Clinicopathological characterisation of small (2 cm or less) proximal and distal gastric carcinomas in a Chinese population

Clinical significance of systemic inflammation response index and platelet-lymphocyte ratio in patients with adenocarcinoma of the esophagogastric junction and upper gastric cancer

Background

Tumor immunity plays an important role in assessing the tumor progression. The purpose of this study was to investigate the prognostic value of combined systemic inflammation response index (SIRI) and platelet-lymphocyte ratio (PLR) of gastroesophageal junction cancer (AEG) and upper gastric cancer (UGC) patients.

Methods

In this retrospective study, patients from 2003 to 2014 were divided into training and validation sets. The prognostic accuracy of each variable was compared using time-independent ROC analysis. The scoring system was calculated by cut-off values of SIRI and PLR in 5-year. Kaplan-Meier and Log-rank tests were used to analyze overall survival (OS). Chi-square test was used to analyze the association between clinical characteristics and the scoring system. Univariate and multivariate analyses based on the competitive risk regression model were used to analyze independent predictors of death due to AGC and UGC. R software was used to construct the Nomogram model of risk assessment.

Results

Patients with SIRI-PLR = 2 had worse survival time than those with 0 and 1 (P < 0.001) and more suitable for postoperative adjuvant chemotherapy (P = 0.002). High PLR patients were more suitable for proximal gastrectomy (P = 0.049). SIRI-PLR were independent predictors in training set (P < 0.001), which could be combined with age, pTNM stage and postoperative chemotherapy to construct Nomogram for predicting OS.

Conclusions

Preoperative SIRI-PLR score was an independent predictor for patients with AEG and UGC. The Nomogram model constructed by age, SIRI-PLR, pTNM stage and postoperative chemotherapy can correctly predict the prognosis of patients.

Correlation of the detection rate of upper GI cancer with artificial intelligence score: results from a multicenter trial (with video)

BACKGROUND AND AIMS

The quality of EGD is a prerequisite for a high detection rate of upper GI lesions, especially early gastric cancer. Our previous study showed that an artificial intelligence system, named intelligent detection endoscopic assistant (IDEA), could help to monitor blind spots and provide an operation score during EGD. Here, we verified the effectiveness of IDEA to help evaluate the quality of EGD in a large-scale multicenter trial.

METHODS

Patients undergoing EGD in 12 hospitals were consecutively enrolled. All hospitals were equipped with IDEA developed using deep convolutional neural networks and long short-term memory. Patients were examined by EGD, and the results were recorded by IDEA. The primary outcome was the detection rate of upper GI cancer. Secondary outcomes were part scores, total scores, and endoscopic procedure time, which were analyzed by IDEA.

RESULTS

A total of 17,787 patients were recruited. The total detection rate of cancer-positive cases was 1.50%, ranging from .60% to 3.94% in each hospital. The total detection rate of early cancer-positive cases was .36%, ranging from .00% to 1.58% in each hospital. The average total score analyzed by IDEA ranged from 64.87 ± 16.87 to 83.50 ± 9.57 in each hospital. The cancer detection rate in each hospital was positively correlated with total score (r = .775, P = .003). Similarly, the early cancer detection rate was positively correlated with total score (r = .756, P = .004).

CONCLUSIONS

This multicenter trial confirmed that the quality of the EGD result is positively correlated with the detection rate of cancer, which can be monitored by IDEA. (Clinical trial registration number: ChiCTR2000029001.).

Evaluation of the effects of an artificial intelligence system on endoscopy quality and preliminary testing of its performance in detecting early gastric cancer: a randomized controlled trial

BACKGROUND

Esophagogastroduodenoscopy (EGD) is a prerequisite for detecting upper gastrointestinal lesions especially early gastric cancer (EGC). An artificial intelligence system has been shown to monitor blind spots during EGD. In this study, we updated the system (ENDOANGEL), verified its effectiveness in improving endoscopy quality, and pretested its performance in detecting EGC in a multicenter randomized controlled trial.

