The risk factors for lymph node metastasis in early gastric cancer patients who underwent endoscopic resection: is the minimal lymph node dissection applicable? A retrospective study

Re-evaluation of the role of endoscopic submucosal dissection in the treatment of early gastric cancer based on additional gastrectomy results

Endoscopic submucosal dissection (ESD) plays a pivotal role in treating early gastric cancer (EGC). Some patients require additional gastrectomy because of non-curative ESD. This study aimed to analyze the clinical factors associated with non-curative ESD and to re-evaluate the role of ESD according to its indication criteria. Altogether, 134 patients who had undergone additional gastrectomy with lymphadenectomy for non-curative ESD based on the pathological results of ESD specimens were included. Their data including pre-ESD diagnosis, reasons for requesting additional gastrectomy, and surgical outcomes were analyzed retrospectively. Of the 134 patients with EGC in the final pathology of ESD specimens, 56 underwent staging ESD for a diagnostic approach, of whom 28 were diagnosed with atypical glands and 28 with high-grade dysplasia (HGD) prior to ESD. The remaining 78 patients of the 134 were identified to have EGC and received ESD for therapy. Based on the pathological results of ESD specimens, additional gastrectomy was commissioned with non-curative ESD because of one or more causes such as deep submucosal invasion, lymphatic invasion, positive vertical margin, undifferentiated histology, positive lateral margin, and venous invasion. Regarding surgical specimens, 13 patients had lymph node metastasis (LNM) and 9 had local residual tumor; one of them had both LNM and a local residual tumor. In patients with atypical glands, 4 had LNM and 3 had a local residual tumor; one of them had both LNM and a local residual tumor, and then died of multiple organ metastasis. In patients with HGD, 4 had LNM and 1 had a local residual tumor. Additionally, 4 patients who were absolutely indicated for ESD had LNM, of whom 2 had atypical glands, and the other 2 had HGD. Similarly, in 6 patients with a local residual tumor absolutely indicated for ESD, 2 had atypical glands and 1 had HGD. Positive vertical margin, lymphatic invasion, and deep submucosal invasion were identified as independent risk factors for LNM. ESD may play diagnostic and therapeutic roles in determining the optimal treatment of EGC when the diagnosis is equivocal or insufficient in endoscopic assessments for gastric cancer screening.

Prognostic Implication of Lymphovascular Invasion in Early Gastric Cancer Meeting Endoscopic Submucosal Dissection Criteria: Insights from Radical Surgery Outcomes

BACKGROUND

The management of early gastric cancer (EGC) has witnessed a rise in the utilization of endoscopic submucosal dissection (ESD) as a treatment modality, although prognostic markers are needed to guide management strategies. This study investigates the prognostic implications of lymphovascular invasion (LVI) in ESD-eligible EGC patients, specifically its implications for subsequent radical surgery.

MATERIAL AND METHODS

A retrospective, multicenter study from two primary hospitals analyzed clinicopathological data from 1369 EGC patients eligible for ESD, who underwent gastrectomy at Shanghai Cancer Center and Huashan Hospital between 2009 and 2018. We evaluated the relationship between LVI and lymph node metastasis (LNM), as well as the influence of LVI on recurrence-free survival (RFS) and overall survival (OS).

RESULTS

We found a strong association between LVI and LNM (p < 0.001). Advanced machine learning approaches, including Random Forest, Gradient Boosting Machine, and eXtreme Gradient Boosting, confirmed the pivotal role of LVI in forecasting LNM from both centers. Multivariate analysis identified LVI as an independent negative prognostic factor for both RFS and OS, with hazard ratios of 4.5 (95% CI: 2.4-8.5, p < 0.001) and 4.4 (95% CI: 2.1-8.9, p < 0.001), respectively.

CONCLUSIONS

LVI is crucial for risk stratification in ESD-eligible EGC patients, underscoring the necessity for radical gastrectomy. Future research should explore the potential incorporation of LVI status into existing TNM staging systems and novel therapeutic strategies.

Endoscopic Submucosal Dissection in the Stomach and Duodenum: Techniques, Indications, and Outcomes

Gastric endoscopic submucosal dissection (ESD) is established for management of early gastric cancer (EGC). Diagnosis of EGC relies on adequate endoscopic assessment involving lesion size, histopathology, presence of ulceration, and depth of invasion. Absolute indications for endoscopic resection of EGC are if patients are presumed to have a less than 1% risk of lymph node metasta endoscopic submucosal dissectionsis, and long-term outcomes are similar to those with surgical gastrectomy. Duodenal ESD is more technically difficult and requires expertise in ESD in other locations.

Risks and benefits of additional surgery for early gastric cancer in the upper third of the stomach meeting non-curative resection criteria after endoscopic submucosal dissection

Background

Additional surgery is recommended after non-curative endoscopic submucosal dissection for early gastric cancer. However, it is not easy to recommend for tumors located in the upper third of the stomach, because it would be a total or proximal gastrectomy. This study aimed to evaluate the actual risks and benefits of additional gastrectomy for upper third tumors.

Methods

We reviewed the clinicopathological data of patients who underwent total or proximal gastrectomy for early gastric cancer in the upper third of the stomach between March 2002 and January 2021. The incidence of lymph node metastasis and postoperative complications were calculated, and risk factors for lymph node metastasis were identified using logistic regression analysis. Survival rates were analyzed using the Kaplan–Meier method and log-rank test.

Results

A total of 523 patients underwent total or proximal gastrectomy for early gastric cancer; 379 of them had tumors meeting the non-curative resection criteria for endoscopic submucosal dissection. The overall lymph node metastasis rate was 9.5%, and lymphovascular invasion was the only significant risk factor for lymph node metastasis (p < 0.001). The most common sites of lymph node metastasis were stations 1, 3, and 7, with their rates being 3.2%, 3.7%, and 3.2%, respectively. Overall and severe (Clavien–Dindo grade III or higher) postoperative complication rates were 21.1% and 14.0%, respectively, while postoperative mortality was 0.5% (2/379). The 5-year overall survival rates for patients with and without lymph node metastasis were 96.1% and 81.1%, respectively (p = 0.076).

Conclusions

Before planning an additional gastrectomy after non-curative endoscopic resection for the upper third tumor, we should consider both the benefit of the 9.5% curability for lymph node metastasis and the risks of the 21% postoperative complications and 0.5% mortality.

Therapeutic approach to non-curative resection after endoscopic treatment in early gastric cancer

Background: Endoscopic resection is indicated for early or superficial gastrointestinal neoplasms with a negligible risk of lymph node metastasis. This procedure could preserve the organ while allowing en bloc resection of tumors, irrespective of the size and location of the lesion. Histological evaluation of the resected specimen determines whether curative resection, which implies a favorable long-term outcome, was achieved. If the resected specimen reveals non-curative, additional treatment is necessary as it is strongly associated with recurrence.Current Concepts: Surgical resection is recommended after non-curative resection of gastrointestinal neoplasms. However, rather than surgical resection, additional endoscopic treatment can be recommended if non-curative resection is solely because of the positive involvement at the horizontal resection margin without any other findings compatible with the non-curative resection criteria.Discussion and Conclusion: Adopting precise indications of endoscopic resection is important to reduce the risk of non-curative resection. If curative resection is not achieved after endoscopic resection, additional treatment should be considered to prevent local recurrence as well as lymph node metastasis.

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.

The Modified eCura System for Identifying High-Risk Lymph Node Metastasis in Patients with Early Gastric Cancer Resected by Endoscopic Submucosal Dissection

Background: Endoscopic submucosal dissection (ESD) is widely used for early gastric cancer (EGC) in patients without lymph node metastasis (LNM). Prediction of LNM after ESD is important to determine prognosis in patients with EGC. In this regard, the eCura system was applied to predict LNM after noncurative ESD for EGC. This study aimed to identify risk factors for LNM and improve the accuracy of the eCura system for predicting the risk of LNM after ESD. Methods: A total of 150 patients who underwent noncurative resection of EGC by ESD were retrospectively enrolled at five institutions in Japan. All patients underwent additional surgery with lymph node resection after ESD. The risk factors for LNM among clinicopathological parameters were examined and receiver operating characteristic curve (ROC) analysis was used to determine the optimal cutoff point for predicting high LNM risk using the modified eCura system. Results: Of 150 patients, 19 (13%) had LNM. In the multivariate analysis, lymphatic invasion, and tumor size >30 mm were independent risk factors for LNM. Using a cutoff score of ≥4 for predicting high risk based on the eCura system, the rate of LNM was significantly higher in the high-risk group (4–7 points) than in the low-risk group (0–3 points) (odds ratio 12.0, 95% confidence interval 3.7–54.2, p < 0.0001). Conclusions: An eCura score ≥4 may improve the prediction of LNM risk after ESD in patients with EGC in the intermediate-risk group (2–4 points) of the eCura system, suggesting better treatment strategies for patients. Further prospective and long-term follow-up studies are needed to validate the efficacy of the modified system.

