Endoscopic Resection for Undifferentiated-Type Early Gastric Cancer: Immediate Endoscopic Outcomes and Long-Term Survivals

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.

Endoscopic treatment for early gastric cancer

Background: In Korea, the number of screening endoscopies to detect early stage gastric neoplasms has increased exponentially following the active implementation of the National Cancer Screening Program.Current Concepts: Endoscopic treatment, including endoscopic mucosal resection and endoscopic submucosal dissection, is recognized as a minimally invasive treatment method with low morbidity and mortality for gastric dysplasia or early gastric cancer. Owing to improvement in the detection of early gastric cancer and advances in techniques, cases of endoscopic resection have increased and indications have been expanded. Endoscopic resection can preserve gastric function with excellent maintenance of the patient’s quality of life, and previous studies have shown better long-term follow-up outcomes compared to those with surgery. However, the fundamental limitation of endoscopic procedures is that gastric lymph-node dissection is not possible using endoscopic resection.Discussion and Conclusion: Although the usefulness of endoscopic resection is proven for tumors with a very low risk of lymph-node metastasis, follow-up examination using endoscopy and computed tomography should be performed for at least 5 years after curative resection of early gastric cancer.

Diffuse-type Gastric Cancer

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

Scoring Model Based on Nodal Metastasis Prediction Suggesting an Alternative Treatment to Total Gastrectomy in Proximal Early Gastric Cancer

Purpose

Total gastrectomy (TG) with lymph node (LN) dissection is recommended for early gastric cancer (EGC) but is not indicated for endoscopic resection (ER). We aimed to identify patients who could avoid TG by establishing a scoring system for predicting lymph node metastasis (LNM) in proximal EGCs.

Materials and Methods

Between January 2003 and December 2017, a total of 1,025 proximal EGC patients who underwent TG with LN dissection were enrolled. Patients who met the absolute ER criteria based on pathological examination were excluded. The pathological risk factors for LNM were determined using univariate and multivariate logistic regression analyses. A scoring system for predicting LNM was developed and applied to the validation group.

Results

Of the 1,025 cases, 100 (9.8%) showed positive LNM. Multivariate analysis confirmed the following independent risk factors for LNM: tumor size >2 cm, submucosal invasion, lymphovascular invasion (LVI), and perineural invasion (PNI). A scoring system was created using the four aforementioned variables, and the areas under the receiver operating characteristic curves in both the training (0.85) and validation (0.84) groups indicated excellent discrimination. The probability of LNM in mucosal cancers without LVI or PNI, regardless of size, was <2.9%.

Conclusions

Our scoring system involving four variables can predict the probability of LNM in proximal EGC and might be helpful in determining additional treatment plans after ER, functioning as a good indicator of the adequacy of treatments other than TG in high surgical risk patients.

Incidence and treatment outcomes of metachronous gastric cancer occurring after curative endoscopic submucosal dissection of undifferentiated-type early gastric cancer: Japan Clinical Oncology Group study-post hoc analysis of JCOG1009/1010

BACKGROUND AND AIMS

A drawback of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is the development of metachronous gastric cancer (MGC). While MGC after ESD for differentiated-type (D-) EGC was well understood, little is known about MGC occurring after ESD for undifferentiated-type (UD-) EGC, because ESD had not been indicated. We evaluated the incidence and treatment outcomes of MGC after ESD of UD-EGC.

METHODS

This study is a post hoc analysis of JCOG1009/1010, a multicenter trial to evaluate the efficacy and safety of ESD for UD-EGC. The patients who underwent curative ESD of index solitary UD-EGC were analyzed. Surveillance endoscopy was performed biannually for the first 3 years and thereafter annually. We assessed the time to MGC occurrence after ESD, lesion characteristics, and treatment outcomes of MGC. Time to MGC occurrence was estimated by cumulative incidence function, with death and total gastrectomy as competing risks.

