Lymph node metastasis of early gastric cancer with submucosal invasion

Frequency of lymph node metastasis according to tumor location in clinical T1 early gastric cancer: supplementary analysis of the Japan Clinical Oncology Group study (JCOG0912)

BACKGROUND

The frequency of lymph node metastases per lymph node site in early gastric cancer has not been well clarified from the data based on prospective studies. This exploratory analysis aimed to determine the frequency and location of lymph node metastases in clinical T1 gastric cancer using the data from JCOG0912 to investigate the validity of the extent of standard lymph node dissection defined in Japanese guidelines.

METHODS

This analysis included 815 patients with clinical T1 gastric cancer. The proportion of pathological metastasis was identified for each lymph node site per tumor location (middle third and lower third) and four equal parts of the gastric circumference. The secondary aim was identification of the risk factor for lymph node metastasis.

RESULTS

Eighty-nine patients (10.9%) had pathologically positive lymph node metastases. Although the overall frequency of metastases was low (0.3-5.4%), metastases were widely located in each lymph node sites when primary lesion was in the middle third of the stomach. No. 4sb and 9 showed no metastasis when primary lesion was in the lower third of the stomach. Lymph node dissection of metastatic nodes resulted in a 5-year survival in more than 50% of patients. A tumor greater than 3 cm and a T1b tumor were associated with lymph node metastasis.

CONCLUSIONS

This supplementary analysis demonstrated that nodal metastasis from early gastric cancer is widely and disorderly not depending on the location. Thus, systematic lymph node dissection is necessary to cure the early gastric cancer.

Transcriptome analysis reveals the essential role of NK2 homeobox 1/thyroid transcription factor 1 (NKX2-1/TTF-1) in gastric adenocarcinoma of fundic-gland type

BACKGROUND

Gastric adenocarcinoma of fundic-gland type (GA-FG) is a gastric malignancy with little relation to Helicobacter pylori. Clinical characteristics of GA-FG have been established, but molecular mechanisms leading to tumorigenesis have not yet been elucidated.

METHODS

We subjected three GA-FG tumors-normal mucosa pairs to microarray analysis. Network analysis was performed for the top 30 up-regulated gene transcripts, followed by immunohistochemical staining to confirm the gene expression analysis results. AGS and NUGC4 cells were transfected with the gene-encoding NK2 homeobox 1/thyroid transcription factor 1 (NKX2-1/TTF-1) to evaluate transcriptional changes in its target genes.

RESULTS

Comprehensive gene expression analysis identified 1410 up-regulated and 1395 down-regulated gene probes with ≥ two-fold difference in expression. Among the top 30 up-regulated genes in GA-FG, we identified transcription factor NKX2-1/TTF-1, a master regulator of lung/thyroid differentiation, together with surfactant protein B (SFTPB), SFTPC, and secretoglobin family 3A member 2(SCGB3A2), which are regulated by NKX2-1/TTF-1. Immunohistochemical analysis of 16 GA-FG specimens demonstrated significantly higher NKX2-1/TTF-1 and SFTPB levels, as compared to that in adjacent normal mucosa (P < 0.05), while SCGB3A2 levels did not differ (P = 0.341). Transduction of NKX2-1/TTF-1 into AGS and NUGC4 cells induced transactivation of SFTPB and SFTPC, indicating that NKX2-1/TTF-1 can function as normally in gastric cells as it can in the lung cells.

CONCLUSIONS

Our first transcriptome analysis of GA-FG indicates significant expression of NKX2-1/TTF1 in GA-FG. Immunohistochemistry and cell biology show ectopic expression and normal transactivation ability of NKX2-1/TTF-1, suggesting that it plays an essential role in GA-FG development.

Clinical significance of the number of retrieved lymph nodes in early gastric cancer with submucosal invasion

The prognosis of early gastric cancer (EGC) with submucosal invasion is favorable; however, several cases of recurrence have been reported even after curative gastrectomy. This study aimed to investigate risk factors and evaluate the clinical significance of the number of retrieved lymph nodes (LNs) in EGC with submucosal invasion. We retrospectively analyzed the data of 443 patients with gastric cancer with submucosal invasion after curative gastrectomy for recurrent risk factors. Recurrence was observed in 22 of the 443 gastric cancer patients with submucosal invasion. In the univariate analysis, the risk factors for recurrence were the number of retrieved LNs ≤ 25 and node metastasis. In the multivariate analysis, retrieved LNs ≤ 25 (hazard ratio [HR] = 5.754, P-value = .001) and node metastasis (HR = 3.031, P-value = .029) were independent risk factors for recurrence after curative gastrectomy. Body mass index was related to retrieved LNs ≤ 25 in univariate and multivariate analyses (HR = .510, P = .002). The number of retrieved LNs and node metastases were independent risk factors for EGC with submucosal invasion. For EGC with submucosal invasion, retrieved LNs > 25 are necessary for appropriate diagnosis and treatment.

The prognostic role of tumor size in stage T1 gastric cancer

BACKGROUND

The purpose was to assess the contribution of tumor size to the prognosis of patients with gastric cancer.

METHODS

Patient data were sourced from the Surveillance, Epidemiology, and End Results program (SEER) database. Cox proportional risk regression was performed to determine the prognostic role of tumor size. Kaplan-Meier curves were conducted to calculate survival curves. Consistency index (c-index) and subject exercise curve (ROC) were utilized to assess the predictive ability of each factor on the prognosis of gastric cancer.

RESULTS

Tumor size is preferable to other widely accepted prognostic clinical features in forecasting the survival of patients with gastric cancer.

CONCLUSIONS

The discriminatory ability of tumor size at T1 stage is superior to many other clinical prognostic factors.

Preceding endoscopic submucosal dissection in submucosal invasive gastric cancer patients does not impact clinical outcomes

Submucosal deep invasion of gastric cancer (T1b2; depth of submucosal invasion ≥ 500 μm) is a risk factor for lymph node metastasis and, thus, is one of the criteria for curative treatment. Our aim was to evaluate the specific influence of endoscopic submucosal dissection (ESD) on the prognosis of patients with T1b2 gastric cancer. This was a retrospective analysis of 248 consecutive patients, with 252 pT1b2 gastric cancer lesions, who underwent ESD prior to additional surgery (Group A, n = 101) or surgery only (Group B, n = 147). After propensity score-matching (for sex, age, tumor diameter and gross type), we compared pathological characteristics between the 2 groups and the prognosis over a follow-up period ≥ 60 months. Compared to Group B, patients in Group A were older, with a higher proportion of men. The proportion of depressed and undifferentiated type tumors was greater in Group B than A, with larger tumor size and depth of submucosal invasion as well. There was no incidence of local recurrence, but distant metastasis was identified in 5% of cases in Group A and 3% in Group B. After propensity score-matching, there were no difference in the 5-year overall survival rate between Group A and B (87.5% vs. 91.2%, respectively), nor in the 5-year disease-specific survival rate (96.3% vs. 96.4%, respectively). ESD prior to surgery for T1b2 gastric cancer did not adversely affect clinical outcomes after additional surgery.

Preoperative imaging evaluation of the absolute indication criteria for endoscopic submucosal dissection in early gastric cancer patients

Introduction

Gastric cancer (GC) is a common malignant tumor with a high mortality rate.

Aim

To determine the accuracy of preoperative imaging information obtained from the combined use of general gastroscopy (GS), endoscopic ultrasonography (EUS), and multi-detector computed tomography (MDCT) regarding absolute indication of endoscopic submucosal dissection (ESD) in early gastric cancer (EGC).

Material and methods

The relationship between clinical features of 794 EGC patients and lymph node metastasis (LNM) was analyzed. Multivariate logistic regression analysis was used to investigate the risk factors for LNM. Additionally, the accuracy of diagnosis of imaging techniques for ESD indications was determined by receiver operating characteristic (ROC) analysis.

