The decision criterion of histological mixed type in "T1/T2" gastric carcinoma--comparison between TNM classification and Japanese Classification of Gastric Cancer

The Percentage of Signet Ring Cells Is Inversely Related to Aggressive Behavior and Poor Prognosis in Mixed-Type Gastric Cancer

Background and Objectives

Only recently the percentage of signet ring cells (SRCs) in gastric cancer (GC) has been proposed as an independent predictor of survival. High amounts of SRCs have been related to lower recurrence and mortality rates, better prognosis, and favorable clinicopathological features in a poorly cohesive histotype. It is not known what the effect of SRC percentage in mixed-type GC is. We investigate the role of SRCs as a prognostic marker in mixed-histotype GC.

Methods

A retrospective analysis was performed through a prospectively maintained database of patients with diagnosed “mixed-type” gastric carcinoma, defined according to 2019 WHO classification. These patients underwent surgery between 1995 and 2016, and their tissue samples were stored in a tissue bank. All slides were analyzed, and patients were divided into three groups according to the percentage of SRCs: “Group 1” (displaying ≤10% of SRCs), “Group 2” (displaying <90% but >10% of SRCs), and “Group 3” (displaying ≥90% of SRCs). We compared clinical and pathological features as well as prognostic factors between the different groups.

Results

Among 164 enrolled patients, 68.9% were male and 31.1% were female (p = 0.612). The mean (±SD) age at diagnosis was 71.4 ± 9.6 years. Ninety-eight (59.7%) patients were classified as “Group 1”, 66 (40.3%) as “Group 2”, and none as “Group 3”. Five-year overall survival was remarkably higher in Group 2 (73.8%) in comparison to Group 1 (35.4%), p < 0.001. Mortality risk was three times higher in patients with ≤10% SRC pattern compared to those with >10% [HR 2.70 (95% CI 1.72–4.24)]. After adjusting according to potential confounding factors, SRC percentage was still an independent predictor of survival.

Conclusions

The proportion of SRCs is inversely related to aggressive behavior and poor prognosis in mixed-type GCs, highlighting the role of SRC amount as an independent predictor of survival.

Relationship between histological mixed-type early gastric cancer and lymph node metastasis: A systematic review and meta-analysis

The clinicopathological features of early gastric cancer (EGC) with mixed-type histology (differentiated and undifferentiated) are incompletely understood, and the capacity of endoscopic submucosal dissection (ESD) to treat mixed-type cancer remains controversial. This systematic review analyzed the rate of lymph node metastasis (LNM) in mixed-type EGC. We gathered articles published up to February 21, 2021, that analyzed the relationship between LNM and mixed-type EGC from Embase, PubMed, and Web of Science. The primary outcome was the LNM rate associated with different histological types of EGC, and the secondary outcomes were the odds ratios (ORs) for LNM risk factors among EGC patients. From the 24 studies included in this meta-analysis, the overall rate of LNM in predominantly differentiated mixed-type (MD) EGC was 12%, whereas the LNM rate in predominantly undifferentiated mixed-type (MU) EGC was 22%. We further divided these studies into 2 groups according to the depth of invasion. In mixed-type mucosal EGC, the pooled LNM rate was 15%; in submucosal EGC, the rate was 33% for MU, which was higher than the rates for pure types (pure differentiated type, 13%; pure undifferentiated type, 21%; p<0.05). The LNM rate of MD was 20%, it was higher than those of the pure differentiated type and nearly the same as pure undifferentiated type. Other pooled statistics showed that submucosal invasion, pure undifferentiated EGC, and mixed-type EGC were independent risk factors for LNM. This meta-analysis showed that MD submucosal EGC has a high rate of LNM and is highly correlated with LNM; thus, the management of MD EGC as purely differentiated EGC according to the indications for ESD is inappropriate, and the mixed type should be added as a parameter in these indications.

Histopathological validation of magnifying endoscopy for diagnosis of mixed-histological-type early gastric cancer

BACKGROUND

The undifferentiated-type (UDT) component profoundly affects the clinical course of early gastric cancers (EGCs). However, an accurate preoperative diagnosis of the histological types is unsatisfactory. To date, few studies have investigated whether the UDT component within mixed-histological-type (MT) EGCs can be recognized preoperatively.

AIM

To clarify the histopathological characteristics of the endoscopically-resected MT EGCs for investigating whether the UDT component could be recognized preoperatively.