RESULTS

A total of 198 patients were included in this study. During a median follow-up period of 5.8 years, 4 patients (2%) developed MGC. Median time to MGC occurrence was 4.5 years (range: 3.1-5.4). Five-year cumulative incidence of MGC was 1.0% (95% CI: 0.2-3.3%). Two MGCs were histologically D-EGC, and the remaining two were UD-EGC. The median tumor size of MGCs was 1.0 cm (range: 0.7-1.7), and the depth of invasion (M/SM1/SM2) was 2/1/1, respectively. Three patients achieved curative resection with repeated ESD.

CONCLUSIONS

MGC does not occur commonly after curative ESD of UD-EGC, and repeated ESD could contribute to stomach preservation.

Controversies in EUS: Do we need miniprobes?

This is the fifth in a series of papers entitled "Controversies in EUS." In the current paper, we deal with high-resolution catheter probes, otherwise known as EUS miniprobes (EUS-MPs). The application of miniprobes for early carcinomas in the entire intestinal tract, for subepithelial lesions, and for findings in the bile duct and pancreatic duct as well as endobronchial use is critically discussed. Submucous lesions, especially in the colon, but also early carcinomas in special cases are considered the most important indications. The argument is illustrated by numerous examples.

[Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer]

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Comparison between endoscopic submucosal resection and surgery for the curative resection of undifferentiated-type early gastric cancer within expanded indications: a nationwide multi-center study

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) for undifferentiated early gastric cancer (UD EGC) has debate due to the risk of lymph node metastasis. We investigated the outcomes of ESD compared to those of surgery for the UD EGC within expanded indication.

METHODS

We reviewed 971 UD EGC patients performed ESD across 18 hospitals in Korea and 1812 patients who underwent surgical resection in two hospitals between February 2005 and May 2015. Of these cases, we enrolled a curative resected ESD group of 328 patients and surgery group of 383 cases within an expanded indication. Overall outcomes and one-to-one propensity score-matched (218 ESD group vs 218 surgery group cases) outcomes for these two groups were analyzed.

RESULTS

Over the 75.6 month median follow-up period for the 711 enrolled cases, recurrences occurred in 22 patients (6.7%) in the ESD group but not in the surgery group. Overall survival (OS) was higher in the surgery group (p = 0.0316) in all cases, but there was no significant difference after propensity score matching (p = 0.069). According to the histologic type in propensity score matching, the OS of signet ring cell carcinoma and poorly differentiated carcinoma patients did not differ between the ESD and surgery groups (p = 0.1189 and p = 0.3087, respectively). In the surgery group involving expanded criteria, lymph node metastasis was found in six cases (1.56%).

CONCLUSIONS

Although ESD shows comparable outcomes to surgery for the UD EGC within expanded indications, appropriate patient selection is needed for the ESD due to the possibility of lymph node metastasis.

Clinical practice guideline for endoscopic resection of early gastrointestinal cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Prediction model for curative endoscopic submucosal dissection of undifferentiated-type early gastric cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) is an effective treatment for early gastric cancer (EGC); however, its curative resection rate is low for undifferentiated-type EGC. We developed and externally validated a prediction model for curative ESD of undifferentiated-type EGC.

METHODS

In this cross-sectional study, we included 448 patients who underwent ESD for undifferentiated-type EGC at 18 hospitals in Korea between 2005 and 2015 in the development cohort and 1342 patients who underwent surgery at two hospitals in the validation cohort. A prediction model was developed using the logistic regression model.

RESULTS

Endoscopic tumor size 1-2 cm (odds ratio [OR], 2.40; 95% confidence interval [CI] 1.54-3.73), tumor size > 2 cm (OR, 14.00; 95% CI 6.81-28.77), and proximal tumor location from the lower to upper third of the stomach (OR, 1.45; 95% CI 1.03-2.04) were independent predictors of non-curative ESD. A six-score prediction model was developed by assigning points to endoscopic tumor size > 2 cm (five points), tumor size 1-2 cm (two points), upper third location (two points), and middle third location (one point). The rate of curative ESD ranged from 70.6% (score 0) to 11.6% (score 5) with an area under the receiver operating characteristic curve (AUC) of 0.720 (95% CI 0.673-0.766). The model also showed good performance in the validation cohort (AUC, 0.775; 95% CI 0.748-0.803).

CONCLUSIONS

This six-score prediction model may help in predicting curative ESD and making informed decisions about the treatment selection between ESD and surgery for undifferentiated-type EGC.