Results

Data showed that tumor size > 2 cm (p = 0.0071), T1b stage (p < 0.0001), undifferentiated histology (p < 0.0001), and vascular invasion (p = 0.0007) were independent risk factors for LNM in patients with EGC. Indications for ESD have a specificity of 100% for the diagnosis of patients with LNM. Additionally, the diagnostic efficacy of the use of GS, EUS, and MDCT in identifying node positive status, T1a disease, tumor size ≤ 2 cm, and ulceration was found to be moderate with area under the curve (AUC) of receiver operating characteristic curve (ROC) of 0.71, 0.64, 0.72, and 0.68, respectively. Furthermore, the use of imaging techniques for overall indication criteria for ESD had a moderate utility value with an AUC of 0.71.

Conclusions

Our data suggested that, based on the combined use of GS, EUS, and MDCT, a high specificity of patient selection for ESD treatment can be achieved.

Precision surgical approach with lymph-node dissection in early gastric cancer

The gravest prognostic factor in early gastric cancer is lymph-node metastasis, with an incidence of about 10% overall. About two-thirds of early gastric cancer patients can be diagnosed as node-negative prior to treatment based on clinic-pathological data. Thus, the tumor can be resected by endoscopic submucosal dissection. In the remaining third, surgical resection is necessary because of the possibility of nodal metastasis. Nevertheless, almost all patients can be cured by gastrectomy with D1+ lymph-node dissection. Laparoscopic or robotic gastrectomy has become widespread in East Asia because perioperative and oncological safety are similar to open surgery. However, after D1+ gastrectomy, functional symptoms may still result. Physicians must strive to minimize post-gastrectomy symptoms and optimize long-term quality of life after this operation. Depending on the location and size of the primary lesion, preservation of the pylorus or cardia should be considered. In addition, the extent of lymph-node dissection can be individualized, and significant gastric-volume preservation can be achieved if sentinel node biopsy is used to distinguish node-negative patients. Though the surgical treatment for early gastric cancer may be less radical than in the past, the operative method itself seems to be still in transition.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CHARACTERIZATION OF THE MUCIN PHENOTYPE CAN PREDICT GASTRIC CANCER RECURRENCE AFTER ENDOSCOPIC MUCOSAL RESECTION

BACKGROUND

Endoscopic mucosal resection is still considered an accepted treatment for early gastric cancer for selected cases. Histopathologic criteria for curative endoscopic resection are intramucosal well-differentiated adenocarcinoma, lateral and deep margins free of tumor, no histological ulceration, and no venous or lymphatic embolism. A 5% local recurrence rate has been described even when all the above-mentioned criteria are met. On the other hand, antigen expression by tumoral cells has been related to the biological behavior of several tumors.

OBJECTIVE

To evaluate whether early gastric cancer mucin immunoexpression, p53 and Ki-67, can predict recurrence after endoscopic mucosal resection, even when standard histopathologic criteria for curative measures have been attempted.

METHODS

Twenty-two patients with early gastric cancer were considered to have been completely resected by endoscopic mucosal resection. Local recurrence occurred in 5/22 (22.7%). Immunohistochemical study was possible in 18 (81.8%) resected specimens. Patients were divided in two groups: those with and those without local recurrence. They were compared across demographic, endoscopic, histologic data, and immunohistochemical factors for MUC2, MUC5a, CD10, p53, and Ki-67.

RESULTS

Mucin immunoexpression allowed a reclassification of gastric adenocarcinoma in intestinal (10), gastric (2), mixed (4), and null phenotypes (2). Mixed phenotype (positive for both MUC2 and MUC5a) was found in 80% of cases in the local recurrence group, while the intestinal type (positive MUC2 and negative MUC5a) was found in 76.9% of cases without local recurrence (P=0.004). Other observed features did not correlate with neoplastic recurrence.

CONCLUSION

The mixed phenotype of early gastric adenocarcinoma is associated with a higher probability of local recurrence after endoscopic mucosal resection.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Therapeutic outcomes of endoscopic submucosal dissection for early gastric cancer: single-center study

OBJECTIVES

Endoscopic submucosal dissection (ESD) has been widely accepted for selected patients with early gastric cancer (EGC). The aim of this study was to assess the therapeutic outcomes after ESD according to the pathological extent.

PATIENTS AND METHODS

From January 2005 to December 2014, a total of 599 patients with 611 lesions were enrolled in this study. The tumors were categorized according to pathological results on the basis of absolute criteria (AC), expanded criteria (EC), EC with undifferentiated histology [(EC-U), mucosal cancer, ulcer (-), ≤20 mm], or beyond EC (BEC). The therapeutic outcomes among the four groups were analyzed retrospectively.

RESULTS

The number of patients in the AC, EC, EC-U, and BEC groups was 447, 91, 19, and 54. The complete resection rates of EGC were 97.8, 84.6, 94.4, and 45.5% (P=0.001) and en bloc resection rates in the AC, EC, EC-U, and BEC groups were 99.1, 98.9, 100, and 98.1% (P=0.833), respectively. The 5-year disease-free survival rate in the AC, EC, EC-U, and BEC groups was 90.6, 88.7, 75.0, and 83.3% (P=0.394). In multivariate analysis, undifferentiated histology (P=0.001) and tumor size (>30 mm, P=0.017) were risk factors related to local recurrence.

CONCLUSION

The efficacy of ESD for EGCs in EC is almost equal to that in AC when complete resection was achieved. However, the indication for ESD should be decided conservatively because the complete resection rate of EGC in the EC group was significantly lower than that in the AC group. Undifferentiated histology and tumor size over 30 mm were risk factors related to local recurrence.

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

Background

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

Methods

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

Results

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

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

Conclusions

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

Laparoscopic proximal gastrectomy for early gastric cancer

The incidence of proximal early gastric cancer (EGC) is increasing, and while laparoscopic proximal gastrectomy (LPG) has been performed as a surgical option, it is not yet the standard treatment, because there is no established common reconstruction method following proximal gastrectomy (PG). We reviewed the English-language literature to clarify the current status and problems associated with LPG in treating proximal EGC. This procedure is considered indicated for EGC located in the upper third of the stomach with clinical T1N0, but not when it can be treated endoscopically. No operative mortality or conversion to open surgery was reported in our review, suggesting that this procedure is technically feasible. The most frequent postoperative complication involved problems with anastomoses, possibly caused by the technical complexity of the reconstruction. Although various reconstruction methods following open PG (OPG) and LPG have been reported, there is no standard reconstruction method. Well-designed multicenter, randomized, controlled, prospective trials to evaluate the various reconstruction methods are necessary.

Mixed Carcinoma as an Independent Prognostic Factor in Submucosal Invasive Gastric Carcinoma

Mixed carcinoma shows a mixture of glandular and signet ring/poorly cohesive cellular histological components and the prognostic significance of each component is not fully understood. This study aimed to investigate the significance of the poorly cohesive cellular histological component as a risk factor for lymph node metastasis and to examine the diagnostic reliability of endoscopic biopsy. Clinicopathologic characteristics of 202 patients who underwent submucosal invasive gastric carcinoma resection with lymph node dissection in 2005-2012 were reviewed. Mixed carcinoma accounted for 27.2% (56/202) of cases. The overall prevalence of lymph node metastasis was 17.3% (35/202). Lymphatic invasion (P < 0.001), family history of carcinoma (P = 0.025), tumor size (P = 0.004), Lauren classification (P = 0.042), and presence of any poorly cohesive cellular histological component (P = 0.021) positively correlated with the lymph node metastasis rate on univariate analysis. Multivariate analyses revealed lymphatic invasion, family history of any carcinoma, and the presence of any poorly cohesive cellular histological component to be significant and independent factors related to lymph node metastasis. Review of preoperative biopsy slides showed that preoperative biopsy demonstrated a sensitivity of 63.6% and a specificity of 100% in detecting the presence of the poorly cohesive cellular histological component, compared with gastrectomy specimens. The presence of any poorly cohesive cellular histological component was an independent risk factor associated with lymph node metastasis in submucosal invasive gastric carcinoma. Endoscopic biopsy had limited value in predicting the presence and proportion of the poorly cohesive cellular histologic component due to the heterogeneity of mixed carcinoma.

