Predictive factors for lymph node metastasis in patients with poorly differentiated early gastric cancer

Comparison of long-term outcomes of endoscopic submucosal dissection and surgery for undifferentiated-type early gastric cancer meeting the expanded criteria: a systematic review and meta-analysis

BACKGROUND

There have been concerns over the long-term outcomes of endoscopic submucosal dissection (ESD) for undifferentiated-type early gastric cancer (UD EGC). We aimed to compare the long-term outcomes of ESD and surgery for patients with UD EGC.

METHODS

We searched PubMed, Embase, and Cochrane Library databases through March 2021 to identify studies that compared the long-term outcomes of ESD and surgery for UD EGC meeting expanded criteria for curative resection. The risk of bias was assessed with the Cochrane tool for non-randomized studies. The risk ratio (RR) was estimated using a fixed-effect model.

RESULTS

Overall, 1863 patients from five retrospective cohort studies, including 908 patients with propensity score matching (PSM), were eligible for meta-analysis. ESD was associated with inferior overall survival (OS) compared to surgery in the overall cohort (RR 2.11; 95% CI 1.26-3.55) but not in the PSM cohort (RR 1.18; 95% CI 0.60-2.32). In the PSM cohort, ESD had a lower disease-free survival (DFS) (RR 2.49; 95% CI 1.42-4.35) and higher recurrence (RR 12.61; 95% CI 3.43-46.37), gastric recurrence (RR 11.25; 95% CI 3.06-41.40), and extragastric recurrence (RR 4.23; 95% CI 0.47-37.93). Recurrence outcomes were similar between the overall and PSM cohorts. Disease-specific survival was not significantly different between the two groups in both the overall and PSM cohorts.

CONCLUSION

Although OS after curative ESD for UD EGC was not different from that after surgery in the PSM cohort, DFS and recurrence were inferior after ESD. Limitations included a lack of randomized trials. Further prospective studies comparing the long-term outcomes of ESD and surgery for UD EGC are needed (PROSPERO CRD 42021237097).

Long-term outcomes of endoscopic submucosal dissection and surgery for undifferentiated intramucosal gastric cancer regardless of size

BACKGROUND

The clinical outcomes of endoscopic submucosal dissection (ESD) for undifferentiated (UD) intramucosal early gastric cancer (EGC) compared with those of surgery, regardless of lesion size, are not well known. Furthermore, there is a concern regarding the treatment plan before and after ESD in cases of UD intramucosal EGC within expanded indications.

AIM

To evaluate clinical outcomes of ESD compared with those of surgery in UD intramucosal EGC patients regardless of tumor size.

METHODS

We enrolled patients with UD intramucosal EGC after ESD with complete resection or surgery from January 2005 to August 2020 who met the within or beyond expanded indications with lesion size > 2 cm (the only non-curative factor). Overall, 123 and 562 patients underwent ESD and surgery, respectively. After propensity-score matching, clinical and long-term outcomes, i.e., recurrence-free survival (RFS) and overall survival (OS), were analyzed. The multivariable Cox proportional hazard model with treatment modality and ESD indication was used to evaluate the recurrence risk.

RESULTS

After matching, 119 patients each were finally enrolled in the ESD and surgery groups. The median length of hospital stay was shorter in the ESD group than surgery group (4.0 vs 9.0 days, P < 0.001). Four cases of recurrence after ESD were local recurrences, all of which occurred within 1 year. Total recurrence was seven (5.9%) and two (1.7%) in the ESD and surgery groups, respectively. No difference was observed between the two groups with respect to OS (P = 0.948). However, the ESD group had inferior RFS compared with the surgery group (P = 0.031). ESD was associated with the risk of recurrence after initial treatment in all enrolled patients (hazard ratio, 5.2; 95% confidence interval: 1.0-25.8, P = 0.045).

CONCLUSION

Although OS was similar between the two groups, surveillance endoscopy was important for the ESD than for the surgery group because RFS was inferior and local recurrence was an issue.

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.