Clinical outcomes of endoscopic resection for undifferentiated intramucosal early gastric cancer larger than 2 cm

BACKGROUND

This study investigated the long-term clinical outcomes of endoscopic resection (ER) for undifferentiated-type (UD) early gastric cancer (EGC), with tumor size > 2 cm as the only non-curative factor.

METHODS

From among 1123 patients who underwent ER for UD EGC at 18 tertiary hospitals in Korea between 2005 and 2014, we identified 216 patients with UD intramucosal EGC > 2 cm, which was completely resected, with negative resection margins, and absence of ulceration and lymphovascular invasion. The patients were divided into the additional surgery (n = 40) or observation (n = 176) groups, according to post-ER management and were followed up for a median duration of 59 months for recurrence and 90 months for overall survival.

RESULTS

Lymph node (LN) or distant metastasis or cancer-related mortality was not observed in the surgery group. In the observation group, two (1.1%) patients developed LN or distant metastasis with a 5-year cumulative risk of 0.7%, and one (0.6%) patient died of gastric cancer. The 5- and 8-year overall survival rates were 94.1% and 89.9%, respectively, in the observation group and 100.0% and 95.2%, respectively, in the surgery group (log-rank P = 0.159). Cox regression analysis did not reveal an association between the observation group and increased mortality.

CONCLUSION

The risk of LN or distant metastasis was not negligible, but as low as 1% for patients undergoing non-curative ER for UD EGC, with tumor size > 2 cm as the only non-curative factor. Close observation may be an alternative to surgery, especially for older patients or those with poor physical status.

Endoscopic Resection of Undifferentiated-type Early Gastric Cancer

Early detection of gastric cancer is crucial because the survival rate can be improved through curative treatment. Although surgery and gastrectomy with lymph node dissection remain as the gold standard for curative treatment, early gastric cancer (EGC) with negligible risk of lymph node metastasis can be treated with endoscopic resection (ER), such as endoscopic submucosal dissection. Among gastric cancers, undifferentiated-type cancer is distinguished from differentiated-type cancer in various aspects in terms of clinical features and pathophysiology. The undifferentiated-type cancer is also known to be associated with an aggressive behavior and a poor prognosis. Therefore, the indication of ER for undifferentiated EGC is limited compared with differentiated-type. Recent studies have reported that ER for undifferentiated EGC is safe and shows favorable short- and long-term outcomes. However, it is necessary to understand the details of the research results and to selectively accept them. In this review, we aimed to evaluate the current practice guidelines and the short-term and long-term outcomes of ER for undifferentiated type EGC.

Clinicopathological Features and Prognostic Implication of Gastric Carcinoma with Lymphoid Stroma

Methods

This study included 34 eligible studies and 1757 GCLSs. The clinicopathologic characteristics of GCLS were investigated from eligible studies, and the meta-analysis was performed. In addition, we compared the survival rates between GCLS and non-GCLS.

Results

The estimated rate of GCLS was 0.062 (95% confidence interval (CI) 0.040-0.097). GCLS was significantly correlated with the diffuse type of Lauren's classification, proximal tumor location, less-frequent lymphatic invasion, and lower pTNM stage. However, there was no significant difference in age, sex, tumor differentiation, vascular invasion, perineural invasion, pT stage, lymph node metastasis, and distant metastasis between GCLS and non-GCLS patients. EBV positive rates in GCLS and non-GCLS patients were 0.723 (95% CI 0.643-0.791) and 0.064 (95% CI 0.039-0.103), respectively. HER2 expression in GCLS was significantly lower than that in non-GCLS. GCLS patients had a more favorable prognosis than that of non-GCLS patients (hazard ratio 0.500, 95% CI 0.305-0.821).