METHODS

ENDOANGEL was developed using deep convolutional neural networks and deep reinforcement learning. Patients undergoing EGD in five hospitals were randomly assigned to the ENDOANGEL-assisted group or to a control group without use of ENDOANGEL. The primary outcome was the number of blind spots. Secondary outcomes included performance of ENDOANGEL in predicting EGC in a clinical setting.

RESULTS

1050 patients were randomized, and 498 and 504 patients in the ENDOANGEL and control groups, respectively, were analyzed. Compared with the control group, the ENDOANGEL group had fewer blind spots (mean 5.38 [standard deviation (SD) 4.32] vs. 9.82 [SD 4.98]; P < 0.001) and longer inspection time (5.40 [SD 3.82] vs. 4.38 [SD 3.91] minutes; P < 0.001). In the ENDOANGEL group, 196 gastric lesions with pathological results were identified. ENDOANGEL correctly predicted all three EGCs (one mucosal carcinoma and two high grade neoplasias) and two advanced gastric cancers, with a per-lesion accuracy of 84.7 %, sensitivity of 100 %, and specificity of 84.3 % for detecting gastric cancer.

CONCLUSIONS

In this multicenter study, ENDOANGEL was an effective and robust system to improve the quality of EGD and has the potential to detect EGC in real time.

Is cardia cancer a special type of gastric cancer? A differential analysis of early cardia cancer and non-cardia cancer

Background: The prognosis of early cardia cancer and non-cardia cancer is still controversial. It is difficult to collect a large number of cases with complete information in clinical practice. Our study was aimed to identify the differences in clinicopathological characteristics and outcomes of early cardia gastric cancer and non-cardia gastric cancer. Methods: All cases analyzed were from Surveillance, Epidemiology, and End Results database. The data of the patients with early gastric cancer from 2004 to 2010 was retrospectively analyzed. Patients were distributed to cardia cancer group and non-cardia cancer group. Univariate and multivariate analyses were performed to examine differences between groups. The competitive risk model was made to compare the association with cardia cancer and non-cardia cancer about the causes of death. Propensity score matching (PSM) was performed to reduce the bias. Results: We found that cardia cancer was more common in male patients and the White than that in non-cardia cancer at early stage, signet ring cell carcinoma was more common in non-cardia cancer, and the differentiation of non-cardia cancer was worse. Univariate analysis showed that age, marital status, race, tumor location, histology, grade, stage, and operation or not can determine the prognosis. And the prognosis of patients with cardia cancer was worse than that of non-cardia cancer, according to lymph node metastasis and the depth of tumor invasion. Multivariate analysis showed cardia cancer was an independent prognostic factor for poor prognosis. After PSM, cardia cancer still exhibited poor prognosis. Conclusions: At early stage, cardia cancer had a poor prognosis compared with non-cardia cancer. The prevention and treatment of early cardia cancer need to be seriously treated.

Integrated clinicopathological and immunohistochemical analysis of gastric adenocarcinoma with hepatoid differentiation: an exploration of histogenesis, molecular characteristics, and prognostic markers

In addition to hepatoid adenocarcinoma (HAC), gastric adenocarcinoma with enteroblastic differentiation (GAED) and common adenocarcinoma (COM) could also show hepatoid differentiation, which presents a poor prognosis. To elucidate the histogenesis and development of gastric cancer with hepatoid differentiation, we identified 55 cases by histological morphology and a panel of markers, including α-fetoprotein (AFP), Glypican 3 (GPC3) and SALL4, then clinicopathological parameters, pathomorphological characteristics, mucin phenotypes, molecular features, Immunoscore and survival analysis were assessed. A mixture of three types (COM + GAED + HAC) was most commonly observed in the same case, and typical transitions between each histological subtype were frequently seen. Hyaline globule and pink amorphous substance were often present. HER2 was amplified in 21.8% of cases. All the tumors showed intestinal phenotype (69.1%) and mixed gastric/intestinal phenotype (30.9%) and were all defined to chromosomal instable (CIN)/genomically stable (GS) group. Considering that 83.6% cases presented TP53 gene mutation phenotype and 61.8% cases showed ≥10% aberrant E-cadherin expression, the precise molecule classification is ambiguous. Survival analysis showed that patients with high SALL4 expression, high preoperative serum AFP level, or low Immunoscore had a significantly poor overall survival (OS). Moreover, SALL4, HER2, and Immunoscore had an independent influence on OS. In conclusion, we suggest that the development of gastric adenocarcinoma with hepatoid differentiation might a continuously progressive profile: from intestinal-type COM adenocarcinoma to GAED and then HAC. CIN/GS subtypes might be where they belonged. SALL4, HER2, and Immunoscore may be potential therapeutic targets.