Machine learning predicts lymph node metastasis of poorly differentiated-type intramucosal gastric cancer

To construct a machine learning algorithm model of lymph node metastasis (LNM) in patients with poorly differentiated-type intramucosal gastric cancer. 1169 patients with postoperative gastric cancer were divided into a training group and a test group at a ratio of 7:3. The model for lymph node metastasis was established with python machine learning. The Gbdt algorithm in the machine learning results finds that number of resected nodes, lymphovascular invasion and tumor size are the primary 3 factors that account for the weight of LNM. Effect of the LNM model of PDC gastric cancer patients in the training group: Among the 7 algorithm models, the highest accuracy rate was that of GBDT (0.955); The AUC values for the 7 algorithms were, from high to low, XGB (0.881), RF (0.802), GBDT (0.798), LR (0.778), XGB + LR (0.739), RF + LR (0.691) and GBDT + LR (0.626). Results of the LNM model of PDC gastric cancer patients in test group : Among the 7 algorithmic models, XGB had the highest accuracy rate (0.952); Among the 7 algorithms, the AUC values, from high to low, were GBDT (0.788), RF (0.765), XGB (0.762), LR (0.750), RF + LR (0.678), GBDT + LR (0.650) and XGB + LR (0.619). Single machine learning algorithm can predict LNM in poorly differentiated-type intramucosal gastric cancer, but fusion algorithm can not improve the effect of machine learning in predicting LNM.

Risk factors of lymph node metastasis after non-curative endoscopic resection of undifferentiated-type early gastric cancer

BACKGROUND

This study aimed to investigate risk factors for lymph node (LN) or distant metastasis after non-curative endoscopic resection (ER) of undifferentiated-type early gastric cancer (EGC).

METHODS

Of 1124 patients who underwent ER for undifferentiated-type gastric cancer at 18 tertiary hospitals across six geographic areas in Korea between 2005 and 2014, 634 with non-curative ER beyond the expanded criteria were retrospectively enrolled. According to the treatment after ER, patients were divided into additional surgery (n = 270) and follow-up (n = 364) groups. The median follow-up duration was 59 months for recurrence and 84 months for mortality.

RESULTS

LN metastasis was found in 6.7% (18/270) of patients at surgery. Ulcer [odds ratio (OR) 3.83; 95% confidence interval (CI) 1.21-12.13; p = 0.022] and submucosal invasion (OR 10.35; 95% CI 1.35-79.48; p = 0.025) were independent risk factors. In the follow-up group, seven patients (1.9%) developed LN or distant recurrence. Ulcer [hazard ratio (HR) 7.60; 95% CI 1.39-35.74; p = 0.018], LVI (HR 6.80; 95% CI 1.07-42.99; p = 0.042), and positive vertical margin (HR 6.71; 95% CI 1.28-35.19; p = 0.024) were independent risk factors. In the overall cohort, LN metastasis rates were 9.6% in patients with two or more risk factors and 1.2% in those with no or one risk factor.

CONCLUSIONS

LVI, ulcer, submucosal invasion, and positive vertical margin are independently associated with LN or distant metastasis after non-curative ER of undifferentiated-type EGC. Surgical resection is strongly recommended for patients with two or more risk factors.

The Suggestion of Revised Criteria for Endoscopic Resection of Differentiated-Type Submucosal Gastric Cancer

BACKGROUND

Early gastric cancer that meets the expanded criteria for endoscopic resection (ER) is expected to be associated with a negligible risk for lymph node metastasis (LNM); however, recent studies have reported LNM in submucosal gastric cancer patients who met the existing criteria. In this study, we develop the revised criteria for ER of submucosal gastric cancer with the aim of minimizing LNM.

METHODS

We analyzed the clinicopathological data of 2461 patients diagnosed with differentiated, submucosal gastric cancer who underwent surgery at three tertiary hospitals between March 2001 and December 2012, and re-analyzed the pathological slides of all patients. The depth of submucosal invasion was measured histopathologically in two different ways (the classic and alternative methods) to obtain accurate data.

RESULTS

Of the enrolled subjects, 306 (17.0%) had LNM. The width of submucosal invasion correlated well with the LNM. We defined the depth and width of submucosal infiltration associated with the lowest incidence of LNM. None of the 254 subjects developed LNM when the following criteria were met: tumor diameter ≤ 3 cm, submucosal invasion depth < 1000 μm (as measured using the alternative method), submucosal invasion width < 4 mm, no lymphovascular invasion, and no perineural invasion; however, LNM was observed in 2.7% of subjects (6/218) who met the existing criteria.

CONCLUSIONS

We revised the criteria for ER by adopting the alternative method to measure the depth of submucosal invasion and adding the width of such invasion. Our criteria better predicted LNM than the current criteria used to select ER to treat submucosal gastric cancer.

