than pure-type early gastric cancer (only differentiated or only undifferentiated components). Therefore, we investigated the expansion of lymph node metastasis in mixed-type submucosal invasive gastric cancer in order to establish the most appropriate treatment for mixed-type cancer.

METHODS

We retrospectively analyzed 279 consecutive patients with submucosal invasive gastric cancer who underwent curative gastrectomy for gastric cancer between 1996 and 2015. We classified the patients into the mixed-type and pure-type groups according to histologic examination and evaluated the expansion of lymph node metastasis.

RESULTS

The rate of lymph node metastasis was 23.7% (66/279) in the total patients, 36.4% (36/99) in the mixed-type group, and 16.6% (30/180) in the pure-type group. The significant independent risk factors for lymph node metastasis were tumor size ≥2.0 cm (P = 0.014), mixed-type gastric cancer (P < 0.001), and lymphatic invasion (P < 0.001). Lymphatic invasion and lymph node metastasis had a strong relationship in mixed-type group. The rates of no. 7 lymph node metastasis in the total patients and mixed-type group were 2.9% (8/279) and 5.1% (5/99), respectively; the rates of no. 8a lymph node metastasis were 1.4% (4/279) and 4.0% (4/99), respectively.

CONCLUSION

Mixed histological type is an independent risk factor for lymph node metastasis. Lymph node metastasis in mixed-type gastric cancer involves expansion to the no. 7 and no. 8a lymph nodes. Therefore, lymphadenectomy for mixed-type submucosal invasive gastric cancer requires D1+ or D2 dissection.

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.

Long-term oncological outcomes of submucosal manipulation during non-curative endoscopic submucosal dissection for submucosal invasive gastric cancer: a multicenter retrospective study in Japan

BACKGROUND

Sufficient information is not available on the extent to which lymph node metastasis (LNM) and prognosis are affected by submucosal manipulation during endoscopic submucosal dissection (ESD) for submucosal invasive gastric cancer (SMGC). We aimed to identify the effects of submucosal manipulation during ESD on LNM and prognosis in patients with SMGC.

METHODS

From 19 institutions in Japan, 2526 patients who failed to meet the current curative criteria for ESD between 2000 and 2011 were recruited. After exclusion, 1969 patients were remained. Based on the treatment strategy after ESD, 1064 patients underwent additional radical surgery. A total of 890 of 1064 patients with SMGC, LNM and cancer recurrence, and prognosis were retrospectively reviewed.

RESULTS

The median follow-up duration was 67 months. A total of 214 patients had SM1 (depth of tumor invasion from the muscularis mucosae <500 μm) invasive cancer and 676 patients had SM2 (depth of tumor invasion from the muscularis mucosae ≥500 μm) invasive cancer. LNM was found in 84 patients (9.4%), and 14 patients (1.6%) developed cancer recurrence. The 3-year and 5-year overall survival rates were 96.1 and 91.7%, respectively. The 3-year and 5-year disease-specific survival rates were 99.3 and 98.5%, respectively.

CONCLUSIONS

The rates of LNM and cancer recurrence, and prognosis of patients who underwent additional radical surgery after non-curative ESD for SMGC were excellent. Submucosal manipulation during ESD for SMGC does not seem to enhance the risk for LNM or worsen the prognosis compared to surgical series.

A Scoring System to Stratify Curability after Endoscopic Submucosal Dissection for Early Gastric Cancer: "eCura system"

OBJECTIVES

Although radical surgery is recommended for patients not meeting the curative criteria for endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) because of the potential risk of lymph node metastasis (LNM), this recommendation may be overestimated and excessive. We aimed to establish a simple scoring system for decision making after ESD.

METHODS

This multicenter retrospective study consisted of two stages. First, the risk-scoring system for LNM was developed using multivariate logistic regression analysis in 1,101 patients who underwent radical surgery after having failed to meet the curative criteria for ESD of EGC. Next, the system was internally validated by survival analysis in another 905 patients who also did not meet the criteria and did not receive additional treatment after ESD.

RESULTS

In the development stage, based on accordant regression coefficients, five risk factors for LNM were weighted with point values: three points for lymphatic invasion and 1 point each for tumor size >30 mm, positive vertical margin, venous invasion, and submucosal invasion ≥500 μm. Then, the patients were categorized into three LNM risk groups: low (0-1 point: 2.5% risk), intermediate (2-4 points: 6.7%), and high (5-7 points: 22.7%). In the validation stage, cancer-specific survival differed significantly among these groups (99.6, 96.0, and 90.1%, respectively, at 5 years; P<0.001). The C statistic of the system for cancer-specific mortality was 0.78.

