Recurrence in early gastric cancer with lymph node metastasis

A machine learning model for predicting the lymph node metastasis of early gastric cancer not meeting the endoscopic curability criteria

BACKGROUND

We developed a machine learning (ML) model to predict the risk of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) who did not meet the existing Japanese endoscopic curability criteria and compared its performance with that of the most common clinical risk scoring system, the eCura system.

METHODS

We used data from 4,042 consecutive patients with EGC from 21 institutions who underwent endoscopic submucosal dissection (ESD) and/or surgery between 2010 and 2021. All resected EGCs were histologically confirmed not to satisfy the current Japanese endoscopic curability criteria. Of all patients, 3,506 constituted the training cohort to develop the neural network-based ML model, and 536 constituted the validation cohort. The performance of our ML model, as measured by the area under the receiver operating characteristic curve (AUC), was compared with that of the eCura system in the validation cohort.

RESULTS

LNM rates were 14% (503/3,506) and 7% (39/536) in the training and validation cohorts, respectively. The ML model identified patients with LNM with an AUC of 0.83 (95% confidence interval, 0.76-0.89) in the validation cohort, while the eCura system identified patients with LNM with an AUC of 0.77 (95% confidence interval, 0.70-0.85) (P = 0.006, DeLong's test).

CONCLUSIONS

Our ML model performed better than the eCura system for predicting LNM risk in patients with EGC who did not meet the existing Japanese endoscopic curability criteria. We developed a neural network-based machine learning model that predicts the risk of lymph node metastasis in patients with early gastric cancer who did not meet the endoscopic curability criteria.

Challenges in early detection and endoscopic resection of esophageal cancer: There is a long way to go

The publication by Qu et al provided a comprehensive discussion about the epidemiology, etiology, histopathology, early detection, and endoscopic treatment of esophageal carcinoma (EC) and summarized the progress in the advanced technologies for screening and endoscopic resection for EC. In this editorial, we will provide deeper insight into the challenges that hinder practical application of these advanced technologies along with the role of these technologies in upper endoscopy quality. More efforts need to be made to overcome the challenges and add the value of these technologies in upper endoscopy quality. Clinical outcomes of management strategies after noncurative endoscopic dissection for early EC patients need further investigation. The experiences with noncurative endoscopic resection of other organs may have certain implications for noncurative resection of early EC.

Interpretable deep learning model to predict lymph node metastasis in early gastric cancer using whole slide images

In early gastric cancer (EGC), the presence of lymph node metastasis (LNM) is a crucial factor for determining the treatment options. Endoscopic resection is used for treatment of EGC with minimal risk of LNM. However, owing to the lack of definitive criteria for identifying patients who require additional surgery, some patients undergo unnecessary additional surgery. Considering that histopathologic patterns are significant factor for predicting lymph node metastasis in gastric cancer, we aimed to develop a machine learning algorithm which can predict LNM status using hematoxylin and eosin (H&E)-stained images. The images were obtained from several institutions. Our pipeline comprised two sequential approaches including a feature extractor and a risk classifier. For the feature extractor, a segmentation network (DeepLabV3+) was trained on 243 WSIs across three datasets to differentiate each histological subtype. The risk classifier was trained with XGBoost using 70 morphological features inferred from the trained feature extractor. The trained segmentation network, the feature extractor, achieved high performance, with pixel accuracies of 0.9348 and 0.8939 for the internal and external datasets in patch level, respectively. The risk classifier achieved an overall AUC of 0.75 in predicting LNM status. Remarkably, one of the datasets also showed a promising result with an AUC of 0.92. This is the first multi-institution study to develop machine learning algorithm for predicting LNM status in patients with EGC using H&E-stained histopathology images. Our findings have the potential to improve the selection of patients who require surgery among those with EGC showing high-risk histological features.

Establishment and validation of a risk score model based on EUS: assessment of lymph node metastasis in early gastric cancer

BACKGROUND AND AIMS

Lymph node metastasis significantly affects the prognosis of early gastric cancer patients. EUS plays a crucial role in the preoperative assessment of early gastric cancer. This study evaluated the efficacy of EUS in identifying lymph node metastasis in early gastric cancer patients and developed a risk score model to aid in choosing the best treatment options.

METHODS

We retrospectively analyzed the effectiveness of EUS for detecting lymph node metastasis in early gastric cancer patients. A risk score model for predicting lymph node metastasis preoperatively was created using independent risk factors identified through binary logistic regression analysis and subsequently validated. Receiver operating characteristic curves were generated for both the development and validation cohorts.

RESULTS

The overall accuracy of EUS in identifying lymph node metastasis was 85.3%, although its sensitivity (29.2%) and positive predictive value (38.7%) were relatively low. Patients were categorized based on preoperative risk factors for lymph node metastasis, including tumor size of ≥20 mm, lymph nodes of ≥10 mm, body mass index of ≥24 kg/m2, and lymph node metastasis on CT scans. A 7-point risk score model was developed to assess the likelihood of lymph node metastasis. The areas under the receiver operating characteristic curve for the development and validation sets were 0.842 and 0.837, respectively, with sensitivities of 64% and 79%, respectively.

CONCLUSIONS

We developed a practical risk score model based on preoperative factors to help EUS predict lymph node metastasis in early gastric cancer patients, guiding the selection of optimal treatment approaches for these patients.

Development and validation of a predictive model associated with lymph node metastasis of gastric signet ring carcinoma patients

The risk factors for lymph node metastasis (LNM) in patients with gastric signet ring cell carcinoma (GSRC) have not been well-defined. This study was designed to prognosticate LNM in patients with GSRC by constructing and verifying a nomogram. A total of 2789 patients with GSRC from the Surveillance, Epidemiology, and End Results (SEER) database and Yijishan Hospital of Wannan Medical College (YJS) were retrospectively reviewed. A predictive model was established using logistic regression based on the SEER cohort. The performance of the model was evaluated using the concordance index (C-index) and decision curve analysis (DCA). In addition, its robustness was validated using the YJS cohort. Four independent predictors of LNM were identified in the SEER cohort. Next, a nomogram was constructed by incorporating these predictors. The C-index were 0.800 (95% confidence interval [CI] = 0.781-0.819) and 0.837 (95% CI = 0.784-0.890) in the training and external validation cohorts, respectively. The outcomes of DCA supported good clinical benefits. The proposed model for evaluating the LNM in patients with GSRC can help to avoid the misdiagnosis risk of N-stage, assist to screen the population suitable for neoadjuvant therapy and help clinicians to optimize clinical decisions.

Feasibility for the application of expanded endoscopic resection criteria in mucosal undifferentiated gastric cancer

BACKGROUND & AIM

The indication of endoscopic submucosal dissection (ESD) for mucosal undifferentiated early gastric cancer (EGC) remains controversial because of risk of lymph node metastasis (LNM). The aim of this study was to identify risk factors for lymph node metastasis (LNM) in mucosal undifferentiated EGC, and further to confirm feasibility of the ESD for the treatment of mucosal undifferentiated EGC.

METHODS

We retrospectively reviewed data of patients who underwent surgical resection with lymph node dissection of T1a stage primary gastric adenocarcinoma at three medical centers between 2012 and 2022. We evaluated the frequency of lymph node metastasis and the associated risk factors, as well as the lymph node metastasis rate in the expanded indication of mucosal undifferentiated EGC.