Intramucosal-lymphatic invasion has a slight impact on lymph node metastasis in patients with early gastric cancer

PURPOSE

Lymphatic invasion (LI) is associated with lymph node metastasis (LNM) and a poor prognosis in patients with early gastric cancer (EGC). Although the impact of the LI volume on LNM has been described, no reports have assessed the impact of its depth on LNM.

METHODS

A total of 360 EGC patients with pathologically proven LI who underwent radical gastrectomy with lymphadenectomy between January 2005 and June 2018 at our institution were extracted from our database. Patients were divided into 2 groups: the mLI group, in which LI was limited to the muscularis mucosae (n = 34); and the smLI group, in which LI reached the submucosal region (n = 326). Clinicopathological features, including the LNM incidence, were compared between the groups.

RESULTS

LNM was recognized in 3 patients (9%) in the mLI group and 101 (31%) in the smLI group (P = 0.005). In the mLI group, LNM was not recorded in any patients who met the curative criteria of ESD other than mLI.

CONCLUSIONS

LI limited to the mucosal region does not seem to be a strong indicator for LNM. When pathological findings of an endoscopic submucosal dissection specimen show only mLI as a non-curative criterion, the probability of LNM may be very low.

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

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

CD9-positive exosomes from cancer-associated fibroblasts stimulate the migration ability of scirrhous-type gastric cancer cells

Background:

Crosstalk between cancer cells and fibroblasts is crucial for tumour progression. It has been reported that exosomes derived from cancer cells play an important role in the intracellular communications involved in the development of carcinoma. However, the role of exosomes from fibroblasts remains unclear. This study aimed to clarify the effect of exosomes from fibroblasts on the motility of gastric cancer cells.

Methods:

5 gastric cancer cell lines were used: OCUM-12, NUGC-3, MKN45, FU97 and MKN74. 2 cancer-associated fibroblasts (CAFs) were used. CD9 expression of exosomes from fibroblasts was examined by western blot. The effect of exosomes on the motility of cancer cells was analysed by migration assays. MMP2 was examined by RT-PCR or gelatin zymography. Then, CD9 and MMP2 expressions of 619 gastric cancers were analysed by immunohistochemistry.

Results:

Exosomes from CAFs were taken into scirrhous-type gastric cancer cells, namely OCUM-12 cells and NUGC-3 cells, but not into other types of gastric cancer cells. Exosomes from CAFs were positive for CD9. Exosomes from CAFs significantly stimulated the migration and invasion of OCUM-12 and NUGC-3 cells, which was inhibited by anti-CD9 antibody or CD9-siRNA. MMP2 expression of OCUM-12 and NUGC-3 cells was significantly decreased by CD9-siRNA. 116 CD9-positive cases were significantly correlated with scirrhous-type gastric cancer, lymph node metastasis and venous invasion. The 5-year survival rate of patients with CD9-positive tumours was significantly lower (P<0.001) than in those with CD9-negative tumours.

Conclusions:

CD9-positive exosomes from CAFs might stimulate the migration ability of scirrhous-type gastric cancer cells.

1H NMR metabolic profiling of gastric cancer patients with lymph node metastasis

INTRODUCTION

Gastric cancer (GC) is a malignant tumor worldwide. As primary pathway for metastasis, the lymphatic system is an important prognostic factor for GC patients. Although the metabolic changes of gastric cancer have been investigated in extensive studies, little effort focused on the metabolic profiling of lymph node metastasis (LNM)-positive or negative GC patients.

OBJECTIVES

We performed ¹H NMR spectrum of GC tissue samples with and without LNM to identify novel potential metabolic biomarkers in the process of LNM of GC.

METHODS

¹H NMR-based untargeted metabolomics approach combined with multivariate statistical analyses were used to study the metabolic profiling of tissue samples from LNM-positive GC patients (n = 40), LNM-negative GC patients (n = 40) and normal controls (n = 40).

RESULTS

There was a clear separation between GC patients and normal controls, and 33 differential metabolites were identified in the study. Moreover, GC patients were also well-classified according to LNM-positive or negative. Totally eight distinguishing metabolites were selected in the metabolic profiling of GC patients with LNM-positive or negative, suggesting the metabolic dysfunction in the process of LNM. According to further validation and analysis, especially BCAAs metabolism (leucine, isoleucine, valine), GSH and betaine may be as potential factors of diagnose and prognosis of GC patients with or without LNM.

CONCLUSION

To our knowledge, this is the first metabolomics study focusing on LNM of GC. The identified distinguishing metabolites showed a promising application on clinical diagnose and therapy prediction, and understanding the mechanism underlying the carcinogenesis, invasion and metastasis of GC.

