Clinical application of early gastric carcinoma with lymphoid stroma based on lymph node metastasis status

Association between pathological T1 colorectal cancer with lymphoid follicular replacement and risk of lymph node metastasis

BACKGROUND AND AIM

Endoscopic resection (ER) is widely performed to treat early colorectal cancer. However, additional surgery for pathological T1 colorectal cancer (pT1CRC) after ER is controversial because of the imprecise prediction of lymph node metastasis (LNM). Recently, several patients of pT1CRC with lymphoid follicular replacement (LFR) without LNM have been reported. This study aimed to investigate the clinicopathological features and risk of LNM in patients with pT1CRC with LFR.

METHODS

We retrospectively analyzed patients who underwent ER or surgical resection and were diagnosed with pT1CRC between January 2010 and December 2020. We defined pT1CRC with LFR as the replacement of a part of the lymphoid follicular component within the submucosal area by adenocarcinoma, with no invasion into other submucosal areas.

RESULTS

Among the 600 eligible patients, the incidence rate of pT1CRC with LFR was 6.7% (40/600). Patients with pT1CRC with LFR represented 14.3% (37/258) of the endoscopically treated patients and 0.9% (3/342) of the surgically treated patients. For patients with pT1CRC with LFR, 80.0% (32/40) had flat and depressed lesions, and 35.0% (14/40) had submucosal invasion depth ≥1000 μm. Patients with pT1CRC with LFR had negative lymphovascular invasion, differentiated type, and budding grade 1. In the median follow-up of 61 months, patients with pT1CRC with LFR had no LNM.

CONCLUSIONS

The presence of LFR in pT1CRC may be associated with a low risk of LNM. In patients with pT1CRC with LFR, follow-up without additional surgery is possible even if the submucosal invasion depth is ≥1000 μm.

Clinicopathological Characteristics and Lymph Node Metastasis Rates in Early Gastric Lymphoepithelioma-Like Carcinoma: Implications for Endoscopic Resection

Background/Aims

Lymphoepithelioma-like carcinoma (LELC) is a rare subtype of gastric cancer. We aimed to identify the clinicopathological features and rate of lymph node metastasis (LNM) to investigate the feasibility of endoscopic submucosal dissection for early gastric LELC confined to the mucosa or submucosa.

Methods

We compared the clinicopathological characteristics of 116 early gastric LELC patients and 5,753 early gastric well- or moderately differentiated (WD or MD) tubular adenocarcinoma patients treated by gastrectomy.

Results

Compared to WD or MD early gastric cancer (EGC) patients, early LELC patients were younger and had a higher prevalence of proximally located tumors. Despite more frequent deep submucosal invasion (86.2% vs 29.8%), lymphatic invasion was less frequent (6.0% vs 16.2%) in early LELC patients than in WD or MD EGC patients. Among tumors with deep submucosal invasion, the tumor size was smaller, lymphatic invasion was less frequent (6.0% vs 40.2%) and the rate of LNM was lower (10.0% vs 19.4%) in patients with LELC than in those with WD or MD EGC. The overall rate of LNM in early LELC patients was 8.6% (10/116). The risk of LNM in patients with mucosal, shallow submucosal invasive, or deep submucosal invasive LELC was 0% (0/6), 0% (0/10), and 10% (10/100), respectively.

Conclusions

Early LELC is a distinct subtype of EGC with more frequent deep submucosal invasion but less lymphatic invasion and LNM than WD or MD EGCs. Endoscopic submucosal dissection may be considered curative for patients with early LELC confined to the mucosa or shallow submucosa, given its negligible rate of LNM.

Sex-dependent different clinicopathological characterization of Epstein-Barr virus-associated gastric carcinoma: a large-scale study

BACKGROUND

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) has been reported to account for approximately 5-16% of all GCs with good prognosis compared to EBV-negative GC. We evaluated the clinicopathological characteristics of EBVaGC including survival rate in South Korea.

