Clinicopathological Features and Prognosis of Mixed-Type T1a Gastric Cancer Based on Lauren's Classification

Poorly cohesive cells gastric carcinoma including signet-ring cell cancer: Updated review of definition, classification and therapeutic management

While the incidence of gastric cancer (GC) in general has decreased worldwide in recent decades, the incidence of diffuse cancer historically comprising poorly cohesive cells-GC (PCC-GC) and including signet ring cell cancer is rising. Literature concerning PCC-GC is scarce and unclear, mostly due to a large variety of historically used definitions and classifications. Compared to other histological subtypes of GC, PCC-GC is nevertheless characterized by a distinct set of epidemiological, histological and clinical features which require a specific diagnostic and therapeutic approach. The aim of this review was to provide an update on the definition, classification and therapeutic strategies of PCC-GC. We focus on the updated histological definition of PCC-GC, along with its implications on future treatment strategies and study design. Also, specific considerations in the diagnostic management are discussed. Finally, the impact of some recent developments in the therapeutic management of GC in general such as the recently validated taxane-based regimens (5-Fluorouracil, leucovorin, oxaliplatin and docetaxel), the use of hyperthermic intraperitoneal chemotherapy as well as pressurized intraperitoneal aerosol chemotherapy and targeted therapy have been reviewed in depth for their relative importance for PCC-GC in particular.

The Histopathological Types and Distribution Characteristics of Gastric Mixed Tumors

Objective

The present study aimed to investigate the histopathological types and distribution characteristics of gastric mixed tumors.

Methods

Detailed histological observations, together with related immunohistochemical and genetic tests, were analyzed on 960 surgically resected samples in 6 hospitals with gastric mixed tumors from May 2017 to May 2021 in this retrospective study.

Results

Epithelial-derived tumors accounted for 80.10% (769/960) of the gastric mixed tumor samples studied, and tumors of different tissue origins accounting for 10.83% (104/960), mesenchymal-derived tumors accounting for 6.25% (60/960), neuroendocrine tumors accounting for 2.40% (23/960), and lymphoma accounting for 0.42% (4/960). The histological types of gastric mixed tumors identified as most commonly were epithelial originated, followed by mixed tumors of different tissue originated, then mixed neuroendocrine, lymphoma, and mesenchymal originated in sequence. The histological number of gastric mixed tumors was ≤ 3 in 83.23% (799/960) of cases and > 4 in 16.77% (161/960) of cases. The mixed histological patterns of gastric mixed tumors were divided into three types: those with tumor cells interspersed with each other, those with incomplete fibrous tissue separation, and those without fibrous tissue separation. The gene target characteristics of gastric mixed tumors were the existence of multi-gene mutation, including human epidermalgrowth factor receptor-2 (HER2) gene amplification, key result areas (K-ras) and platelet-derived growth factor receptor alpha (PDGFRA).

Conclusion

Gastric mixed tumors should be adequately sampled, each piece of tissue should be involved in the morphological proportional division of the tumor, and any independent histological component should be written into the pathological examination report.

Clinicopathological differences, risk factors and prognostic scores for western patients with intestinal and diffuse-type gastric cancer

BACKGROUND

In the molecular era, the Laurén system is still a cost-effective and widely implemented classification for gastric cancer (GC) and it has been recently associated with clinical, histological and molecular features of these tumors. Despite recent advances in the understanding of the molecular biology of GC, there is a need to develop new prognostic tools for patient stratification in clinical practice. Thus, the identification of easily available prognostic factors in patients with intestinal and diffuse-type tumors can significantly improve risk assessment and patient stratification in GC.

AIM

To identify clinicopathological differences, risk factors, and to develop cost-effective prognostic scores for patients with intestinal and diffuse-type GC.

METHODS

Retrospective study of all patients undergoing surgery for GC at a tertiary referral center from 2001 to 2019. 286 cases met inclusion criteria (intestinal: 190, diffuse: 96). Clinical data and gross findings were collected. All specimens were reviewed by two independent pathologists and a detailed protocol for histologic evaluation was followed. Five tissue microarrays (TMAs) were constructed and sections of the TMA block were immunostained for HERCEPTEST, MSH2, MSH6, MLH1 and PMS2. Statistical analyses were performed and prognostic scores were developed based on hazard ratios.