MMP-2 together with MMP-9 overexpression correlated with lymph node metastasis and poor prognosis in early gastric carcinoma

The aim of this study was to correlate matrix metalloproteinase-2 and matrix metalloproteinase-9 expression with the clinicopathological features and outcome of patients with early gastric cancer and to clinically elucidate more information on the role of matrix metalloproteinase-2 and matrix metalloproteinase-9 protein overexpression with regard to lymph node metastasis of early gastric cancer. The levels of matrix metalloproteinase-2 and matrix metalloproteinase-9 protein expression were assessed by immunohistochemistry. An association was observed between matrix metalloproteinase-2, matrix metalloproteinase-9, and matrix metalloproteinase-2/matrix metalloproteinase-9 overexpression and clinicopathological factors, such as ulceration and lymph node metastasis. Furthermore, matrix metalloproteinase-9 and matrix metalloproteinase-2/matrix metalloproteinase-9 overexpression both were strongly correlated with histological grade. In addition, matrix metalloproteinase-2/matrix metalloproteinase-9 overexpression correlated with deep invasion. Multivariate Cox regression analysis revealed that matrix metalloproteinase-2 and matrix metalloproteinase-9 expression were both independent factors of overall survival in patients with early gastric cancer. In novelty, we found that matrix metalloproteinase-2/matrix metalloproteinase-9 overexpression was an independent indicator of lymph node metastasis in early gastric cancer which will be helpful in clinic to select the appropriate treatment of these patients.

Predictive Value of Preoperative Neutrophil Lymphocyte Ratio in Determining the Stage of Gastric Tumor

BACKGROUND Neutrophil-lymphocyte ratio (NLR) is an indicator of the inflammatory state, and its increase has been shown to be a negative prognostic factor for many malignancies. The aim of this study was to determine whether there was a relationship between NLR and tumor aggressiveness in gastric cancer patients and to investigate the prognostic significance of NLR. MATERIAL AND METHODS The medical records of 189 patients with gastric cancer between January 2009 and January 2014 were examined for the presence of metastasis, tumor staging, tumor differentiation grade, and preoperative NLR value. RESULTS Of the 189 patients, 61 were female (32.2%) and 128 were male (67.7%). Eight-eight patients had NLR values of four or higher. A comparison of the high NLR value group and the low NLR value group found no statistically significant difference for clinicopathological features of age, gender, type of operation, of degree of differentiation; differences ranged from 20.7% to 46.2%, p<0.001. CONCLUSIONS Increase in NLR has been associated with poor prognosis in univariate analysis and variations of this parameter have also been shown to be correlated with tumor progression. NLR values should be considered as a useful follow-up parameter.

Predictive Factors for Lymph Node Metastasis in Undifferentiated Early Gastric Cancer: a Systematic Review and Meta-analysis

OBJECTIVES

Less invasive surgery is gaining popularity for the treatment of early gastric cancer (EGC), but there are no definitive guidelines for the use of less invasive surgery for the treatment of undifferentiated EGC. The aims of this meta-analysis were to identify potential predictive factors for lymph node metastasis (LNM) in undifferentiated EGC and to guide the personalized therapeutic modality for patients with undifferentiated EGC.

METHODS

An extensive search of the PubMed, Embase, and Cochrane Library databases was performed to identify relevant articles involving undifferentiated EGC and LNM. Eligible data were systematically reviewed through a meta-analysis using Review Manager 5.3.

RESULTS

In total, 23 studies were included in this analysis. The meta-analysis found that the variables sex (female), age (greater than 60 years), tumor size (greater than 20 mm), depth of invasion (submucosal invasion), presence of lymphovascular involvement, presence of ulcer findings, histology type (non-signet ring carcinoma), and tumor location (not in the middle part of the stomach) were significantly associated with LNM.

CONCLUSIONS

Eight variables were identified as predictive factors for LNM in undifferentiated EGC. The significance of these variables should be further confirmed during the process of LNM in undifferentiated EGC patients for future clinical application.