METHODS

A total of 4,587 patients with GC who underwent EBV in situ hybridization (EBV-ISH) were prospectively enrolled at the Seoul National University Bundang Hospital from 2003 to 2021. Age, sex, smoking status, cancer type and stage, tumor size and location, histological type, molecular features and survival information were analyzed.

RESULTS

A total of 456 patients with GC (9.9%) were positive for EBV. The EBVaGC group displayed a higher proportion of males (P < 0.001), a predominant presence in the proximal stomach (P < 0.001), a higher proportion of undifferentiated cancer (P < 0.001), and a lower cancer stage (P = 0.004) than the EBV-negative group. Cox multivariate analyses revealed age (hazard ratio [HR] = 1.025, P < 0.001), tumor size (HR = 1.109, P < 0.001), and cancer stage (stage2 HR = 4.761, P < 0.001; stage3 HR = 13.286, P < 0.001; stage4 HR = 42.528, P < 0.001) as significant risk factors for GC-specific mortality, whereas EBV positivity was inversely correlated (HR = 0.620, P = 0.022). Furthermore, the EBVaGC group displayed statistically significant survival advantages over the EBV-negative cancer group in terms of both overall (P = 0.021) and GC-specific survival (P = 0.007) on the Kaplan-Meier survival curve. However, this effect was evident only in males.

CONCLUSIONS

EBVaGC patients showed better prognoses despite their association with proximal location and poorly differentiated histology in male, probably due to the difference in immunity between males and females.

[Infectious Gastric Diseases Other than Helicobacter]

In addition to Helicobacter pylori, the acute bacterial causes of infectious gastritis, include phlegmonous gastritis, gastric tuberculosis, and gastric syphilis. Bacterial gastritis often improves with appropriate broad-spectrum antibiotics, emphasizing the need for prompt diagnosis and treatment based on the clinical and endoscopic findings. Among viral gastritis, cytomegalovirus gastritis, primarily occurring in immunocompromised patients, necessitates antiviral intervention, while immunocompetent individuals typically achieve amelioration by administering proton pump inhibitors. In contrast, most gastric infections caused by the Epstein-Barr virus (EBV) are asymptomatic, but an EBV infection is a cause of stomach cancer. EBV-associated gastric cancer exhibits distinct clinical, pathological, genetic, and post-genetic mutation features, making it clinically significant. The colonization of Candida albicans in the stomach is uncommon, and typical antifungal treatment is unnecessary. Candida infections in gastric ulcers can be treated with anti-ulcer treatment alone. Lastly, anisakidosis in the stomach, which occurs when consuming raw seafood, can manifest in various clinical presentations and is typically treated through endoscopic removal of the nematode. This article aims to contribute to the rapid diagnosis and treatment of rare stomach infections beyond Helicobacter pylori in real clinical situations.

Estimating the Global Burden of Epstein-Barr Virus-Associated Gastric Cancer: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Evidence suggests that a fraction of new gastric cancer cases may be etiologically associated with Epstein-Barr virus (EBV), a known carcinogenic agent. We aimed to systematically explore the proportion of EBV-positive gastric cancer.

METHODS

We did a systematic review (PROSPERO CRD42020164473) from January 1990 to August 2021. For each country and geographical region with available data, pooled prevalence and corresponding 95% confidence intervals (CIs) of EBV in gastric tumors were calculated for 3 subtypes of gastric adenocarcinoma (conventional adenocarcinoma, lymphoepithelioma-like gastric carcinoma, and remnant/stump carcinoma). For conventional adenocarcinoma, prevalence ratios (PRs) were presented for sex, Lauren's classification, gastric cancer stage, and anatomical location of the stomach.

RESULTS

In 220 eligible studies including over 68,000 cases of conventional gastric adenocarcinoma, EBV prevalence in tumor cells was 7.5% (95% CI, 6.9%-8.1%) and was higher in men compared with women (PR, 2.1; 95% CI, 1.9-2.4), in diffuse type compared with intestinal type (PR, 1.3; 95% CI, 1.1-1.5), and in the proximal region compared with the distal region (PR, 2.5; 95% CI, 2.0-3.1). There was no difference in EBV prevalence by gastric cancer stage. EBV prevalence was 75.9% (95% CI, 62.8%-85.5%) among lymphoepithelioma-like gastric carcinoma and 26.3% (95% CI, 22.2%-32.0%) among remnant or stump carcinoma.