Comparison of the overall survival of proximal and distal gastric cancer after gastrectomy: a systematic review and meta-analysis

Background

The aim of this study was to investigate the overall survival (OS) between proximal gastric cancer (PG) and distal gastric cancer (DG) patients after gastrectomy.

Methods

Articles on the prognostic study of PG and DG patients after gastrectomy were collected from the PubMed, EMBASE, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, and VIP databases from the date of establishment until December 2020. The data were statistically analyzed by Stata software (version 11.0, StataCorp).

Results

A total of 10 articles met the inclusion criteria. Meta-analysis showed that the 1-, 3- and 5-year OS rates of PG patients were significantly lower than those of DG patients (RR = 0.898, 95% CI: 0.825 to 0.977, P = 0.013; RR = 0.802, 95% CI: 0.708 to 0.909, P = 0.001; RR = 0.736, 95% CI: 0.642 to 0.844, P = 0.000). After subgroup analysis according to different countries, the combined RR values of were as follows: 1-year OS: eastern countries: RR = 0.966, 95% CI: 0.944 to 0.988, P = 0.003, western countries: RR = 0.687, 95% CI: 0.622 to 0.759, P = 0.000; 3-year OS: eastern countries: RR = 0.846, 95% CI: 0.771 to 0.929, P = 0.000, western countries: RR = 0.742, 95% CI: 0.399 to 1.382, P = 0.348; and 5-year OS: eastern countries: RR = 0.798, 95% CI: 0.716 to 0.889, P = 0.000, western countries: RR = 0.646, 95% CI: 0.414 to 1.008, P = 0.054.

Conclusion

In terms of 1-, 3-, and 5-year OS, PG patients had lower rates than DG patients and the eastern countries/western countries subgroup, but there were no significant differences in 3- and 5-year OS for the western countries. These results merit further clinical validation in future studies.

(Registration ID: UMIN000040393; Date of registration: 2020/05/13)

Unraveling the identity of gastric cardiac cancer

The classification of gastric cardiac carcinoma (GCC) is controversial. It is currently grouped with esophageal adenocarcinoma (EAC) as an adenocarcinoma of the gastroesophageal junction (GEJ). Recently, diagnostic criteria for adenocarcinoma in the GEJ were established and GCC was separated from EAC. We viewed published evidence to clarify the GCC entity for better patient management. GCC arises in the cardiac mucosa located from 3 cm below and 2 cm above the GEJ line. Compared with EAC, GCC is more like gastric cancer and affects a higher proportion of female patients, younger patients, those with a lower propensity for reflux disease, a wider histopathologic spectrum, and more complex genomic profiles. Although GCC pathogenesis mechanisms remain unknown, the two-etiology proposal is appealing: in high-risk regions, the Correa pathway with Helicobacter pylori infection, chronic inflammation, low acid and intestinal metaplasia, dysplasia and carcinoma may apply, while in low-risk regions the sequence from reflux toxin-induced mucosal injury and high acid, to intestinal metaplasia, dysplasia and carcinoma may occur. In early GCC a minimal risk of nodal metastasis argues for a role of endoscopic therapy, whereas in advanced GCC, gastric cancer staging rules and treatment strategy appear to be more appropriate than the esophageal cancer staging scheme and therapy for better prognosis stratification and treatment. In this brief review we share recent insights into the epidemiology, histopathology and genetics of GCC and hope that this will stimulate further investigations in order to improve the clinical management of patients with GCC.