RESULTS

A total of 100 surgically treated patients with mucosal undifferentiated EGC were enrolled. LNM was irrelevant to the age, tumor size, location, and macroscopic type (all P > 0.05), while it was significantly associated with lymphovascular invasion (LVI, P ＜0.001). And logistic regression analysis showed that the LVI was the only significant risk factors for LNM (OR: 0.34, 95%CI: 0.06-0.204; P ＜0.001). Of 44 mucosal undifferentiated EGC patients satisfying the expanded indication of ESD, 3 patients (6.8%) showed LN metastasis, all of them with undifferentiated cancer without ulceration, less than 2.0 cm in size.

CONCLUSIONS

Because LNM is present in mucosal undifferentiated EGC patients who satisfied the expanded indication of ESD, ESD cannot be considered a better choice than surgery for all undifferentiated EGC patients. LVI was significant risk factors for LNM in patients with mucosal undifferentiated EGC.

Clinical implications of micro lymph node metastasis for patients with gastric cancer

BACKGROUND

Lymph node size is considered as a criterion for possible lymph node metastasis in imageology. Micro lymph nodes are easily overlooked by surgeons and pathologists. This study investigated the influencing factors and prognosis of micro lymph node metastasis in gastric cancer.

METHODS

191 eligible gastric cancer patients who underwent D2 lymphadenectomy from June 2016 to June 2017 in the Third Surgery Department at the Fourth Hospital of Hebei Medical University were retrospectively analyzed. Specimens were resected en bloc and the postoperative retrieval of micro lymph nodes was carried out by the operating surgeon for each lymph node station. Micro lymph nodes were submitted for pathological examination separately. According to the results of pathological results, patients were divided into the "micro-LNM (micro lymph node metastasis)" group (N = 85) and the "non micro-LNM" group (N = 106).

RESULTS

The total number of lymph nodes retrieved was 10,954, of which 2998 (27.37%) were micro lymph nodes. A total of 85 (44.50%) gastric cancer patients had been proven to have micro lymph node metastasis. The mean number of micro lymph nodes retrieved was 15.7. The rate of micro lymph node metastasis was 8.1% (242/2998). Undifferentiated carcinoma (90.6% vs. 56.6%, P = 0.034) and more advanced Pathological N category (P < 0.001) were significantly related to micro lymph node metastasis. The patients with micro lymph node metastasis had a poor prognosis (HR for OS of 2.199, 95% CI = 1.335-3.622, P = 0.002). For the stage III patients, micro lymph node metastasis was associated with shorter 5-year OS (15.6% vs. 43.6%, P = 0.0004).

CONCLUSIONS

Micro lymph node metastasis is an independent risk factor for poor prognosis in gastric cancer patients. Micro lymph node metastasis appears to be a supplement to N category in order to obtain more accurate pathological staging.

Risk of lymph node metastasis in early gastric cancer for a Western population

INTRODUCTION

Endoscopic resection (ER) of early gastric cancer (EGC) is increasingly used in Eastern countries due to their low rates of lymph node metastasis (LNM); however, there is a paucity of evidence in Western countries. We investigated LNM and its effect on overall survival (OS) in Western patients with EGC.

METHODS

Patients diagnosed with T1 gastric cancer between 2000 and 2017 were retrospectively evaluated. Univariate Kaplan-Meier, multivariate logistic and Cox-regression models were used to assess the associations between clinical characteristics, LNM, and OS.

RESULTS

Among 86 patients, median age was 68 years and 72% were male. Node positivity was 30%. Two percent of patients met the classical guidelines for ER and all were node-negative, while 16% met expanded criteria of which 14% were node-positive. T1b disease (odds ratio [OR] 41.2 [95% confidence interval [CI] 1.62-1048], p = 0.02) and lymphovascular/perineural invasion (OR 18.0 [95% CI 2.41-134], p = 0.01) were predictive of node positivity. The 5-year OS for node-negative and node-positive patients was 84% and 53% (p = 0.004), respectively.

CONCLUSIONS

The risk of LNM in Western patients with EGC is higher; therefore, generalizability of the expanded criteria for ER should be interpreted with caution.

A Novel Method for Dynamically Assessing the Prognosis of Patients with pT1 Gastric Cancer: A Large Population-Based Dynamic Prognostic Analysis

Background

While early gastric cancer (EGC) patients are likely to experience relatively long postoperative survival, certain disease-related findings are associated with a poorer prognosis. This study sought to develop and validate a novel predictive model capable of estimating conditional disease-specific survival (CDSS) in EGC patients.

Methods

A total of 3016 patients diagnosed with pT1NxM0 GC after gastrectomy between 1998 and 2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) database and were separated into training and validation cohorts. Kaplan‒Meier curves and log-rank tests were employed to evaluate DSS, after which univariate and multivariate Cox regression analyses were used to construct a predictive nomogram and to estimate CDSS at 1, 2, and 3 years postoperatively in these patients.

Results

In the training cohort, the 3-year CDSS rose from 89.1% to 94.6% from 0 to 5 years postoperatively, while the 5-year CDSS rose from 84.5% to 92.0%. Cox regression analyses led to the construction of a nomogram that was able to reliably predict 3- and 5-year CDSS at 1, 2, and 3 years postoperatively (all P < 0.05) based upon patient age, tumor size, pT stage, pN stage, and the number of retrieved lymph nodes. This model exhibited good discriminative power in the training and validation cohorts (concordance index: 0.791 and 0.813, respectively), and nomogram calibration curves confirmed that actual and predicted survival outcomes were close to one another.

Conclusions

We herein developed a nomogram capable of accurately predicting the CDSS of EGC patients that had survived for multiple years after undergoing surgery.

18F-FDG PET/CT Radiomics for Preoperative Prediction of Lymph Node Metastases and Nodal Staging in Gastric Cancer

OBJECTIVES

The accurate assessment of lymph node metastases (LNMs) and the preoperative nodal (N) stage are critical for the precise treatment of patients with gastric cancer (GC). The diagnostic performance, however, of current imaging procedures used for this assessment is sub-optimal. Our aim was to investigate the value of preoperative 18F-FDG PET/CT radiomic features to predict LNMs and the N stage.

METHODS

We retrospectively collected clinical and 18F-FDG PET/CT imaging data of 185 patients with GC who underwent total or partial radical gastrectomy. Patients were allocated to training and validation sets using the stratified method at a fixed ratio (8:2). There were 2,100 radiomic features extracted from the 18F-FDG PET/CT scans. After selecting radiomic features by the random forest, relevancy-based, and sequential forward selection methods, the BalancedBagging ensemble classifier was established for the preoperative prediction of LNMs, and the OneVsRest classifier for the N stage. The performance of the models was primarily evaluated by the AUC and accuracy, and validated by the independent validation methods. Analysis of the feature importance and the correlation were also conducted. We also compared the predictive performance of our radiomic models to that with the contrast-enhanced CT (CECT) and 18F-FDG PET/CT.

RESULTS

There were 185 patients-127 men, 58 women, with the median age of 62, and an age range of 22-86 years. One CT feature and one PET feature were selected to predict LNMs and achieved the best performance (AUC: 82.2%, accuracy: 85.2%). This radiomic model also detected some LNMs that were missed in CECT (19.6%) and 18F-FDG PET/CT (35.7%). For predicting the N stage, four CT features and one PET feature were selected (AUC: 73.7%, accuracy: 62.3%). Of note, a proportion of patients in the validation set whose LNMs were incorrectly staged by CECT (57.4%) and 18F-FDG PET/CT (55%) were diagnosed correctly by our radiomic model.

CONCLUSION

We developed and validated two machine learning models based on the preoperative 18F-FDG PET/CT images that have a predictive value for LNMs and the N stage in GC. These predictive models show a promise to offer a potentially useful adjunct to current staging approaches for patients with GC.