CONCLUSIONS

Assuming a causal association between EBV and gastric cancer, our findings, when applied to the GLOBOCAN 2020 gastric cancer incidence, suggest that primary prevention such as the development of an effective EBV vaccine might prevent 81,000 EBV-associated gastric cancer cases worldwide annually.

Clinical Significance of Epstein-Barr Virus and Helicobacter pylori Infection in Gastric Carcinoma

Background/Aims

Epstein-Barr virus (EBV) and Helicobacter pylori (HP) coinfection may synergistically induce severe inflammatory responses in the stomach tissue, increasing the risk of developing gastric cancer. We aimed to analyze the effect of EBV and HP coinfection on the clinicopathologic features and prognosis of gastric cancer, as well as to evaluate the role of EBV infection in non-gastric carcinoma with lymphoid stroma (non-GCLS).

Methods

Overall, 956 patients who underwent surgery for gastric cancer between September 2014 and August 2015 were eligible and divided into groups, according to GCLS morphology, EBV infection, and HP infection. Clinicopathologic characteristics and oncologic outcomes were analyzed retrospectively.

Results

EBV and HP coinfection was significantly associated with male sex, proximal location, GCLS morphology, and equivocal p53 expression (p<0.001). Multivariate analysis revealed that EBV infection alone (hazard ratio [HR], 0.362; 95% CI, 0.131 to 0.996; p=0.049) and lower third location (HR, 0.624; 95% CI, 0.413 to 0.943; p=0.025) were inversely correlated with overall survival. During median follow-up period of 72 months, overall survival rate was not significantly different between the EBV and HP coinfection group and others (97.6% vs 86.8%; log-rank p=0.144). In non-GCLS patients (n=920), overall survival rate was not significantly different between the EBV infection group and others (96.9% vs 86.4%; log-rank p=0.126).

Conclusions

EBV and HP coinfection is not an independent prognostic factor for gastric cancer. EBV infection status, regardless of HP infection, affects the clinicopathologic features of all types of gastric cancer. However, it does not lead to a significant difference in overall survival of non-GCLS patients.

Profiling chromosomal-level variations in gastric malignancies

Aneuploidy arises from persistent chromosome segregation errors, or chromosomal instability. Although it has long been known as a hallmark of cancer cells, reduced cellular fitness upon induced ploidy alterations hinders the understanding of how aneuploidy relates to cancer development in the body. In this study, we employed the fluorescence in situ hybridization (FISH) analysis targeting centromeres to indicate ploidy changes, and quantitatively evaluated the ploidy statuses of gastric tumors derived from a total of 214 patients, ranging from early to advanced diseases. We found that cancer cells reveal a marked elevation of aneuploid population, increasingly in cases diagnosed in advanced stages. The expansion of aneuploid population is well associated with p53 deficiency, consistent with its essential role in genome maintenance. Comparisons among multiple locations within the tumor, or between the primary and metastatic tumors, indicated that cancer cells mostly remain their ploidy alterations throughout the primary tumors, but metastatic tumors may be consisted of cells with either increased or decreased levels of aneuploidy. We also found that a notable proportion of polyploid cells are often present already in chronic gastritis epithelia. These observations underscore that the chromosome-level variations are widespread in gastric cancers, shaping their genetic heterogeneity and malignant properties.

Clinicopathological features of Epstein-Barr virus-associated superficial early stage gastric cancer treated with endoscopic submucosal dissection

BACKGROUND

Epstein-Barr virus (EBV) is known to be involved in gastric carcinogenesis. EBV-associated early gastric carcinoma (EBVEGC) has a lower incidence of lymph node involvement and could be an expanded indication for endoscopic submucosal dissection (ESD) treatment.