Predictive value for lymph node metastasis of epithelial-mesenchymal transition and cancer stem cell marker expression in early gastric cancer

BACKGROUND

Minimally invasive therapies, including endoscopic mucosal resection or sentinel node navigation surgery, have been widely applied in early gastric cancer because of their benefits in promoting patient quality of life. However, lymph node dissection is beyond the capability of endoscopic therapy, and in sentinel node navigation surgery, the potential for skip metastasis is not negligible. Therefore, the possibility of lymph node metastasis is the most important factor to consider when deciding whether to apply the minimally invasive therapies. In the present study, the significance of epithelial mesenchymal transition and stem cell marker expression in lymph node metastasis in early gastric cancer was investigated.

METHODS

We evaluated the significance of the expression of 5 epithelial mesenchymal transition-related markers (E-cadherin, MMP7, S100A, Snail-1, and HGF) and 6 stem cell markers (ALDH1, SOX2, CD24, CD44, CD54, and CD133) in 119 early gastric cancer specimens using immunohistochemistry. Because protein expression is heterogeneous in gastric cancer, we analyzed the expression of these markers in two selected regions (one each at the superficial zone and the deep invasive front).

RESULTS

Expression of E-cadherin, MMP7, HGF, and CD133 at the deep invasive front was associated with the absence of lymph node metastasis (P=0.013, 0.018, <0.001, and 0.026, respectively). Presence of diffuse-type component, lymphatic invasion, and lack of expression of HGF and CD133 at the deep invasive front were independent predictive markers of lymph node metastasis (P=0.019, <0.001, 0.015, and 0.047, respectively).

CONCLUSIONS

Lymph node metastasis is strongly associated with expression status of HGF and CD133 at the deep invasive front, suggesting the usefulness of these proteins as independent predictive markers of lymph node metastasis in early gastric cancer.

Expression of Vav3 protein and its prognostic value in patients with gastric cancer

Vav3 is associated with tumor growth, apoptosis, invasion, metastasis and angiogenesis. In this study, we detected the expression of Vav3 in gastric cancer tissues, and explored its role in invasion, metastasis and prognosis of gastric cancer. Vav3, MMP-2, MMP-9, TIMP-1 and TIMP-2 in primary lesion and pericarcinous tissues were tested with Immunohistochemistry and Western blot. Results showed a higher expression of Vav3 in primary lesion than in pericarcinous tissue, and the expression of Vav3 was significantly correlated with MMP-2, MMP-9 and TIMP-1 in gastric cancer tissues. Overexpression of Vav3 was associated with poorer differentiation, advanced clinical stage, more significant infiltration depth, lymphatic metastasis, and perineural invasion. Results of Kaplan-Meier verified that overexpression of Vav3 was related to poorer prognosis and shorter survival time. Moreover, Cox proportional hazard model revealed that overexpression of Vav3 was an independent risk factor of prognosis for patients with gastric cancer. In all, we conclude that overexpression of Vav3 is an independent risk factor for prognosis of gastric cancer, and can be used as a prognostic indicator. This may be because that Vav3 could regulate genes which associated with the invasion and metastasis.

Applicability of endoscopic submucosal dissection for undifferentiated early gastric cancer: Mixed histology of poorly differentiated adenocarcinoma and signet ring cell carcinoma is a worse predictive factor of nodal metastasis

BACKGROUND

Endoscopic submucosal dissection (ESD) is not considered an appropriate treatment for undifferentiated early gastric cancer (UEGC) due to the higher risk of nodal metastases. We aimed to investigate predictive factors for nodal metastases in UEGCs, determine whether the tumor histology is an independent factor for it, and explore whether ESD is applicable for UEGC.

METHODS

We reviewed the medical records of 1837 patients who underwent curative gastrectomy for poorly differentiated adenocarcinoma, signet ring cell carcinoma, and a mixed type of both tumors between 2008 and 2012.

RESULTS

Nodal metastases were found in 208 (11.3%) patients. Multivariate analysis revealed that lymphovascular invasion and tumor histology were significantly associated with nodal metastases in mucosal cancers, the rates of which were higher in mixed type tumors (6.3%) than in the other two types (2.0-2.5%; p = 0.005). No nodal metastases were observed in poorly differentiated adenocarcinomas <2 cm and signet ring cell carcinomas <1 cm without lymphovascular invasion and confined to the mucosa.

CONCLUSION

Mixed type tumors should not be considered for endoscopic resection. ESD might be applicable for mucosal tumors with poorly differentiated adenocarcinoma <2 cm and signet ring cell carcinoma <1 cm without lymphovascular invasion.