Clinical significance of additional gastrectomy after non-curative endoscopic submucosal dissection for early gastric cancer: a retrospective single-center study

Purpose

Additional surgery is recommended for patients after a non-curative endoscopic submucosal dissection (ESD) to prevent residual cancer (RC) or lymph node metastasis (LNM). We aimed to evaluate the clinicopathologic characteristics of patients who underwent an additional gastrectomy after a non-curative ESD procedure and identify the risk factors of RC and LNM.

Methods

We retrospectively assessed the clinicopathological factors of 73 patients who underwent additional gastrectomy following a non-curative ESD between January 2009 and December 2019 at our center.

Results

RC and LNM rates after additional gastrectomy were 9.6% and 8.2%, respectively. Invasion deeper than 500 μm (P=0.045), positive horizontal resection margin (P<0.001), and positive ESD margin (P=0.001) were identified as statistically significant factors in univariate analysis for RC, but not in multivariate analysis. Lymphatic invasion was the only risk factor found to be significant in both univariate and multivariate analyses (P=0.005 and P=0.012).

Conclusion

Additional gastrectomy is necessary to prevent RC or LNM after non-curative ESD. Lymphatic invasion was also associated with LNM in patients who underwent an additional gastrectomy after a non-curative ESD, and in such cases, active treatment is required.

Endoscopic instruments and techniques in endoscopic submucosal dissection for early gastric cancer

Introduction: Endoscopic submucosal dissection (ESD) is a less invasive local treatment for early gastric cancer (EGC).Areas covered: Japanese guidelines have recently expanded the endoscopic treatment indications for EGC. ESD is sometimes performed for lesions with a relative indication that has not previously been considered for ESD. ESD procedures are technically difficult, especially for larger and more invasive lesions. Complete resection and accurate histological assessment of EGC lesions are essential to evaluate endoscopic curability. Various endoscopic instruments, including three types of endoscopic knives and specific hemostatic forceps, have been developed, and endoscopic techniques, including the traction method, have been modified to simplify the procedure.Expert opinion: An insulated-tip knife with large tissue contact allows us to perform faster incisions, while a needle-type knife with minimal tissue contact allows us to perform precise incisions. Furthermore, a scissor-type knife with grasping tissues allows us to perform more secure incision. The traction method enables the operator to proceed with submucosal dissection procedures. In cases with small lesions, snaring can be used, as well as knife dissection. Understanding the features of each endoscopic instrument and technique is essential because appropriate selection and usage contribute to successful and safe ESD procedures.

Effect of non-curative endoscopic submucosal dissection on short-term outcomes of subsequent surgery for early gastric cancer

BACKGROUND

With growing incidence of early gastric cancer (EGC), endoscopic submucosal dissection (ESD) is widely performed as a standard treatment for mucosal cancer. Due to the increasing application of ESD, the number of non-curative resection after ESD is also growing, leading to escalating number of patients who require additional gastrectomy with lymph node dissection after non-curative ESD. However, effects of ESD prior to surgery on technical difficulties during operation for EGC remain unclear. Therefore, this study aimed to determine the effect of non-curative ESD on short-term surgical outcomes in patients who underwent additional surgical treatment using propensity score matching method.

METHODS

To evaluate the effect of ESD on short-term surgical outcomes in patients who underwent additional surgical treatment after a non-curative ESD procedure, patients were divided into two groups: (1) those who underwent additional gastrectomy after non-curative resection of ESD [ESD + Surgery (ES) Group], and (2) those who underwent gastrectomy as the initial treatment [Surgery Only (SO) Group]. To minimize differences in baseline demographic features that could potentially be associated with short-term outcomes, propensity-scored matching analysis was performed.

RESULTS

After propensity-scored matching (1:1 matching), 140 patients altogether were selected and analyzed in this study. Complications were experienced by 18 (25.7%) patients in the ES group and 13 (18.6%) patients in the SO group, showing no significant (p < 0.416) difference between the two groups.

CONCLUSIONS

Additional surgery after non-curative ESD can be safely applied, even within one month after ESD in terms of short-term complications.

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.

Integrating No.3 lymph nodes and primary tumor radiomics to predict lymph node metastasis in T1-2 gastric cancer

BACKGROUND

This study aimed to develope and validate a radiomics nomogram by integrating the quantitative radiomics characteristics of No.3 lymph nodes (LNs) and primary tumors to better predict preoperative lymph node metastasis (LNM) in T1-2 gastric cancer (GC) patients.

METHODS

A total of 159 T1-2 GC patients who had undergone surgery with lymphadenectomy between March 2012 and November 2017 were retrospectively collected and divided into a training cohort (n = 80) and a testing cohort (n = 79). Radiomic features were extracted from both tumor region and No. 3 station LNs based on computed tomography (CT) images per patient. Then, key features were selected using minimum redundancy maximum relevance algorithm and fed into two radiomic signatures, respectively. Meanwhile, the predictive performance of clinical risk factors was studied. Finally, a nomogram was built by merging radiomic signatures and clinical risk factors and evaluated by the area under the receiver operator characteristic curve (AUC) as well as decision curve.

RESULTS

Two radiomic signatures, reflecting phenotypes of the tumor and LNs respectively, were significantly associated with LN metastasis. A nomogram incorporating two radiomic signatures and CT-reported LN metastasis status showed good discrimination of LN metastasis in both the training cohort (AUC 0.915; 95% confidence interval [CI] 0.832-0.998) and testing cohort (AUC 0.908; 95% CI 0.814-1.000). The decision curve also indicated its potential clinical usefulness.

CONCLUSIONS

The nomogram received favorable predictive accuracy in predicting No.3 LNM in T1-2 GC, and the nomogram showed positive role in predicting LNM in No.4 LNs. The nomogram may be used to predict LNM in T1-2 GC and could assist the choice of therapy.

Prevalence and risk factors for lymph node metastasis after noncurative endoscopic resection for early gastric cancer: a systematic review and meta-analysis

BACKGROUND

Additional surgery for all patients with noncurative resection after endoscopic resection (ER) for early gastric cancer (EGC) may be excessive due to the relatively low rate of lymph node metastasis (LNM) in such patients. However, the prevalence and risk factors for LNM after noncurative ER have not been consistent across studies.

METHODS

We performed a systematic review of electronic databases through August 10, 2018 to identify cohort studies with patients who underwent additional surgery after noncurative ER for EGC. The prevalence of LNM in such patients was extracted for all studies. Odds ratios (ORs) were combined using random-effects meta-analyses to assess the risk of LNM, when possible.

RESULTS

We identified 24 studies comprising 3877 patients with 311 having LNM (pooled prevalence, 8.1%). The risk of LNM was significantly increased in lymphatic invasion (OR [95% confidence interval] = 4.22 [2.88-6.19]), lymphovascular invasion (LVI) (4.17 [2.90-5.99]), vascular invasion (2.38 [1.65-3.44]), positive vertical margin (2.16 [1.59-2.93]), submucosal invasion depth of ≥ 500 μm (2.14 [1.48-3.09]), and tumor size > 30 mm (1.77 [1.31-2.40]). In contrast, there was no significant association between undifferentiated-type or ulceration (scar) and LNM. When studies were restricted to those that evaluated the adjusted OR, the risk of vascular invasion for LNM did not reach statistical significance.

CONCLUSIONS

Several pathological factors, most notably lymphatic invasion and LVI, were associated with LNM in patients with noncurative resection after ER for EGC. Lymphatic and vascular invasion should be assessed separately instead of LVI (PROSPERO CRD42018109996).

Long-term Clinical Outcomes and Risk of Peritoneal Seeding after Endoscopic Submucosal Dissection for Early Gastric Cancer: A Focus on Perforation during the Procedure

Background/Aims

The risk of peritoneal seeding following perforation after endoscopic resection in patients with early gastric cancer is unclear. The purpose of this study was to investigate long-term clinical outcomes including peritoneal seeding and overall survival rate following gastric perforation during endoscopic submucosal dissection (ESD).

Methods

Between January 2002 and March 2015, 556 patients were diagnosed with early gastric cancer and underwent ESD. Among them, 34 patients (6.1%) experienced gastric perforation during ESD. Clinicopathological data of these patients were reviewed to determine the clinical outcome and evidence of peritoneal seeding.