Conclusion

GCLS comprised 6.2% of overall GC and more frequent in the proximal portion of the stomach. Since GCLS was associated with better prognosis, the histologic finding can be useful for predicting the patient's prognosis.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Long-term outcomes of endoscopic submucosal dissection versus surgery for treating early gastric cancer of undifferentiated-type

Application of endoscopic submucosal dissection (ESD) for treating undifferentiated-type early gastric cancers (EGCs) remains controversial. Therefore, we aimed to compare long-term outcomes of ESD with those of surgery for patients with undifferentiated-type EGCs by a retrospective study.We retrospectively reviewed data of patients who underwent curative ESD or gastrectomy for undifferentiated-type EGCs between 2010 and 2017. Gastric cancers were undifferentiated-type adenocarcinoma without ulceration confined to the mucosal layer and 2 cm or smaller in size. Demographics, complications, recurrence cancer rates, and survival data were collected and compared.Forty patients who underwent curative ESD and 52 patients who underwent surgery were included. The median follow-up duration was 74.6 months. There was no significant difference of metachronous gastric cancer rate (5.0% vs 3.8%, P = .75) or total cancer recurrence rate (10.0% vs 3.8%, P = .33) between the 2 groups. The 5-year overall survival, disease-free survival, recurrence-free survival rates did not significantly differ between the 2 groups (P = .72, .26, .27 respectively). There were no gastric cancer-related deaths in either group.Long-term outcomes after curative ESD for undifferentiated-type EGCs that met the expanded indication were comparable to that achieved with surgery. ESD without additional surgery is an acceptable choice to treat undifferentiated-type EGCs that meet the curative criteria.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by <i>en bloc</i> fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Possible indication of endoscopic resection in undifferentiated early gastric cancer

Endoscopic resection for early gastric cancer (EGC) without lymph node metastasis may be a valuable treatment option. To date, endoscopic resection for undifferentiated EGC is being investigated. We evaluated the risk of lymph node metastasis in undifferentiated EGC by examining the preoperative endoscopic findings and operated pathologic specimen. The medical records of patients who underwent surgical resection because of undifferentiated EGC between November 2008 and December 2015 were reviewed retrospectively. The risk factors associated with lymph node metastasis and the lymph node metastasis rate in the expanded indication of undifferentiated EGC were evaluated. A total of 376 patients with undifferentiated EGC (233 signet ring cell type and 143 poorly differentiated type) were analyzed. Lymph node metastasis was found in 9.8% of the patients. Among the patients who met the expanded criteria (59 patients), only one patient had lymph node metastasis (signet ring cell type without ulceration and 15 mm in size). The risk factors associated with lymph node metastasis were lesion size >20 mm (OR 3.013), scar deformity (OR 2.248), surface depression (OR 2.360), submucosal invasion (OR 3.427), and lymphovascular invasion (OR 6.296). Before endoscopic resection of undifferentiated EGC, careful selection of patients should be considered. The undifferentiated EGC with size ≥15 mm, scar deformity, surface depression, submucosal invasion, and lymphovascular invasion should be considered surgical resection instead of endoscopic resection.

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.

A Single-Center Experience of Endoscopic Resection for Early Gastric Cancer with Lymphoid Stroma

Purpose

This study aimed to evaluate immediate outcomes and clinical courses of patients with early gastric carcinoma with lymphoid stroma (GCLS) who underwent endoscopic resection.

Materials and Methods

We retrospectively reviewed the medical records of 40 patients (mean age, 56.9 years; 90.0% male) who underwent endoscopic resection and were pathologically diagnosed with GCLS confined to the mucosa or to the submucosa between March 1998 and December 2017.

Results

Forty GCLS lesions in 40 patients were treated using endoscopic resection. Only 4 (10%) patients received diagnosis of GCLS before endoscopic resection. Fourteen (35.0%) lesions were intramucosal cancers and 26 (65.0%) exhibited submucosal invasion. En bloc resection (97.5%) was achieved for all lesions except one, with no significant complications. The complete resection rate was 85.0% (34 of 40 lesions). After endoscopic resection, 17 patients were referred for surgery and underwent gastrectomy with lymph node (LN) dissection because of deep submucosal invasion (n=16) and misclassification as undifferentiated cancer (n=1). No LN metastasis was determined in the specimens obtained during surgery. During a mean follow-up period of 49.7 months for 23 patients without surgical treatment, no regional LN enlargements, distant metastases, or gastric cancer-related deaths were found, although 1 metachronous lesion (undifferentiated adenocarcinoma, follow-up duration: 7 months) was observed.