Predictors of Lymph Node Metastasis in Western Early Gastric Cancer

BACKGROUND

The application of endoscopic and local resection for early gastric cancer (EGC) is limited by the risk of regional lymph node (LN) metastasis. We sought to determine the incidence and predictors of LN metastasis in a contemporary cohort of Western patients with early gastric cancer.

METHODS

Sixty-seven patients with pT1 gastric adenocarcinoma underwent radical surgery without neoadjuvant therapy at our institution between 1995 and 2011, and clinicopathologic factors predicting LN metastasis were analyzed.

RESULTS

LN metastases were present in 15/67 (22 %) pT1 tumors, including 1/23 (4 %) T1a tumors and 14/44 (32 %) T1b tumors. Tumor size, site, degree of differentiation, macroscopic tumor sub-classification, perineural invasion status, and depth of submucosal tumor penetration did not predict LN metastasis. The presence of lymphovascular invasion (LVI) and positive nodal status by endoscopic ultrasound (EUS) were the only factors that predicted LN metastasis on multivariate analysis. T1a tumors without LVI had a 0 % rate of positive LN, whereas T1b tumors with LVI had a 64.3 % rate of positive LN.

CONCLUSIONS

EGC limited to the mucosa, without evidence of LVI, and N0 on EUS, may be considered for limited resection. However, any EGC with submucosal invasion, LVI, or positive nodes on EUS should undergo radical resection with lymphadenectomy.

Prediction of the indication criteria for endoscopic resection of early gastric cancer

AIM: To find risk factors of lymph node metastasis (LNM) in early gastric cancer (EGC) and to find proper endoscopic therapy indication in EGC.

METHODS: We retrospectively reviewed the 2270 patients who underwent curative operation for EGC from January 2001 to December 2008. EGC was defined as malignant lesions that do not invade beyond the submucosal layer of the stomach wall irrespective of presence of lymph node metastasis.

RESULTS: Among 2270 enrolled patients, LNM was observed in 217 (9%) patients. LNM in intramucosal (M) cancer and submucosal (SM) cancer was detected in 38 (2.8%, 38/1340) patients and 179 (19%, 179/930) patients, respectively. In univariate analysis, the risk factors for LNM in EGC were size of tumor, Lauren classification, ulcer, lymphatic invasion, vascular invasion, and depth of invasion. However, in multivariate analysis, size of tumor, lymphatic invasion, vascular invasion, and depth of invasion were risk factors for LNM in EGC. Size of tumor, lymphatic invasion, vascular invasion, and depth of invasion were risk factors for LNM in cases of intramucosal cancer and submucosal cancer. In particular, there was no lymph node metastasis in cases of well differentiated early gastric cancer below 1 cm in size without ulcer regardless of lymphovascular invasion.

CONCLUSION: Tumor size, perilymphatic-vascular invasion, and depth of invasion were risk factors for LNM in EGC. There was no LNM in EGC below 1 cm regardless risk factors.

Tumor Budding Is Independently Predictive for Lymph Node Involvement in Early Gastric Cancer

BACKGROUND

The most important prognostic factor for early gastric cancer (EGC) is the lymph node status. It is important to predict early lesions without lymph node metastasis (LNM) before proceeding to radical surgery in locally excised lesions. Tumor budding is a feature known to be related to aggressive tumor behavior in several solid tumors. We aimed to assess the predictive value of tumor budding for LNM in pT1a and pT1b gastric cancer.

METHODS

We retrospectively investigated radical gastrectomy specimens for of 126 EGC patients and assess the possible relation between the clinicopathologic features, including age, gender, tumor location, tumor size, macroscopic tumor type, histologic differentiation, depth and width of submucosal invasion, lymphovascular invasion, and tumor budding with lymph node involvement.

RESULTS

Among the 126 EGCs, 38 were stages as pT1a and 88 as pT1b. LNM rate in pT1a tumors was 13% whereas it was 33% in pT1b tumors. Tumor budding was the only factor significantly and independently related to LNM in pT1a patients. Female gender and tumor budding were found to be independent risk factors in pT1b group. Other clinicopathologic features were not related to LNM.

CONCLUSION

Based on these results, we suggest that budding is a promising parameter to assess for prediction of LNM in EGC removed by endoscopic surgery, and to decide on the appropriate surgical approach.

Risk of lymph node metastases from early gastric cancer in relation to depth of invasion: experience in a single institution

BACKGROUND

An accurate assessment of potential lymph node metastasis is important for the appropriate treatment of early gastric cancers. Therefore, this study analyzed predictive factors associated with lymph node metastasis and identified differences between mucosal and submucosal gastric cancers.

MATERIALS AND METHODS

A total of 518 early gastric cancer patients who underwent radical gastrectomy were reviewed in this study. Clinicopathological features were analyzed to identify predictive factors for lymph node metastasis.

RESULTS

The rate of lymph node metastasis in early gastric cancer was 15.3% overall, 3.3% for mucosal cancer, and 23.5% for submucosal cancer. Using univariate analysis, risk factors for lymph node metastasis were identified as tumor location, tumor size, depth of tumor invasion, histological type and lymphovascular invasion. Multivariate analysis revealed that tumor size >2 cm, submucosal invasion, undifferentiated tumors and lymphovascular invasion were independent risk factors for lymph node metastasis. When the carcinomas were confined to the mucosal layer, tumor size showed a significant correlation with lymph node metastasis. On the other hand, histological type and lymphovascular invasion were associated with lymph node metastasis in submucosal carcinomas.

CONCLUSIONS

Tumor size >2 cm, submucosal tumor, undifferentiated tumor and lymphovascular invasion are predictive factors for lymph node metastasis in early gastric cancer. Risk factors are quite different depending on depth of tumor invasion. Endoscopic treatment might be possible in highly selective cases.

Clinical significance of a papillary adenocarcinoma component in early gastric cancer: a single-center retrospective analysis of 628 surgically resected early gastric cancers

BACKGROUND

We recently reported that the presence of a papillary adenocarcinoma (pap) component was an independent risk factor for lymphatic involvement in endoscopically resected early gastric cancer (EGC). This study aimed to investigate the potential association between the presence of a pap component in EGC and lymph node metastasis (LNM).

METHODS

In order to evaluate the association between LNM and clinicopathological features, including a pap component, we reviewed 628 surgically resected EGCs at our institution between 2009 and 2012. Clinicopathological features included age, gender, tumor location, macroscopic type, tumor size, histological type, depth, ulcerative findings, and lymphatic and venous involvement. In addition, the association between clinicopathological features and lymphatic involvement was also evaluated.

RESULTS

LNM was observed in 52 cases (8.3%). Univariate analyses revealed a significant correlation between a pap component and LNM as well as tumor size, depth, macroscopic type, a poorly differentiated adenocarcinoma component, and lymphatic and venous involvement. The percentage of positive LNM among the EGC cases with a pap component was significantly higher than in those without the component (18.2 vs. 7.3%, P = 0.010). Via multivariate analyses lymphatic involvement was identified as the strongest risk factor for LNM [odds ratio (OR) 14.1] and a pap component was revealed as an independent risk factor for lymphatic involvement (OR 3.1).

CONCLUSION

Our study revealed that EGC cases with a pap component were at higher risk of lymphatic involvement and showed a higher percentage of positive LNM. More attention should be paid to a pap component in EGC.

Is endoscopic resection an alternative to surgery for early low-risk submucosal gastric cancers: analysis of a large surgical database

BACKGROUND

Although endoscopic resection (ER) for early gastric cancers (EGCs) has become popular with the development of endoscopic instruments and skillful endoscopists, the risk of lymph node metastasis (LNM) is still an obstacle in performing ER. In this study, we aimed to identify the risk factors of LNM and validated the expanded criteria, with the goal of suggesting modified criteria for ER in submucosal EGCs.

METHODS

Of patients who underwent gastrectomy with LN dissection and were diagnosed as EGCs with depth of invasion such as sm1, sm2 or ≤ 500 μm from 1999 to 2008, 318 EGCs with submucosal invasion ≤ 500 μm were enrolled through pathologic evaluations. To identify the risk factors of LNM, a multivariate analysis of clinicopathologic factors was performed. By combining the independent risk factors of LNM, the risk of LNM was analyzed.