Results

Among 34 patients with perforation, macroperforations occurred during ESD in 17 cases (50%), and microperforation was identified in the remaining 17 cases (50%). All patients except one who underwent emergency surgery due to severe panperitonitis were managed successfully by endoscopic clipping (n=27) or conservative medical treatment (n=6). No evidence of peritoneal seeding after perforation associated with ESD was found in our cohort. Cumulative survival rates did not differ between the perforation and non-perforation groups (p=0.691). Furthermore, mortality was not associated with perforation. In addition, multivariate analysis showed that tumor size and achievement of curative resection were related to cancer recurrence. Perforation was not associated with cancer recurrence and survival.

Conclusions

Perforation associated with ESD does not lead to worse clinical outcomes such as peritoneal seeding or cumulative survival rate. Therefore, periodic follow-up might be possible if curative resection was achieved even if perforation occurred during ESD.

Validity of additional surgical resection by comparing the operative risk with the stratified lymph node metastatic risk in patients with early gastric cancer after endoscopic submucosal dissection

Background

Treatment guidelines for early gastric cancer (EGC) recommend additional gastrectomy for lesions which do not achieve curative resection after ESD, due to the potential risk of lymph node metastasis (LNM). However, many cases are found to have no LNMs, and additional gastrectomy itself can be a considerable risk especially in elderly patients.

Methods

We retrospectively stratified the risk of LNM according to the total number of four LNM risk factors (RFs) that resulted in non-curative resection for ESD in 861 EGC patients who underwent gastrectomy. Next, we compared this stratification risk to the surgical risk based on the National Clinical Database (NCD) risk calculator in 58 patients who underwent additional gastrectomy.

Results

As the total number of LNM RFs increased, the frequency of LNM also increased significantly (0/1RF 0.76%, 2RFs 15.08%, 3RFs 33.87%, 4RFs 50.00%; p < 0.01). The estimated frequency of LNM was found to be lower than the predicted value of in-hospital mortality rate based on the NCD risk calculator in 25.0% of 0/1RF patients.

Conclusion

These findings indicate, at least, that we should discuss the indication of additional gastrectomy individually for each patient from both perspectives of LNM and surgical risks.

Risk Factors Associated with Lymph Node Metastasis for Early Gastric Cancer Patients Who Underwent Non-curative Endoscopic Resection: a Systematic Review and Meta-analysis

BACKGROUND

Recently, increased evidence indicated that additional surgery should be performed in highly selected patients with non-curative endoscopic resection. In this study, we performed a systematic review and meta-analysis to evaluate the risk factors associated with lymph node metastasis for the patients with non-curative endoscopic resection of early gastric cancer.

METHODS

The related studies were identified by searching PubMed and Embase databases. According to the status of lymph node metastasis, all patients were classified into node-negative group and node-positive group. The relevant clinicopathologic factors were extracted, and the pooled odds ratio (OR) and 95% confidence interval (CIs) were assessed using a fixed effects model or random effects model.

RESULTS

A total of nine relevant studies involving 1720 early gastric cancer patients who underwent additional surgery following the non-curative endoscopic resection were included in this meta-analysis. The results indicated that deeper submucosal invasion (SM2) (OR 3.44, 95% CI 1.94-6.10, P < 0.001; I² = 0%), positive vertical margin (OR 2.35, 95% CI 1.57-3.53, P < 0.001; I² = 0%), lymphatic invasion (OR 11.06, 95% CI 5.47-22.36, P < 0.001; I² = 0%), and vascular invasion (OR 2.79, 95% CI 1.68-4.64, P < 0.001; I² = 0%) were significantly associated with lymph node metastasis for these patients. However, horizontal margin, tumor size, differentiation type, and ulceration were not identified as risk factors associated with lymph node metastasis.

CONCLUSION

Lymphatic invasion, vascular invasion, deeper submucosal invasion (SM2), and positive vertical margin should be strongly considered in selecting the candidates for additional surgery treatment.

Additional gastrectomy in early-stage gastric cancer after non-curative endoscopic resection: a meta-analysis

Background and objective

The role of additional gastrectomy after non-curative endoscopic resection remains uncertain. The present meta-analysis aimed to explore the risk factors for early-stage gastric-cancer patients after non-curative endoscopic resection and evaluate the efficacy of additional gastrectomy.

Methods

Relevant studies that reported additional gastrectomy after non-curative endoscopic resection were comprehensively searched in MedLine, Web of Science and EMBASE. We first investigated the risk factors for residual tumor and lymph-node metastasis after non-curative endoscopic resection and then analysed the survival outcome, including 5-year overall survival (OS) and 5-year disease-free survival, of additional gastrectomy.

Results

Twenty-one studies comprising 4870 cases were included in the present study. We found that residual tumor was associated with larger tumor size (>3 cm) (odds ratio [OR] = 2.81, P < 0.001), undifferentiated tumor type (OR = 1.78, P = 0.011) and positive horizontal margin (OR = 9.78, P < 0.001). Lymph-node metastasis was associated with larger tumor size (>3 cm) (OR = 1.73, P < 0.001), elevated tumor type (OR = 1.60, P = 0.035), deeper tumor invasion (>SM1) (OR = 2.68, P < 0.001), lymphatic invasion (OR = 4.65, P < 0.001) and positive vertical margin (OR = 2.30, P < 0.001). Patients who underwent additional gastrectomy had longer 5-year OS (hazard ratio [HR] = 0.34, P < 0.001), 5-year disease-free survival (HR = 0.52, P = 0.001) and 5-year disease-specific survival (HR = 0.50, P < 0.001) than those who did not. Moreover, elderly patients also benefited from additional gastrectomy regarding 5-year OS (HR = 0.41, P = 0.001).

Conclusions

Additional gastrectomy with lymph-node dissection might improve the survival of early-stage gastric-cancer patients after non-curative endoscopic resection. However, risk stratification should be performed to avoid excessive treatment.

The distribution pattern of metastatic lymph nodes after non-curative endoscopic resection in early gastric cancer

BACKGROUND AND OBJECTIVES

Additional surgery should be done after non-curative endoscopic resection (ER) in early gastric cancer (EGC) due to the risk of lymph node metastasis (LNM). However, the distribution pattern of LNM in these patients is complicated and unpredictable. The aim of this study is to identify any different distribution patterns of LNM in patients with EGC who underwent additional surgery after non-curative (ER) comparing to those without ER.

METHODS

Patients who underwent surgery for EGC between 2001 and 2016 were included. Enrolled patients were divided into two groups, those who underwent additional surgery after non-curative ER and those who underwent direct surgery without a history of ER. Demographics, tumor characteristics and LNM distribution pattern were analyzed.

RESULTS

Among 4295 patients with EGC, 404 patients had a history of preoperative ER, and 3891 patients did not. After the application of exclusion criteria, 23 (7.1%) of 322 patients undergoing additional surgery had LNM. The additional surgery group showed less LNM, fewer nodal stations and more restricted distribution pattern of LNM.

CONCLUSIONS

The distribution pattern of LNM in EGC is complicated. However, more restricted locoregional LNM could be expected in cases of additional surgery after non-curative ER than after direct surgery.

Anthracosilicosis mimicking extensive nodal metastasis from early gastric cancer: A case report

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Anthracosilicosis can mimic extensive node metastasis from gastric cancer.

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The PET-CT scan is not specific enough to detect metastatic lymph nodes precisely.

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Surgical exploration should be considered when the result of imaging studies is doubtful.

Introduction

Lymph node metastasis is one of the most important prognostic factors in gastric cancer and precise assessment of nodal status facilitates optimal therapeutic decisions. Many diagnostic modalities including endoscopic ultrasound (EUS), computed tomography (CT), and sometimes, positron emission tomography (PET) have been utilized to improve diagnostic accuracy in detecting metastatic lymph nodes; however, their accuracy remains unsatisfactory.

Presentation of case

We report a case of a 73-year old male patient who was erroneously diagnosed with stage IV gastric cancer due to the distant nodal metastasis from early gastric cancer lesion during the initial staging process. However, surgical exploration revealed an anthracosilicosis-associated lymphadenopathy that mimicked extensive distant nodal metastasis in the preoperative CT and PET-CT scans. The patient was finally diagnosed with stage I gastric cancer confined to the mucosa without nodal metastasis.

Discussion

We report a rare case of gastric cancer concurrent extensive nodal involvement of anthracosilicosis mimicking metastatic nodal disease in the imaging studies. This case implies that PET-CT scan for clinical staging is not specific enough to clearly delineate malignant lesions, causing a diagnostic dilemma.

Conclusion

When the characteristics of the primary tumor is poorly correlated to the findings of imaging studies, surgical exploration can be a viable option for a definitive diagnosis before making a hasty decision based only upon the diagnostic imaging results.