A nomogram for predicting the likelihood of lymph node metastasis in early gastric signet ring cell carcinoma: A single center retrospective analysis with external validation

Treatment algorithm has not been established for early gastric cancer with signet ring cell carcinoma (SRC), which has a reported low rate of lymph node metastasis (LNM) similar to differentiated cancer. A cohort of 256 patients with early gastric SRC at our center between January 2002 and December 2015 were retrospectively reviewed. Multivariate logistic regression analysis was used to determine the independent factors of LNM. A nomogram for predicting LNM was constructed and internally validated. Additional external validation was performed using the database from Cancer Institute Ariake Hospital in Tokyo (n = 1273). Clinical performance of the model was assessed by decision analysis of curve. The overall LNM incidence was 12.9% (33/256). The multivariate logistic model identified sex, tumor size, and LVI as covariates associated with LNM. Subsequently, a nomogram consisted of sex, tumor size, and depth of invasion was established. The model showed qualified discrimination ability both in internal validation (area under curve, 0.801; 95% confidence interval [CI], 0.729-0.873) and in external dataset (area under curve, 0.707; 95% CI, 0.657-0.758). Based on the nomogram, treatment algorithm for early gastric SRC was proposed to assist clinicians in making better decisions. We developed a nomogram predicting risk of LNM for early gastric SRC, which should be helpful for patient counseling and surgical decision-making.

How to Interpret the Pathological Report before and after Endoscopic Submucosal Dissection of Early Gastric Cancer

Possible lymph node metastasis (LNM) and residual cancer are major concerns in endoscopic submucosal dissection (ESD) for early gastric cancer. To reduce the risk of LNM and cancer recurrence, the proper indications for ESD should be considered. Histology, size, depth of invasion, and presence of ulceration should be thoroughly evaluated before proceeding with ESD. However, with incomplete information, discrepancies often arise between the pathological diagnosis based on the forceps biopsy and that based on the totally resected specimen. In addition, the presence of lymphovascular involvement and histological homogeneity can be clarified only after ESD. If the pathological diagnosis changes after ESD, we should reevaluate the curativeness and reformulate the goal of treatment. Additional surgery is a reasonable strategy for non-curative ESD, but a patient's other health conditions should also be considered. It is simple to read pathological reports before and after ESD, but it can be a complicated art to interpret the report and formulate an optimal approach. In this review, various considerations regarding the pathological diagnosis will be discussed.

A Risk Prediction Model Based on Lymph-Node Metastasis in Poorly Differentiated-Type Intramucosal Gastric Cancer

Background and Aim

Endoscopic submucosal dissection (ESD) for undifferentiated type early gastric cancer is regarded as an investigational treatment. Few studies have tried to identify the risk factors that predict lymph-node metastasis (LNM) in intramucosal poorly differentiated adenocarcinomas (PDC). This study was designed to develop a risk scoring system (RSS) for predicting LNM in intramucosal PDC.

Methods

From January 2002 to July 2015, patients diagnosed with mucosa-confined PDC, among those who underwent curative gastrectomy with lymph node dissection were reviewed. A risk model based on independent predicting factors of LNM was developed, and its performance was internally validated using a split sample approach.

Results

Overall, LNM was observed in 5.2% (61) of 1169 patients. Four risk factors [Female sex, tumor size ≥ 3.2 cm, muscularis mucosa (M3) invasion, and lymphatic-vascular involvement] were significantly associated with LNM, which were incorporated into the RSS. The area under the receiver operating characteristic curve for predicting LNM after internal validation was 0.69 [95% confidence interval (CI), 0.59–0.79]. A total score of 2 points corresponded to the optimal RSS threshold with a discrimination of 0.75 (95% CI 0.69–0.81). The LNM rates were 1.6% for low risk (<2 points) and 8.9% for high-risk (≥2 points) patients, with a negative predictive value of 98.6% (95% CI 0.98–1.00).

Conclusions

A RSS could be useful in clinical practice to determine which patients with intramucosal PDC have low risk of LNM.

Endoscopic resection of early gastric cancer: current status and new approaches

Endoscopic resection (ER) of early gastric cancer (EGC) has been an optimal treatment for selected patients. As endoscopic submucosal dissection (ESD) has been widely used for treatment of EGC, concerns have been asked to achieve curative resection for EGC while guaranteeing precise prediction of lymph node metastasis (LNM). Moreover, a new microscopic imaging for precise endoscopic diagnosis of EGC is introduced. This review covers the current status and new approaches of ER of EGC.

Feasible endoscopic therapy for early gastric cancer

AIM

To analyze the relationship between lymph node metastasis and clinical pathology of early gastric cancer (EGC) in order to provide criteria for a feasible endoscopic therapy.