RESULTS

Intestinal and diffuse-type GC showed different epidemiological, clinicopathological and prognostic features. Diffuse tumors were significantly associated with younger age, less symptomatology, flat morphology, deeper invasion, perineural infiltration, advanced stage at diagnosis, administration of adjuvant therapy and poorer prognosis. Intestinal lesions were fungoid or polypoid, showed necrosis, desmoplasia, microsatellite instability and HERCEPTEST positivity and were diagnosed at earlier stages. Tumor depth, desmoplasia, macroscopic type and lymph node involvement were independently related to the Laurén subtype. Furthermore, intestinal and diffuse GC were associated with different risk factors for progression and death. Vascular invasion, perineural infiltration and growth pattern were important prognostic factors in intestinal-type GC. On the contrary, tumor size and necrosis were significant prognosticators in diffuse-type GC. Our recurrence and cancer-specific death scores for patients with intestinal and diffuse-type GC showed an excellent patient stratification into three (diffuse GC) or four (intestinal) prognostic groups.

CONCLUSION

Our findings support that Laurén subtypes represent different clinicopathological and biological entities. The development of specific prognostic scores is a useful and cost-effective strategy to improve risk assessment in GC.

Higher Lymph Node Metastasis Rate and Poorer Prognosis of Intestinal-Type Gastric Cancer Compared to Diffuse-Type Gastric Cancer in Early-Onset Early-Stage Gastric Cancer: A Retrospective Study

Background: The incidence of early-onset gastric cancer (GC) that was diagnosed at <50 years is increasing, but there is a knowledge gap on early-onset early-stage GC (EEGC) that was defined as early-onset GC limited to the mucosa or submucosa. Therefore, we comprehensively analysed the clinical features based on Lauren type.

Methods: Logistic and Cox analyses were used to investigate risk factors for lymph node metastasis (LNM) and prognosis, respectively. Propensity score matching (PSM) was used to adjust confounding factors. Protein mass spectrometry analysis was used to explore the molecular mechanism of LNM.

Result: Our study included 581 patients with EEGC from the Surveillance, Epidemiology, and End Results (SEER) database and 226 patients with EEGC from our own centre. We identified intestinal type, T1b stage, and tumour size (>3 cm) as risk factors for LNM using SEER and our own data. We also found that the prognosis of patients with intestinal-type EEGC was poorer than patients with diffuse-type EEGC, and T1b stage and positive LNM were hazard factors for survival. After analysing the expression of proteins between positive and negative LNM in the intestinal or diffuse type, we found no similar proteins between these groups. The differentially expressed genes (DEGs) in the intestinal type functioned as epithelial cell signalling in Helicobacter pylori. The DEGs in the diffuse type functioned in the tricarboxylic acid cycle (TCA cycle) and oxidative phosphorylation.

Conclusion: For EEGC, our study was the first report to demonstrate that the intestinal type was a risk factor for LNM and survival compared to the diffuse type, and the oncogenic expression promoting the occurrence of LNM was different. These findings suggest that clinicians should pay more attention to intestinal-type EEGC than diffuse-type EEGC.

Differential prognostic implications of gastric adenocarcinoma based on Lauren's classification: a Surveillance, Epidemiology, and End Results (SEER)-based cohort study

Background

Our study aims to analyze the association between Lauren's classification and gastric adenocarcinoma prognosis using comprehensive statistical analyses.

Methods

According to the selection criteria, patients were included from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression, propensity score matching, and a multivariate competing risk model were used to investigate the association between Lauren's classification and prognosis. Subgroup analysis was used to investigate the role of confounding factors on the association between Lauren types and prognosis.

Results

After exclusion, a total of 20,218 patients from the SEER database were included, with 14,374 intestinal types and 5,844 diffuse types. The univariate Cox regression analysis revealed that the diffuse type had a poorer cancer-specific survival (CSS) rate [hazard ratio (HR), 1.44; 95% confidence interval (CI), 1.38-1.50]. After adjusting for confounding variables, the diffuse type also showed a higher risk of cancer-specific death (HR, 1.20; 95% CI, 1.15-1.20). Sensitivity analysis showed that after propensity score matching, the diffuse type had a poorer CSS rate (HR, 1.23; 95% CI, 1.10-1.36), and the competing risk model further validated these results [subdistribution HR (SHR), 1.32; 95% CI, 1.23-1.41]. Moreover, subgroup analysis demonstrated stable results in the subgroups, except for patients with T1 stage (HR, 1.06; 95% CI, 0.87-1.28) and a tumor size <2 cm (HR, 1.00; 95% CI, 0.83-1.21).