Propensity score-matching analysis to compare clinical outcomes of endoscopic submucosal dissection for early gastric cancer in the postoperative and non-operative stomachs

Background

Endoscopic submucosal dissection (ESD) of the postoperative stomach (ESD-P) for early gastric cancer (EGC) is considered a technically difficult procedure. However, it is difficult to compare the outcomes of ESD-P and ESD of the non-operative stomach (ESD-N) because their baseline characteristics are different. Therefore, we aimed to compare the technical outcomes of ESD-P with those of ESD-N using a propensity score-matching analysis to compensate for the differences.

Methods

The chart records of 1046 patients with EGC who were treated with ESD between January 2004 and July 2016 at Kitakyushu Municipal Medical Center in Japan were reviewed in this retrospective study. Multivariate analyses and propensity score-matching were performed for age, sex, lesion location, lesion size, tumor invasion, tumor size, ulcer (scar), and operator skill. The primary outcome was procedure time. Secondary outcomes were percentages of en bloc, complete, and curative resections, and percentages of adverse events, which were evaluated between the two groups.

Results

Forty-one patients were in the ESD-P group and 1005 patients were in the ESD-N group. Propensity score-matching created 41 matched pairs. According to the adjusted comparisons, ESD-P required a significantly longer procedure time (85 min vs 51 min, p < 0.001). Other treatment outcomes showed an en bloc resection rate of 100% for both groups (p = 1) and complete resection rates of 95.1 and 97.6% (p = 1), curative resection rates of 90.2 and 90.2% (p = 1), perforation during ESD rates of 2.4 and 0% (p = 1), and postprocedure bleeding rates of 2.4 and 2.4% (p = 1) for the ESD-P and ESD-N groups, respectively. For the ESD-P group, lesions on the suture line or anastomotic site were significantly associated with longer procedure times (p = 0.038).

Conclusions

ESD-P was a more time-consuming procedure than ESD-N. However, ESD-P and ESD-N achieved high rates of curative resection with a low rate of adverse events for the treatment of EGC. ESD could be selected as the treatment for EGC even in the postoperative stomach provided that careful attention is given to lesions on the suture line or anastomotic site.

Quality in upper gastrointestinal endoscopic submucosal dissection

Progress in the endoscopy technology field led to an increase in the diagnosis of early gastrointestinal (GI) superficial lesions and to an improvement of their treatment. Endoscopic submucosal dissection (ESD) has been developed in Japan with the aim of removing such lesions in one piece, in order to obtain a curative resection and to minimize the risk of local recurrence, and to preserve the native organ. ESD is widely used in Asia for the treatment of early upper and lower GI lesions and is currently gaining attention in Western countries too. However, ESD can be safely performed only by expert endoscopists and in specific clinical settings. Therefore, prior to decide whether ESD is feasible or not, the target lesion must be carefully assessed, in order to understand whether or not it is eligible for submucosal dissection. The aim of this paper is to review indications, limitations and technical aspects of upper GI ESD.

Is the eCura system useful for selecting patients who require radical surgery after noncurative endoscopic submucosal dissection for early gastric cancer? A comparative study

BACKGROUND

We have established a risk-scoring system, termed the "eCura system," for the risk stratification of lymph node metastasis in patients who have received noncurative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We aimed to clarify whether this system contributes to the selection of patients requiring radical surgery after ESD.

METHODS

Between 2000 and 2011, 1,969 patients with noncurative ESD for EGC were included in this multicenter study. Depending on the treatment strategy after ESD, we had patients with no additional treatment (n = 905) and those with radical surgery after ESD (n = 1,064). After the application of the eCura system to these patients, cancer recurrence and cancer-specific mortality in each risk category of the system were compared between the two patient groups.

RESULTS

Multivariate Cox analysis revealed that in the high-risk category, cancer recurrence was significantly higher (hazard ratio = 3.13, p = 0.024) and cancer-specific mortality tended to be higher (hazard ratio = 2.66, p = 0.063) in patients with no additional treatment than in those with radical surgery after ESD, whereas no significant differences were observed in the intermediate-risk and low-risk categories. In addition, cancer-specific survival in the low-risk category was high in both patient groups (99.6 and 99.7%). A limitation of this study is that it included a small number of cases with undifferentiated-type EGC (292 cases).

CONCLUSIONS

The eCura system is a useful aid for selecting the appropriate treatment strategy after noncurative ESD for EGC. However, caution is needed when applying this system to patients with undifferentiated-type EGC.

Lymph node metastasis can be determined by just tumor depth and lymphovascular invasion in early gastric cancer patients after endoscopic submucosal dissection

PURPOSE

Endoscopic submucosal dissection (ESD) is a minimally invasive treatment for early gastric cancer (EGC) with negligible risk of lymph node metastasis (LNM). When a patient is determined to have noncurative resection after ESD, additional surgical resection with lymph node dissection is recommended. Previous studies report that LNM is found in about 10% of these patients. It may be possible to avoid unnecessary surgical resection by selecting patients properly. We aimed to clarify the risk factors associated with LNM in EGC patients who underwent ESD and to develop a highly accurate diagnostic algorithm for LNM.

PATIENTS AND METHODS

Among 1005 patients with EGC who underwent ESD, 423 patients who could be followed up for more than 3 years after treatment or who underwent additional surgical resection were examined. We used the leave-one-out method to explore the combination of predictive factors of LNM and differentiated LNM by a unique classifier.

RESULTS

Curative resection was achieved in 322 patients, whereas noncurative resection was achieved in 101 patients. In the noncurative resection group, LNM occurred in eight patients with additional surgical resection and one patient during follow-up. The combination of depth of invasion, lymphatic, and venous invasion showed the highest diagnostic performance and could differentiate LNM with 100% sensitivity, 86% specificity, and 86% diagnostic accuracy.

CONCLUSION

More than 500 μm submucosal invasion and lymphatic and venous invasion will be useful in assessing LNM after ESD for patients with EGC. When these three factors are not observed, follow-up alone might be appropriate and it may be possible to reduce unnecessary surgical resection.

[Treatment Strategies after Non-curative Endoscopic Resection of Early Gastric Cancer]

The cases of non-curative endoscopic resection (NCR) of early gastric cancer have increased due to the widespread use of endoscopic submucosal dissection (ESD). NCR is associated with augmenting chances of local recurrence and lymph node metastasis (LNM). Therefore, some additional treatment strategies after NCR are needed. Treatment strategies for NCR should be determined by considering the risk of residual tumor or local recurrence and LNM. Additional surgical treatment such as gastrectomy and lymph node dissection are recommended in patients who have high-risk of LNM. Close observation without additional treatment is considered for selected patients with a less possibility of local recurrence or LNM. Also it may be suggested if there is no or less benefit from surgery in elderly patients or patients with underlying diseases. Additional endoscopic procedures including ESD, endoscopic mucosal resection or argon coagulation therapy are suggested alternatively for highly selected patients not at risk of LNM based on the absolute or expanded criteria of ESD.

Survival Benefit of Additional Surgery After Non-curative Endoscopic Submucosal Dissection for Early Gastric Cancer: A Propensity Score Matching Analysis

BACKGROUND AND PURPOSE

Previous studies comparing survival outcomes between patients who did and did not undergo additional surgery after non-curative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) were limited in that the baseline characteristics differed significantly between the groups. We aimed to address this limitation and compared survival outcomes between these two groups using propensity score matching analysis.

METHODS

The study enrolled 1969 consecutive patients who underwent non-curative ESD for EGC between 2000 and 2011 at any of 19 institutions across Japan. Using propensity score matching analysis, patients who underwent additional surgery (n = 1064) were compared with patients who did not (n = 905). Overall survival (OS) and disease-specific survival (DSS) after ESD were compared between both groups.

RESULTS

Propensity score matching analysis yielded 553 matched pairs and well-balanced baseline characteristics between the two groups. The 5-year OS rates were 91.0% in the additional surgery group and 75.5% in the no additional surgery group, and the 5-year DSS rates were 99.0 and 96.8%, respectively. OS and DSS in the additional surgery group were significantly higher than in the no additional surgery group (OS, p < 0.001; DSS, p = 0.013). In Cox proportional hazard analysis, additional surgery significantly reduced gastric cancer-related death after non-curative ESD for EGC (hazard ratio 0.33, 95% confidence interval 0.12-0.79, p = 0.012).

CONCLUSIONS

Our findings suggest that additional surgery reduces mortality after non-curative ESD for EGC. We recommend additional surgery for patients after non-curative ESD for EGC.

Clinical outcomes of early gastric cancer patients after noncurative endoscopic submucosal dissection in a large consecutive patient series

BACKGROUND

Clinical outcomes of early gastric cancer (EGC) patients after noncurative endoscopic submucosal dissection (ESD) have not been fully elucidated; we therefore aimed to clarify these outcomes.