AIM

To clarify the prevalence and clinicopathological features of EBVEGC.

METHODS

This study reviewed 618 lesions in 519 patients treated with ESD between 2014 and 2016. Tissue microarray sections were subjected to in situ hybridization staining for EBV-encoded small RNA transcripts (EBER). Lesions positive for EBER were compared with control lesions and were retrospectively analyzed.

RESULTS

12 (1.9%) of the 618 lesions were EBVEGC. EBVEGCs were more frequently located near the atrophic border than control lesions in the middle or upper stomach and were reddish. EBVEGC invasion was deeper and more often histologically undifferentiated. On narrow-band imaging magnifying endoscopy, the EBVEGC group significantly more often showed an endoscopic lace pattern, defined as an absent or obscure microsurface pattern and a microvascular pattern of a tiny, dense, and irregular subepithelial capillary network. The rate of curative resection was significantly lower in the EBVEGC group.

CONCLUSIONS

Only 1.9% of the ESD specimens were EBV-positive. Endoscopic features could raise clinical suspicion of EBV infection.

Short-term outcomes of three rare cases of intramucosal Epstein-Barr virus-associated gastric cancer treated with endoscopic submucosal dissection

Epstein-Barr virus-associated gastric cancer (EBVaGC) is a subtype of gastric cancer morphologically characterized by massive lymphocyte infiltration. We herein report the short-term outcomes of three rare cases of intramucosal EBVaGC treated with endoscopic submucosal dissection (ESD). Histologically, the lesions exhibited poorly to moderately differentiated tubular adenocarcinoma without lymphovascular invasion, and in situ hybridization revealed EBV-encoded small RNA. Helicobacter pylori infection was not found in any of the lesions. During the 3 to 12 months of follow-up following ESD, none of the ESD-treated patients showed evidence of local recurrence or distant metastases. Essential characteristics of intramucosal EBVaGC may include lymphocyte infiltration into the mucosal stroma or cancer nests as well as the presence of a lace pattern. We believe that ESD might be a safe and suitable treatment method for intramucosal EBVaGC that avoids needless surgery, particularly in patients with severe comorbidities or a high operational risk.

Epstein-Barr Virus-Associated Gastric Cancer: Old Entity with New Relevance

Gastric cancer (GC) represents a major public health issue worldwide, being the fifth most common cancer and one of the leading causes of death by cancer. In 2014, The Cancer Genome Atlas (TCGA) established that tumors positive for Epstein-Barr virus (EBV) are considered a specific subtype of GC (EBVaGC). Several meta-analyses have shown that EBVaGC represents almost 10% of all gastric cancer worldwide, with small differences in the geographic distribution. This tumor subtype has a high potential of being clinically relevant and studies have shown that it has specific features, a better prognosis, and increased overall survival. In this review, we summarize some of the most frequent aspects of EBVaGC, including the specific features of this GC subtype, data regarding the potential steps of EBVaGC carcinogenesis, and perspectives on treatment opportunities.

Incidence and survival rates of lymphoepithelioma-like gastric carcinoma: analysis of the Korea Central Cancer Registry Database

BACKGROUND

Lymphoepithelial carcinoma of the stomach (LEGC) is a rare type of gastric carcinoma. There is a limited understanding of the incidence and survival rates of LEGC. The aim was to investigate the nationwide incidence and survival rates of LEGC in Korea using the Korea Central Cancer Registry.

METHODS

The data on LEGC were retrieved from the Korea Central Cancer Registry of Korean Cancer Center. The age and sex of the patients and the Surveillance, Epidemiology, and End Results (SEER) summary stage of the tumor were analyzed, and the relative survival rates (RSRs) were calculated. The Korea Central Cancer Registry has data of patients with LEGC from 1993 to 2017 but is approved to use personal information only from 2006 to 2017 due to privacy restrictions of the institute. The RSRs, as calculated data, were able to be disclosed from 1993 to 2017.