High frequency of bone recurrence as an initial recurrence site after radical surgery in T1N3 gastric cancer: a propensity score matching analysis

PURPOSE

T1 gastric cancer (GC) with seven or more metastatic lymph nodes is extremely rare, and very few clinical studies have been conducted to evaluate the clinicopathological features of their recurrence.

METHODS

We retrospectively analyzed the outcomes of T1 GC and T2-4 GC patients who had multiple nodal metastases after radical surgery from 2006 to 2020. Propensity score matching was performed to compare the two groups of patients.

RESULTS

After propensity score matching, 18 of 22 patients in the T1 group and 36 of 144 patients in the T2-4 group were selected. Recurrence occurred in six patients (33.3%) in the T1 group. In the T1 group, the most common site of initial recurrence was bone (15.0%). The prevalence of bone recurrence was significantly higher in the T1 group than in the T2-4 group (P = 0.02). The median interval time between radical surgery and bone recurrence was 24 months, and the median survival time after bone recurrence was 14 months.

CONCLUSION

Bone recurrence was more frequently identified as an initial recurrence site in T1 GC cases with multiple metastases after radical surgery compared with that in T2-4 GC cases. Careful attention should be paid to postoperative bone recurrence in the long-term postoperative course of these patients.

Prognostic impact of lymph node micrometastasis in patients with gastric cancer

PURPOSE

The clinical significance of lymph node micrometastasis (LNMM) remains controversial in gastric cancer (GC). In this study, we investigated the prognostic impact of LNMM in patients with GC.

METHODS

A total of 624 patients with pathologically lymph node metastasis-negative (pN0) and N1 status (pN1) who underwent gastrectomy between 2004 and 2018 were enrolled in this retrospective study. The diameter of tumor cell clusters in metastatic lymph nodes was measured in 120 patients with pN1 GC.

RESULTS

Patients with lymph node tumors < 1500 μm in diameter (LNMM) had a significantly better prognosis than those with tumors ≥ 1500 μm in diameter (p = 0.012; log-rank test). Cox's proportional hazards model revealed that LNMM (p = 0.016), several dissected lymph nodes (p = 0.049), and the provision of adjuvant chemotherapy (p = 0.002) were independent prognostic factors for the overall survival of patients with pN1 GC. There was no significant difference in the overall survival between patients with LNMM who received chemotherapy and those who did not (p = 0.332).

CONCLUSIONS

LNMM is associated with a favorable prognosis and maybe an independent prognostic marker in patients with pN1 GC. LNMM in GC may be considered a factor preventing adjuvant chemotherapy.

Gastric cancer detection using the serum pepsinogen test method

BACKGROUND

Gastric cancer (GC) is the eighth most common cause of cancer deaths in Croatia and one of the most common causes of cancer deaths worldwide. A reliable diagnostic tool for the early detection of GC is essential.

OBJECTIVE

We previously suggested a pepsinogen test method to reduce the mortality from GC by allowing early detection. Here, we report an updated analysis from a prospective single-center clinical study to evaluate the sensitivity and specificity of the pepsinogen test method and to determine whether this test can be used as a part of routine laboratory assessment of high-risk patients.

METHODS

We present mature data of the pepsinogen test method in the Croatian population after a median follow-up of 36 months. Statistical analyses were performed using a Mann-Whitney U test, multiple logistic regression, and receiver operating characteristics (ROC) to evaluate the predictive power of the assayed biomarkers.

RESULTS

Of the 116 patients, 25 patients had GC and 91 demonstrated a nonmalignant pathology based on tissue biopsy. Cutoff values were pepsinogen I ⩽70 and pepsinogen I/II ratio ⩽3.0. Using ROC curve analysis, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were determined to be 87.22%, 78.12%, 90.10%, 71.43%, and 92.86%, respectively, for the diagnosis of GC. The area under the curve was 0.700 (95% confidence interval 0.57-0.83).

CONCLUSION

Pepsinogen tests are valuable for screening a population in need of further diagnosis and could help to avoid unnecessary invasive endoscopic procedures.

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

BACKGROUND AND STUDY AIM

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Construction and Validation of a Risk-Scoring Model that Preoperatively Predicts Lymph Node Metastasis in Early Gastric Cancer Patients

OBJECTIVE

The aim of this study was to create a risk-scoring model to preoperatively predict the incidence of lymph node metastasis (LNM) in early gastric cancer (EGC) patients to guide treatment.

METHODS

To construct the risk-scoring model, we retrospectively analyzed a primary cohort of 548 EGC patients. Univariate analysis and logistic regression were performed. A risk-scoring model for predicting LNM in EGC patients was developed based on preoperative factors, and another cohort of 73 patients was then analyzed to validate the model.

RESULTS

In the primary cohort, LNM was pathologically confirmed in 72 (13.1%) patients. In the multivariate analysis, the presence of ulceration and tumor size on gastroscopy, undifferentiated histological type, and presence of enlarged lymph nodes on computed tomography or endoscopic ultrasonography were independent risk factors for LNM. A 17-point risk-scoring model was developed to predict LNM risk. The cut-off score of the model was 8, and the area under the receiver operating characteristic curve (AUC) of the model was 0.835 [95% confidence interval (CI) 0.784-0.886]. In the validation cohort, the AUC of the model was 0.829 (95% CI 0.699-0.959).

CONCLUSIONS

We developed and validated an effective 17-point risk-scoring model that could preoperatively predict LNM for EGC patients.

Oncological outcomes in patients with pT1N0-3 or pT2-3N0 gastric cancer after curative resection without adjuvant chemotherapy

PURPOSE

The survival outcomes of pT1N0-3 or pT2-3N0 gastric cancer after curative resection are favorable without adjuvant chemotherapy. However, some patients develop recurrence and details of these recurrences remain unclear. This study aimed to evaluate the prognostic factors in patients with pT1N0-3 or pT2-3N0 gastric cancer.

METHODS

We retrospectively reviewed the medical records of 1219 patients with pT1N0-3 or pT2-3N0 gastric cancer who underwent curative gastrectomy without neoadjuvant or adjuvant chemotherapy between April 2007 and March 2012 at Cancer Institute Hospital.

RESULTS

This cohort included 895 pT1N0, 73 pT1N1, 23 pT1N2, 6 pT1N3, 130 pT2N0, and 92 pT3N0 patients. The 5-year overall survival (OS) and 5-year relapse-free survival (RFS) for pT1N0-3 and pT2-3N0 gastric cancer were 98.9% (95% CI 98.1-99.4) and 97.7% (95% CI 96.7-98.4), respectively. Age (HR 3.56, 95% CI 2.10-6.03) and lymphovascular involvement (hazard ratio (HR) 2.98, 95% CI 1.76-5.04) were independent prognostic factors in a multivariate analysis for RFS. The 5-year RFS for patients aged ≥75 years or with lymphovascular involvement were 94.4% (95% CI 89.8-97.0) and 95.1% (95% CI 92.5-96.8), respectively.

CONCLUSION

The survival outcomes of pT1N0-3 and pT2-3N0 were excellent, even in patients with aged >75 years or lymphovascular involvement which were risk factors. However, the sample size of T1N3 gastric cancer is small, so larger sample size and risk factor analysis are required.