METHODS

Clinical data of the 525 EGC patients who underwent surgical operations between January 2009 and March 2014 in the West China Hospital of Sichuan University were analyzed retrospectively. Clinical pathological features were compared between different EGC patients with or without lymph node metastasis, and investigated by univariate and multivariate analyses for possible relationships with lymph node metastasis.

RESULTS

Of the 2913 patients who underwent gastrectomy with lymph node dissection, 529 cases were pathologically proven to be EGC and 525 cases were enrolled in this study, excluding 4 cases of gastric stump carcinoma. Among 233 patients with mucosal carcinoma, 43 (18.5%) had lymph node metastasis. Among 292 patients with submucosal carcinoma, 118 (40.4%) had lymph nodemetastasis. Univariate analysis showed that gender, tumor size, invasion depth, differentiation type and lymphatic involvement correlated with a high risk of lymph node metastasis. Multivariate analysis revealed that gender (OR = 1.649, 95%CI: 1.091-2.492, P = 0.018), tumor size (OR = 1.803, 95%CI: 1.201-2.706, P = 0.004), invasion depth (OR = 2.566, 95%CI: 1.671-3.941, P = 0.000), histological differentiation (OR = 2.621, 95%CI: 1.624-4.230, P = 0.000) and lymphatic involvement (OR = 3.505, 95%CI: 1.590-7.725, P = 0.002) were independent risk factors for lymph node metastasis. Comprehensive analysis showed that lymph node metastasis was absent in patients with tumor that was limited to the mucosa, size ≤ 2 cm, differentiated and without lymphatic involvement.

CONCLUSION

We propose an endoscopic therapy for EGC that is limited to the mucosa, size ≤ 2 cm, differentiated and without lymphatic involvement.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk Factors for Lymph Node Metastasis in Early Gastric Cancer with Signet Ring Cell Carcinoma

BACKGROUND

Gastrectomy was reported to be an excessive approach for early gastric cancer with signet ring cell carcinoma. This study was conducted to explore the feasibility of endoscopic submucosal dissection for early gastric with signet ring cell carcinoma.

METHODS

Data from 1067 patients who underwent gastrectomy for early gastric cancer were collected retrospectively. The association between the clinicopathological factors and the lymph node metastasis was analyzed by univariate and multivariate logistic regression analyses.

RESULTS

Lymph node metastasis was confirmed in 17.2 % (184/1067) of patients. Meanwhile, the incidence of lymph node metastasis with each histology type was 13.1 % (26/198), 9.8 % (34/347), and 23.8 % (124/522) for signet ring cell carcinoma, differentiated carcinomas, and undifferentiated carcinomas, respectively. Signet ring cell carcinoma occurs more in women and young patients, with a higher predominance for mucosa. Various factors-including sex, tumor size, depth of tumor, and lymphovascular invasion-were found to be associated with lymph node metastasis for signet ring cell carcinoma (P < 0.05). Multivariate analysis revealed that tumor size (7.489, 95 % CI 2.025-27.701) and lymphovascular invasion (18.434, 95 % CI 3.256-104.359) were independent risk factors for lymph node metastasis (P < 0.05). Further analysis reveals there was no positive lymph node in patients with signet ring cell carcinoma when tumor confined to mucosa, size ≤2 cm and without lymphovascular invasion and ulceration.

CONCLUSIONS

Given the low risk of lymph node involvement, we recommend that endoscopic submucosal dissection be safely applied for early gastric signet ring cell carcinoma when tumor confined to mucosa, size ≤2 cm, and without lymphovascular invasion and ulceration.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients' desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Stratifying the risk of lymph node metastasis in undifferentiated-type early gastric cancer

AIM: To study how lymph node metastasis (LNM) risk is stratified in undifferentiated-type early gastric cancer (undiff-EGC) dependent on combinations of risk factors.

METHODS: Five hundred and sixty-seven cases with undiff-EGC undergoing gastrectomy with lymphadenectomy were examined retrospectively. Using clinicopathological factors of patient age, location, size, an endoscopic macroscopic tumor form, ulceration, depth, histology, lymphatic involvement (LI) and venous involvement (VI), LNM risk was examined and stratified by conventional statistical analysis and data-mining analysis.