Conclusions

Diffuse-type gastric adenocarcinoma had an overall poorer prognosis compared to the intestinal type. However, in patients with T1 stage and tumor size <2 cm, the diffuse type had a comparable survival rate with the intestinal type.

Comparison of clinicopathological features and long-term prognosis between mixed predominantly differentiated-type and pure differentiated-type early gastric cancer

Background

Recent studies have shown that mixed predominantly differentiated-type (MD) early gastric cancer (EGC) might have more malignant potential than pure differentiated-type (PD) EGC. However, no study has analyzed all differentiated-type EGC cases treated endoscopically and surgically. This study aimed to compare the differences in clinicopathological features and long-term prognosis between MD- and PD-EGC.

Methods

We evaluated all patients with differentiated-type EGCs who were treated endoscopically and surgically in our hospital between January 2010 and October 2014. The clinicopathological features and long-term prognosis of MD-EGC were compared with those of PD-EGC.

Results

A total of 459 patients with 459 lesions were evaluated in this study; of them, 409 (89.1%) and 50 (10.9%) were classified into the PD and MD groups, respectively. Submucosal invasion was found in 96 (23.5%) patients of the PD group and in 33 (66.0%) patients of the MD group (p < 0.01). The rates of positive lymphatic and vascular invasion and ulceration were significantly higher in the MD group than in the PD group (p < 0.01). The proportion of patients with lymph node metastasis was also significantly higher in the MD group than in the PD group (5 (10%) vs 6 (1.5%), p < 0.01). The 5-year overall and EGC-specific survival rates in the PD group were 88.3 and 99.5%, respectively, while they were 94.0 and 98.0% in the MD group, respectively.

Conclusions

MD-EGC has more malignant potential than PD-EGC. However, the long-term prognosis of MD-EGC is good and is not significantly different from that of PD-EGC when treated appropriately.

Is there still a place for conventional histopathology in the age of molecular medicine? Laurén classification, inflammatory infiltration and other current topics in gastric cancer diagnosis and prognosis

Gastric cancer (GC) is the fifth most common cancer and the third cause of cancer-related deaths worldwide. In western countries, more than half of GC patients are diagnosed at advanced stages and 5-year survival rates range between 20-30%. The only curative treatment is surgery, and despite recent advances in oncological therapies, GC prognosis is still poor. The main prognostic tool for patient categorization and treatment selection is the TNM classification, but its limitations are being increasingly recognized. Early recurrences may occur in early-stage disease, and patients at the same stage show heterogeneous outcomes. Thus, there is a need to improve GC stratification and to identify new prognostic factors, which may allow us to select drug-susceptible populations, refine patient grouping for clinical trials and discover new therapeutic targets. Molecular classifications have been developed, but they have not been translated to the clinical practice. On the other hand, histological assessment is cheap and widely available, and it is still a mainstay in the era of molecular medicine. Furthermore, histological features are acquiring new roles as reflectors of the genotype-phenotype correlation, and their potential impact on patient management is currently being analyzed. The aim of this literature review is to provide a modern overview of the histological assessment of GC. In this study, we discuss recent topics on the histological diagnosis of GC, focusing on the current role of Laurén classification and the potential value of new histological features in GC, such as inflammatory infiltration and tumor budding.

Mixed histology poses a greater risk for noncurative endoscopic resection in early gastric cancers regardless of the predominant histologic types

OBJECTIVES

Clinicopathologic characteristics and treatment outcomes of mixed-histological-type (MT) early gastric cancers (EGCs) treated with endoscopic submucosal dissection (ESD) have not been sufficiently elucidated. We aimed to clarify them in comparison with pure-histological-type EGCs.

METHODS

We used 3022 consecutive EGCs in 2281 patients treated with ESD from our prospectively maintained database. Cases were stratified into four groups according to the final diagnosis of the resected specimen are as follows: 2780 pure differentiated-type (DT), 127 DT-predominant MT (D-MT), 87 pure undifferentiated-type (UDT), and 28 UDT-predominant MT (U-MT). Clinicopathologic characteristics and treatment outcome were compared between pure DT and D-MT, and between pure UDT and U-MT separately. Risk factors for deep submucosal invasion, lymphovascular invasion, and a final diagnosis of MT were identified using multivariate analysis.