METHODS

A total of 3058 consecutive patients with 3474 clinically diagnosed EGCs at initial onset underwent ESD with curative intent at our hospital between 1999 and 2010. We retrospectively assessed the following clinical outcomes of noncurative gastric ESD patients with a possible risk of lymph node (LN) metastasis by dividing patients into two groups with different treatment strategies (additional gastrectomy and simple follow-up): presence of LN metastasis at the time of gastrectomy, incidence of LN and distant metastases during the follow-up period, clinicopathological factors associated with metastasis, and 5-year disease-specific survival (DSS).

RESULTS

After exclusion of 75 noncurative ESD patients with only a positive horizontal margin, 569 noncurative ESD patients with a possible risk of LN metastasis were identified. Among the 356 patients undergoing additional gastrectomy, LN metastasis was identified in 18 patients. A positive vertical margin with submucosal invasion (odds ratio 3.6) and lymphovascular invasion (odds ratio 3.5) were significantly associated with LN metastasis. The 5-year DSS rate was 98.8 %. Among the 212 patients who underwent simple follow-up, LN and/or distant metastases were found in eight patients. In this group, lymphovascular invasion (hazard ratio 6.6) was significantly associated with metastasis with a 5-year DSS rate of 96.8 %.

CONCLUSIONS

Additional gastrectomy should be performed particularly in noncurative gastric ESD patients with lymphovascular invasion or a positive vertical margin with submucosal invasion.

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.

Predictive factors for lymph node metastasis in early gastric cancer with lymphatic invasion after endoscopic resection

BACKGROUND

Lymph node (LN) metastasis is found in only about 5-10% of the patients who undergo additional surgery after non-curative endoscopic resection. Lymphatic invasion after endoscopic submucosal dissection (ESD) is regarded as non-curative resection due to risk of reginal LN metastasis. This study was aimed to identify clinicopathologic predictive factors for LN metastasis in early gastric cancer (EGC) with lymphatic invasion after endoscopic resection.

METHODS

Among a total of 2036 patients who underwent endoscopic resection for EGC at Samsung Medical Center from April 2000 to May 2011, 146 patients were diagnosed with lymphatic invasion. And 123 patients who had gastrectomy with LN dissection due to presence of lymphatic invasion as one of the non-curative factors were included in this study. Demographics, endoscopic tumor findings, histological findings, surgical findings with pathologic reports, and follow-up data were collected from the patient's medical records. Pathological re-evaluation of resected specimens was performed.

RESULTS

Among a total of 123 patients, LN metastases were found in seven patients (5.7%). The univariate analysis revealed that the LN metastasis was significantly more frequent in patients with certain morphology of lymphatic invasion that shows adhesion to endothelium of lymphatic tumor emboli (p = 0.016), higher number of lymphatic tumor emboli in whole section (p < 0.001) and papillary adenocarcinoma component (p = 0.024). In multivariate analysis, the number of lymphatic tumor emboli [OR 93.5, 95% CI (2.62-3330.81)] and the presence of papillary adenocarcinoma component [OR 552.5, 95% CI (1.20-254871.81)] were identified as independent predictors of LN metastasis in patients with lymphatic invasion after endoscopic resection.

CONCLUSIONS

The number of lymphatic tumor emboli and the presence of papillary adenocarcinoma component were significant predictors for LN metastasis in patients with lymphatic invasion after endoscopic resection.

The Effect of Endoscopic Resection on Short-Term Surgical Outcomes in Patients with Additional Laparoscopic Gastrectomy after Non-Curative Resection for Gastric Cancer

Purpose

Endoscopic submucosal dissection (ESD) in early gastric cancer causes an artificial gastric ulcer and local inflammation that has a negative intraprocedural impact on additional laparoscopic gastrectomy in patients with noncurative ESD. In this study, we analyzed the effect of ESD on short-term surgical outcomes and evaluated the risk factors.

Materials and Methods

From January 2003 to January 2013, 1,704 patients of the National Cancer Center underwent laparoscopic gastrectomy with lymph node dissection because of preoperative stage Ia or Ib gastric cancer. They were divided into 2 groups: (1) with preoperative ESD or (2) without preoperative ESD. Clinicopathologic factors and short-term surgical outcomes were retrospectively evaluated along with risk factors such as preoperative ESD.

Results

Several characteristics differed between patients who underwent ESD-surgery (n=199) or surgery alone (n=1,505). The mean interval from the ESD procedure to the operation was 43.03 days. Estimated blood loss, open conversion rate, mean operation time, and length of hospital stay were not different between the 2 groups. Postoperative complications occurred in 23 patients (11.56%) in the ESD-surgery group and in 189 patients (12.56%) in the surgery-only group, and 3 deaths occurred among patients with complications (1 patient [ESD-surgery group] vs. 2 patients [surgery-only group]; P=0.688). A history of ESD was not significantly associated with postoperative complications (P=0.688). Multivariate analysis showed that male sex (P=0.008) and laparoscopic total or proximal gastrectomy (P=0.000) were independently associated with postoperative complications.

Conclusions

ESD did not affect short-term surgical outcomes during and after an additional laparoscopic gastrectomy.

Is radical surgery necessary in all patients who do not meet the curative criteria for endoscopic submucosal dissection in early gastric cancer? A multi-center retrospective study in Japan

BACKGROUND

Although radical surgery is routinely performed for patients who do not meet the curative criteria for endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) due to the risk of lymph node metastasis (LNM), this standard therapeutic option may be excessive given the lower number of patients with LNM. Therefore, we aimed to investigate long-term outcomes and validate risk factors predicting recurrence after ESD.

METHODS

Of 15,785 patients who underwent ESD for EGC at 19 institutions between 2000 and 2011, 1969 patients not meeting the curative criteria were included in this multi-center study. Based on the treatment strategy after ESD, patients were divided into radical surgery (n = 1064) and follow-up (no additional treatment, n = 905) groups.

RESULTS

Overall survival (OS) and disease-specific survival (DSS) were significantly higher in the radical surgery group than in the follow-up group (p < 0.001 and p = 0.012, respectively). However, the difference in 3-year DSS between the groups (99.4 vs. 98.7 %) was rather small compared with the difference in 3-year OS (96.7 vs. 84.0 %). LNM was found in 89 patients (8.4 %) in the radical surgery group. Lymphatic invasion was found to be an independent risk factor for recurrence in the follow-up group (hazard ratio 5.23; 95 % confidence interval 2.01-13.6; p = 0.001).

CONCLUSIONS

This multi-center study, representing the largest cohort to date, revealed a large discrepancy between OS and DSS in the two groups. Since follow-up with no additional treatment after ESD may be an acceptable option for patients at low risk, further risk stratification is needed for appropriate individualized treatment strategies.

Survival benefit of additional surgery after noncurative endoscopic resection in patients with early gastric cancer

BACKGROUND AND AIMS

Excellent long-term outcome is expected for early gastric cancers (EGCs) after endoscopic submucosal dissection (ESD). However, if ESD is considered noncurative at the pathologic evaluation, additional surgery is recommended. We evaluated whether long-term outcome is compromised if additional surgery is not performed for EGCs that are out-of-indication.

METHODS

We retrospectively analyzed a cohort of patients with EGC not meeting ESD indications whose initial treatment was either ESD (n = 219) or surgery (n = 1799). Among them, 127 patients who underwent additional surgery after initial ESD and 67 patients who did not were matched using propensity scores to patients who initially underwent standard surgery, at a 1:1 ratio. Overall mortality and gastric cancer recurrence were compared.

RESULTS

The overall mortality and gastric cancer recurrence rates were not significantly different between the 127 patients who underwent initial ESD with additional surgery and the corresponding initial standard surgery patients. However, the overall mortality of the 67 patients who underwent ESD without additional surgery (5-year mortality, 26.0%; 95% CI, 13.5%-49.9%) was higher than that of the matched initial standard surgery patients (5-year mortality, 14.5%; 95% CI, 6.3%-33.6%; P = .04). Gastric cancer recurrence was also higher in ESD patients without additional surgery (5-year recurrence, 17.0%; 95% CI, 7.6%-37.8%) than in the matched initial surgery group (0%; P = .002). In multivariate analyses, ESD without additional surgery was a significant risk factor for overall mortality and gastric cancer recurrence.

CONCLUSIONS

Additional surgery should be encouraged after non-curative ESD to obtain long-term outcomes comparable with those of initial standard surgery. (Clinical trial registration number: NCC2015-0093.).