Conclusions

In patients with early GCLS, endoscopic resection is technically feasible and has favorable clinical outcomes. Therefore, endoscopic resection might represent an alternative treatment modality in patients with early GCLS with a low likelihood of LN metastasis.

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.

Predictive factors for lymph node metastasis and defining a subgroup treatable for laparoscopic lymph node dissection after endoscopic submucosal dissection in poorly differentiated early gastric cancer

AIM

To investigate the predictive factors of lymph node metastasis (LNM) in poorly differentiated early gastric cancer (EGC); to guide the individual application of a combination of endoscopic submucosal dissection (ESD) and laparoscopic lymph node dissection (LLND) in a suitable subgroup of patients with poorly differentiated EGC.

METHODS

We retrospectively analyzed 138 patients with poorly differentiated EGC who underwent gastrectomy with lymphadenectomy between January 1990 and December 2015. The association between the clinicopathological factors and the presence of LNM was retrospectively analyzed by univariate and multivariate logistic regression analyses. Odds ratios (OR) with 95% confidence interval (95%CI) were calculated. We further examined the relationship between the positive number of the significant predictive factors and the LNM rate.

RESULTS

The tumor diameter (OR = 13.438, 95%CI: 1.773-25.673, P = 0.029), lymphatic vessel involvement (LVI) (OR = 38.521, 95%CI: 1.975-68.212, P = 0.015) and depth of invasion (OR = 14.981, 95%CI: 1.617-52.844, P = 0.024) were found to be independent risk factors for LNM by multivariate analysis. For the 138 patients diagnosed with poorly differentiated EGC, 21 (15.2%) had LNM. For patients with one, two and three of the risk factors, the LNM rates were 7.7%, 47.6% and 64.3%, respectively. LNM was not found in 77 patients that did not have one or more of the three risk factors.

CONCLUSION

ESD might be sufficient treatment for intramucosal poorly differentiated EGC if the tumor is less than or equal to 2 cm in size and when LVI is absent upon postoperative histological examination. ESD with LLND may lead to the elimination of unnecessary gastrectomy in poorly differentiated EGC.

Long-term outcomes of endoscopic submucosal dissection versus surgery in early gastric cancer meeting expanded indication including undifferentiated-type tumors: a criteria-based analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) meeting the expanded indication is considered investigational. We aimed to compare long-term outcomes of ESD and surgery for EGC in the expanded indication based on each criterion.

METHODS

This study included 1823 consecutive EGC patients meeting expanded indication conditions and treated at a tertiary referral center: 916 and 907 patients underwent surgery or ESD, respectively. The expanded indication included four discrete criteria: (I) intramucosal differentiated tumor, without ulcers, size >2 cm; (II) intramucosal differentiated tumor, with ulcers, size ≤3 cm; (III) intramucosal undifferentiated tumor, without ulcers, size ≤2 cm; and (IV) submucosal invasion <500 μm (sm1), differentiated tumor, size ≤3 cm. We selected 522 patients in each group by propensity score matching and retrospectively evaluated each group. The primary outcome was overall survival (OS); the secondary outcomes were disease-specific survival (DSS), recurrence-free survival (RFS), and treatment-related complications.

RESULTS

In all patients and subgroups meeting each criterion, OS and DSS were not significantly different between groups (OS and DSS, all patients: p = 0.354 and p = 0.930; criteria I: p = 0.558 and p = 0.688; criterion II: p = 1.000 and p = 1.000; criterion III: p = 0.750 and p = 0.799; and criterion IV: p = 0.599 and p = 0.871). RFS, in all patients and criterion I, was significantly shorter in the ESD group than in the surgery group (p < 0.001 and p < 0.003, respectively). The surgery group showed higher rates of late and severe treatment-related complications than the ESD group.

CONCLUSIONS

ESD may be an alternative treatment option to surgery for EGCs meeting expanded indications, including undifferentiated-type tumors.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: short- and long-term outcomes

BACKGROUND AND AIMS

Application of endoscopic submucosal dissection (ESD) for undifferentiated-type early gastric cancers (EGCs) remains controversial owing to limited data regarding long-term outcomes. We aimed to evaluate the feasibility of ESD for undifferentiated-type EGCs that meet the expanded criteria (EC).