Prognosis of Stage IIB Early Gastric Cancer Has a Unique and Dismal Property Putatively Requiring Postoperative Adjuvant Chemotherapy

Pathological T1 (pT1) gastric cancer showed excellent prognosis; however, lymph node metastasis sometimes reflects patients with dismal prognosis. In this study, we investigated prognosis of pT1 gastric cancer with lymph node metastasis to identify prognostic factors. Among 1442 gastric cancer patients between 2002 and 2010, 73 (5%) of pT1 with lymph node metastasis were identified. Univariate prognostic factors were applied to multivariate Cox proportional hazards model. First, among the 1442 patients, pT1 was composed of 333 patients with pT1a and 423 patients with pT1b, which included 9 (2.7%) and 64 cases (15.1%) with lymph node metastasis, respectively. Secondly, 10 (13.7%) patients of the 73 patients with lymph node metastasis showed tumor relapse. Univariate negative prognostic factors were tumor size (P = 0.03), intraoperative bleeding (P = 0.03), and perioperative transfusion (POT; P = 0.001), as well as 14th JGCA (Japanese Gastric Cancer Association) Stage (P &lt; 0.0001), and multivariate analysis identified 14th JGCA Stage (P = 0.0004) and POT (P = 0.03) as independent prognostic factors. Third, pT1 gastric cancer representing pN3 (Stage IIB) was rare (n = 4) and unique entity from a prognostic point of view, exhibiting dismal prognosis (0% at 5 years). We thereafter identified 17 such cases from 5204 gastric cancer cases including the earliest cases. Prognosis of the 17 patients was unique in that recurrences occurred even 5 years after curative operation, and the frequent recurrent sites were bone. pT1 gastric cancer prognosis is robustly affected by pN3 and POT, and Stage IIB disease showed unique prognosis requiring special attention even after 5 years of operation.

Decision-making of adjuvant therapy in pT1N1M0 gastric cancer: Should radiotherapy be added to chemotherapy? A propensity score-matched analysis

Background: Early gastric cancer (EGC) with metastatic lymph nodes (mLNs) has a relatively higher recurrence rate and poorer prognosis than EGC without mLNs. However, the postoperative treatment directions of pT1N1M0 vary from different guidelines. This study attempted to confirm the value of postoperative treatments in pT1N1M0 GC patients.

Methods: Overall, 379 patients with pT1N1M0 GC following gastrectomy from 2000 to 2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score-matched (PSM) analysis was used to reduce bias. Overall survival was analyzed by Kaplan-Meier method and the log-rank test. Cox proportional hazards regression analyses were used to confirm the independent prognostic factors.

Results: Before matching, the results of survival analyses indicated that adjuvant chemotherapy (ACT) and chemoradiotherapy (ACRT) could significantly prolong the survival time of the cohort (P < 0.05). After PSM analysis, 136 patients remained and ACRT maintained significance in the survival analysis (P = 0.018). Furthermore, patients with well or moderately differentiated GC (HR = 0.226, P =0.018) or intestinal type GC (HR = 0.380, P = 0.040) achieved a significantly superior prognosis with ACRT, compared to patients receiving ACT.

Conclusion: The survival benefit of ACRT and ACT for pT1N1M0 GC patients following gastrectomy was confirmed in the SEER cohort. RT added to ACT might be recommended according to Lauren's classification and tumor grade in clinical decision making.

Abundance of CD163-Positive Tumor-Associated Macrophages in the Early Gastric Cancer Predicts the Recurrence after Curative Resection

BACKGROUND

We aimed to investigate the prognostic value of M2 macrophages to predict the recurrence of early gastric cancer (EGC).

METHODS

A retrospective analysis was carried out among EGC patients (95 non-recurrence and 78 recurrence) who underwent surgery at Luhe People's Hospital of Nanjing. A 5-year recurrence status was utilized to classify the patients into the recurrence group and non-recurrence group. CD163 and proliferating cell nuclear antigen were utilized as markers to detect M2 macrophages and proliferation. Cumulative tumor recurrence curve was adopted to analyze the association between the number of tumor-associated macrophages (TAMs) and the recurrence of EGC. Colony formation and invasion abilities of MKN45 (JCRB0254, human gastric epithelial cell line) with or without M2 macrophage coculture were detected in vitro, and the xenograft model was utilized to detect in vivo effect of M2 macrophages on tumor growth.

RESULTS

The number of CD163+ macrophages and expression of transforming growth factor-β1, matrix metallopeptidase 9, and vascular endothelial growth factor A were significantly different between the EGC recurrence and non-recurrence group. The cumulative tumor recurrence rate was found to be dependent on the infiltration number of TAMs. M2 macrophages promoted the proliferation and invasion of human MKN45 cells in vitro, as well as tumor growth in the xenograft model.

CONCLUSION

The abundance of CD163+-positive TAMs in EGC predicts the recurrence after curative resection.

Numerous lymph node metastases in early gastric cancer without preoperatively enlarged lymph nodes: a case report

BACKGROUND

According to the 2018 Japanese gastric cancer treatment guidelines (ver. 5), a reduced extent of lymphadenectomy (D1 or D1+) is indicated for cT1 N0 tumors that do not meet the criteria for endoscopic resection. However, early gastric cancer with multiple lymph node metastases is not unknown, and cases have been reported. We report a case of a patient with early gastric cancer and numerous nodal metastases who underwent laparoscopic proximal gastrectomy based on a preoperative diagnosis of T1 N0.

CASE PRESENTATION

A 69-year-old woman underwent emergent endoscopic hemostasis for massive hematemesis of the stomach, and endoscopic examination showed ulceration with a visible vessel. Pathological biopsy examination of the ulcer identified poorly differentiated adenocarcinoma with signet ring cells. The patient was diagnosed with early gastric cancer that was not indicated for endoscopic resection because of the ulceration and histological type. Endoscopic ultrasound showed that the third layer was poorly demarcated at the ulcer scar, indicating invasion to the submucosal layer. Computed tomography did not reveal enlarged lymph nodes or distant metastasis. The preoperative diagnosis was early gastric cancer of the fundus without nodal metastasis, and laparoscopic proximal gastrectomy with D1+ lymphadenectomy was performed. The initial postoperative pathological diagnosis was intramucosal carcinoma without lymphovascular invasion; however, the presence of 26 lymph node metastases was revealed unexpectedly. Additional pathological examination of more resected specimens transected every 2-3 mm revealed that only one lesion contained a small number of cancer cells in the lymphatic duct below the muscularis mucosa.

CONCLUSIONS

We report a case of early gastric cancer with 26 nodal metastases in which lymph node involvement was not identified prior to surgery. These findings indicate that the extent of lymphadenectomy and the surgical procedure should be carefully decided even in cT1 N0 early gastric cancer when several risk factors for lymph node metastasis are present.

History and future perspectives in Japanese guidelines for endoscopic resection of early gastric cancer

Japanese guidelines for gastric cancer treatment were first published in 2001 for the purpose of showing the appropriate indication for each treatment method, thereby reducing differences in the therapeutic approach among institutions, and so on. With the accumulation of evidence and the development and prevalence of endoscopic submucosal dissection (ESD), the criteria for the indication and curability of endoscopic resection (ER) for early gastric cancer (EGC) have expanded. However, several problems still remain. Although a risk-scoring system (eCura system) for predicting lymph node metastasis (LNM) may help treatment decision in patients who do not meet the curative criteria for ER of EGC, which is referred to as eCura C-2 in the latest guidelines, additional gastrectomy with lymphadenectomy may be excessive for many patients, even those at high risk for LNM. Less-invasive function-preserving surgery, such as non-exposed endoscopic wall-inversion surgery with laparoscopic sentinel node sampling, may overcome this problem. In addition, further less-invasive treatment, such as ER with chemotherapy, should be established for patients who prefer not to undergo additional gastrectomy.