RESULT

LNM were detected in 35 cases (11.0 %). Tumors >30 mm in size and with lymphatic invasion were identified as an independent risk factor for LNM in EGCs with depth of invasion ≤ 500 μm. Among 94 cases meeting the expanded criteria, two cases (2.1 %) were found to have LNM. Based on the submucosal invasion <300 μm, there was no LNM in EGCs with a size ≤ 30 mm and no lymphovascular invasion, regardless of differentiation grade.

CONCLUSION

To exclude the possibility of LNM, applying the modified criteria based on the submucosal invasion <300 μm in performing ER might be worthwhile.

Early gastric cancer with mixed histology predominantly of differentiated type is a distinct subtype with different therapeutic outcomes of endoscopic resection

BACKGROUND

Safety of endoscopic resection (ER) for early gastric cancers (EGC) with mixed histology predominantly of differentiated type has not been securely established, since those lesions tend to exhibit lymph node metastasis, compared to pure differentiated type. The purpose of this study was to evaluate clinicopathologic characteristics, therapeutic outcomes, and risk for lymph node metastasis in predominantly differentiated mixed EGC treated by ER.

METHODS

A total of 1,016 patients with 1,039 EGCs underwent ER between January 2007 and June 2013. Enrolled lesions were divided into groups of either pure differentiated (n = 1,011) or predominantly differentiated mixed (n = 28), according to the presence of mixed histology predominantly of differentiated type in ER specimen.

RESULTS

Mixed histology predominantly of differentiated type was diagnosed in 2.7% of lesions. Larger size, mid-third location, and moderately differentiated histology on forceps biopsy were independent risk factors for the predominantly differentiated mixed histologic type of EGC in multivariate analysis. En bloc resection rate tended to be lower, and complete and curative resection rates were significantly lower in the predominantly differentiated mixed group. The rate of lymph node metastasis in the lesions with additional operation tended to be higher, in this mixed histology group.

CONCLUSIONS

Larger size, mid-third location, and moderately differentiated histology on forceps biopsy carry the significant risk for mixed histology predominantly of differentiated type. EGC with predominantly differentiated mixed histologic type affects therapeutic outcomes and consequent clinical course accompanied by possibly higher risk for lymph node metastasis. The safety of ER for predominantly differentiated mixed EGC should be validated by further prospective investigation.

Enhanced intensity on preoperative double contrast-enhanced sonography as a useful indicator of lymph node metastasis in patients with gastric cancer

OBJECTIVES

The aim of this study was to investigate the predictive value of enhanced intensity on double contrast-enhanced sonography in assessing lymph node metastasis of gastric cancer.

METHODS

A total of 357 patients with gastric cancer were enrolled in this study. Double contrast-enhanced sonography, in which an oral ultrasound contrast agent is combined with an intravenous contrast agent, was performed preoperatively, and the data were analyzed quantitatively. The predictive ability of enhanced intensity, a quantitative double contrast-enhanced sonographic measure, for lymph node metastasis was evaluated retrospectively.

RESULTS

Compared to negative lymph node metastasis cases, the presence of thicker lesions, deeper invasion, poorer differentiation, and higher enhanced intensity were found in positive cases (P< .05). An enhanced intensity cutoff value of 16.91 dB was the best point for balancing the sensitivity and specificity (71.50% and 79.30%, respectively) for prediction of lymph node metastasis, with the highest Youden index of 0.508. The area under the receiver operating characteristic curve was 0.828 (P < .001; 95% confidence interval, 0.786-0.870). In cases in which the lesions were hyperenhanced (enhanced intensity >16.91 dB), the lesions were significantly thicker and had deeper invasion, poorer differentiation, and more positive metastasis findings compared to non-hyperenhanced cases (enhanced intensity ≤16.91 dB; P < .05). On logistic regression analysis, the enhanced intensity of primary tumors and the invasion depth were significantly associated with lymph node metastasis.

CONCLUSIONS

Double contrast-enhanced sonography with quantitative analysis may be considered a novel alternative imaging modality for noninvasive preoperative evaluation of lymph node metastasis with good reliability.

[Comparison on the long term outcome between endoscopic submucosal dissection and surgical treatment for undifferentiated early gastric cancer]

BACKGROUND/AIMS

There are controversies on the efficacy and safety of endoscopic submucosal dissection (ESD) for un-differentiated early gastric cancer (EGC) despite the expansion of ESD indications. The aim of this study was to evaluate the long term outcome of ESD compared to that of surgical treatment in patients with undifferentiated EGC.

METHODS

A total of 76 patients who underwent ESD for undifferentiated EGC and 149 patients who met the ESD indication and received surgical treatment from January 2005 to December 2010 at Chonnam National University Hwasun Hospital were included.

RESULTS

In the ESD group, en bloc resection and complete resection were achieved in 84.2% (64/76) and 76.3% (58/76) of patients, respectively. Among these patients, 58 (76.3%) met the ESD indication (indication group), and the remaining 18 (23.7%) did not meet the ESD indication (above indication group). Complete resection rates for indication group and above indication group were 86.2% (50/58) and 44.4% (8/18), respectively (p<0.05). The mean follow-up period was 42.2 ± 19.2 months. Total recurrence rates in the ESD group and operation group were 14.1% (9/76) and 0.7% (1/149), respectively (p<0.05). The main complication of ESD was bleeding (5.2%, 4/76). In the operation group, 2 (1.3%) patients died from postoperative bleeding and leakage of anastomosis site.

CONCLUSIONS

ESD may be a feasible and safe treatment modality compared to that of surgical treatment for undifferentiated EGC when managed according to the expanded criteria. However, close endoscopic surveillance is required in this group because of higher incidence of intragastric recurrence.

Unveiling lymph node metastasis in early gastric cancer

With respect to gastric cancer treatment, improvements in endoscopic techniques and novel therapeutic modalities [such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD)] have been developed. Currently, EMR/ESD procedures are widely accepted treatment modalities for early gastric cancer (EGC). These procedures are most widely accepted in Asia, including in Korea and Japan. In the present era of endoscopic resection, accurate prediction of lymph node (LN) metastasis is a critical component of selecting suitable patients for EMR/ESD. Generally, indications for EMR/ESD are based on large Japanese datasets, which indicate that there is almost no risk of LN metastasis in the subgroup of EGC cases. However, there is some controversy among investigators regarding the validity of these criteria. Further, there are currently no accurate methods to predict LN metastasis in gastric cancer (for example, radiologic methods or methods based on molecular biomarkers). We recommend the use of a 2-step method for the management of early gastric cancer using endoscopic resection. The first step is the selection of suitable patients for endoscopic resection, based on endoscopic and histopathologic findings. After endoscopic resection, additional surgical intervention could be determined on the basis of a comprehensive review of the endoscopic mucosal resection/endoscopic submucosal dissection specimen, including lymphovascular tumor emboli, tumor size, histologic type, and depth of invasion. However, evaluation of clinical application data is essential for validating this recommendation. Moreover, gastroenterologists, surgeons, and pathologists should closely collaborate and communicate during these decision-making processes.

[Therapeutic outcomes of endoscopic submucosal dissection in undifferentiated-type early gastric cancer]

BACKGROUND/AIMS

Endoscopic submucosal dissection (ESD) has been accepted as a standard treatment of early gastric cancer (EGC). However, the indication of ESD in undifferentiated-type EGC was controversial. The aim of this study was to evaluate the therapeutic outcomes of ESD in undifferentiated-type EGC according to expanded indication.

METHODS

At Soonchunhyang University Bucheon Hospital, a total of 82 lesions in 81 patients with undifferentiated-type EGC were treated with ESD. The therapeutic outcomes of ESD were evaluated by resection method (en bloc resection; piecemeal resection), histologic curative resection, complications and recurrence rates after ESD.