RESULTS: LNM was positive in 44 of 567 cases (7.8%). Univariate analysis revealed > 2 cm, protrusion, submucosal (sm), mixed type, LI and VI as significant prognostic factors and > 2 cm and LI-positive were independent factors by multivariate analysis. In preoperatively evaluable factors excluding LVI, sm and > 2 cm were independent factors. According to the depth and size, cases were categorized into the low-risk group [m and ≤ 2 cm, 0% (LNM incidence)], the moderate-risk group (m and > 2 cm, 5.6%; and sm and ≤ 2 cm, 6.0%), and the high-risk group (sm and > 2 cm, 19.3%). On the other hand, LNM occurred in 1.4% in all LI-negative cases, greatly lower than 28.2% in all LI-positive cases, and LNM incidence was low in LI-negative cases even in the moderate- and high-risk groups.

CONCLUSION: LNM-related factors in undiff-EGC were depth and size preoperatively while those were LI and size postoperatively. Among these factors, LI was the most significantly correlated factor.

Ever-changing endoscopic treatment for early gastric cancer: Yesterday-today-tomorrow

Endoscopic resection has been an optimal treatment for selected patients with early gastric cancer (EGC) based on advances in endoscopic instruments and techniques. As endoscopic submucosal dissection (ESD) has been widely used for treatment of EGC along with expanding ESD indication, concerns have been asked to achieve curative resection for EGC while guaranteeing precise prediction of lymph node metastasis (LNM). Recently, new techniques including ESD or endoscopic full-thickness resection combined with sentinel node navigation enable minimal tumor resection and a laparoscopic lymphadenectomy in cases of EGC with high risk of LNM. This review covers the development and challenges of endoscopic treatment for EGC. Moreover, a new microscopic imaging and endoscopic techniques for precise endoscopic diagnosis and minimally invasive treatment of EGC are introduced.

Prognostic role of lymph node metastasis in early gastric cancer

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: Do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients’ desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Inhibition of gastric cancer cell growth and invasion through siRNA-mediated knockdown of guanine nucleotide exchange factor Vav3

Vav3, a Rho GTPase guanine nucleotide exchange factor, is associated with tumor growth, apoptosis, invasion and metastasis, and angiogenesis. However, the role of Vav3 in gastric cancer remains unclear. In this study, Vav3 expression was blocked by specific siRNA in gastric cancer cell line MGC803. MTT was used to assay cell proliferation activity; wound healing assay and transwell assay were applied to detect cell migration and invasion ability; and qRT-PCR and Western blot were employed to detect expression levels of Vav3 as well as proliferation, migration, and invasion-related genes. The results showed that Vav3 expression in gastric cancer tissues and cell lines was significantly upregulated and was higher than that in adjacent tissues of cancer and normal gastric mucosal cell lines. Vav3 knockdown inhibited proliferation, migration, and invasion of MGC803 gastric cancer cells. The expression of P21, P27, TIMP-1, and TIMP-2 was upregulated, while proliferating cell nuclear antigen, cyclin E1, matrix metalloproteinase (MMP)-2, and MMP-7 were downregulated by Vav3 knockdown in MGC803 gastric cells. In conclusion, Vav3 is involved in the proliferation, migration, and invasion of gastric cancer cell as a tumor oncogene.

Lymphatic vascular invasion is an independent correlated factor for lymph node metastasis and the prognosis of resectable T2 gastric cancer patients

The objective of this study was to investigate the independent correlated factors for lymph node metastasis (LNM) and prognosis in T2 gastric cancer patients. A total of 135 pathologically confirmed T2 gastric cancer patients who received a gastrectomy at the Beijing University Cancer Hospital from Dec 1999 to Dec 2006 were studied retrospectively. The potential correlated factors for LNM and patients' prognosis were analyzed, including gender, age, tumor location and size, depth of invasion, lymphatic vascular invasion (LVI), differentiation grade, histological type, Borrmann type, LNM, distant metastasis, TNM stage, and whether the patient was treated with a radical gastrectomy. LNM occurred in 69 patients, which represents a rate of LNM of 51.1 %. Multivariate logistic regression analysis showed that LVI and TNM stage were independent risk factors for LNM (p values were 0.002 and 0.029, respectively). The median follow-up time was 60.3 months. Multivariable survival analysis revealed that age (<60 vs. ≥ 60), TNM stage and LVI were independent prognostic factors for gastric cancer patients (p values were <0.001, 0.047, and 0.001, respectively). In conclusion, LVI was an independent factor for LNM and the prognosis of resectable T2 gastric cancer patients.