Distinct clinicopathological differences between early gastric cardiac and non-cardiac carcinomas: a single-center retrospective study of 329 radical resection cases

Background

Early gastric carcinoma is heterogeneous and can be divided into early gastric cardiac carcinoma (EGCC) and early gastric non-cardiac carcinoma (EGNCC) groups. At present, differences in clinicopathology remains obscure between EGCC and EGNCC fundus–corpus and antrum–angularis–pylorus subgroups, especially between EGCC with and without oesophageal invasion.

Methods

In this study, we studied 329 consecutive early gastric carcinoma radical gastrectomies with 70 EGCCs and 259 EGNCCs.

Results

Compared to the EGNCC antrum–angularis–pylorus (n = 181), but not fundus–corpus (n = 78), sub-group, EGCC showed significantly older age, lower prevalence of the grossly depressed pattern, better tumor differentiation, higher percentage of tubular/papillary adenocarcinoma, but lower frequency of mixed poorly cohesive carcinoma with tubular/papillary adenocarcinoma, and absence of lymph node metastasis (LNM) in tumors with invasion up to superficial submucosa (SM1). In contrast, pure poorly cohesive carcinoma was less frequently seen in EGCCs than in EGNCCs, but mixed poorly cohesive carcinoma with tubular/papillary adenocarcinomas was significantly more common in the EGNCC antrum–angularis–pylorus sub-group than in any other group. No significant differences were found between EGCC and EGNCC sub-groups in gender, tumor size, H. pylori infection rate, and lymphovascular/perineural invasion. EGCC with oesophageal invasion (n = 22), compared to EGCC without (n = 48), showed no significant differences in the H. pylori infection rate and oesophageal columnar, intestinal, or pancreatic metaplasia, except for a higher percentage of the former in size > 2 cm and tubular differentiation.

Conclusions

There exist distinct clinicopathologic differences between EGCC and EGNCC sub-groups; EGCC was indeed of gastric origin. Further investigations with larger samples are needed to validate these findings.

Comparing blind spots of unsedated ultrafine, sedated, and unsedated conventional gastroscopy with and without artificial intelligence: a prospective, single-blind, 3-parallel-group, randomized, single-center trial

BACKGROUND AND AIMS

EGD is the most vital procedure for the diagnosis of upper GI lesions. We aimed to compare the performance of unsedated ultrathin transoral endoscopy (U-TOE), unsedated conventional EGD (C-EGD), and sedated C-EGD with or without the use of an artificial intelligence (AI) system.

METHODS

In this prospective, single-blind, 3-parallel-group, randomized, single-center trial, 437 patients scheduled to undergo outpatient EGD were randomized to unsedated U-TOE, unsedated C-EGD, or sedated C-EGD, and each group was then divided into 2 subgroups: with or without the assistance of an AI system to monitor blind spots during EGD. The primary outcome was the blind spot rate of these 3 groups with the assistance of AI. The secondary outcomes were to compare blind spot rates of unsedated U-TOE, unsedated, and sedated C-EGD with or without the assistance of AI, respectively, and the concordance between AI and the endoscopists' review.

RESULTS

The blind spot rate with AI-assisted sedated C-EGD was significantly lower than that of unsedated U-TOE and unsedated C-EGD (3.42% vs 21.77% vs 31.23%, respectively; P < .05). The blind spot rate of the AI subgroup was lower than that of the control subgroup in all 3 groups (sedated C-EGD: 3.42% vs 22.46%, P < .001; unsedated U-TOE: 21.77% vs 29.92%, P < .001; unsedated C-EGD: 31.23% vs 42.46%, P < .001).

CONCLUSIONS

The blind spot rate of sedated C-EGD was the lowest among the 3 types of EGD, and the addition of AI had a maximal effect on sedated C-EGD. (Clinical trial registration number: ChiCTR1900020920.).