RESULTS

Between 2006 and 2017, the total number of LEGC was 1,030, and the trend of incidence increased ty time (p = .002). In the SEER stage, the proportion of localized stage was 54.3% in 2006, and 73.9% in 2017, which increased from 2006 to 2017 significantly (p = .002). The RSR was higher in men than in women. The cumulative 5-year RSRs were 98.0% in the localized stage and 88.0% in the regional stage during 1993-2017. The 5-year RSRs increased 79.5% in 1996-2000 to 93.4% in 2013-2017.

CONCLUSIONS

The incidence of LEGC is low, which has been increasing in recent years in South Korea. The prognosis of LEGC is good even at advanced stages and gets better as time goes by. Our findings provide useful insights to clinicians about LEGC and inform patients about the survival rate.

A rare case of Epstein-Barr virus-positive early gastric carcinoma with lymphoid stroma successfully treated by endoscopic submucosal dissection alone

Gastric carcinoma with lymphoid stroma (GCLS), a rare subset of gastric cancer, has a low frequency of lymphovascular invasion and a relatively better prognosis compared with conventional gastric cancer. We herein report a rare case of early GCLS successfully treated by endoscopic submucosal dissection alone. The lesion was located in the upper gastric body and approximately 9 mm in size. We assessed that the lesion was within an absolute indication for endoscopic resection. We performed endoscopic submucosal dissection and succeeded in en bloc resection. A histopathological assessment disclosed that the carcinoma was poorly differentiated with massive infiltration of lymphocyte and invaded the submucosal layer massively at 1000 μm in depth. There were no visible lymphovascular invasions in the specimen. Since the Epstein-Barr virus (EBV)-encoded small RNA in situ hybridization revealed that cancer cells were positive for EBV, the patient was finally diagnosed with EBV-positive GCLS. We persuaded the patient to receive an additional surgery; however, the patient refused to undergo it. The patient has been followed for more than 5 years without recurrence.

Epstein-Barr Virus-associated Gastric Carcinoma

Epstein-Barr virus-associated gastric carcinoma (EBVaGC) comprises approximately 10% of all gastric cancers and is now defined as one of the four subtypes of gastric cancer according to the molecular classification proposed by the Cancer Genome Atlas project. EBVaGC has characteristic genetic profiles that harbor a DNA methylation phenotype, frequent mutations in PIK3CA and ARID1A, and amplification of JAK2 and programmed death-ligand (PD-L)1/PD-L2. Therefore, EBVaGC shows several distinct clinicopathological features, including a male predominance, proximal stomach location, gastric carcinoma with lymphoid stroma histology, low risk of lymph node metastasis, and favorable prognosis. In clinical practice, patients with early EBVaGC might be good candidates for endoscopic resection or minimally invasive surgery since the rate of lymph node metastasis is very low, even with deep submucosal invasion. Furthermore, in the case of advanced EBVaGC, the applicability of immunotherapy has been investigated based on its increased expression of PD-L1 and high immunogenicity. In conclusion, EBV can serve as a biomarker in gastric cancer, and further identification of other molecular characteristics of EBVaGC is essential for new potential therapeutic targets.

Clinicopathological Features and Prognostic Implication of Gastric Carcinoma with Lymphoid Stroma

Methods

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

Results

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

Conclusion

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

Very low risk of lymph node metastasis in Epstein-Barr virus-associated early gastric carcinoma with lymphoid stroma

Background

Epstein-Barr virus-associated early gastric carcinoma with lymphoid stroma (EBV-GCLS) is a rare variant of early gastric carcinomas. Clinicopathological features of this variant remain obscure, especially in Chinese patients. Therefore, we collected EBV-GCLS cases and studied clinicopathology and prognosis.

Methods

By a retrospective review of 595 consecutive radical gastrectomies for early gastric carcinoma from 2006 to 2018, we identified 8 (1.3%, 8/595) EBV-GCLS cases. Clinicopathologic characteristics were compared between EBV-GCLSs and 109 conventional early gastric carcinomas, which were divided into intramucosal, SM1, and SM2 subgroups. The latter 2 subgroups were classified according to the submucosal invasion depth below or over 500 μm.