METHODS

This was a single-center retrospective study. First, we attempted to clarify the histopathological characteristics of the endoscopically-resected MT EGCs with emphasis on the UDT component. Histopathological examination investigated each lesion’s UDT component: (1) Whole mucosal layer occupation of the UDT component; (2) UDT component exposure to the surface of the mucosa; and (3) existence of a clear border between the differentiated-type and UDT components. Then, preoperative endoscopic images with magnifying endoscopy with narrow-band imaging (ME-NBI) were examined to identify whether the endoscopic UDT component finding was recognizable within the area where it was present in the histopathological examination. The preoperative biopsy results and comparative relationships between endoscopic and histopathological findings were also examined.

RESULTS

In the histopathological examination, the whole mucosal layer occupation of the UDT component and exposure of the UDT component to the mucosal surface were observed in 67.3% (33/49) and 79.6% (39/49) of samples, respectively. A clear distinction of the border between the differentiated-type and UDT components could not be drawn in 65.3% (32/49) of MT lesions. In the endoscopic examination, the preoperative endoscopic images showed that only 24.5% (12/49) of MT EGCs revealed the UDT component within the area where it was present histopathologically. Histopathological UDT predominance was the single significant factor associated with the presence of the endoscopic UDT component finding (61.5% vs 11.1%, P = 0.0009). Only 26.5% (13/49) of the lesions were diagnosed from the pretreatment biopsy as having a UDT component. Combined results of the pretreatment biopsy and ME-NBI showed the preoperative presence of the UDT component in 40.8% (20/49) of MT EGCs.

CONCLUSION

Recognition of a UDT component within MT EGCs is difficult even when pretreatment biopsy and ME-NBI are combined. Endoscopic resection plays a significant role in both treatment and diagnosis.

Endoscopic Submucosal Dissection of Early Gastric Cancer with Mixed-Type Histology: A Systematic Review

BACKGROUND

Endoscopic submucosal dissection (ESD) criteria are histologically categorized by early gastric cancer (EGC) with differentiated- and undifferentiated-type histology. However, EGC is histologically heterogenous and there have been no separate criteria for EGC with mixed-type histology [EGC-MH; differentiated-type predominant EGC mixed with an undifferentiated component (EGC-MD) or undifferentiated-type predominant EGC mixed with a differentiated component (EGC-MU)]. Moreover, therapeutic outcomes of ESD for EGC-MH have not been clearly described.

AIM

This study aimed to evaluate the feasibility of ESD for EGC-MH.

METHODS

We searched core databases for specific inclusion factors: patients with EGC-MH, intervention of ESD, and at least one of the following outcomes: rate of en bloc, complete, curative resection, recurrence, procedure-related adverse event, lymphovascular invasion (LVI), or lymph node metastasis (LNM) that enabled evaluation of feasibility of ESD.

RESULTS

A total of eight (systematic review) and four studies (meta-analysis) were included. There was no robustness in age, location, or morphology of EGC-MH. Moderately differentiated adenocarcinoma was frequent in pre-ESD biopsy. EGC-MH showed larger size, deeper invasion, and higher rates of LVI/LNM than pure-type EGC. Total en bloc, complete resection, and curative resection rates were 94.6% (95% confidence interval 86.6-97.9%), 77.8% (57.9-89.9%), and 55.1% (50.4-59.6%), respectively. There was no LNM or extra-gastric recurrence after ESD if the EGC-MD met the curative resection criteria. However, the EGC-MD itself was a risk factor for non-curative resection. (Margin positivity was the most common reason.) CONCLUSIONS: Although ESD seems to be technically feasible, inaccurate prediction of lateral or vertical margin leads to lower curative resection rate. Application of more strict indication is needed for EGC-MH.

Clinicopathological risk factors for gastric cancer: a retrospective cohort study in China

OBJECTIVE

To examine the potential clinicopathological factors affecting the prognosis of patients with gastric cancer after surgical treatment in China.

METHODS

Between 1 January 2001 and 31 December 2012, a total of 716 patients aged 22-84 years with gastric cancer were enrolled in the study. Survival analysis techniques including log rank test and Cox proportional hazard regression model were applied to evaluate the prognostic significance of clinicopathological characteristics in terms of survival time.

RESULTS

Of the 24 demographic and pathological variables collected in the data, 16 prognostic factors of gastric cancer were found to have statistically significant influences on survival time from the unadjusted analyses. The adjusted analysis furtherly revealed that age, age square, lymph node metastasis rate group, tumour size group, surgical type II, number of cancer nodules, invasion depth group and the interaction between surgical type II and tumour size group were important prognosis and clinicopathological factors for gastric cancer in Chinese.

CONCLUSION

Our study with relatively large sample size and many potential risk factors enable us to identify independent risk factors associated with the prognosis of gastric cancer. Findings from the current study can be used to assist clinical decision-making, and serve as a benchmark for the planning of future prognosis and therapy for patients with gastric carcinoma.