RESULTS

The rate on en bloc resection and complete resection rate were 87.8% (72/82) and 80.5% (66/82), respectively. In signet ring cell carcinoma, the complete resection rate was higher than those in poorly differentiated adenocarcinoma and poorly differentiated adenocarcinoma with signet ring cell features, but there was no statistical significance (89.3% vs. 75.0%, 76.7%; p=0.347). The lateral margin positivity rate in poorly differentiated adenocarcinoma, signet ring cell carcinoma and poorly differentiated adenocarcinoma with signet ring cell features were 12.5%, 3.6% and 13.3%, respectively (p=0.395). The vertical margin positivity rate were 12.5%, 3.6% and 10.0%, respectively (p=0.485). The overall recurrence rate was 3.0% during a mean follow-up period of 37.4 months.

CONCLUSIONS

ESD may be considered as a feasible treatment for undifferentiated-type EGC according to expanded indication. The therapeutic outcome of ESD in undifferentiated-type EGC is likely to be favorable, though further longer follow-up studies are needed.

Lymph node metastasis in early gastric cancer: evaluation of a novel method for measuring submucosal invasion and development of a nodal predicting index

After endoscopic resection of early gastric cancer (EGC), it is imperative to accurately determine whether follow-up surgery is indicated, since this technique is used as a first line of treatment. Herein, we developed a scoring system to indicate the risk of lymph node metastasis in submucosal EGC (smEGC), and present a novel method to measure depth of submucosal invasion. In our series, 15.9% of the smEGC presented with lymph node metastasis. A nodal prediction index, based on the variables extracted from the univariate analysis and defined as nodal prediction index = (2.128 × lymphovascular tumor emboli) + (1.083 × submucosal invasion width ≥ 0.75 cm) + (0.507 × submucosal invasion depth ≥ 1000 μm) + (0.515 × infiltrative growth pattern), yielded an area under the receiver operating characteristic curve of 0.809 (P =.000, 95% CI = 0.713-0.096) in a training group, and showed comparable result in validation group (0.886, P =.000, 95% CI = 0.796-0.977). Depth of invasion was statistically higher in the metastatic group when measured from the lowest point of an imaginary line in continuity with the adjacent muscularis mucosa to the point of deepest tumor penetration, but not when using the classic measurement method. The area under the receiver operating characteristic curve of the alternative measurement method was 0.652 (P =.013, 95% CI = 0.550-0.754) compared to 0.620 for the classic measurement method (P =.0480, 95% CI = 0.509-0.731). In deciding whether surgery is indicated after endoscopic submucosal dissection for smEGCs, we recommend to test our alternative method of measuring submucosal invasion and to evaluate our nodal prediction index as an adjunct tool.

Risk of lymph node metastases from intramucosal gastric cancer in relation to histological types: how to manage the mixed histological type for endoscopic submucosal dissection

BACKGROUND

The behavior of early gastric cancer (EGC) with mixed-type histology (differentiated and undifferentiated) is incompletely understood. This study aimed to clarify the clinicopathological features of EGC with mixed-type histology in relation to lymph node (LN) metastasis.

METHODS

Clinicopathological data from 410 patients who underwent surgical resection for intramucosal EGC were reviewed. Lesions were classified into four types according to the proportion of differentiated and undifferentiated components at histopathology: pure differentiated (PD) type, mixed predominantly differentiated (MD) type, mixed predominantly undifferentiated (MU) type, and pure undifferentiated (PU) type. We examined the clinicopathological differences between PD and MD, and between PU and MU, and the rate of LN metastasis according to tumor size and ulceration.

RESULTS

Moderately differentiated adenocarcinoma was the primary component in MD relative to PD (90.7 vs. 46.1 %). Signet ring cell carcinoma was the main component in PU relative to MU (81.5 vs. 33.3 %). LN metastasis was more common in MU than PU (19.0 vs. 6.0 %). For intramucosal tumors larger than 20 mm without lymphovascular invasion and without ulceration, the rate of LN metastasis was 0 % for MD and 24 % for MU. For intramucosal lesions less than 30 mm with ulceration but without lymphovascular invasion, the rate of LN metastasis was 0 % for MD and 20 % for MU.

CONCLUSIONS

Histologically mixed-type EGC with a predominantly undifferentiated component should be managed as an undifferentiated-type tumor. Further investigation is required to determine whether mixed-type EGC with a predominantly differentiated component could be managed the same way as a differentiated-type EGC.

Usefulness of three-dimensional angiographic analysis of perigastric vessels before laparoscopic gastrectomy

BACKGROUND

Recognition of perigastric vessel anatomy is important to safely perform gastric surgery, especially in the case of laparoscopic gastrectomy. This study was designed to reevaluate the efficacy of preoperative three-dimensional (3D) angiography reconstructed from enhanced multidetector-row computed tomography (MDCT) data and to classify right gastric artery (RGA) branching patterns.

METHODS

Perigastric vessel anatomy was preoperatively analyzed using MDCT-based 3D angiography reconstructed by computer software in patients undergoing laparotomic (n = 75) and laparoscopic (n = 25) gastrectomy. Results were compared with intraoperative findings in all cases, and were also compared with maximum intensity projection (MIP) imaging, which is similar to conventional angiography, in 10 patients.

RESULTS

Preoperative diagnoses by 3D angiography were identical to intraoperative findings. The rates of branching patterns of the celiac artery and left gastric vein were comparable with previous reports. The detection rate of the right gastric artery (RGA) was 77.0%. Branching patterns of the hepatic artery were classified into four types: right hepatic artery (RHA) + left hepatic artery (LHA) type, replaced RHA + LHA type, RHA + replaced LHA type, and replaced RHA + replaced LHA type. RGA ramification patterns were classified into three types according to hepatic arterial running patterns: distal (68.8%), proximal (14.3%), and caudal (16.9%). Because of vessel overlapping, RGA ramified points were misdiagnosed under MIP images in two of ten cases (20%).

CONCLUSIONS

Preoperative 3D angiography is useful for a new system of classifying RGA ramification patterns into three types. With this system, surgeons can perform laparoscopic gastrectomy with lymph node dissection more safely.

Risk factors for lymphatic and venous involvement in endoscopically resected gastric cancer

BACKGROUND

Lymphatic and venous involvement is a critical factor in the curability assessment of endoscopically resected gastric cancers; however, the risk factors for lymphatic and venous involvement in endoscopically resected gastric cancers remain unknown.

METHODS

To identify risk factors for lymphatic and venous involvement in endoscopically resected gastric cancers, we retrospectively reviewed a consecutive series of 1229 endoscopically resected gastric cancers in 1083 patients treated between January 2009 and December 2011.

RESULTS

Lymphatic and venous involvement was detected in 57 (4.6%) and 32 (2.6%) lesions, respectively. A multivariate analysis identified a larger tumor size, deeper invasion (submucosal invasion or deeper), and the presence of a papillary or an undifferentiated-type adenocarcinoma component as independent risk factors for lymphatic involvement. As for venous involvement, deeper invasion (≥500 μm submucosal invasion), a macroscopically elevated type, and the presence of an undifferentiated-type adenocarcinoma component were identified as independent risk factors.

CONCLUSIONS

The present study identified the independent risk factors for lymphatic and venous involvement in endoscopically resected gastric cancers. The recognition of these risk factors would help in the selection of lesions that may require a particularly careful histological evaluation.

Prediction of risk factors for lymph node metastasis in early gastric cancer

AIM: To explore risk factors for lymph node metastases in early gastric cancer (EGC) and to confirm the appropriate range of lymph node dissection.

METHODS: A total of 202 patients with EGC who underwent curative gastrectomy with lymphadenectomy in the Department of Surgery, Xinhua Hospital and Ruijin Hospital of Shanghai Jiaotong University Medical School between November 2003 and July 2009, were retrospectively reviewed. Both the surgical procedure and the extent of lymph node dissection were based on the recommendations of the Japanese gastric cancer treatment guidelines. The macroscopic type was classified as elevated (type I or IIa), flat (IIb), or depressed (IIc or III). Histopathologically, papillary and tubular adenocarcinomas were grouped together as differentiated adenocarcinomas, and poorly differentiated and signet-ring cell adenocarcinomas were regarded as undifferentiated adenocarcinomas. Univariate and multivariate analyses of lymph node metastases and patient and tumor characteristics were undertaken.