Randomised controlled trial of WISENSE, a real-time quality improving system for monitoring blind spots during esophagogastroduodenoscopy

OBJECTIVE

Esophagogastroduodenoscopy (EGD) is the pivotal procedure in the diagnosis of upper gastrointestinal lesions. However, there are significant variations in EGD performance among endoscopists, impairing the discovery rate of gastric cancers and precursor lesions. The aim of this study was to construct a real-time quality improving system, WISENSE, to monitor blind spots, time the procedure and automatically generate photodocumentation during EGD and thus raise the quality of everyday endoscopy.

DESIGN

WISENSE system was developed using the methods of deep convolutional neural networks and deep reinforcement learning. Patients referred because of health examination, symptoms, surveillance were recruited from Renmin hospital of Wuhan University. Enrolled patients were randomly assigned to groups that underwent EGD with or without the assistance of WISENSE. The primary end point was to ascertain if there was a difference in the rate of blind spots between WISENSE-assisted group and the control group.

RESULTS

WISENSE monitored blind spots with an accuracy of 90.40% in real EGD videos. A total of 324 patients were recruited and randomised. 153 and 150 patients were analysed in the WISENSE and control group, respectively. Blind spot rate was lower in WISENSE group compared with the control (5.86% vs 22.46%, p<0.001), and the mean difference was -15.39% (95% CI -19.23 to -11.54). There was no significant adverse event.

CONCLUSIONS

WISENSE significantly reduced blind spot rate of EGD procedure and could be used to improve the quality of everyday endoscopy.

TRIAL REGISTRATION NUMBER

ChiCTR1800014809; Results.

Common Locations of Gastric Cancer: Review of Research from the Endoscopic Submucosal Dissection Era

Detection of early-stage gastric cancer improves the prognosis of patients. Endoscopic submucosal dissection (ESD) is a curative and stomach-preserving treatment for early gastric cancer (EGC) associated with a low risk of lymph node metastasis. However, several studies have reported missed diagnosis of gastric cancer. Therefore, endoscopists are required to learn accurate diagnostic skills to eliminate endoscopic blind spots. A systematic screening protocol to map the entire stomach without blind spots reduces the risk of missed lesions. Knowledge of the features of EGC or dysplasia is essential to identify suspicious lesion. Information of the common sites of occurrence of EGC can also enable a detailed endoscopic examination to improve detection rates. Previous reports investigating the location of gastric cancers resected by ESD or surgery showed that the antrum and lesser curvature of stomach were predominantly affected. Helicobacter pylori-induced atrophic changes advance from the antrum to the corpus along the lesser curvature, predominantly affecting these areas. Gastric cancers in the antrum and the lower corpus are also commonly missed during screening examination. Therefore, a careful examination of the lower third stomach is warranted to avoid missing synchronous and metachronous gastric lesions. Knowledge of the location of EGC enables accurate endoscopic examination and detection of EGC in early stage.

Comparison on Clinicopathological Features, Treatments and Prognosis between Proximal Gastric Cancer and Distal Gastric Cancer: A National Cancer Data Base Analysis

Background: The aim of this study was to examine the differences in clinicopathological features, treatment strategies and prognosis between patients with proximal gastric cancer (PGC) and distal gastric cancer (DGC).

Methods: Patients with gastric adenocarcinoma were identified from the National Cancer Database during the years 2004-2015. Survival analysis was performed via Kaplan-Meier and Cox proportional hazards models.

Results: A total of 97,060 patients were identified with gastric adenocarcinoma. DGC was associated with older age, more advanced tumor stage, and poorly differentiated tumors compared with PGC (all p<0.01). In the multivariate analysis, patients with DGC had a worse prognosis compared with those with PGC. In early and locally advanced stage, the prognosis of DGC was better compared with PGC. In distant metastasis stage, the prognosis of DGC was worse compared with PGC. Compared with patients underwent gastrectomy who received adjuvant therapy (AT) in locally advanced stage, a survival benefit was seen for DGC patients who received neoadjuvant therapy (NAT) or NAT plus AT, whereas PGC patients with locally advanced disease did not share this result (p>0.05).