Current status and challenges in sentinel node navigation surgery for early gastric cancer

Although a number of feasibility studies for sentinel node (SN) concepts in gastric cancer have been conducted since 2000, there remains a debate regarding detailed detection techniques and oncological safety. Two important multicenter phase II clinical trials were performed in Japan that used different methods and reached different conclusions; one confirmed acceptable results with a false-negative rate of 7%, and the other showed an unacceptably high false-negative rate of 46.4%. The Sentinel Node Oriented Tailored Approach (SENORITA) trial is a multicenter randomized controlled phase III trial being performed in Korea. Patient enrollment is now complete and the long-term results are currently awaited. Recently, an image-guided SN mapping technique using infrared ray/fluorescence was introduced. This method might be a promising technology because it allows the clear visualization of SNs. With regard to the primary tumor, the non-exposed endoscopic wall-inversion surgery technique and non-exposure endolaparoscopic full-thickness resection with simple suturing technique have been reported. These methods prevent abdominal infection and tumor seeding and can be good alternatives to conventional laparoscopic gastric wedge resection. For indications, SN navigation surgery can be extended to patients who underwent non-curative endoscopic resection. Although a few studies have been performed on these patients, sentinel concepts may be beneficial to patients as they omit the need for additional gastrectomy. SN navigation surgery can lead to actual organ-preserving surgery and plays a key role in improving the quality of life of patients with early gastric cancer in the future.

Risk stratification and predictive risk-scoring model for lymph node metastasis in early gastric cancer

BACKGROUND

We are increasingly experiencing difficulty in deciding whether to perform gastrectomy after noncurative endoscopic resection of early gastric cancer (EGC) for patients at high risk for surgery. If the differences in risk for lymph node metastasis (LNM) on the basis of noncurative status are understood, the decision becomes easier. The present study aimed to stratify the LNM risk and develop and validate a risk-scoring model for predicting LNM.

METHODS

By retrospectively reviewing 3131 patients with solitary EGC who underwent gastrectomy with lymphadenectomy at our institution between July 1997 and May 2013, LNM risk was stratified and a risk-scoring model was developed on the basis of the identified independent risk factors for LNM. The scoring was validated using 352 other surgically resected EGC cases. The discriminatory accuracy of the scoring was measured by area under receiver operating characteristic curve (AUROC).

RESULTS

LNM was detected in 386 of 3131 cases. LNM risk in each subgroup, stratified by the identified independent risk factors, such as tumor size, depth, histological type, ulcerative findings, and lymphovascular involvement, considerably varied from 0 % to >50 % even among the current guidelines' noncurative subgroups. An 11-point scoring model was built, and AUROCs were 0.84 (95 % confidence interval, 0.82-0.86) and 0.82 (0.75-0.88) in the development and validation sets, respectively.

CONCLUSIONS

The present study revealed detailed LNM risk stratification data, and developed and validated an 11-point scoring model.

Prediction of lymph node metastasis and sentinel node navigation surgery for patients with early-stage gastric cancer

Accurate prediction of lymph node (LN) status is crucially important for appropriate treatment planning in patients with early gastric cancer (EGC). However, consensus on patient and tumor characteristics associated with LN metastasis are yet to be reached. Through systematic search, we identified several independent variables associated with LN metastasis in EGC, which should be included in future research to assess which of these variables remain as significant predictors of LN metastasis. On the other hand, even if we use these promising parameters, we should realize the limitation and the difficulty of predicting LN metastasis accurately. The sentinel LN (SLN) is defined as first possible site to receive cancer cells along the route of lymphatic drainage from the primary tumor. The absence of metastasis in SLN is believed to correlate with the absence of metastasis in downstream LNs. In this review, we have attempted to focus on several independent parameters which have close relationship between tumor and LN metastasis in EGC. In addition, we evaluated the history of sentinel node navigation surgery and the usefulness for EGC.

Risk factors for lymph node metastasis and long-term outcomes of patients with early gastric cancer after non-curative endoscopic submucosal dissection

BACKGROUND

The long-term outcomes after non-curative gastric endoscopic submucosal dissection (ESD) are still unknown. We aimed to clarify the pathological risk factors for lymph node metastasis (LNM) of early gastric cancer (EGC) and the long-term outcomes among patients who were judged to have had non-curative ESD.

METHODS

From September 2002 to December 2012, 506 patients who were judged to have had non-curative gastric ESD were enrolled and classified into two groups: (1) those who subsequently underwent additional surgical resection (surgical group, n = 323) and (2) those followed up without additional surgical resection (nonsurgical group, n = 183). We analyzed pathological risk factors for LNM of EGC in the surgical group. Additionally, we compared long-term outcomes in the two groups.

RESULTS

LNM was found pathologically in 9.3 % of the surgical group (30/323) at the additional surgical resection after non-curative ESD. In the multivariate logistic regression analysis, lymphovascular invasion (LVI) was an independent risk factor for LNM in the surgical group (odds ratio 8.57, 95 % confidence interval 2.76-38.14, P < 0.0001). The 5-year cause-specific survival rate was similar in the surgical and nonsurgical groups (98.7 and 96.5 %, respectively; log-rank test, P = 0.07). In contrast, the 5-year cause-specific survival rate of patients with LVI in the surgical group was better than that in the nonsurgical group (98.2 and 79.1 %, respectively; log-rank test, P < 0.0001).

CONCLUSIONS

A detailed assessment of LVI is essential to the pathological evaluation of endoscopically resected specimens. An additional surgical resection should be strongly recommended for patients with LVI.

Expanded endoscopic therapy criteria should be cautiously used in intramucosal gastric cancer

OBJECTIVE

Accurate estimation of lymph node metastasis (LNM) in intramucosal gastric cancer is essential to select less invasive treatment options and even avoid surgery. The aim of this study was to evaluate combined clinicopathological features to predict the presence of LNM.

METHODS

A retrospective review of data from 386 intramucosal gastric cancer patients who underwent gastrectomy with extended lymphadenectomy from 2003 to 2010 was conducted. The mutual relation between clinicopathological characteristics and LNM was analyzed.

RESULTS

LNM was detected in 40 (10.4%) of the 386 patients. Histological type and vascular or lymphatic invasion presence showed a positive correlation with LNM occurrence by univariate analysis. Multivariate analysis revealed that histological type was the only factor associated with LNM. Combined clinicopathologic characteristics would be more predictable for LNM. We found no LNM when we used combined clinicopathological characteristics conforming to Japanese absolute indications for endoscopic therapy. The LNM rate was as high as 8.7% when Japanese expanded criteria were used. Univariate analysis in cancer conformity to expand endoscopic submucosal dissection (ESD) indication also revealed that the undifferential type was the only significant factor for LNM.

CONCLUSIONS

It was possible to predict intramucosal gastric cancer cases without LNM using combined clinicopathological characteristic analysis. Extended indication for ESD should be cautiously used for intramucosal gastric cancer patients.

Additional surgery for non-curative resection after endoscopic submucosal dissection for gastric cancer: a retrospective analysis of 200 cases

PURPOSE

Endoscopic submucosal dissection is recommended for early gastric cancer with a low risk of lymph node metastasis. When the pathological findings do not meet the curative criteria; then, an additional gastrectomy with lymph node dissection is recommended. However, most cases have neither lymph node metastasis nor a local residual tumor during an additional surgery.

METHODS

This was a single-institutional retrospective cohort study, analyzing 200 patients who underwent an additional gastrectomy after non-curative endoscopic submucosal dissection from January 2005 to October 2015. We reviewed the patients' clinicopathological data and evaluated the predictors for the presence of a residual tumor.

RESULTS

Histopathology revealed lymph node metastasis in 15 patients (7.5 %) and a local residual tumor in 23 (11.5 %). A multivariable analysis revealed macroscopic findings (flat/elevated type) (p = 0.011, odds ratio = 4.63), lymphatic invasion (p < 0.0001, odds ratio = 14.2), and vascular invasion (p = 0.04, odds ratio = 4.00) to be predictors for lymph node metastasis. A positive vertical margin (p = 0.0027, odds ratio = 3.26) and horizontal margin (p = 0.0008, odds ratio = 5.74) were predictors for a local residual tumor. All cases with lymph node metastasis had lymphovascular invasion with at least one other non-curative factor.

CONCLUSIONS

The risk of a residual tumor can, therefore, be estimated based on the histopathology of endoscopic submucosal dissection samples. Lymphovascular invasion appears to be a pivotal predictor of lymph node metastasis.

Predictive factors for lymph node metastasis in additional gastrectomy after endoscopic resection of cT1aN0 gastric cancer

PURPOSE

Endoscopic therapy for clinical T1aN0 (cT1aN0) gastric cancer is an excellent therapeutic strategy; however, pathological lymph node metastasis (LNM) occasionally occurs. Patients who have a potential for LNM are subject to additional gastrectomy. Our aim was to identify predictors of LNM in additional gastrectomy.