Results

All 8 EBV-GCLSs occurred in male patients and invaded deep submucosa (SM2) without lymph node metastasis (LNM), four (50%) of which had synchronous non-gastric malignant tumors (3 gastric gastrointestinal stromal tumors and 1 primary clear cell renal cell carcinoma), and four (50%) arose in the proximal stomach. Compared to conventional early gastric carcinomas, EBV-GCLS was significantly more frequent with SM2 invasion, poor differentiation, and synchronous non-gastric carcinoma tumor, but not with age, gender, macroscopic type, location, size, perineural invasion, lymphovascular invasion, and pathologic stage. In invasion-depth stratified comparisons in the SM2 subgroup, the frequency of LNM in EBV-GCLS was significantly lower than that in conventional early gastric carcinomas (p < 0.05) and the 5-year survival rate of patients with EBV-GCLS was better than that with conventional early gastric carcinomas in 3 subgroups (100% vs 91.5, 85.7, 83.9%, respectively), although the differences did not reach a statistically significant level due to the small sample size. Significant differences among 4 subgroups were found in tumor grade, lymphovascular invasion, LNM, pathological stage, and synchronous tumor, but not in age, gender, macroscopic type, tumor size, location, perineural invasion.

Conclusions

Even with poor differentiation and SM2 invasion, EBV-GCLS showed very low risk of LNM and may be a candidate for endoscopic therapy such as endoscopic submucosal dissection.

Clinicopathological Significance of EBV-Infected Gastric Carcinomas: A Meta-Analysis

Background and objectives: The present study aims to elucidate the clinicopathologic significance of Epstein-Barr virus (EBV) infection in gastric carcinomas (GCs) through a meta-analysis. Materials and Methods: Sixty-one eligible studies were included in the present meta-analysis. The included patients, with and without EBV infection, were 2063 and 17,684, respectively. We investigated the clinicopathologic characteristics and various biomarkers, including programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs). Results: The estimated EBV-infected rate of GCs was 0.113 (95% confidence interval (CI): 0.088-0.143). The EBV infection rates in GC cells were 0.138 (95% CI: 0.096-0.194), 0.103 (95% CI: 0.077-0.137), 0.080 (95% CI: 0.061-0.106), and 0.042 (95% CI: 0.016-0.106) in the population of Asia, America, Europe, and Africa, respectively. There was a significant difference between EBV-infected and noninfected GCs in the male: female ratio, but not other clinicopathological characteristics. EBV infection rates were higher in GC with lymphoid stroma (0.573, 95% CI: 0.428-0.706) than other histologic types of GCs. There were significant differences in high AT-rich interactive domain-containing protein 1A (ARID1A) and PD-L1 expressions, and high CD8+ TILs between EBV-infected and noninfected GCs. Conclusions: Our results showed that EBV infection of GCs was frequently found in male patients and GCs with lymphoid stroma. EBV infection was significantly correlated with ARID1A and PD-L1 expressions and CD8+ TILs in GCs.

Postoperative outcomes of gastric carcinoma with lymphoid stroma

BACKGROUND

Gastric carcinoma with lymphoid stroma (GCLS) is a rare subtype of gastric cancer. There have been several reports demonstrating the favorable prognosis of early GCLS without lymph node metastasis (LNM) compared with gastric adenocarcinomas. However, it remains unknown whether advanced GCLS (AGCLS) with LNM has a similar prognosis and clinicopathological features. This study aimed to assess the clinicopathological features of GCLS of all stages.

METHODS

We retrospectively assessed 375 patients who were pathologically diagnosed with gastric cancer and underwent curative surgical resection at Tokyo Medical University, Japan, between September 2013 and October 2019. Of these patients, 357 (95.2%) patients were pathologically diagnosed with gastric adenocarcinomas, and 18 (4.8%) patients were diagnosed with GCLS. The GCLS patients (n = 18) were compared with the gastric adenocarcinoma patients (non-GCLS patients, control) (n = 357) in terms of their clinicopathological features and clinical outcome.