RESULTS

Both D-MT (41.7 vs. 92.0%; P < 0.0001) and U-MT (35.7 vs. 75.9%; P = 0.0002) showed a significantly lower curative resection rate than their pure histologic counterparts. Multivariate analysis revealed that MT was an independent risk factor for deep submucosal (OR 6.55; 95% CI, 4.18-10.14) and lymphovascular (OR 4.74; 95% CI, 2.72-8.29) invasion. Preoperative biopsy results that did not show well-differentiated tubular adenocarcinoma (OR 28.2; 95% CI, 18.9-42.9) were an independent risk factor for a final diagnosis of MT.

CONCLUSIONS

MT poses a greater risk for noncurative resection regardless of the predominant histologic types, reflecting more aggressive malignant potential. Although a biopsy examination rarely shows MT, clinicians should consider the possibility of MT when a biopsy examination does not show well-differentiated tubular adenocarcinoma.

A clinical model to predict distant metastasis in patients with superficial gastric cancer with negative lymph node metastasis and a survival analysis for patients with metastasis

BACKGROUND

Distant metastasis (DM) is relatively rare in superficial gastric cancer (SGC), especially in patients without lymph node metastasis. This study aimed to explore the main clinical risk factors for DM in patients with superficial gastric cancer-no lymph node metastasis (SGC-NLNM) and the prognostic factors for patients with DM.

METHODS

Records of patients with SGC-NLNM between 2004 and 2015 were collected from the public Surveillance, Epidemiology, and End Results (SEER) database. Both univariate and multivariate logistic regressions were performed to analyze the clinical risk factors for DM. The Kaplan-Meier method and Cox regression model were used to identify prognostic factors for patients with DM. A nomogram was built based on multivariate logistic regression and evaluated by the C-index, the calibration, and the area under the receiver operating characteristic curve (AUC).

RESULTS

We developed and validated a nomogram to predict DM in patients with SGC-NLNM, showing that race, age, primary site, depth, size, and grade were independent risk factors. The built nomogram had a good discriminatory performance, with a C-index of 0.836 (95% confidence interval [CI]: 0.813-0.859). Calibration plots showed that the predicted DM probability was identical to the actual observations in both the training and validation sets. AUC was 0.846 (95% CI: 0.820-0.871) and 0.801 (95% CI: 0.751-0.850) in the training and validation sets, respectively. The results of the survival analysis revealed that surgery (hazard ratio [HR] = 0.249; 95% CI, 0.125-0.495), chemotherapy (HR = 0.473; 95% CI, 0.353-0.633), and grade (HR = 1.374; 95% CI, 1.018-1.854) were independent prognostic factors associated with cancer-specific survival (CSS), but radiotherapy was not (log-rank test, p = 0.676).

CONCLUSIONS

We constructed a sensitive and discriminative nomogram to identify high-risk patients with SGC-NLNM who may harbor dissemination at initial diagnosis. The tumor size and primary site were the largest contributors to DM prediction. Compared with radiotherapy, aggressive surgery, and chemotherapy may be better options for patients with DM.

Analysis of the Incidence and Survival of Gastric Cancer Based on the Lauren Classification: A Large Population-Based Study Using SEER

Background: Limited evidence exists on the incidence of gastric cancer (GC), and contradictory results exist for the prognosis of GC based on the Lauren classification. We analyzed the incidence and survival of GC based on the Lauren classification. Methods: The Surveillance, Epidemiology, and End Results (SEER) database from 1975 through 2015 was used to identify all patients with surgically resected, histologically diagnosed intestinal or diffused-type GC. Propensity score matching was used to analyze the association between the Lauren classification type and prognosis. Results: The trend of total GC incidence showed an obvious decrease (APC = -1.51, 95% CI: -2.31 to -1.01) as well as that of the intestinal type (APC = -1.43, 95% CI: -2.01 to -1.12). However, we found that the relative incidence of the diffused type was increased (APC = 0.6, 95% CI: 0.41-0.82). The trend of the total incidence of GC (APC = -1.31, 95% CI: -1.91 to -1.03) and that of the intestinal type (APC = -1.11, 95% CI: -1.53 to -0.98) was decreased in 40-49-year-olds, but that of the diffused type was increased (APC = 1.5, 95% CI: 1.2-1.72). We found that trends in GC incidence exhibited a similar pattern in the regional and distant stages and showed a decrease from 1975 through 2015. However, the incidence rate of the local stage was increased, with an APC of 0.5 (95% CI: 0.3-0.7). We identified 15,989 GC cases from the SEER database, including 13,852 intestinal-type and 2,138 diffused-type cases. The 1,336 intestinal-type cases were matched with 1,336 diffused-type cases using propensity score matching (PSM), and patients with the diffused type had a better prognosis than patients with the intestinal type (HR = 0.56, 95% CI: 0.45-0.78). However, we found that patients with diffused-type GC had worse survival than patients with intestinal-type GC in the cohort from Renji Hospital (P < 0.001). Conclusion: The total incidence of GC and that of the intestinal-type GC decreased, but the incidence of diffused-type GC increased in 40-49-year-olds. Diffused types of GCs may have a different prognosis compared to intestinal-type GCs in different patient cohorts. Nevertheless, these results should be interpreted with caution in assessing the prognosis in combination with other factors.