Indications for adjuvant chemotherapy in patients with AJCC stage IIa T3N0M0 and T1N2M0 gastric cancer-an east and west multicenter study

PURPOSE

To determine the indications for adjuvant chemotherapy (AC) in patients with stage IIa gastric cancer (T3N0M0 and T1N2M0) according to the 7th American Joint Committee on Cancer (AJCC).

METHODS

A total of 1593 patients with T3N0M0 or T1N2M0 stage gastric cancer were identified from the Surveillance, Epidemiology, and End Results (SEER) database for the period 1988.1-2012.12. Cox multiple regression, nomogram and decision curve analyses were performed. External validation was performed using databases of the Fujian Medical University Union Hospital (FJUUH) (n = 241) and Italy IMIGASTRIC center (n = 45).

RESULTS

Cox multiple regression analysis showed that the risk factors that affected OS in patients receiving AC were age > 65 years old, T1N2M0, LN dissection number ≤ 15, tumor size > 20 mm, and nonadenocarcinoma. A nomogram was constructed to predict 5-year OS, and the patients were divided into those predicted to receive a high benefit (points ≤ 188) or a low benefit from AC (points > 188) according to a recursive partitioning analysis. OS was significantly higher for the high-benefit patients in the SEER database and the FJUUH dataset than in the non-AC patients (Log-rank < 0.05), and there was no significant difference in OS between the low-benefit patients and non-AC patients in any of the three centers (Log-rank = 0.154, 0.470, and 0.434, respectively). The decision curve indicated that the best clinical effect can be obtained when the threshold probability is 0-92%.

CONCLUSION

Regarding the controversy over whether T3N0M0 and T1N2M0 gastric cancer patients should be treated with AC, this study presents a predictive model that provides concise and accurate indications. These data show that high-benefit patients should receive AC.

Timing and site-specific trends of recurrence in patients with pathological stage II or III gastric cancer after curative gastrectomy followed by adjuvant S-1 monotherapy

BACKGROUND

Adjuvant S-1 monotherapy prolongs the survival of patients with pathological stage II or III gastric cancer undergoing D2 gastrectomy. This therapeutic regimen is standard in Japan. Unfortunately, some patients who undergo this treatment suffer from recurrent disease. However, information regarding the timing and site-specific trends of recurrence is insufficient.

METHODS

Among 396 patients who underwent D2 gastrectomy followed by adjuvant S-1 monotherapy between 2008 and 2012, 122 experienced a recurrence. We retrospectively determined the timing and sites of recurrence.

RESULTS

The median RFS of the 122 patients was 19.5 months, and their 1-, 3- and 5-year RFS rates were 67.2%, 23.0% and 5.7%, respectively. There were no significant differences in RFS among disease substages. Local recurrence, lymph node involvement and peritoneal and hematogenous metastases were found in 6, 25, 63 and 42 patients, respectively. Approximately 10% of patients presented with contemporaneous sites of recurrence. Local recurrence and lymph node metastasis plateaued 3 years after gastrectomy. Peritoneal and hematogenous metastasis increased within 5 years after surgery. In patients with hematogenous metastasis, the number of liver metastases plateaued but increased in others.

CONCLUSIONS

In patients with recurrent disease who underwent D2 gastrectomy followed by adjuvant S-1 monotherapy, 80% of recurrences occur within 3 years after gastrectomy. The timing of recurrence is not significantly different among substages. Although the rates of local recurrence and lymph node and liver metastasis plateau after 3 years, peritoneal and the other hematogenous metastases increase within 5 years.

Is Additional Surgery Always Sufficient for Preventing Recurrence After Endoscopic Submucosal Dissection with Curability C-2 for Early Gastric Cancer?

BACKGROUND

When a lesion does not meet the curative criteria of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC), referred to as non-curative resection or curability C-2 in the guidelines, an additional surgery is the standard therapy because of the risk of lymph node metastasis (LNM).

OBJECTIVE

This study aimed to identify high-risk patients for recurrence after additional surgery for curability C-2 ESD of EGC.

METHODS

This multicenter retrospective cohort study enrolled 1064 patients who underwent additional surgery after curability C-2 ESD for EGC. We evaluated the recurrence rate and the risk factors for recurrence after additional surgery in these patients.

RESULTS

The 5-year recurrence rate after additional surgery was 1.3%. Multivariate Cox analysis revealed that the independent risk factors for recurrence after additional surgery were LNM (hazard ratio [HR] 32.47; p < 0.001) and vascular invasion (HR 4.75; p = 0.014). Moreover, patients with both LNM and vascular invasion had a high rate of recurrence after additional surgery (24.6% in 5 years), with a high HR (119.32) compared with those with neither LNM nor vascular invasion. Among patients with no vascular invasion, a high rate of recurrence was observed in those with N2/N3 disease according to the American Joint Committee on Cancer TNM staging system (27.3% in 5 years), in contrast with no recurrence in those with N1 disease.

CONCLUSIONS

Patients with both LNM (N1-N3) and vascular invasion, as well as those with N2/N3 disease but no vascular invasion, would be candidates for adjuvant chemotherapy after additional surgery for curability C-2 ESD of EGC.

Risk of lymph node metastasis in undifferentiated-type mucosal gastric carcinoma

BACKGROUND

Endoscopic resection (ER) has come to be recognized as a standard treatment for early gastric cancer (EGC). While its adoption is expanding, ER remains restricted to cases of EGC without lymph node metastasis for the treatment of local resection. On the other hand, histopathological analyses of surgically resected specimens of EGC have revealed the presence of lymph node (LN) metastasis in some cases of mucosal gastric cancer (MGC) and undifferentiated MGC (UD-MGC) is considered to have higher risk of nodal metastases than differentiated MGC (D-MGC). To evaluate the risk factors for LN metastasis in MGC, we investigated the characteristics of UD-MGC associated with LN metastasis.

METHODS

Among all UD-MGC patients who underwent surgery as initial treatment, between January 2000 and March 2016, we reviewed the clinicopathological data, including the preoperative endoscopic findings and histopathological findings in the resected specimens, of the 11 UD-MGC patients who were identified as having lymph node metastasis. Furthermore, in comparison with cases without lymph node metastasis, we examined the possibility of expansion of the indication for local treatment.

RESULTS

In most of the cases of UD-MGC with LN metastasis, the lesions were relatively large (> 20 mm in diameter) and of the clearly depressed type with faded color and apparent border, and histopathology revealed a high percentage of cases with lymphatic invasion and a predominance of signet ring cell carcinomas. No cases with LN metastasis without depressed macroscopic type nor signet ring cell carcinoma component existed. A degree of invasion of lamina propria (LP) or muscularis mucosae (MM) had same relation to the risk of LN metastasis.

CONCLUSIONS

In this study, none of the cases of undifferentiated-type mucosal cancer (UD-MGC) with LN metastasis satisfied the current adoption criteria for ER. We suggested significant risk factors for LN metastasis in UD-MGC cases as depressed tumor type, presence of a signet ring cell carcinoma component, presence of lymphatic tumor invasion, and a large tumor size. More detailed analyses of the endoscopic and histopathological findings may allow further risk classification for LN metastasis in cases of UD-MGC.

Gastric cancer: factors affecting survival

BACKGROUND AND AIM

The present multicenter, retrospective study aimed at determining the factors affecting survival in patients who were operated on due to gastric cancer (GC).