Conclusion: PGC and DGC differed in their clinicopathologic characteristics and prognosis and heterogeneity may be due to differences in tumor biology. Tumor location should be taken into consideration when stratifying patients for optimal therapeutic strategies.

Emerging evidence supports grouping by location of early gastric carcinoma for appropriate clinical management in Chinese patients

Gastric cancer is common in China. At present, early detection with prompt resection of early gastric carcinoma (EGC) is crucial for improving patient's survival. Because of high heterogeneity of EGC in Chinese patients we reviewed recent clinicopathological and molecular evidence and proposed a grouping EGC in three subgroups according to their location for appropriate management. In group 1 (cardia), most patients with EGC in this small location were elderly men. The tumors originated in the cardiac mucosa with a high proportion of cases with slightly elevated gross patterns and intestinal adenocarcinoma histology with moderate to well differentiation. Poorly cohesive carcinoma was infrequent. As the risk for lymph node metastasis in this kind of tumor was significantly lower than that in the distal stomach, endoscopic therapy is preferred. Group 2 (fundus-corpus), many patients with EGC in this large location were young women. The EGCs originated in the oxyntic mucosa with pure and mixed poorly cohesive carcinomas that are more commonly present in this area than in any other. Most tumors were poorly differentiated with a high risk for lymph node metastasis. Thus, endoscopic therapy may be appropriate for intramucosal, but not for submucosal, carcinoma. Group 3 (antrum-pylorus). EGC tumors arose from the antral mucosa, primarily because of Helicobacter pylori infection, following the Correa gastric cancer tumorigenetic pathway. Erosive and ulcerated gross patterns were most frequently observed. While most EGCs in this location were mainly intestinal adenocarcinomas, poorly differentiated EGCs were substantial in number. Because the risk of lymph node metastasis remains to be illustrated, clinical management requires an individualized approach. This preliminary observation requires verification in large nationwide multicenter studies.

Low risk of lymph node metastasis in 495 early gastric cardiac carcinomas: a multicenter clinicopathologic study of 2101 radical gastrectomies for early gastric carcinoma

Clinical decision-making on endoscopic vs. surgical resection of early gastric cardiac carcinoma remains challenging because of uncertainty on risk of lymph node metastasis. The aim of this multicenter study was to investigate risk factors of lymph node metastasis in early gastric cardiac carcinoma. Guided with the World Health Organization diagnostic criteria, we studied 2101 radical resections of early gastric carcinoma for risk factors associated with lymph node metastasis, including tumor location, gross pattern, size, histology type, differentiation, invasion depth, lymphovascular, and perineural invasion. We found that the risk of lymph node metastasis was significantly lower in early gastric cardiac carcinomas (6.7%, 33/495), compared with early gastric non-cardiac carcinomas (17.1%, 275/1606) (p < 0.0001). In early gastric cardiac carcinoma, no lymph node metastasis was identified in intramucosal carcinoma (0/193) and uncommon types of carcinomas (0/24), irrespective of the gross pattern, size, histologic type, differentiation, and invasion depth. Ulceration, size > 3 cm, and submucosal invasion were not significant independent risk factors for lymph node metastasis. In 33 early gastric cardiac carcinomas with lymph node metastasis, either lymphovascular invasion or poor differentiation was present in 16 (48.5%) cases and together in six cases. By multivariate analysis, independent risk factors of lymph node metastasis in early gastric cardiac carcinoma included lymphovascular invasion (Odds Ratio (OR): 7.6, 95% Confidence Interval (CI): 2.8-20.2) (p < 0.0001) and poor differentiation (OR: 6.0, 95% CI: 1.4-25.9) (p < 0.05). In conclusion, lymph node metastasis was not identified in early gastric cardiac intramucosal carcinoma and uncommon types of carcinoma. The risk of lymph node metastasis was also significantly lower in tumors with submucosal invasion, especially for cases without lymphovascular invasion or poor differentiation. These results lend support to the role of endoscopic therapy in the treatment of patients with early gastric cardiac carcinoma.