RESULTS: The lymph node metastases rate in patients with EGC was 14.4%. Among these, the rate for mucosal cancer was 5.4%, and 8.9% for submucosal cancer. Univariate analysis showed an obvious correlation between lymph node metastases and tumor location, depth of invasion, morphological classification and venous invasion (χ² = 122.901, P = 0.001; χ² = 7.14, P = 0.008; χ² = 79.523, P = 0.001; χ² = 8.687, P = 0.003, respectively). In patients with submucosal cancers, the lymph node metastases rate in patients with venous invasion (60%, 3/5) was higher than in those without invasion (20%, 15/75) (χ² = 4.301, P = 0.038). Multivariate logistic regression analysis revealed that the depth of invasion was the only independent risk factor for lymph node metastases in EGC [P = 0.018, Exp (B) = 2.744]. Among the patients with lymph node metastases, 29 cases (14.4%) were at N1, seven cases were at N2 (3.5%), and two cases were at N3 (1.0%). Univariate analysis of variance revealed a close relationship between the depth of invasion and lymph node metastases at pN₁ (P = 0.008).

CONCLUSION: The depth of invasion was the only independent risk factor for lymph node metastases. Risk factors for metastases should be considered when choosing surgery for EGC.

Surgical outcomes and clinicopathological characteristics of patients who underwent potentially noncurative endoscopic resection for gastric cancer: a report of a single-center experience

Background. Standard treatment of early gastric cancer (EGC) after endoscopic resection with risk factors of nodal metastases and incomplete resection is controversial. We investigated optimal management for the patients with potentially noncurative EGC after endoscopic resection. Methods. We retrospectively examined clinicopathological data and surgical outcomes of all patients with clinically solitary gastric adenocarcinoma who underwent curative surgery after a single peroral endoscopic resection at the Digestive Disease Center of Showa University Northern Yokohama Hospital between April 2001 and December 2012. Fisher's exact test was used for univariate analysis. For multivariate analysis, stepwise multiple linear regression was used to identify independent predictors related to lymph node metastasis and remnant of primary tumor. Results. A total of 41 patients were studied. Four patients (9.8%) had lymph node metastases. Primary tumors remained in 6 patients (14.6%). Only venous invasion was statistically significant to lymph node metastasis (P = 0.017). With respect to remnant of the primary tumor, pT1b2 tumor invasion (P = 0.015) and horizontal margin (P = 0.013) were statistically significant. Conclusions. Surgery with limited lymphadenectomy is recommended for tumors with venous invasion or pT1b2 tumor invasion, and additional endoscopic resection may be allowed for tumors with horizontal involvement.

Suitability of endoscopic submucosal dissection for treatment of submucosal gastric cancers

BACKGROUND

Endoscopic submucosal dissection (ESD) is not considered appropriate for all submucosal cancers owing to the risk of lymph node metastasis and difficulty estimating the deep margin status. This study aimed to determine predictive factors for lymph node metastases in submucosal cancer and to explore in which patients ESD might be feasible.

METHODS

Details of patients who had curative gastrectomy for submucosal gastric cancer at Asan Medical Centre from 2007 to 2011 were reviewed retrospectively to determine the relationship between lymph node metastasis and clinicopathological characteristics, including age, sex, tumour location, size, gross appearance, depth of invasion, histological type/differentiation, presence of lymphovascular/perineural invasion, and immunohistochemical staining results for p53, human epidermal growth factor receptor (HER) 1 and HER2.

RESULTS

A total of 1773 patients were analysed. The presence of lymphovascular invasion was related most strongly to lymph node metastasis. Multivariable analysis revealed that depth of invasion, tumour size, differentiation, gross appearance and perineural invasion were also related. Metastatic lymph nodes were found in four of 105 patients who met the classical criteria for ESD; all showed a moderately differentiated histological appearance. No lymph node metastases were observed in well differentiated SM1 tumours of any size (infiltration into upper third of submucosa), or in well differentiated SM2 (infiltration into middle third of submucosa) tumours of 2 cm or less without lymphovascular invasion.

CONCLUSION

Patients with well differentiated SM1 cancer of any size and those with well differentiated SM2 cancer of 2 cm or less without lymphovascular invasion may be suitable candidates for ESD.

Laparoscopy-assisted proximal gastrectomy with sentinel node mapping for early gastric cancer

BACKGROUND

Laparoscopy-assisted proximal gastrectomy (LAPG) remains a relatively uncommon procedure because of certain technical issues, such as curability, safety, and retention of postoperative patients' quality of life. The aim of the present study was to evaluate the feasibility of a newly developed LAPG procedure for early-stage proximal gastric cancer.

METHODS

We enrolled 37 consecutive patients who were preoperatively diagnosed with cT1N0M0 primary gastric cancer in the upper third of the stomach with the primary tumor diameter less than 4 cm. Laparoscopy-assisted proximal gastrectomy with sentinel node (SN) mapping and esophagogastric anastomosis with a circular stapler and transoral placement of the anvil was attempted.

RESULTS

The LAPG procedure was completed in 36 patients. It was converted to laparoscopy-assisted total gastrectomy in one patient because one SN detected intraoperatively was positive for metastasis by intraoperative pathological diagnosis. There were no severe postoperative complications in any patient. Only one patient (3%) complained of mild reflux symptoms immediately after operation, which were graded endoscopically as B by the Los Angeles Classification of gastroesophageal reflux disease; however, the symptoms were controlled well by a proton-pump inhibitor. Sentinel nodes were detected successfully in 37 (100%) of our patients. The mean number of dissected lymph nodes and identified SNs per case was 29.7 and 5.8, respectively. The sensitivity of prediction of nodal metastasis (including isolated tumor cells) and diagnostic accuracy based on SN status were 100% (3/3) and 100% (37/37), respectively. All patients have been free from recurrence for a median follow-up period of 26 months.

CONCLUSIONS

This study reveals that our novel LAPG approach is curative and represents a feasible minimally invasive surgical procedure with minimal morbidity and postoperative reflux esophagitis in patients with upper-third early-stage gastric cancer.

Clinicopathological characteristics and treatment strategies in early gastric cancer: a retrospective cohort study

Background

Both endoscopic and surgical approaches are employed in the treatment of early gastric cancer (EGC). The aim of this study was to establish appropriate treatment strategies for early gastric cancer.

Methods

We retrospectively examined clinicopathological data of EGC patients who had undergone surgery.

Results

A total of 327 patients (204 males and 123 females, mean age 63.2 years) were eligible for inclusion in the study. The median follow-up period was 31 months. Of 161 mucosal (pT1a) tumors, 87 were mainly undifferentiated and 110 had an undifferentiated component. Four patients with pT1a tumors had lymph node metastases; all these tumors were signet-ring cell carcinomas and were macroscopic type 0-IIc with ulceration, and only one of them had lymphatic invasion. Among patients with submucosal tumors, four of 43 patients with pT1b1 tumors and 37 of 123 patients with pT1b2 tumors had nodal metastases. Lymph node metastases were significantly higher in mixed undifferentiated type group than differentiated type group for both groups, pT1a-pT1b1 (p = 0.0251) and pT1b2 (p = 0.0430) subgroups. Only four of 45 patients with nodal metastases were diagnosed preoperatively by computed tomography (sensitivity 8.9%, specificity 96.2%). Nine patients with pT1b tumors had recurrence after surgery, and died. The sites of initial recurrence were liver, bone, peritoneum, distant nodes, and the surgical anastomosis.

Conclusions

The incidence of nodal metastases was approximately 5% in undifferentiated type mucosal (pT1a) tumors, and higher in submucosal (pT1b) tumors. The sensitivity of preoperative diagnosis of nodal metastases in EGC using computed tomography was relatively low in this study. Therefore at present surgery with adequate lymphadenectomy should be performed as curative treatment for undifferentiated type EGC.

Predicting lymph node status in patients with early gastric carcinoma using double contrast-enhanced ultrasonography

INTRODUCTION

Double contrast-enhanced ultrasonography (DCUS) is a new method we used in predicting lymph node metastasis (LNM) in patients with early gastric cancer.

MATERIAL AND METHODS

Seventy-six patients with early gastric cancer diagnosed by gastroscope and confirmed by pathology after operation were examined using DCUS preoperatively. Group N1 included 15 patients with LNM and group N0 61 patients without LNM.