PATIENTS AND METHODS

The data of 234 patients, who underwent elective surgery due to GC were retrospectively analyzed. The demographic characteristics, tumor localization and diameter, type of resection and lymph node dissection, experience of the operating surgeon (senior or junior), tumor grade, pT stage, number of lymph nodes harvested, number of lymph nodes with and without metastasis, tumor stage and survival data were recorded.

RESULTS

Survival was better a tumor diameter <4 cm, lower localization, experience of the operating surgeon (senior), without metastatic lymph nodes, tumor grade and decreased invasion depth (p < .05). There was no statistically significant difference between D1 LND and D2 LND with respect to survival (p = .793). Mortality was higher and survival was lower in patients with metastatic lymph nodes (p = .001). A number of harvested lymph nodes of 16 or more increased mortality (p = .003). Also, as disease stage increased, there was a decrease in survival and increase in mortality rates (p = .001).

CONCLUSIONS

Survival outcomes in resectable GCs are affected by the experience of the surgeon and patient-related factors at the time of surgery, including tumor size, T stage, and presence of metastatic lymph nodes.

A Risk-Scoring Model for Predicting Lymph Node Metastasis in Early Gastric Cancer Patients: a Retrospective Study and External Validation

BACKGROUND

The possibility of lymph node metastasis (LNM) is critical to the assessment of the indication for endoscopic submucosal dissection. Thus, the aim of this study is to identify the risk factors for LNM and construct a risk-scoring model for patients with early gastric cancer to guide treatment.

METHODS

A retrospective examination of reports and studies carried out January 2000 and December 2014 was conducted. A risk-scoring model for predicting LNM was developed based on the data thus collected. In addition, the model is subject to verification and validation by three institutions.

RESULTS

Of the 1029 patients, 228 patients (22%) had LNM. Multivariate analysis showed that female, depressed type, undifferentiated type, submucosa, tumor size, and lymphovascular invasion were significantly associated with LNM. An 11-point risk-scoring model was used to predict LNM risk. An area under the receiver operating characteristic (AUROC) of the risk-scoring model was plotted using the development set and the AUROC of the model [0.76 (95% CI 0.73-0.80)] to predict LNM risk. After internal and external validation, the AUROC curve for predicting LNM was 0.77 (95% CI 0.68-0.86), 0.82 (95% CI 0.72-0.91), and 0.82 (95% CI 0.70-0.94), respectively.

CONCLUSIONS

A risk-scoring model for predicting LNM was developed and validated. It could help with personalized care for patients with EGC.

Young Age and Risk of Lymph Node Metastasis in Differentiated Type Early Gastric Cancer

BACKGROUND

Young patients with gastric cancer reportedly have a worse prognosis than older patients due to delayed diagnosis and more aggressive tumor behavior. However, it is unclear whether this applies to early gastric cancer (EGC), for which endoscopic resection is indicated. We investigated the association between age and lymph node metastasis (LNM).

METHODS

We identified 4055 patients diagnosed with EGC of differentiated histology who underwent surgery. The association between age and LNM was examined using logistic regression for each T stage separately with adjustments for multiple covariates. We compared LNM rates for each of the Japanese Endoscopic Resection Guidelines criteria in younger (< 40 years) and older patients (40 years).

RESULTS

The median number of lymph nodes examined was the same for T1a and T1b stages (n = 34). The median number of lymph nodes examined was not significantly different within T1a stage (P = 0.093), but within T1b stage, the number of lymph nodes examined was significantly different (P = 0.019). The highest number was between 50 and 59 years (median = 37), and the lowest number was in the 20 to 49 years and older than 70 age brackets (median = 34). LNM rate and age were not significantly associated within each stage (P values 0.269, 0.783 for T1a and T1b, respectively). Among patients fulfilling endoscopic resection criteria, the LNM rate in younger patients was lower than in older patients.

CONCLUSIONS

In differentiated-type EGC, young age at diagnosis was not associated with LNM rate. Therefore, endoscopic resection criteria for early gastric cancer can be applied to younger patients.

Risk Factors for Lymph Node Metastasis in Western Early Gastric Cancer After Optimal Surgical Treatment

BACKGROUND

Lymph node metastasis (LNM) has a strong influence on the prognosis of patients with early gastric cancer (EGC). As minimally invasive treatments are considered appropriate for EGC, and lymphadenectomy may be restricted or even eliminated in some cases; it is imperative to identify the main risk factors for LNM to individualize the therapeutic approach. This study aims to evaluate the risk factors for LNM in EGC and to determine the adequacy of the endoscopic resection criteria in a western population.

METHODS

EGC patients who underwent gastrectomy with lymphadenectomy were retrospectively analyzed utilizing a prospective database. The clinicopathological variables were assessed to determine which factors were associated to LNM.

RESULTS

Among 474 enrolled patients, 105 had EGC (22.1%). LNM occurred in 13.3% of all EGC (10% T1a; 15.4% T1b). Tumor size, venous, lymphatic, and perineural invasions were confirmed as independent predictors of LNM by multivariate analysis. Expanded criteria were safely adopted only in selected cases, and 13.6% of patients who matched expanded indication had LNM.

CONCLUSIONS

Tumor size, venous, lymphatic, and perineural invasions were associated with LNM and should be considered as surrogate markers for surgical treatment of EGC. Expanded criteria for endoscopic resection can be safely adopted only in selected cases.

Tumour infiltrating lymphocytes are predictors of lymph node metastasis in early gastric cancers

Lymph node metastasis (LNM) is an important factor for predicting prognosis and selecting appropriate treatment in early gastric cancers (EGCs). We investigated the histopathological and microenvironmental predictors of LNM in EGCs. We retrieved 43 cases of EGC without LNM and 59 cases with LNM. Clinicopathological variables and tumour-infiltrating lymphocytes (TILs), Crohn's-like lymphoid reaction (CLR), tumour stromal percentage (TSP), and FOXA1 expression were evaluated and correlated with LNM. Among the 102 cases, 68 cases (66.7%) had low TILs and 34 cases (33.3%) had high TILs. High TILs were significantly correlated with the absence of LNM (p<0.001), less extent of invasion (p=0.004), absence of LVI (p=0.035), conspicuous CLR (p<0.001), and the absence of TSP (p=0.009). Conspicuous CLR was observed in 47 cases (46.1%) and TSP was present in 17 cases (16.7%) and neither was correlated with LNM. High FOXA1 expression was significantly associated with presence of LNM, low TILs, and submucosal invasion. In multivariate analysis, low TILs (p=0.023), LVI (p=0.008), and submucosal invasion (p=0.001) were independent predictive factors for LNM in EGCs. Evaluation of TILs in biopsied or endoscopically resected EGC specimens may help to predict LNM and select subsequent proper treatment modalities and follow-up.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Five-year Survival Associated with Stage I Gastric Cancer after Resection of Early Recurrence at Nodal Station No. 14v: a Case Report

The role of nodal station No. 14v (along the superior mesenteric vein) in lymphadenectomy for distal gastric cancer remains elusive. A 73-year-old woman underwent endoscopic submucosal dissection for gastric cancer, and was referred to our division for additional surgery because of pathologically non-curative resection. A laparoscopic distal gastrectomy with D1+ dissection was performed, with a final diagnosis of pT1bN1M0, Stage IB (2 nodal metastases to No. 6). Four months post-surgery, abdominal computed tomography revealed a 14-mm solitary nodule along the superior mesenteric vein. The lesion was excised and pathologically identified as a lymph node metastasis. Adjuvant chemotherapy with tegafur-gimeracil-oteracil potassium (S-1) was administered for the metastasis. Presently the patient survives without recurrence, 5.5 years after the second operation. Our findings suggest that there is lymphatic flow from the No. 6 to the No. 14v nodal station. Some patients with a No. 6 metastasis may benefit from a No. 14v lymphadenectomy, even in early-staged disease.