Clinicopathological Features and Increased Expression of Toll-Like Receptor 4 of Gastric Cardia Cancer in a High-Risk Chinese Population

The incidence of gastric cardia cancer (GCC) is high in China. However, the clinicopathological characteristics and the carcinogenesis of GCC are unclear. Toll-like receptor 4 (TLR4) is an important innate immunity receptor and has a role in non-GCC (NGCC). We compared the clinicopathological characteristics of GCC patients from a high-risk area in China to esophageal cancer (EC) patients. Immunohistochemistry for TLR4 was performed in 201 histological samples of normal gastric cardia mucosa (n = 11), gastric cardia inflammation (n = 87), and GCC (n = 103). We included 84 patients with EC and 99 with GCC. GCC tissue was more poorly differentiated than EC tissue and more invasive, with more histomorphologic variation. Lymph node metastasis was more frequent in GCC than in EC. The Helicobacter pylori infection rate was higher but not significantly with GCC than EC. Survival was shorter with lymph node metastasis. We found a statistically significant trend for progressive increase of TLR4 expression from normal mucosa to inflammation in GCC. GCC in this high-risk area displays clinicopathologic characteristics different from those of EC and different from those of gastroesophageal junction carcinomas in other countries, although this was not analyzed statistically. Increased TLR4 expression in gastric cardia lesions may be associated with GCC tumorigenesis.

Clinicopathology of Early Gastric Carcinoma: An Update for Pathologists and Gastroenterologists

BACKGROUND

The WHO defines early gastric carcinoma (EGC) as invasive carcinoma up to the submucosal layer, regardless of nodal metastasis. The recent study results indicate that EGC varies in location, histology, nodal metastasis, and prognosis.

SUMMARY

The heterogeneity in EGC may be related to various types of epithelial stem cells. The most important stem cells include Lgr5+ cells at the base of a gastric unit in the antrum-pylorus-cardia, Mist1+ cells at the isthmus/Troy+ cells at the base in the corpus-fundus, and Sox2+ cells at the base in almost all regions. Dysregulation of these cells along with environmental factors transform stem cells in different regions into malignancy in genetically susceptible populations.

KEY MESSAGE

The 2 most vulnerable regions for EGC have been found along the lesser curvature: the cardia in elderly patients and antrum-angularis in mid-aged and elderly patients. Most hereditary early-onset gastric carcinomas are concentrated in the corpus-fundus of young women. By histology, the most common EGC type is tubular adenocarcinoma in many growth patterns, starting in the neck of a gastric unit. Worse prognosis has been found in early papillary, compared to tubular, adenocarcinoma, related to deeper penetration, more lymphovascular invasion, and more liver and nodal metastases. Contrary to the common belief, intramucosal signet ring cell carcinoma demonstrates low risk of nodal metastasis, comparable to early intestinal-type EGC.

PRACTICAL IMPLICATIONS

The overall risk for nodal metastasis in EGC is low but significant. It is urgent to organize multicenter studies on risk of nodal metastasis in EGC in order to establish more reliable clinical practice guidelines to treat EGC patients.

Worse Prognosis in Papillary, Compared to Tubular, Early Gastric Carcinoma

Purpose: Papillary early gastric carcinoma (EGC) is uncommon but shows worse prognosis in our most recent study in a Chinese population with unknown reasons. The aim of the present study was to further investigate risk factors for worse prognosis in patients with papillary adenocarcinoma, compared to those with tubular adenocarcinoma.

Methods: We searched the electronic pathology databank for radical gastrectomy cases over an 8-year period at a single medical center in Nanjing, China, and identified consecutive 240 EGC cases that were classified as either papillary (n=59) or tubular (n=181) EGC tumors in accordance with the World Health Organization (WHO) gastric cancer diagnosis criteria. We investigated and compared clinicopathologic risk factors for prognosis between papillary and tubular EGC groups. All patients were followed up and their 5-year survival rate was compared statistically with the Kaplan-Meier method with a log rank test.