High Level of Legumain Was Correlated With Worse Prognosis and Peritoneal Metastasis in Gastric Cancer Patients

Background: Accumulating evidence has demonstrated that legumain (LGMN) is abnormally expressed in several malignancies and functions as an oncogene. However, the association between LGMN and gastric cancer (GC) has not yet been fully elucidated. In this study, we performed a comprehensive analysis of the role of LGMN in clinicopathologic characteristics and survival of GC patients.

Methods: The study had two patient cohorts, The Cancer Genome Atlas (TCGA) cohort and the Zhongshan Hospital cohort, both of which were used to analyze the role of LGMN in GC samples. The relationship between LGMN and clinicopathologic characteristics was determined by the Chi-square test and logistic regression analysis. The Kaplan–Meier method and Cox proportional hazards regression analysis were conducted to investigate the prognostic role of LGMN in GC patients. Moreover, a nomogram was constructed based on the factors that were independently associated with peritoneal metastasis. Finally, the gene set enrichment analysis (GSEA) was conducted to explore the underlying pathways through which LGMN was involved in GC progression.

Results: The mRNA and protein levels of LGMN were significantly upregulated in GC tissues, especially for diffuse-type GC. High level of LGMN was independently associated with poor prognosis in both TCGA and Zhongshan cohorts. Further analysis showed that increased protein level of LGMN was related to peritoneal metastasis in GC patients. In a nomogram model, the LGMN expression could help predict the possibility of peritoneal metastasis in GC patients. LGMN was a strong determinant for prediction of peritoneal metastasis. GC patients with high LGMN expression tended to have worse survival together with more frequent diffuse-type tumors and increased risk of peritoneal metastasis. The GSEA results showed that focal adhesion, ecm receptor interaction, cell adhesion molecules cams, TGF-β signaling pathway, JAK-STAT signaling pathway, gap junction, etc. were differentially enriched in the phenotype with high LGMN expression.

Conclusion: LGMN was an independent prognostic factor for OS in GC patients. Increased expression of LGMN was significantly associated with peritoneal metastasis. The nomogram based on LGMN might guide the clinical decisions for patients with GC.

Comparable rates of lymph node metastasis and survival between diffuse type and intestinal type early gastric cancer patients: a large population-based study

BACKGROUND AND AIMS

Limited evidence and contradictory results exist regarding the impact of Lauren type, namely diffuse and intestinal types, of lymph node metastasis (LNM) and prognosis for early gastric cancer (EGC). We aimed to compare LNM and prognosis between diffuse and intestinal type EGCs using comprehensive statistical analysis.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify all patients with surgically resected, histologically diagnosed, intestinal or diffuse type EGC. Multivariate logistic regression, multivariate Cox regression, multivariate competing risk model, and propensity score matching were used to analyze association the Lauren type and LNM or prognosis.

RESULTS

We identified 5593 EGCs from the SEER database, including 4376 intestinal types and 1217 diffuse types. No positive association was found between LNM and Lauren type (odds ratio, .93; 95% confidence interval [CI], .70-1.24; P = .62) after adjustment for other risk factors. Moreover, diffuse-type EGCs showed a similar prognosis to intestinal type EGCs in both multivariate Cox regression (HR [hazard ratio], .95; 95% CI, .77-1.18; P = .66) and the multivariate competing risk model (subdistribution HR [SHR], .99; 95% CI, .80-1.22; P = .926). Propensity score matching was used, and 733 diffuse types were matched with 733 intestinal types. We did not find any association between the Lauren type and LNM (odds ratio, .98; 95% CI, .71-1.37; P = .934) or prognosis in the univariate Cox regression (HR, .98; 95% CI, .76-1.26; P = .893) and univariate competing risk model (SHR, .98; 95% CI, .76-1.26; P = .893).