Is adjuvant chemotherapy necessary in pT1N1 gastric cancer?

Background

Due to a lack of consensus on adjuvant treatments for pT1N1 gastric cancer, surgeons face a dilemma when deciding treatments for patients with pT1N1 gastric cancer after gastrectomy. The objective of this study was to determine survival benefits of adjuvant chemotherapy and risk factors for tumor recurrence in gastric cancer patients with pT1N1.

Methods

Between 1996 and 2010, 510 patients who underwent curative resection for pT1N1 gastric cancer at three institutes were divided into two groups: adjuvant chemotherapy group (N = 150) and surgery-only group (N = 360). Disease-free survival rates and risk factors for tumor recurrence were analyzed.

Results

During the median follow-up of 78 months, 7.5% of patients experienced tumor recurrence (7.3% in adjuvant chemotherapy group and 7.5% in surgery-only group). The 5-year disease-free survival rate was 91.8% in the adjuvant chemotherapy group and 94.6% in the surgery-only group without significant difference between the two. In univariate analysis, older age (>65 years), male gender, body mass index <25 kg/m², elevated gross type, and differentiated histology were associated with tumor recurrence. Multivariate analysis showed that advanced age and male gender were independent risk factors for tumor recurrence. In addition, adjuvant chemotherapy showed no benefitial effect on tumor recurrence in pT1N1 gastric cancer.

Conclusions

Adjuvant chemotherapy did not show any oncologically benefitial effect on tumor recurrence, it might be unnecessary for pT1N1 gastric cancer after curative surgery.

Prognostic factors for survival in patients with pT1 N+ or T2–3 N0 gastric cancer in Japan

Background

The outcome for pT1 N+ or pT2–3 N0 gastric cancer is favourable, but some patients suffer from recurrent disease. The aim of this study was to identify prognostic factors in patients with pT1 N+ or pT2–3 N0 gastric cancer.

Methods

This was a multicentre, retrospective cohort study. All patients with pT1 N+ or pT2–3 N0 gastric cancer who underwent curative gastrectomy at five high-volume, specialized cancer centres in Japan between 2000 and 2008 were included. Demographic, clinical, surgical and pathological data were collected. Independent prognostic factors were identified using a Cox proportional hazards regression model.

Results

Some 1442 patients were included. The 5-year overall survival rate for patients with pT1 N+ or pT2–3 N0 gastric cancer was 92·0 per cent. Multivariable analysis for overall survival identified age (hazard ratio (HR) 2·67, 95 per cent c.i. 2·09 to 3·43), sex (HR 0·57, 0·39 to 0·83) and clinical tumour depth (cT) (HR 1·45, 1·06 to 1·98) as independent prognostic factors.

Conclusion

Survival of patients with pT1 N+ or pT2–3 N0 gastric cancer is good. Age 65 years or above, male sex and cT2-4 category are associated with worse overall survival.

N staging: the role of the pathologist

Gastric cancer is the second cause of cancer-related mortality worldwide. Metastases, including lymph nodes ones, heavily influence the prognosis of this disease. The pathological detection of positive lymph nodes is pivotal for an optimal prognostication and clinical management of affected individuals. Several factors influence the pathological investigation of surgical specimens, ultimately affecting the number of retrieved lymph nodes and, with it, the reliability of N staging. The pathologist plays a central role in optimizing this process. Factors influencing lymph node retrieval and analysis will be herein reviewed, together with the procedures adopted for an optimal pathological analysis of lymph nodes in gastric cancer.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk factors for lymph node metastasis in mucosal gastric cancer and re-evaluation of endoscopic submucosal dissection

Purpose

The selection of the appropriate treatment strategy for patients with mucosal gastric cancer (MGC) remains controversial. In the present study, we aimed to determine the risk factors for lymph node (LN) metastasis in MGC and reassess the role of endoscopic submucosal dissection (ESD).

Methods

We examined 1,191 MGC patients who underwent curative gastrectomy between January 2005 and December 2014. We determined the clinicopathologic risk factors for LN metastasis among the MGC patients.

Results

Among 1,191 patients with MGC, 42 patients (3.5%) had LN metastasis. Univariate analysis indicated that age ≤ 50 years (P = 0.045), tumor invasion to the muscularis mucosa (P < 0.001), tumor size > 2 cm (P = 0.014), presence of ulceration (P = 0.01), diffuse type as per Lauren classification (P = 0.005), and undifferentiated-type histology (P = 0.001) were associated with LN metastasis. Moreover, multivariate analysis indicated that tumor invasion to the muscularis mucosa (P = 0.001; odds ratio [OR], 4.909), presence of ulceration (P = 0.036; OR, 1.982), and undifferentiated-type histology (P = 0.025; OR, 4.233) were independent risk factors for LN metastasis. In particular, LN metastasis was observed in some MGC cases with indications for ESD, including absolute indications (1 of 179, 0.6%) and expanded indications (9 of 493, 1.8%).

Conclusion

Although MGC patients can be treated via ESD, we recommend that they undergo a more aggressive treatment strategy if they have tumor invasion to the muscularis mucosa, ulceration, or undifferentiated-type histology in the final pathology report.

Comparison of FLT-PET/CT and CECT in gastric cancer diagnosis

AIM

To date, no data are available on the use of 18-fluorothymidine positron emission tomography/computed tomography (FLT-PET/CT) for preoperative gastric cancer staging. Herein, we attempt to assess the value of FLT-PET/CT for preoperative gastric cancer staging in comparison with contrast-enhanced computed tomography (CECT).

MATERIALS AND METHODS

In a group of 96 gastric cancer patients, 96 FLT-PET/CT, 56 abdominal cavity CECT, and 51 resective operations were done. All three (FLT-PET/CT, CECT, and resective operation) were done in 29 patients. The results of FLT-PET/CT, CECT, and histopathological examinations were used to assess the ability of FLT-PET/CT and CECT to identify primary tumors, regional nodal metastases, and distant abdominal metastases. Assessment of regional lymph nodes was based on SUVmax in FLT-PET/CT and SAD (short-axis diameter) in CECT.

RESULTS

In the group of 56 patients examined with FLT-PET/CT and CECT, identification of the primary tumor was possible in 56 cases (100%) and in 53 cases (94.6%), respectively, (p = 0.013). Using ROC curve, the sensitivity and specificity of FLT-PET/CT in metastatic regional lymph node assessment were higher than those of CECT (p = 0.0033). FLT-PE/CT enabled identification of a greater number of extraregional abdominal metastases than CECT (n = 56; 19 vs. 15, respectively), but the difference was not statistically significant (p > 0.41).

CONCLUSIONS

The ability of FLT-PET/CT to identify primary tumors is greater than that of CECT, and thus FLT-PET/CT was better in evaluating regional nodal metastases. FLT-PET/CT enabled identification of a greater number of abdominal metastases than CECT, but the difference was not statistically significant.