METHODS

One hundred and twelve cT1aN0 gastric cancer patients undergoing additional gastrectomy after endoscopic resection were identified between 1997 and 2013. Predictors for LNM were initially selected by a univariate analysis and applied to a multivariate analysis.

RESULTS

(1) Twelve patients (10.7 %) had LNM following additional gastrectomy. (2) Clinicopathological factors significantly associated with LNM were the depth of invasion (SM2 or deeper, designated as SM2) (p = 0.0018) and rigorous lymphatic invasion (ly2,3) (p < 0.001). (3) The univariate predictors for LNM were applied to the multivariate logistic regression model, and SM2 (p = 0.0027) and ly2,3 (p = 0.0028) remained significant predictors. (4) When classified into 2 × 2 subgroups, the predictability for LNM was as follows: SM2 plus ly2,3 (46.7 %), SM2 plus ly0,1 (10.0 %), M,SM1 plus ly2,3 (0 %), and M,SM1 plus ly0,1 (0 %).

CONCLUSIONS

In cT1aN0 gastric cancer patients, both SM2 and ly2,3 are significant predictors for LNM that may be important as references for additional gastrectomy after endoscopic resection.

Is It Reasonable to Treat Early Gastric Cancer with Mucosal Infiltration and Well Differentiation by Endoscopic Submucosal Resection?

BACKGROUND

While limited endoscopic submucosal dissection (ESD) is increasingly applied in the treatment of early gastric cancer, preoperative prediction of lymph node metastasis is very critical for determining treatment strategies preoperatively. Thus, the aim of this study was to accurately assess the prevalence and pattern of lymph node metastasis in early gastric cancer patients and to identify the best candidates for ESD.

METHODS

From September 2008 to December 2013, a total of 539 patients with early gastric cancer were retrospectively analyzed in the present study. Of them, 503 patients underwent radical gastrectomy and 36 patients underwent ESD. The clinicopathological features were collected and correlations with lymph node metastasis were analyzed. The survival rates of patients were also analyzed.

RESULTS

Lymph node metastasis was observed in 80 of 503 patients (15.9 %). Among these, the rate for mucosal cancer was 8.3 %, and 20.1 % for submucosal cancer. By univariate analysis, risk factors for lymph node metastasis were growth pattern, tumor size, pathological type, depth of invasion, lymphatic-vascular invasion, and neural invasion. By multivariate analysis, risk factors for lymph node metastasis were tumor size, pathological type, depth of invasion, and lymphatic-vascular invasion. The incidence of lymph node metastasis was 0 % in the well-differentiated mucosal cancers, irrespective of tumor size. For the well-differentiated mucosal cancers, the overall survival rates were comparable between patients underwent gastrectomy with lymph node dissection and patients underwent ESD (100 vs 100 %).

CONCLUSIONS

The most important factors for predicting lymph node metastasis in early gastric cancer are tumor size, pathological type, depth of invasion, and lymphatic-vascular invasion. Well-differentiated mucosal gastric cancers could be candidates for ESD.

Difficulty of predicting the presence of lymph node metastases in patients with clinical early stage gastric cancer: a case control study

BACKGROUND

The relationship between pathological factors and lymph node metastasis of pathological stage early gastric cancer has been extensively investigated. By contrast, the relationship between preoperative factors and lymph node metastasis of clinical stage early gastric cancer has not been investigated. The present study was to investigate discrepancies between preoperative and postoperative values.

METHODS

From January 2011 to December 2013, 1042 patients with clinical stage early gastric cancer who underwent gastrectomy with lymphadenectomy were enrolled. Preoperative and postoperative values were collected for subsequent analysis. Receiver operating characteristics curves were computed using independent predictive factors.

RESULTS

Several discrepancies were observed between preoperative and postoperative values, including existence of ulcer, gross type, and histology (all McNemar p-values were <0.001). Multivariate analyses identified the following independent predictive factors for lymph node metastasis: postoperative values including age (p = 0.002), tumor size (p < 0.001), and tumor depth (p < 0.001); preoperative values including age (p = 0.017), existence of ulcer (p = 0.037), tumor size (p = 0.009), and prediction of the presence of lymph node metastasis in computed tomography scans (p = 0.002). These postoperative and preoperative independent predictive factors produced areas under the receiver operating characteristics curves of 0.824 and 0.660, respectively.

CONCLUSIONS

Surgeons need to be aware of limitations in preoperative predictions of the presence of lymph node metastasis for clinical stage early gastric cancer.

Optimal management for patients not meeting the inclusion criteria after endoscopic submucosal dissection for gastric cancer

BACKGROUND

The necessity of additional gastrectomy for patients not meeting the inclusion criteria after endoscopic submu cosal dissection (ESD) is controversial. The aim of this study was to elucidate the risk factors for lymph node metastasis (LNM) and residual cancer (RC) in patients not meeting the inclusion criteria after ESD and to determine additional treatment strategies.

METHODS

Of 1443 gastric cancer patients who underwent ESD between 2004 and 2013, 167 patients diagnosed as having a lesion not meeting the inclusion criteria after ESD were retrospectively analyzed. Of the 167 cases, 100 cases underwent additional gastrectomy, and 67 cases were observed without surgery.

RESULTS

Overall, 9.0 % (9/100) and 9.0 % (9/100) of patients not meeting the inclusion criteria after ESD presented with LNM and RC, respectively, but neither was observed in 83 patients (83.0 %). Multivariate analysis revealed that lymphovascular involvement (LVI) (OR 38.38; 95 % CI 1.94-761.43, p = 0.017) and undifferentiated type (OR 45.58; 95 % CI 2.88-720.94, p = 0.007) were independent risk factors for LNM, and positive horizontal margin was an independent risk factor for RC (OR 9.48; 95 % CI 1.72-52.13, p = 0.010). In differentiated types without LVI, no cases had LNM (0/38) in the additional gastrectomy group, and there was no lymph node or distant recurrence (0/39) in the observation group.

CONCLUSIONS

Additional treatment is necessary for patients with LVI, undifferentiated type, and positive horizontal margin. Careful follow-up may be acceptable for patients with the differentiated type without LVI, especially for the elderly or patients with severe comorbidities.

Prospective Multicenter Feasibility Study of Laparoscopic Sentinel Basin Dissection for Organ Preserving Surgery in Gastric Cancer: Quality Control Study for Surgical Standardization Prior to Phase III Trial

The clinical application of sentinel node biopsies in early gastric cancer is still controversial even though it appears promising. This study was conducted as a prerequisite quality control for surgical standardization of laparoscopic sentinel basin dissection (SBD) prior to the initiation of a phase III trial.Laparoscopic SBD was performed in patients with preoperative stage T1-2N0 and tumor size <4 cm in diameter. Intraoperative endoscopic submucosal injection of a standardized dual tracer was administered. All retrieved sentinel basin nodes (SBN) were investigated with intraoperative frozen hematoxylin and eosin (H&E) staining. A strict checklist consisting of 7 essential steps was followed during laparoscopic SBD as the quality control study for a phase III trial. Completion of all essential steps in the checklist for 10 cases was used to define a qualified institution.Seven institutions participated and 112 patients were enrolled in this study. However, 4 patients were excluded owing to screening failure. The mean number of cases required for institutional qualification was 15 cases (range, 13-20 cases). Sentinel basins (SB) were detected and dissected in 100 of the 108 patients (92.6%); the median number of SB and SBN was 2 and 7, respectively. Lymph node metastases were detected in 10 patients by postoperative permanent H&E staining and they were detected by SBD in all 10 patients. Frozen results of SBN were compatible with permanent staining reports.Laparoscopic SBD is feasible and demonstrated improved sensitivity in detecting metastatic lymph nodes compared to the previous study. A future phase III randomized trial comparing laparoscopic SBD with organ-preserving gastrectomy and laparoscopic standard gastrectomy seems promising for qualified institutions.

Effect of rescue surgery after non-curative endoscopic resection of early gastric cancer

BACKGROUND

Whether rescue surgery confers a survival benefit in patients undergoing non-curative endoscopic resection of early gastric cancer remains controversial.

METHODS

This was a retrospective review of patients who underwent non-curative endoscopic resection of at least one lesion of differentiated-type early gastric cancer between 2000 and 2011. Patients with a positive lateral resection margin as the only non-curative factor were excluded. Outcome was investigated by univariable (Kaplan-Meier) and multivariable (Cox proportional hazards) analysis.