Consensus on the pathological definition and classification of poorly cohesive gastric carcinoma

BACKGROUND AND AIMS

Clinicopathological characteristics of gastric cancer (GC) are changing, especially in the West with a decreasing incidence of distal, intestinal-type tumours and the corresponding increasing proportion of tumours with Laurén diffuse or WHO poorly cohesive (PC) including signet ring cell (SRC) histology. To accurately assess the behaviour and the prognosis of these GC subtypes, the standardization of pathological definitions is needed.

METHODS

A multidisciplinary expert team belonging to the European Chapter of International Gastric Cancer Association (IGCA) identified 11 topics on pathological classifications used for PC and SRC GC. The topics were debated during a dedicated Workshop held in Verona in March 2017. Then, through a Delphi method, consensus statements for each topic were elaborated.

RESULTS

A consensus was reached on the need to classify gastric carcinoma according to the most recent edition of the WHO classification which is currently WHO 2010. Moreover, to standardize the definition of SRC carcinomas, the proposal that only WHO PC carcinomas with more than 90% poorly cohesive cells having signet ring cell morphology have to be classified as SRC carcinomas was made. All other PC non-SRC types have to be further subdivided into PC carcinomas with SRC component (< 90% but > 10% SRCs) and PC carcinomas not otherwise specified (< 10% SRCs).

CONCLUSION

The reported statements clarify some debated topics on pathological classifications used for PC and SRC GC. As such, this consensus classification would allow the generation of evidence on biological and prognostic differences between these GC subtypes.

Differential analysis of lymph node metastasis in histological mixed-type early gastric carcinoma in the mucosa and submucosa

AIM

To investigate the relationship between histological mixed-type of early gastric cancer (EGC) in the mucosa and submucosa and lymph node metastasis (LNM).

METHODS

This study included 298 patients who underwent gastrectomy for EGC between 2005 and 2012. Enrolled lesions were divided into groups of pure differentiated (pure D), pure undifferentiated (pure U), and mixed-type according to the proportion of the differentiated and undifferentiated components observed under a microscope. We reviewed the clinicopathological features, including age, sex, location, size, gross type, lymphovascular invasion, ulceration, and LNM, among the three groups. Furthermore, we evaluated the predictors of LNM in the mucosa-confined EGC.

RESULTS

Of the 298 patients, 165 (55.4%) had mucosa-confined EGC and 133 (44.6%) had submucosa-invasive EGC. Only 13 (7.9%) cases of mucosa-confined EGC and 30 (22.6%) cases of submucosa-invasive EGC were observed to have LNM. The submucosal invasion (OR = 4.58, 95%CI: 1.23-16.97, P = 0.023), pure U type (OR = 4.97, 95%CI: 1.21-20.39, P = 0.026), and mixed-type (OR = 5.84, 95%CI: 1.05-32.61, P = 0.044) were independent risk factors for LNM in EGC. The rate of LNM in mucosa-confined EGC was higher in the mixed-type group (P = 0.012) and pure U group (P = 0.010) than in the pure D group, but no significant difference was found between the mixed-type group and pure U group (P = 0.739). Similarly, the rate of LNM in the submucosa-invasive EGC was higher in the mixed-type (P = 0.012) and pure U group (P = 0.009) than in the pure D group but was not significantly different between the mixed-type and pure U group (P = 0.375). Multivariate logistic analysis showed that only female sex (OR = 5.83, 95%CI: 1.64-20.70, P = 0.028) and presence of lymphovascular invasion (OR = 13.18, 95%CI: 1.39-125.30, P = 0.020) were independent risk factors for LNM in mucosa-confined EGC, while histological type was not an independent risk factor for LNM in mucosa-confined EGC (P = 0.106).

CONCLUSION

For mucosal EGC, histological mixed-type is not an independent risk factor for LNM and could be managed in the same way as the undifferentiated type.

Early gastric cancer with a mixed-type Lauren classification is more aggressive and exhibits greater lymph node metastasis

BACKGROUND

The clinicopathological features of mixed-type (MT) early gastric cancer (EGC) according to Lauren's classification remain uninvestigated. This study aimed to clarify the clinicopathological features of MT EGC, particularly in relation to lymph node metastasis (LNM) and long-term survival.

METHODS

This study included 5309 patients who underwent gastrectomy for EGC. The clinicopathological features, LNM, and long-term outcomes of patients with MT carcinomas were compared with those of patients with intestinal-type (IT) and diffuse-type (DT) cancers. Furthermore, we evaluated the predictors of LNM in each Lauren classification subgroup.