Identifying Reproducible Molecular Biomarkers for Gastric Cancer Metastasis with the Aid of Recurrence Information

To precisely diagnose metastasis state is important for tailoring treatments for gastric cancer patients. However, the routinely employed radiological and pathologic tests for tumour metastasis have considerable high false negative rates, which may retard the identification of reproducible metastasis-related molecular biomarkers for gastric cancer. In this research, using three datasets, we firstly shwed that differentially expressed genes (DEGs) between metastatic tissue samples and non-metastatic tissue samples could hardly be reproducibly detected with a proper statistical control when the metastatic and non-metastatic samples were defined by TNM stage alone. Then, assuming that undetectable micrometastases are the prime cause for recurrence of early stage patients with curative resection, we reclassified all the “non-metastatic” samples as metastatic samples whenever the patients experienced tumour recurrence during follow-up after tumour resection. In this way, we were able to find distinct and reproducible DEGs between the reclassified metastatic and non-metastatic tissue samples and concordantly significant DNA methylation alterations distinguishing metastatic tissues and non-metastatic tissues of gastric cancer. Our analyses suggested that the follow-up recurrence information for patients should be employed in the research of tumour metastasis in order to decrease the confounding effects of false non-metastatic samples with undetected micrometastases.

An Early Gastric Cancer Patient With Pleural Metastatic Recurrence

A 72-year-old male patient was diagnosed with depressed-type gastric cancer in the body of stomach [preoperative diagnosis: T2 (MP), N0, M0, P0, H0, cStage IB] and underwent distal gastrectomy and D2 dissection in January 2011. The pathological classification was T1b (SM), por2, 24 × 45 mm, ly3, v1, N2 (6/14), M0, P0, CY0, H0, fStage IIA. Continuous increase of serum carbohydrate antigen 19-9 (CA19-9) followed 1-year postoperative S-1 adjuvant chemotherapy, so S-1 was resumed despite not identifying the site of recurrence. In December 2012, pleural metastasis was suspected based on fluorine 18-fluorodeoxyglucose FDG standardized uptake value 14 × 23 mm in size on the right diaphragm (pleural cavity side) found on positron emission tomography-computed tomography. No other metastasis was found. Serum CA19-9 continued to increase. In April 2013, the patient underwent thoracoscopic removal of pleural metastasis on the right diaphragm (cytology of pleural effusion: class II). Pleural metastasis of gastric cancer was diagnosed based on the same histology as the gastric tumor. Elastica van Gieson (EvG) staining showed intravascular tumor thrombus, suggesting hematogenous metastasis. The tumor markers temporarily decreased after the surgery, but started to increase again. The patient is being treated with chemotherapy on an outpatient basis.

Early Gastric Cancer Recurrence Following Curative Resection Presenting as Biliary Tract Dilatation, Pancreatic Duct Dilatation and Intestinal Wall Thickening

Early gastric cancer, especially cancer confined to the mucosa (stage T1a), is known to have a high cure rate with rare recurrence. We herein report the case of a 40-year-old female who initially presented with biliary tract dilatation, pancreatic duct dilatation and intestinal wall thickening 3 years after curative resection of pT1aN0 stage gastric cancer. The intestinal resection specimen revealed tumor cells spreading through the subserosa to the submucosa sparing mucosal membrane, which made exploratory laparotomy the only approach to confirm the diagnosis. It is always important to be aware of malignancy recurrence and clinicians should not hesitate to choose exploratory laparotomy to avoid any delay in the diagnosis and treatment.

Lymph Node Metastasis, a Unique Independent Prognostic Factor in Early Gastric Cancer

Background

Lymph node metastasis (LNM) has been shown to be related to the prognosis of early gastric cancer (EGC). The choice of optimal treatment depends on an accurate pre-operative assessment of LNM status in EGC patients. However, in China, where EGC cases account for only a small part of gastric cancer (GC) cases, there are not enough data to make an accurate assessment. Therefore, this study, which involved a relatively large number of EGC patients, aimed to explore the relationship between clinicopathological characteristics and LNM in EGC.

Methods

Clinicopathological data from 205 EGC patients who underwent surgical resection at Sun Yat-Sen University Cancer Center from January 2000 to December 2011 were retrospectively analyzed. Clinicopathological characteristics were assessed to identify effective predictive factors for LNM and overall survival.

Results

LNM occurred in 52 (25.37%) EGC cases; of these cases, 18 occurred in intra-mucosal cancers (13 N1, 4 N2 and 1 N3), and 34 occurred in sub-mucosal cancers (22 N1, 7 N2 and 5 N3). Logistic regression analysis demonstrated that tumor differentiation (P=0.002), depth of tumor infiltration (P=0.004), vessel invasion (P=0.012), tumor size (P=0.020) and gender (P=0.022) were risk factors associated with LNM in EGC, listed in order of priority. The overall survival rate was 90.2%. Kaplan-Meier survival analysis showed that overall survival of EGC patients was significantly correlated with LNM (P=0.001), N staging (P<0.001) and invasion of lymphatic or blood vessels (P=0.010), but it was not correlated with tumor size, depth of tumor infiltration or tumor cell differentiation. Moreover, a multiple Cox regression analysis demonstrated that only N staging (P=0.001) could serve as an independent prognostic predictor in EGC patients.

Conclusions

Because LNM independently predicts the prognosis of EGC, endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) and laparoscopic partial gastrectomy should be cautiously used in high-risk EGC patients. A pre-operative assessment of LNM status based on clinicopathological factors may be useful for therapy planning.

Metachronous Liver Metastasis Resulting from Early Gastric Carcinoma after Subtotal Gastrectomy Following Endoscopic Resection: A Case Report

Hepatic metastasis of early gastric cancer (EGC) following subtotal gastrectomy with lymphadenectomy is rare. We report the case of a 61-year-old male patient who was diagnosed with EGC that was initially treated using endoscopic submucosal dissection (ESD) and subsequently underwent laparoscopic subtotal gastrectomy. Histopathological examination of the patient's ESD specimen showed a moderately differentiated tubular adenocarcinoma invading the submucosa without lymphatic invasion. The deep margin of the specimen was positive for adenocarcinoma, and he subsequently underwent laparoscopic distal gastrectomy. The patient developed liver metastasis 15 months after the operation and then underwent liver resection. Histology of the resected specimen confirmed the diagnosis of two foci of metastatic adenocarcinoma originating from stomach cancer. Immunohistochemical analysis of the specimen demonstrated overexpression of human epidermal growth factor receptor 2. The patient was treated with trastuzumab in combination with chemotherapy consisting of capecitabine and cisplatin. Twenty-four months after the operation, the patient remained free of recurrence.

Impact of extranodal extension on prognosis in lymph node-positive gastric cancer

BACKGROUND

The TNM classification system is used widely for tumour staging, and directs the treatment and prognosis of patients with cancer. The aim of this study was to assess the prognostic value of extranodal extension (ENE) in patients with early gastric cancer.

METHODS

All patients who underwent gastrectomy with lymphadenectomy for primary gastric cancer with lymph node metastases between January 2003 and June 2006 were reviewed. Histological slides of metastatic nodes were reviewed by two gastrointestinal pathologists. The association of ENE with clinicopathological characteristics was assessed. The disease-specific survival rate was calculated by the Kaplan-Meier method, and a multivariable Cox regression model was used to identify independent prognostic factors.

RESULTS

Some 1143 patients were included. ENE was associated with advanced pT and pN category, larger tumour size and lymphovascular/perineural invasion. In multivariable analysis, pT category, pN category, ENE, lymphovascular invasion and perineural invasion were found to be independent prognostic factors in node-positive gastric carcinoma. The 5-year survival rate of patients with ENE was 48·1 per cent, compared with 78·2 per cent for patients without ENE (P < 0·001). In the subgroup of patients with early gastric cancer, ENE was associated with a worse 5-year survival rate in patients with early (T1) gastric cancer: 75 per cent in patients with ENE versus 96·9 per cent in those without (P < 0·001).

CONCLUSION

ENE is an independent prognostic factor in patients with early and advanced gastric cancer.