RESULTS

Some 341 patients underwent non-curative endoscopic resection for at least one lesion of differentiated-type early gastric cancer. Sixty-seven patients with a positive lateral resection margin as the only non-curative factor were excluded, leaving 274 patients for analysis; 194 had rescue surgery and 80 had no additional treatment. The median duration of follow-up was 60·5 months. Patients who had rescue surgery were younger, had a lower Charlson co-morbidity index score, smaller tumours and a higher lymphovascular invasion rate than patients with no treatment. Among 194 patients who had rescue surgery, intragastric local residual tumours were found in ten (5·2 per cent) and lymph node metastases in 11 (5·7 per cent). Patients with lymph node metastasis were significantly older than those without metastasis; no other significant differences were found. Univariable analysis showed that patients aged less than 65 years, those with a Charlson co-morbidity index score below 4 and patients undergoing rescue surgery had significantly longer overall survival. Five-year overall survival rates in the rescue surgery and no-treatment groups were 94·3 and 85 per cent respectively. In multivariable analysis, rescue surgery was identified as the only independent predictor of overall survival after non-curative endoscopic resection of early gastric cancer.

CONCLUSION

Rescue surgery confers a survival benefit after non-curative endoscopic resection of early gastric cancer.

Frequency of lymph node metastasis according to the size of tumors in resected pulmonary adenocarcinoma with a size of 30 mm or smaller

Background:

This study analyzed the relation between the tumor size and the lymph node metastasis in adenocarcinoma of the lung with a size of 30 mm or smaller.

Methods:

Four hundred thirteen patients who had undergone curative resection for lung adenocarcinoma were enrolled. If the tumor presented ground-glass opacities on the preoperative high-resolution computed tomography, both the total size including ground-glass opacities and the solid size alone were measured. To calculate the rates of lymph node metastasis by the tumor size, the tumors were divided into six groups by their sizes: 5 mm or less, 6 to 10 mm, 11 to 15 mm, 16 to 20 mm, 21 to 25 mm, and 26 to 30 mm.

Results:

The average numbers of dissected lymph nodes and dissected lymph node stations were 17 and 5, respectively. Seventy-five patients (18%) were postoperatively discovered to have positive nodes. The rates of node metastasis in each total size group were 0/1 (0%), 0/29 (0%), 5/77 (7%), 17/121 (14%), 27/101 (27%), and 26/84 (31%), respectively. The rates of node metastasis in each solid size group were 0/37 (0%), 1/53 (2%), 9/88 (10%), 17/104 (16%), 23/78 (30%), and 25/53 (47%), respectively. The area under the curve of receiver operating characteristic curves for the total size was measured as 0.701, and that for the solid size was measured as 0.777. By multivariate analysis, solid size, maximum standardized uptake value, and lymphovascular invasion were independent significant predictive factors.

Conclusions:

Solid size, maximum standardized uptake value, and lymphovascular invasion were independent predictors for lymph node metastasis of lung adenocarcinoma. The size of the solid component explained the relation between the tumor size and the lymph node metastasis more accurately than that explained by the total tumor size on high-resolution computed tomography.

Predictors of lymph node metastasis in patients with non-curative endoscopic resection of early gastric cancer

BACKGROUND

Although surgery is recommend for non-curative endoscopic resection of early gastric cancer (EGC), only a part of patients are found to have lymph node (LN) metastasis. This study aimed to identify the predictors of LN metastasis in patients with non-curative endoscopic resection.

METHODS

Between April 2005 and July 2013, consecutive patients who received non-curative endoscopic resection and then underwent gastrectomy with lymphadenectomy or followed at least 1 year with abdominal computed tomography were retrospectively enrolled at a single tertiary hospital. Non-curative resection was defined as a resection beyond the expanded criteria in pathologic mapping. The predictors for LN metastasis were identified by fitting a multivariate logistic regression model.

RESULTS

Among the 1783 consecutive patients who received endoscopic resection of EGC, non-curative resection was performed in 323 (18.1%) patients. Of these patients, a total of 267 patients were enrolled, and the rate of LN metastasis was 6.7% (18/267). In multivariate analysis, venous invasion [odds ratio (OR), 7.83; 95% confidence interval (CI) 2.20-27.86; p = 0.001], sm2 invasion (tumor invasion ≥500 µm into submucosa; OR 4.98; 95% CI 1.34-18.47; p = 0.016), or antral tumor location (OR 12.65; 95% CI 1.57-102.00; p = 0.017) were independent predictors for LN metastasis. The rates of LN metastasis were 1.1% (95% CI 0-2.7) for patients with one or no predictor and 17.8% (95% CI 9.7-25.8) for those with two or more predictors.

CONCLUSIONS

Additional gastrectomy with lymphadenectomy after non-curative endoscopic resection of EGC is recommended for the patients with two or more identified predictors. However, close follow-up without immediate surgery might be considered cautiously for those with only one or no predictor.

Long-term clinical outcomes of endoscopic resection for early gastric cancer

BACKGROUND

We aimed to evaluate long-term clinical outcomes of endoscopic resection for early gastric cancer (EGC).

PATIENTS AND METHODS

From 2005 through 2011, 961 patients with EGC were treated with endoscopic submucosal dissection (ESD). Patients were grouped as standard and expanded criteria, while those who did not meet the expanded criteria were regarded as the group beyond the expanded criteria. Complete resection rate and the long-term clinical outcomes were compared among the three groups.

RESULTS

Complete resection rate was significantly higher in the standard group than in expanded and beyond the expanded group; 96.1% for standard, 92.5% for expanded, 55.5% for beyond the expanded indication group. During a mean follow-up of 42 months, local tumor recurrence developed more frequently in beyond the expanded group (7.8%) than in the standard and expanded group (1.8%). Metachronous cancer incidence (6.5%) did not differ significantly between the three groups. Two-thirds of recurred or metachronous tumors were treated with additional ESD. Lymph node metastasis developed in 0.6%. Five-year overall survival rate was 94.8% (96.6% for standard, 94.2% for expanded, 84.4% for beyond expanded, P < 0.001) and disease-free survival rate was 99.1% (100, 99.3, 92.8%, respectively, P < 0.001).

CONCLUSIONS

Endoscopic resection for EGC showed favorable long-term clinical outcomes in the patients within the standard and expanded criteria, whereas less favorable clinical outcomes in the patients beyond the expanded criteria.

Tumor differentiation is not a risk factor for lymph node metastasis in elderly patients with early gastric cancer

BACKGROUND

The aim of this study was to identify risk factors for lymph node metastasis in elderly patients (70 years or more) with early gastric cancer.

METHODS

We reviewed the prospectively collected database of 6893 patients with early gastric cancer who had undergone curative gastrectomy in 3 tertiary cancer centers between January 2003 and December 2009 in Korea. Patients were sorted into 4 groups according to age: less than 50, fifties, sixties, and 70 years or more. Risk factors for lymph node metastasis in early gastric cancer were analyzed.

RESULTS

One thousand and thirty five patients (15.0%) were 70 years or more. As age increased, the frequency of large differentiated tumor, lymphatic and submucosa invasion increased. Old age was associated with a lower risk for lymph node metastasis in patients with early gastric cancer (Odds ratio [OR], OR, 0.622; 95% CI, 0.5466-0.830, P = 0.010). Ulceration or differentiation of tumor was not associated with lymph node metastasis in elderly patients with early gastric cancer.

CONCLUSIONS

Elderly patients with undifferentiated type histology early gastric cancer without other risk factors for lymph node metastasis may be candidates for endoscopic resection.

Prognostic role of lymph node metastasis in early gastric cancer

OBJECTIVE

To clarify the relationship between clinicopathological features and lymph node metastasis and to propose the potential indications of lymph node metastasis for prognosis in early gastric cancer (EGC) patients.

METHODS

We retrospectively observed 226 EGC patients with lymph node resection, and analyzed the associations between lymph node metastasis and clinicopathological parameters using the chi-square test in univariate analysis and logistic regression analysis in multivariate analysis. Overall survival analysis was determined using the Kaplan-Meier and log-rank test. We conducted multivariate prognosis analysis using the Cox proportional hazards model.

RESULTS

Of all the EGC patients, 7.5% (17/226) were histologically shown to have lymph node metastasis. The differentiation, lymphovascular invasion and depth of invasion were independent risk factors for lymph node metastasis in EGC. The 5- and 10-year survival rates were significantly lower in patients with lymph node metastasis than in those without and the patients also had shorter progress-free survival time. Lymph node metastasis and tumor size were independent prognostic factors for EGC. The status of the lymph nodes was a significant factor in predicting recurrence or metastasis after surgery.

CONCLUSIONS

The undifferentiated carcinoma and lymphovascular and/or submucosal invasion were associated with a higher incidence of lymph node metastasis in EGC patients, whom need to perform subsequent D2 lymphadenectomy or laparoscopic lymph node dissection and more rigorous follow-up or additional chemotherapy/radiation after D2 gastrectomy for poor prognosis and high recurrence/metastasis rate.