Results: Compared to tubular EGCs, papillary EGCs were significantly more common in elderly patients, more frequently occurred in the proximal stomach with protruding/elevated growth patterns, submucosal invasion, and a micropapillary component. Although lymphovascular invasion (16.9%), nodal (13.6%) and distant (11.8%) metastases in papillary EGCs were more frequent than those (8.3%, 7.2%, and 3.7%, respectively) in tubular EGCs, the differences approached but did not reach statistically significant levels. Significant risk factors for nodal metastasis included lymphovascular invasion in both EGC groups, but the ulcerative pattern and submucosal invasion only in tubular EGCs. The 5-year survival rate was significantly worse in papillary (80.5%) than in tubular (96.8%) EGCs.

Conclusions: Compared to tubular EGCs, papillary EGCs diagnosed with the WHO criteria in Chinese patients were more frequent in elderly patients, proximal stomach and showed the significantly worse 5-year survival rate with more protruding/elevated growth patterns and the micropapillary component. Further studies in larger samples are urgently needed to validate these findings for precision individualized EGC patient management.

Risk factors of lymph node metastasis in early gastric carcinomas diagnosed by WHO criteria in 379 Chinese patients

OBJECTIVE

To investigate risk factors of lymph node metastasis (LNM) in Chinese early gastric carcinoma (EGC) patients diagnosed using the World Health Organization (WHO) criteria and compare the differences in those factors between proximal (PGC) and distal gastric carcinoma (DGC).

METHODS

Among 3 176 gastric cancer resections we identified 379 (11.9%) consecutive EGC (104 PGC and 275 DGC) with lymphadenectomy performed at the Affiliated Nanjing Drum Tower Hospital of Nanjing University (Nanjing, Jiangsu Province, China) between January 2005 and December 2012. Endoscopic and clinicopathological features related to LNM were analyzed.

RESULTS

LNM occurred in 49 (12.9%) EGC, including three PGC and 46 DGC. In early DGC, middle age (41-60 years), tumor size ≥3.1 cm, submucosal invasion, poorly cohesive carcinoma, micropapillary adenocarcinoma and lymphovascular invasion were risk factors by univariate analysis. In contrast, no risk factors of LNM were identified in early PGC. By multivariate analysis, female sex (odds ratio [OR] 2.4), DGC (OR 8.1), poorly cohesive carcinoma (OR 8.8) and lymphovascular invasion (OR 38.8) were found to be significant independent risk factors for LNM. The risk of LNM was effectively stratified using a scoring model of mild (score ≤3.5), moderate (score 4.0-8.5) and high (score ≥16) risk groups.

CONCLUSIONS

LNM occurred in 12.9% of EGC diagnosed with the WHO criteria in Chinese patients. Independent risk factors of LNM were identified in early DGC only and included female sex, DGC, poorly cohesive carcinoma and lymphovascular invasion. Early PGC has a much lower risk for LNM than early DGC.

Recent advances in proximal gastric carcinoma

The American Joint Committee on Cancer (AJCC) staging scheme requires staging proximal gastric carcinoma (PGC) as esophageal adenocarcinoma (EAC), which has been shown to be controversial by recent research results. To update the current research findings on PGC, we systematically reviewed and analyzed the scientific evidence on key arguments related to PGC. The data of high-quality research articles showed that PGC arised in the cardiac mucosa in the proximal stomach within 3 cm below the gastroesophageal junction. Its incidence is rising in East Asian countries, but decreasing in the West, and plateaued at a low level in the United States. PGC is a slowly progressive cancer with unknown independent risk factors and the mechanisms of pathogenesis. This carcinoma exhibits a wide histopathological spectrum and heterogeneous post-resection patient survival characteristics, and cannot be adequately staged for prognotic stratification by the current AJCC staging classification. The results on PGC genomics reveal unique genetic profiles, especially in East Asian populations. In conclusion, mounting evidence defies a simple placement of PGC in a single category of EAC for disease classification; further investigations on the mechanisms of PGC pathogenesis are urgently needed.