RESULTS

Patients with MT carcinomas were likelier to have larger tumors, submucosal invasion, lymphovascular invasion, and LNM than those with IT or DT carcinomas. Multivariate logistic regression analysis revealed that the Lauren classification was a significant predictor of LNM (P < 0.001). The significant predictors of LNM in MT carcinomas were female sex, greater tumor size, presence of submucosal invasion, and lymphovascular invasion. However, the overall survival of patients with MT carcinoma was not significantly different from that of patients with IT or DT carcinomas (P = 0.104).

CONCLUSIONS

The presence of MT EGC carries a higher risk of LNM compared with the presence of IT or DT carcinomas. Therefore, MT carcinomas should be managed with gastrectomy that includes lymph node dissection instead of endoscopic resection.

Early signet ring cell carcinoma of the stomach is related to favorable prognosis and low incidence of lymph node metastasis

BACKGROUND

The aim of this study was to evaluate the clinical characteristics of early signet ring cell carcinoma of the stomach (SRC) and to investigate the optimal treatment strategy for early SRC.

METHODS

A total of 746 patients with pT1 gastric cancer (GC), who had undergone surgical resection between 1997 and 2012 were analyzed. Of these, 190 patients with SRC were enrolled in this study.

RESULTS

(i) The patients with SRC showed a significantly longer overall survival (P = 0.012) and disease free survival (P = 0.004) than patients with the other histological types. Multivariate analysis identified SRC as an independent factor predicting favorable prognosis in pT1 GC (HR = 0.38; 95% CI: 0.11-0.96; P = 0.041). Specifically, in undifferentiated pT1 GC, SRC was significantly less associated with lymph node metastasis (LNM) (OR = 0.39; 95% CI: 0.15-0.96; P = 0.042). (ii) From the viewpoint of a histological mixed-type, pure-SRC with pT1a was not associated with LNM regardless of tumor size (0.0%, 0/110), whereas mixed-SRC was an independent risk factor for LNM (OR = 7.19; 95% CI: 1.51-43.9; P = 0.012).

CONCLUSIONS

Patients with early SRC have a favorable prognosis with a low incidence of LNM. However, care should be taken with mixed-SRC, which consists of SRC and other histological types. J. Surg. Oncol. 2016;114:607-612. © 2016 Wiley Periodicals, Inc.

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

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

Histological mixed-type as an independent risk factor for nodal metastasis in submucosal gastric cancer

Recent studies reported that the histological mixed-type, which consists of differentiated and undifferentiated components, was related to the aggressive clinical features of gastric cancer as well as its poor outcomes. This study was designed to investigate the influences of the mixed-type on lymph node metastasis in patients with submucosal gastric cancer. We analyzed a total of 239 consecutive patients who underwent curative gastrectomy for submucosal gastric cancer between 2004 and 2012 from their hospital records. The overall prevalence of histological mixed-type in submucosal gastric cancer was 46.9 % (112/239). The histological mixed-type correlated more strongly with lymph node metastasis (P = 0.0016; 25.0 % (28/112)) than the undifferentiated type in the Japanese classification of gastric carcinoma (JCGC) (P = 0.2779; 20.5 % (17/83)) and 7th tumor-node-metastasis (TNM) (P = 0.0476; 20.7 % (31/150)) classifications. Univariate and multivariate logistic regression analyses identified a tumor size of 25 mm or greater (P = 0.0003, OR 4.51 (95 % CI 1.95-11.9)) and the histological mixed-type (P = 0.0316, OR 4.02 (95 % CI 1.12-19.2)) as independent risk factors for lymph node metastasis. The incidence of lymph node metastasis was high in patients with both these factors (33.8 % (23/68)) and low in patients without both factors (3.0 % (2/67)). These results suggest that the histological mixed-type correlated more strongly with lymph node metastasis than the undifferentiated type in the JCGC and TNM classifications and highlight its usefulness as a risk factor for lymph node metastasis in submucosal gastric cancer.

Liver Metastasis of Early Gastric Cancer with Mixed Histology after Endoscopic Submucosal Dissection

The Japanese Classification of Gastric Carcinoma histologically classifies endoscopically resected gastric cancer into differentiated and undifferentiated types according to the presence or absence of tubular structures on histology. The former includes papillary adenocarcinoma and tubular types, and the latter includes poorly differentiated adenocarcinoma, signet ring cell carcinoma and mucinous adenocarcinoma. However, gastric cancer sometimes contains a mixture of differentiated and undifferentiated components, and the clinical outcomes of the histological mixture are unknown, especially following endoscopic resection of early gastric cancer (EGC). This case was within the guideline indications for endoscopic submucosal resection (ESD), although it contained a partly signet ring cell carcinoma component; it recurred after 19 months with multiple lymph node and liver metastases. This case shows that additional surgical resection after ESD should be performed for patients with any mixed signet ring cell component, even in mild or moderately differentiated EGC.