METHODS

We performed a retrospective analysis of 66 patients who underwent ESD for undifferentiated-type EGC between January 2005 and December 2014. We evaluated the rates of en bloc, complete, and curative resections along with overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS).

RESULTS

Of the 66 patients, the EC group included 38 patients and the beyond-EC group included 28 patients. The overall rates of en bloc, complete, and curative resection of the 66 lesions were 92.4% (61/66), 65.2% (43/66), and 48.5% (32/66), respectively. Of the 34 patients with non-curative resection, 18 underwent additional surgery. Local remnant cancer was detected in 1 patient (1/18, 5.6%), and none of the 18 patients had lymph node metastasis. On multivariate analysis, tumors > 2 cm [odd ratio (OR) 6.183, 95% confidence interval (CI) 1.279-29.880, p = 0.023) and submucosal invasion depth (OR 6.226, 95% CI 1.881-20.606, p = 0.003) were independent predictors of incomplete resection. All 26 patients with more than 1 year of follow-up after curative resection survived without any evidence of local or distant recurrences over a median follow-up period of 36 months. The OS, DSS, and RFS rates of patients with curative ESD were 93.8, 100, and 100%, respectively.

CONCLUSIONS

ESD may have favorable long-term outcomes in patients with undifferentiated-type EGC after curative resection.

Gastric Adenocarcinoma: A Multimodal Approach

Despite its declining incidence, gastric cancer (GC) remains a leading cause of cancer-related deaths worldwide. A multimodal approach to GC is critical to ensure optimal patient outcomes. Pretherapy fine resolution contrast-enhanced cross-sectional imaging, endoscopic ultrasound and staging laparoscopy play an important role in patients with newly diagnosed ostensibly operable GC to avoid unnecessary non-therapeutic laparotomies. Currently, margin negative gastrectomy and adequate lymphadenectomy performed at high volume hospitals remain the backbone of GC treatment. Importantly, adequate GC surgery should be integrated in the setting of a multimodal treatment approach. Treatment for advanced GC continues to expand with the emergence of additional lines of systemic and targeted therapies.

Therapeutic Outcomes of Endoscopic Resection of Early Gastric Cancer with Undifferentiated-Type Histology: A Korean ESD Registry Database Analysis

Background/Aims

To assess the therapeutic outcomes of endoscopic resection (ER) of early gastric cancer (EGC) with undifferentiated-type histology.

Methods

Cases of ER of EGC with undifferentiated-type histology in the Korean endoscopic submucosal dissection (ESD) registry database were identified and reviewed. The immediate outcomes, including en bloc resection, complete resection, and curative resection rates, and long-term outcomes, including recurrence and survival rates, were extracted and analyzed.

Results

From 2006 to 2015, 275 EGCs with undifferentiated-type histology from 275 patients were identified. The immediate outcomes were as follows: en bloc resection rate: 92.4%; complete resection rate: 80%; and curative resection rate: 36.4%. Compared to patients with lesions that were beyond the expanded indication, those with expanded indication lesions showed better therapeutic outcomes. There was no difference in immediate outcomes between patients with poorly differentiated adenocarcinoma (PDC) and signet ring cell carcinoma (SRC). However, compared to ER of SRC, ER of PDC had a stronger association with submucosal invasion (41.9% vs. 23.6%, p=0.003). With regard to long-term outcomes, there was no difference between lesions with curative and non-curative resections in the recurrence and mortality rates. These rates also did not differ between PDC and SRC (median follow up: 3.96 years).

Conclusions

ER confined to expanded indication lesions can be considered for treatment of EGC with undifferentiated-type histology.

A case of undifferentiated-type mucosal gastric cancer with multiple lymph node metastases fulfilling the curative criteria for endoscopic resection according to routine pathological analysis

BACKGROUND

Endoscopic resection is accepted as the standard treatment for early mucosal gastric cancer, and its indications have recently been expanded while its long-term outcomes are still unclear. Herein, we present a didactic case of undifferentiated-type mucosal gastric cancer fulfilling the expanded indication and curative criteria for endoscopic submucosal dissection (ESD), having synchronous multiple lymph node metastases.