CONCLUSIONS

This scoring system predicted cancer-specific survival in patients who did not meet the curative criteria after ESD for EGC. ESD without additional treatment may be an acceptable option for patients at low risk.

Early gastric cancer with a mixed-type Lauren classification is more aggressive and exhibits greater lymph node metastasis

BACKGROUND

The clinicopathological features of mixed-type (MT) early gastric cancer (EGC) according to Lauren's classification remain uninvestigated. This study aimed to clarify the clinicopathological features of MT EGC, particularly in relation to lymph node metastasis (LNM) and long-term survival.

METHODS

This study included 5309 patients who underwent gastrectomy for EGC. The clinicopathological features, LNM, and long-term outcomes of patients with MT carcinomas were compared with those of patients with intestinal-type (IT) and diffuse-type (DT) cancers. Furthermore, we evaluated the predictors of LNM in each Lauren classification subgroup.

RESULTS

Patients with MT carcinomas were likelier to have larger tumors, submucosal invasion, lymphovascular invasion, and LNM than those with IT or DT carcinomas. Multivariate logistic regression analysis revealed that the Lauren classification was a significant predictor of LNM (P < 0.001). The significant predictors of LNM in MT carcinomas were female sex, greater tumor size, presence of submucosal invasion, and lymphovascular invasion. However, the overall survival of patients with MT carcinoma was not significantly different from that of patients with IT or DT carcinomas (P = 0.104).

CONCLUSIONS

The presence of MT EGC carries a higher risk of LNM compared with the presence of IT or DT carcinomas. Therefore, MT carcinomas should be managed with gastrectomy that includes lymph node dissection instead of endoscopic resection.

Long-term outcomes of endoscopic submucosal dissection for early gastric cancer: a multicenter collaborative study

OBJECTIVE

The indications for endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC) have been expanded. However, the long-term outcomes of ESD remain unclear. We retrospectively investigated the long-term outcomes of ESD in patients with EGC.

METHODS

We retrospectively studied patients with EGC who underwent ESD at 11 institutions between January 2003 and December 2010. A total of 6456 patients (7979 lesions) who met the absolute indications for ESD and 4202 patients (5781 lesions) who met the expanded indications for ESD were studied. Clinicopathological features, clinical course, and outcomes were studied in 67 patients in whom local recurrence or metastatic recurrence was diagnosed as of March 31, 2014. The median follow-up period was 56 months.

RESULTS

Local recurrence was diagnosed in 14 patients (0.22%) who met the absolute indications and 53 patients (1.26%) who met the expanded indications. The rate of local recurrence was significantly higher in patients with expanded-indication lesions (p < 0.05). As additional treatment for recurrence, most patients received endoscopic treatment. Metastatic recurrence did not develop in any patient with absolute-indication lesions, but was diagnosed in 6 patients (0.14%) with expanded-indication lesions (p < 0.05). The histological type was undifferentiated mixed type in half the patients. Three patients died of primary gastric cancer.

CONCLUSIONS

ESD for expanded-indication lesions of EGC is considered an effective therapy associated with an extremely low rate of metastatic recurrence on long-term follow-up. However, fully informed consent concerning the risk of metastatic recurrence should be obtained before ESD, and close postoperative follow-up is essential.

Histology-based prediction of lymph node metastases in early gastric cancer as decision guidance for endoscopic resection

Background

Selected cases of early gastric cancer (EGC) can be successfully treated by endoscopic therapy if the risk of concurrent lymph node metastases (LNM) is negligible. Criteria for endoscopic resection based on risk factor analyses for LNM have been established mainly in Asia. However, it is not clear to what extent these recommendations can be transferred to Western collectives. The aim of this study was to analyze predictors for LNM in EGC in a Western study population.

Methods

From our institutional archive, we selected all patients with gastric adenocarcinoma who had undergone gastrectomy with lymphadenectomy (1972 – 2005). Among 1970 patients 275 cases with EGC were identified. Clinical and pathological data were collected and logistic regression analyses performed.

Results

LNM were present in 36/275 (13.1%) patients. With deeper invasion proportion of LNM increased. At submucosa level (sm1), patients were almost five times more likely to have LNM than at mucosa levels.

Multivariable logistic regression analysis revealed lymphovascular invasion, diffuse- and mixed-type, and invasion depth as significant independent histopathological predictors of LNM. In patients with intestinal type according to Lauren and no lymphovascular invasion, we found only one LNM-positive case out of 43 patients in the pT1b (sm1 and sm2) groups.

Conclusions

Our results underline the recommendation of most guidelines that endoscopic resection is sufficient for pT1a ECG because of the low incidence of LNM in this group. However, there seems also a role for endoscopic therapy in cases of pT1b (sm1/2) EGC with intestinal type differentiation and no lymphovascular invasion.