RESULTS

In group N1, 13 patients (87%) had marked hyperenhancement during early arterial phase using DCUS, and 2 patients (13%) were unmarked as hyperenhancement. In group N0, 24 patients (39%) had marked hyperenhancement during early arterial phase using DCUS, and 37 patients (61%) had unmarked hyperenhancement. The sensitivity and specificity of marked hyperenhancement in predicting LNM in patients with early gastric cancer was 86.7% and 60.7% respectively, and the Youden's index was 0.474. The κ value of this method was 0.89.

CONCLUSIONS

Double contrast-enhanced ultrasonography is a new valuable method to evaluate LNM at an early stage of gastric cancer and prognosis of early gastric cancer preoperatively.

Endoscopic ultrasonography is valuable for identifying early gastric cancers meeting expanded-indication criteria for endoscopic submucosal dissection

BACKGROUND

Endoscopic ultrasonography (EUS) has become a reliable method for predicting the invasion depth of early gastric cancer (EGC). This study evaluated the accuracy of EUS in identifying lesions meeting expanded-indication criteria for endoscopic submucosal dissection (ESD) and analyzed clinicopathologic factors influencing the diagnostic accuracy of EUS in assessing tumor invasion depth.

METHODS

This study investigated 542 EGCs of 515 patients who underwent EUS pretreatment. The pretreatment EUS-determined diagnosis was compared with the final histopathologic evaluation of resected specimens, and the impact of various clinicopathologic parameters on diagnostic accuracy was analyzed.

RESULTS

The diagnostic accuracy of EUS in identifying lesions meeting expanded-indication criteria for ESD was 87.8% (259/295) for differentiated adenocarcinoma (D-type) 30 mm in diameter or smaller, 43.5% (10/23) for D-type tumor larger than 30 mm in diameter, and 75% (42/56) for undifferentiated adenocarcinoma (UD-type) 20 mm in diameter or smaller. Using multivariate analysis, the diagnostic accuracy of EUS in predicting tumor invasion depth was determined to be decreased significantly by ulcerous change and large tumor size (diameter, ≥30 mm).

CONCLUSION

For patients with EGC, D-type lesions 30 mm in diameter or smaller and UD-type lesions 20 mm in diameter or smaller can be diagnosed with high accuracy by EUS, but larger D-type lesions (diameter, >30 mm) should be considered carefully in terms of EUS-based treatment decisions. Findings of ulceration and large tumors are associated with incorrect diagnosis of tumor invasion depth by EUS.

Lymph node dissection in the resection of gastric cancer: review of existing evidence

Gastric cancer is one of the leading causes of cancer-related death worldwide. Surgery is the only curative therapy for localized gastric cancer, but the extent of regional lymphadenectomy has been a matter of considerable debate. Extended resections that are regarded as standard procedures in some Asian countries, including Japan and Korea, have not been shown to be as effective in Western countries. The extent of lymphadenectomy for advanced gastric cancer has been studied in many prospective randomized controlled trials. On the other hand, patients with early gastric cancer have an excellent survival rate (>90%) after radical surgery. Lymph node metastasis from early gastric cancer is relatively infrequent. Therefore, it might be practical to perform less invasive surgery for early gastric cancer. In this review article, we examine the evidence for lymph node dissection as radical surgery in advanced gastric cancer and the possibility of limited resection for early gastric cancer.

Surveillance and treatment for second primary cancer in the gastric tube after radical esophagectomy

BACKGROUND

Recent improvement in the survival of patients after esophagectomy for esophageal cancer has led to increasing occurrence of second primary cancer in the pulled-up stomach as gastric tube cancer (GTC). However, a treatment strategy for GTC including surveillance has not been established. The aims of this study are to clarify the incidence and clinicopathological characteristics of GTC and to assess the treatment results of endoscopic resection.

METHODS

Twenty-five patients with 29 GTC lesions treated between 1989 and 2007 were analyzed retrospectively.

RESULTS

The median interval between esophagectomy and GTC detection was 86 months, and the 10-year cumulative incidence rate of GTC was 8.6%. Of 18 asymptomatic GTCs, 17 lesions (94.4%) were detected by periodic endoscopy and 15 (88.2%) of them were treated endoscopically. Of all 29 GTCs, endoscopic submucosal dissection (ESD) was performed in 10 GTCs with a completely curative resection rate of 90%, which was significantly higher than that of 7 GTCs treated with endoscopic mucosal resection (EMR) (14.3%, P = 0.004). In these 17 GTCs, no cancer recurrence developed during a median follow-up period of 24 months, and the 3-year survival rate was 80.8%.

CONCLUSIONS

For patients after esophagectomy with gastric pull-up, long-term follow-up including periodic endoscopy is necessary to detect a potentially curable GTC. ESD is a feasible and safe procedure for GTC, with oncologically favorable features.

Simultaneous adenocarcinoma and leiomyoma of the stomach presenting as a collision tumor

A 68-year old Japanese man was referred to the Cancer Institute Hospital for the treatment of a rectal cancer. Preoperative esophagogastroduodenoscopy revealed a submucosal tumor with ulcer formation near the esophagogastric junction of the stomach. The initial treatment strategy was to perform a proximal gastrectomy with limited lymph node dissection as well as a simultaneous anterior resection. However, histopathological examination of a biopsy specimen of the submucosal tumor revealed a moderately differentiated adenocarcinoma, and therefore a total gastrectomy with D2 lymph node dissection was performed. Histopathological examination of the resected specimen revealed both adenocarcinoma and leiomyoma presenting as a collision tumor. Preoperative accurate histopathological diagnosis of a gastric submucosal tumor is generally difficult. Consequently, surgical resection of large gastric submucosal tumors may be indicated in the absence of histopathological confirmation of the diagnosis. However, in this case preoperative histopathological diagnosis enabled surgeons to perform the appropriate surgery. We conclude that to determine the appropriate treatment strategy, preoperative histopathological examination of tumors should be performed even in a case of suspected submucosal tumor, particularly if mucosal ulceration is present.

[Surgical treatment of gastric carcinoma]

The gastric cancer is the most common cancer in Korea. The only treatment modality showing improved survival for gastric cancer is curative surgical resection, which comprises the resection of stomach, proper lymphadenectomy, and reconstruction. However, specific surgical procedures should be decided according to the location of the cancer, advancement of the tumor, and patients condition. Surgical treatment for gastric cancer has been developed toward two directions that are minimal invasive surgery for early gastric cancer and multi-disciplinary approach for advanced gastric cancer. Laparoscopic surgery for early gastric cancer has been accepted for minimally invasive surgery. Moreover, the advancement of diagnostic tools to assess biological aggressiveness of the tumor enables physicians to perform endoscopic resection or minimized resection for early gastric cancer. Recently, surgeons try to extend the application of laparoscopic gastric resection and D2 lymphadenectomy to advanced gastric cancer. However, technical and oncological evidences based on clinical trials should be filed up before adopting it as a standard therapy. In case of advanced gastric cancer, in addition to radical surgery, various treatment modalities including chemotherapy, radiation, and molecular target therapy also have been applied in many clinical trials. However, it should be stressed that a prerequisite for precise evaluation of the efficacy of these combined treatment modalities would be the standardization of surgical procedure.

Predictive factors for local recurrence and incomplete resection of early gastric cancer treated by endoscopic resection: a Western experience

BACKGROUND

Early gastric cancer (EGC) is defined as adenocarcinoma limited to the mucosa or submucosa regardless of lymph node involvement. Local EGC recurrence rates have been described in up to 6% of cases.

OBJECTIVES

To evaluate predictive factors for incomplete resection and local recurrence of EGC treated by endoscopic mucosal resection (EMR) that was followed up for at least one year.

METHODS

From June 1994 to December 2005, 46 patients with EGC underwent EMR. Possible predictive factors for incomplete endoscopic resection and local recurrence were identified by medical chart analysis. Demographic, endoscopic and histopathological data were retrospectively evaluated. EMR was considered complete or incomplete. Patients from the complete resection group were divided into subgroups (with and without local EGC recurrence).