CASE PRESENTATION

A 40-year-old woman was found to have a Helicobacter pylori infection at a standard health check with no abdominal symptoms. She received an upper gastrointestinal endoscopy and found to have an undifferentiated-type mucosal gastric cancer with the size of 15 mm in diameter without ulceration, which fulfilled the expanded indication for ESD. According to patient's preference, we performed laparoscopy-assisted distal gastrectomy with D1+ lymph node dissection, and routine pathological analysis revealed a predominantly signet ring cell carcinoma limited to the mucosa without ulceration or any vessel involvement; on the other hand, 15 lymph node metastases were detected. Then, we added deep sectioning of the whole tumoral area at a thickness of 20 μm and immunohistochemical analyses. As the result, an isolated lymphatic capillary involvement of the extremely superficial submucosa was identified in a single histological section, and pathological diagnosis was corrected to ly1. She received postoperative adjuvant chemotherapy with an S-1 oral agent and had no recurrence under strict surveillance for 1 year postoperatively.

CONCLUSIONS

When we perform ESD for undifferentiated-type gastric cancer, deep sectioning of the whole tumoral area into thin slices and immunohistochemical staining using D2-40 should be practically considered.

Effect of World Health Organization (WHO) Histological Classification on Predicting Lymph Node Metastasis and Recurrence in Early Gastric Cancer

Background

The World Health Organization (WHO) histological classification for gastric cancer is widely accepted and used. However, its impact on predicting lymph node metastasis and recurrence in early gastric cancer (EGC) is not well studied.

Material/Methods

From 1987 to 2005, 2873 EGC patients with known WHO histological type who had undergone curative resection were enrolled in this study. In all, 637 well-differentiated adenocarcinomas (WD), 802 moderately-differentiated adenocarcinomas (MD), 689 poorly-differentiated adenocarcinomas (PD), and 745 signet-ring cell adenocarcinomas (SRC) were identified.

Results

The distribution of demographic and clinical features in early gastric cancer among WD, MD, PD, and SRC were significantly different. Lymph node metastasis was observed in 317 patients (11.0%), with the lymph node metastasis rate being 5.3%, 14.8%, 17.0%, and 6.3% in WD, MD, PD, and SRC, respectively. Univariate and multivariate analyses indicated that gender, tumor size, gross appearance, depth of invasion, and WHO classification were significantly associated with lymph node metastasis. Recurrence was observed in 83 patients (2.9%), with the recurrence rate being 2.2%, 4.5%, 3.0%, and 1.6% in WD, MD, PD, and SRC, respectively. Multivariate analysis confirmed that MD, elevated gross type, and lymph node metastasis were independent risk factors for recurrence in EGC. MD patients showed worse disease-free survival than non-MD patients (P=0.001).

Conclusions

WHO classification is useful and necessary to evaluate during the perioperative management of EGC. Treatment strategies for EGC should be made prudently according to WHO classification, especially for MD patients.

An innovative procedure of laparoscope combined with endoscopy for gastrointestinal stromal tumor resection and cholecystectomy: A case report and literature review

The present study reports a novel approach to laparoscopic and endoscopic cooperative surgery for gastric gastrointestinal stromal tumor (GIST) resection and cholecystectomy, and conducts a review of the associated literature. The novel surgical procedure was performed on one patient who was diagnosed with a GIST and cholecystic polypus. The GIST was resected using an insulation-tipped diathermic electrosurgical knife under the guide of an endoscope. Subsequently, a cholecystectomy was performed by inserting two more 5-mm trocars and instruments transumbilically, guided using an endoscope. The tumor and the gallbladder were exteriorized using a peroral approach and the incision lining of the stomach was sutured laparoscopically. The procedure was successfully performed and the patient experienced no discomfort during the 5-year follow-up. In conclusion, the present study demonstrates that laparoscopic and endoscopic cooperative surgery is feasible and would be an ideal choice for invisible abdominal scar surgery, in particular for multi-visceral resection.