Discrepancies in the histologic type between biopsy and resected specimens: A cautionary note for mixed-type gastric carcinoma

AIM: To evaluate discrepancies between biopsy and resected specimens using the Japanese Classification of Gastric Carcinoma (JCGC) and tumor-node-metastasis (TNM) classification.

METHODS: A total of 376 consecutive paired samples from biopsy and resected gastric specimens, which were derived from curative gastrectomy for gastric cancer between 2008 and 2011, were retrospectively analyzed.

RESULTS: (1) Discrepancies in the histologic type were observed between biopsy and resected specimens; 11.7% (44/376) in the JCGC and 18.1% (68/376) in TNM. In specimens diagnosed as the differentiated type from biopsy specimens, 14.4% (28/195) in the JCGC and 41.1% (67/163) in TNM were finally diagnosed as the undifferentiated type from resected specimens; and (2) the incidence of mixed-type gastric cancer was significantly higher in specimens with discrepancies than in those without in both the JCGC and TNM (both P < 0.0001); 93.2% (41/44) of specimens with discrepancies in the JCGC and 97.1% (66/68) of specimens with discrepancies in TNM were mixed-type gastric cancers.

CONCLUSION: Mixed-type gastric cancer was associated with a high incidence of histologic discrepancies between biopsy and resected specimens in both the JCGC and TNM definitions. Care should be taken in deciding treatments based on diagnosis of the histologic type for mixed-type gastric cancer from biopsy specimens.

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

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

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

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

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

Histological mixed-type as an independent prognostic factor in stage I gastric carcinoma

AIM: To evaluate the clinicopathological features of mixed-type gastric cancer and their influence on prognosis of mixed-type stage I gastric cancer.

METHODS: We analyzed 446 patients who underwent curative gastrectomy for stage I gastric cancer between 1999 and 2009. The patients were divided into two groups: those with differentiated or undifferentiated cancer (non-mixed-type, n = 333) and those with a mixture of differentiated and undifferentiated cancers (mixed-type, n = 113).

RESULTS: The overall prevalence of mixed-type gastric cancer was 25.3% (113/446). Compared with patients with non-mixed-type gastric cancer, those with mixed-type gastric cancer tended to be older at onset (P = 0.1252) and have a higher incidence of lymph node metastasis (P = 0.1476). They also had significantly larger tumors (P < 0.0001), more aggressive lymphatic invasion (P = 0.0011), and deeper tumor invasion (P < 0.0001). In addition, they exhibited significantly worse overall survival rates than did patients with non-mixed-type gastric cancer (P = 0.0026). Furthermore, mixed-type gastric cancer was independently associated with a worse outcome in multivariate analysis [P = 0.0300, hazard ratio = 11.4 (1.265-102.7)].

CONCLUSION: Histological mixed-type of gastric cancer contributes to malignant outcomes and highlight its usefulness as a prognostic indicator in stage I gastric cancer.

Signet ring cell type and other histologic types: differing clinical course and prognosis in T1 gastric cancer

BACKGROUND

The behavior of early stage signet ring cell carcinoma (SRC) is controversial. The purpose of this study was to clarify the behavior of early gastric SRC.

METHODS

We retrospectively analyzed data from 2,085 patients who had undergone curative gastrectomy for early gastric cancer between 1989 and 2000. Clinicopathologic outcomes and prognoses were evaluated, and we investigated whether these variables were correlated with histopathologic type.

RESULTS

Patients with early gastric SRC were younger and had a greater proportion of females than other histologic types. Lymph node metastasis was the only independent prognostic factor for both mucosal and submucosal forms of SRC. Mucosal SRC had a similar rate of lymph node metastasis to poorly differentiated (PD) tubular adenocarcinoma (TUB), and a higher rate than well-differentiated (WD) or moderately differentiated (MD)-TUB. However, its submucosal form had a similar rate of lymph node metastasis to WD-TUB, and a lower rate than MD- or PD-TUB. There was no difference in tumor recurrence or disease-related death according to histopathologic type or depth of invasion.

CONCLUSION

In mucosal gastric cancer, SRC has an unfavorable risk factor of lymph node metastasis than that of others and should not be considered for endoscopic resection. In submucosal gastric cancer, SRC is a more favorable risk factor of lymph node metastasis than that of other histologic types.