RESULTS

Complete resection was possible in 36 cases (76.6%). Predictive factors for incomplete resection were tumour location (P=0.035), histological type (P=0.021), lesion size (P=0.022) and number of resected fragments (P=0.013). On multivariate analysis, undifferentiated histological type (OR 0.8; 95% CI 0.036 to 0.897) and number of resected fragments (OR 7.34; 95% CI 1.266 to 42.629) were independent predictive factors for incomplete resection. In the complete resection group, a larger lesion size was associated with a higher the number of resected fragments (P=0.018). Local recurrence occurred in nine cases (25%). Use of the cap technique was the only predictive factor for local recurrence in five of seven cases (71.4%) (P=0.006).

CONCLUSIONS

A larger lesion size was associated with a higher number of resected fragments. Undifferentiated adenocarcinoma and piecemeal resection were predictive factors for incomplete resection. Technique type was a predictive factor for local EGC recurrence.

Supplementation of endoscopic submucosal dissection with sentinel node biopsy performed by natural orifice transluminal endoscopic surgery (NOTES) (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) is proving to be effective for the resection of selected early gastric and colon cancers. Its application and appropriateness could be extended if a means of determining lymphatic dissemination without recourse to a conventional operation could be provided.

OBJECTIVE

To demonstrate the feasibility of companion sentinel node biopsy (SNB) by natural orifice transluminal endoscopic surgery (NOTES) concurrent with intraluminal ESD in both the sigmoid colon and stomach.

DESIGN

Acute porcine model.

INTERVENTION

Arbitrarily selected mucosal foci were targeted for combined NOTES-SNB and ESD in the sigmoid and stomach of 2 separate anesthetized animals. NOTES peritoneal access was obtained either transgastrically or transvaginally. A second intraluminal endoscope was passed either orally or rectally, as appropriate, to perform submucosal injection for lymphatic mapping under direct vision of the NOTES endoscope. This endoscope then identified the first-order draining (sentinel) nodes and allowed their excisional biopsy. The sigmoid was retracted by magnetic assistance as required, while torque of an intraluminal gastroscope manipulated the stomach. After retrieval of the nodes, 1-cm and 1.5-cm specimens were resected from the sigmoid and stomach, respectively, by conventional ESD. At procedure end, necropsy was performed.

RESULTS

All sentinel nodes were identified, underwent biopsy, and were retrieved intact. ESD was subsequently readily performed without complication. SNB completeness and ESD quality were confirmed postprocedure.

LIMITATIONS

Experimental model with limited sample size.

CONCLUSIONS

Although not yet appropriate for human use, this proposal merits serious consideration as a potential means of augmenting the effectiveness and appropriateness of ESD techniques for GI neoplasia.

Regional nodal staging for early stage colon cancer in the era of endoscopic resection and N.O.T.E.S

Advanced endoscopic technologies and techniques capable of providing localized resection of colonic primaries are entering clinical practice. As much as Natural Orifice Transluminal Endoscopic Surgery (N.O.T.E.S.) may ultimately provide for transmural resection with narrow margins, intraluminal techniques such as endoscopic submucosal resection can now effect excision of early stage tumors from within the colon. However, the limit on the application of these approaches is oncological providence as current staging requires en bloc mesenteric resection in every case to ensure that adequate nodal assessment is assured. Furthermore, this requirement is also a limiting factor on the advance of innovative procedures such as Single-Incision Laparoscopic Surgery and N.O.T.E.S.-hybrid techniques as these approaches, while likely adept at the definitive management of the primary, have limitations regarding their ability to provide full base mesenteric resection (due mostly to constraints on retraction capacity as well as operating field space and exposure). Therefore a means to accurately and efficiently identify those patients who are truly node negative (and so in whom radical mesenteric lymphadenectomy could be avoided) would allow all of these techniques to advance with a clear focus on address of the primary. This review analyses the current state of the art of regional staging in the colonic mesentery in place of formal lymphadenectomy. It includes deliberation of both preoperative non-invasive testing as well as novel means of employing N.O.T.E.S. approaches to allow direct determination of lymph node status (in particular that of sentinel nodes) by either rapid histopathological examination or by emerging technologies such as Optical Coherence Tomography that may provide optical or 'virtual' biopsy.

Predicting lymph node status in early gastric cancer

Accurate prediction of lymph node (LN) status is of crucial importance for appropriate treatment planning in patients with early gastric cancer (EGC). However, there is no definitive consensus yet on which patient and/or tumor characteristics are associated with LN metastasis. A systematic search for studies investigating the relationship between patient and/or tumor characteristics and LN metastasis in EGC was performed in PubMed/MEDLINE. Patient and/or tumor characteristics associated with LN metastasis were identified by meta-analyzing results of individual studies. Forty-five studies were included. Variables significantly associated with LN metastasis in gastric cancer limited to the mucosa were: age younger than 57 years, tumor location in the middle part of the stomach, larger tumor size, macroscopically depressed tumor type, tumor ulcerations, undifferentiated tumors, diffuse tumor type according to the Lauren classification, lymphatic tumor invasion, tumors with a proliferating cell nuclear antigen (PCNA) labeling index of more than 25%, and matrix metalloproteinase-9-positive tumors. Variables significantly associated with LN metastasis in gastric cancer limited to the submucosa were: female sex, tumor location in the lower part of the stomach, larger tumor size, undifferentiated tumors, increasing depth of submucosal invasion, lymphatic tumor invasion, vascular tumor invasion, increased submucosal vascularity, tumors with a PCNA labeling index of more than 25%, tumors with a gastric mucin phenotype, and vascular endothelial growth factor-C-positive tumors. We identified several variables associated with LN metastasis in EGC. These variables should be included in future research, in order to assess which of these variables remain as significant predictors of LN metastasis.

Ancillary N.O.T.E.S. procedures for early stage gastric cancer

The potential for performing truly scarless, safe surgery that at the same time may be less morbid is tempting both patients and physicians alike to seriously consider Natural Orifice Transluminal Endoscopy Surgery (NOTES) for a range of clinical applications. Given the move towards gastric-preservation by minimally invasive techniques for definitive management of early gastric cancer, this radical approach may find a niche within future clinical care paradigms for early stage malignant lesions of the stomach. Indeed already selected T1,N0 adenocarcinoma is being treated and even cured by advanced endoscopic techniques such as Endoscopic Submucosal Dissection. NOTES may initially therefore find a role in furthering the application of such endeavour by ensuring oncological providence in the treatment of those T1 lesions with higher risk of lymphatic metastases that currently are advised to lie outwith the scope of pure endoscopic resection (for reasons of oncological propriety rather than technical capacity). One such means NOTES could supplement ESD is by providing for direct sampling of sentinel nodes from the perigastric lymph basins. Subsequently perhaps a NOTES technique may develop capable of performing localized, full-thickness gastric wedge or sleeve resection for T2,N0 adenocarcinoma (and indeed perhaps other pathologies such as small gastrointestinal stromal tumors). This review examines how advancing technology along with progressive surgical thinking and innovation could lead to NOTES becoming absorbed into clinical care pathways for early gastric malignancy.

Histopathological predictor for regional lymph node metastasis in gastric cancer

Regional lymph node metastasis in gastric cancer is a definitive indicator of the patient's prognosis. The goal of this study was to identify the predictors for lymph node metastasis among all the possible histopathological parameters, especially by conducting an objective discrimination of the lymphatic and blood vessels. A total of 210 resected primary gastric cancers with or without lymph node metastasis were evaluated based on the conventional histopathological parameters together with immunohistochemistry using antisera-recognizing lymphatic endothelial hyaluronan receptor-1 (LYVE-1), von Willebrand factor, and lymphangiogenesis promoter vascular endothelial growth factor-C (VEGF-C) antibodies. A multivariate regression analyses of the results indicated that only lymphatic invasion was a significant independent predictor of lymph node metastasis at any stage of cancer invasion. VEGF-C expression was partially related to lymph node metastasis in early gastric cancer. The identification of lymphatic invasion by LYVE-1 antibody is therefore useful to predict regional lymph node metastasis in gastric cancer.