RESULTS

The GCLS patients showed significantly predominant upper gastric locations (P = 0.003), lower number of LNM (P = 0.01), and better overall survival rate than the non-GCLS patients (P = 0.029). The predominant upper gastric locations (P = 0.0002), lower number of LNM (P = 0.003), and better overall survival rate (P = 0.04) were significantly correlated in the AGCLS with LNM patients compared with the advanced non-GCLS with LNM patients. For survival analyses, surgical procedure, tumor location, and numbers of positive LNM were adjusted by 1:1 propensity score matching. After adjustment, the overall survival rate was significantly higher in the AGCLS group than in the advanced non-GCLS group (P = 0.03).

CONCLUSION

AGCLS has distinct clinicopathological features and clinical behavior that are similar to those of early GCLS. AGCLS with LNM patients showed a significantly lower number of LNM and a better survival rate than advanced non-GCLS with LNM patients. To our knowledge, this study is the first report to describe the clinicopathological features of AGCLS.

Clinical impact of Epstein-Barr virus status on the incidence of lymph node metastasis in early gastric cancer

Epstein-Barr virus-positive gastric cancer (EBVGC) comprises approximately 9% of all gastric cancers and is associated with a low prevalence of lymph node metastasis (LNM). Given that limited data concerning LNM in EBV-related early GC are available, EBV status is not considered an indicator for endoscopic submucosal dissection (ESD). In this review, we focused on pT1 EBVGC and on gastric carcinoma with lymphoid stroma (GCLS), and discuss expanded ESD indications and curative resection criteria. In pT1b EBVGC, the incidence of LNM was low (6/180 patients, 3.3%; 95% confidence interval [CI] 1.2-7.1), especially in lymphovascular invasion-negative EBVGC (1/109 patients, 0.9%). No patients with pT1a EBVGC had LNM (0/38 patients, 0%; 95% CI 0-7.6), even those who did not meet the current curative ESD criteria. Although the frequency of LNM in GCLS was low (5.0-10.6%), the incidence of LNM in non-EBV GCLS was relatively high (10.0-20.0%); therefore, EBV status can be considered a more important factor than GCLS. In summary, the clinicopathological characteristics of EBVGC differ from those of conventional GC, and EBV negativity is a risk factor for LNM in early GC. Therefore, patients in this group are likely to be promising candidates for ESD, and we recommend that EBV status evaluation be included in early GC treatment guidelines.

Gastric submucosa-invasive carcinoma associated with Epstein-Barr virus and endoscopic submucosal dissection: A case report

BACKGROUND

Epstein-Barr virus (EBV)-associated carcinoma is a gastric cancer subtype with a morphology characterized by gastric carcinoma with lymphoid stroma (GCLS). Clinicopathological studies have indicated a better prognosis for GCLS than for common gastric carcinomas. Some previous cases of early gastric cancer associated with EBV had been diagnosed by endoscopic resection.

CASE SUMMARY

We present two GCLS cases subjected to endoscopic submucosal dissection (ESD) for a definitive diagnosis. A protruded gastric lesion was identified by routine endoscopic examination, but forceps biopsy showed no atypical cells before ESD. The resected specimen showed a poorly differentiated adenocarcinoma with lymphoid cells involving the mucosa and submucosa. The final diagnosis was submucosa-invasive poorly differentiated gastric adenocarcinoma. Accordingly, additional gastrectomy was recommended to obtain a complete cure. One patient underwent additional distal gastrectomy with lymph node dissection, but the other was refused because of cardiovascular complications. Both patients remained in remission for more than half a year. EBV positivity was determined by EBV-encoded RNA in situ hybridization. We also conducted a literature review of cases of early gastric cancer associated with EBV that had been diagnosed by ESD.

CONCLUSION

Submucosa-invasive GCLS could be dissected using ESD, and EBV positivity should be subsequently assessed to determine whether or not any additional curative surgery is required. Further prospective investigations on the prevalence of lymph node metastasis in EBV-associated carcinoma should be performed to expand the indications for endoscopic resection.

Epstein-Barr Virus-associated Early Gastric Cancer Treated with Endoscopic Submucosal Dissection: A Possible Candidate for Extended Criteria of Endoscopic Submucosal Dissection

A 73-year-old man visited our hospital for the treatment of an early gastric cancer (GC) lesion. We performed en bloc resection using endoscopic submucosal dissection (ESD) for his GC lesion. The present GC lesion was Epstein-Barr virus (EBV)-associated poorly differentiated-type adenocarcinoma invading into the submucosal layer. Recently, accumulating data has shown that the risk of lymph node metastasis from early EBV GC without local lymphovascular infiltration is low. The present patient has been in good health for over three years since ESD. Some cases of early EBV GC with invasion into the submucosal layer may be candidates for further extension of the ESD criteria.

Pitfalls in the Interpretation of Publications about Endoscopic Submucosal Dissection of Early Gastric Cancer with Undifferentiated-Type Histology

Endoscopic submucosal dissection (ESD) is a standard treatment for patients with gastrointestinal neoplasms with a negligible risk of lymph node metastasis. ESD enables en bloc resection of gastrointestinal neoplasms and organ preservation, thereby, avoiding surgical treatment. Although small (<2 cm) intramucosal early gastric cancer with undifferentiated-type histology (EGC-UH) without ulceration is included in the expanded criteria for ESD, controversies remain due to different biology and characteristics compared to EGC with differentiated-type histology. The authors previously presented studies about the technical feasibility of ESD for these lesions using a meta-analysis and retrospective multicenter analysis. However, many pitfalls were identified in the interpretation of studies analyzing histologic discrepancy, mixed-type histology, criteria-based analysis of therapeutic outcomes, interpretation of curative resection, and long-term clinical outcomes. In this review, the authors discuss pitfalls in the interpretation of publications on ESD for EGC-UH.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusions

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

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.

Epstein-Barr virus positivity among surgically resected intramucosal gastric cancer

Epstein-Barr virus-associated gastric cancer (EBV-GC) accounts for approximately 8% of gastric cancers. However, little is known regarding intramucosal EBV-GC. The present study aimed to evaluate endoscopic and clinicopathological characteristics of intramucosal EBV-GC. Pathological data of 172 patients with 173 intramucosal gastric cancers who received gastrectomy with lymph node dissection were obtained for review. EBV-encoded small RNA in situ hybridization (EBER-ISH) was carried out using a tissue microarray block. Eight intramucosal early gastric cancers (4.6%) were EBER-ISH positive in which no cases had any lymph node metastasis. Macroscopic types were either depressed or flat, dominant histology was mixed type of moderate and poorly differentiated adenocarcinoma. In detail, histological features of "lace pattern" or "lymphocyte infiltration into the stroma or cancer nests" were observed.

Early gastric cancer with lymphoid stroma presenting as a subepithelial lesion diagnosed by endoscopic submucosal dissection

A 53-year-old man underwent an esophagogastroduodenoscopy that showed a 20-mm subepithelial lesion in the middle gastric body. Endoscopic ultrasound revealed a hypoechoic mass located in the submucosa. Biopsy specimens revealed a benign gastric mucosa with severe lymphocytic infiltration in the submucosa. Malignant lymphoma or gastric cancer with lymphoid stroma was suspected. We performed endoscopic submucosal dissection for definitive diagnosis. Histological examination showed undifferentiated adenocarcinoma, which showed positive Epstein-Barr virus-encoded RNA in situ hybridization results, invading the submucosa mixed with dense lymphocytic infiltration. Thus, Epstein-Barr virus-positive gastric cancer with lymphoid stroma was diagnosed. Gastric cancer with lymphoid stroma is a rare subtype of gastric cancer, which is associated with Epstein-Barr virus infection; it sometimes appears as a subepithelial lesion, which makes it difficult to diagnose using standard biopsy. Endoscopic submucosal dissection was useful in obtaining a sufficient tissue for full histological assessment, including immunostaining.