CONCLUSIONS

Diffuse-type EGC may have a comparable risk of LNM and prognosis to intestinal-type EGC. Nevertheless, these results should be carefully interpreted with caution when choosing endoscopic resection instead of surgery, because the treatment choice for EGC depends on the risk of lymphovascular invasion rather than LNM rate or prognosis.

Diverse Expression of IL-32 in Diffuse and Intestinal Types of Gastric Cancer

Introduction

Gastric cancer (GC) represents one of the most common cancers worldwide, frequently diagnosed at advanced stages with poor prognosis, indicating on need for new diagnostic and prognostic markers. The aim of the study was to determine the expression of IL-32, proinflammatory and angiogenic mediators, in patients with diffuse and intestinal gastric cancer and the relationship with clinicopathological aspects.

Material and Methods

The tissue samples of diffuse and intestinal types of tumor of 70 patients with gastric cancer were analyzed. Expression of IL-32, VEGF, IL-17, and CD31 was measured by immunohistochemistry.

Results

IL-32 expression was significantly lower in tissue samples from patients with diffuse type of gastric cancer that is also a severe and more progressive form (TNM stages III and IV, poor histological differentiation, and higher nuclear grade III). Expression of IL-17 was also decreased in patients with diffuse type of gastric cancer. Microvascular density was diminished in diffuse type of gastric cancer.

Conclusions

Downregulated expression of IL-32 in tumor tissue of patients with diffuse type of gastric cancer may implicate on its role in limiting ongoing proinflammatory and proangiogenic processes. This emphasizes on unrecognized role of IL-32 in biology of diffuse type of gastric cancer.

The Characteristics and Prognosis of Diffuse-Type Early Gastric Cancer Diagnosed during Health Check-Ups

Background/Aims

Because of the poor prognosis of diffuse-type gastric cancer, early detection is important. We investigated the clinical characteristics and prognosis of diffuse-type early gastric cancer (EGC) diagnosed in subjects during health check-ups.

Methods

Among 121,111 subjects who underwent gastroscopy during a routine health check-up, we identified 282 patients with 286 EGC lesions and reviewed their clinical and tumor-specific parameters.

Results

Patients with diffuse-type EGC were younger, and 48.1% of them were female. Serum anti-Helicobacter pylori IgG (Hp-IgG) was positive in 90.7% of diffuse-type EGC patients (vs 75.9% of intestinal-type EGC, p=0.002), and the proportion of diffuse-type EGC cases increased significantly with increasing Hp-IgG serum titers (p<0.001). Diffuse-type EGC had pale discolorations on the tumor surface (26.4% vs 4.0% in intestinal-type EGC, p<0.001) and were often located in the middle third of the stomach. Submucosal invasion or regional nodal metastasis was observed more commonly in patients with diffuse-type EGC. However, during the median follow-up period of 50 months, 5-year disease-free survival rates did not differ between the groups.

Conclusions

Diffuse-type EGC shows different clinical and endoscopic characteristics. Diffuse-type EGC is more closely associated with Hp-IgG seropositivity and a higher serum titer. Early detection results in excellent prognosis.

Acquisition of histologic diversity contributes to not only invasiveness but also lymph node metastasis in early gastric cancer

BACKGROUND

As more endoscopic resections are performed in early gastric cancer, the pretreatment prediction of lymph node metastasis (LNM) becomes more important. Some tumor characteristics including histologic type, invasion depth, ulceration, size, and lymphovascular invasion have been used to determine the endoscopic resectability of early gastric cancer; however, a more detailed analysis between clinicopathologic factors and lymph node metastasis is needed.

METHODS

We analyzed the correlation between the clinicopathological findings and LNM with 310 cases of early gastric cancer by dividing invasion depths in detail.

RESULTS

LNM occurred in 3.2% and 16.2% of the T1a and T1b tumors, respectively. LNM was associated with invasion depth (p=0.002) and lymphatic (p<0.001) and perineural (p=0.013) invasion. Among them, lymphatic invasion was the most powerful factor associated with LNM and significantly constant in T1a and T1b. The rate of LNM increased gradually as the tumor invaded deeper, and invasion of the muscularis mucosae layer was associated with an increased mixed adenocarcinoma incidence, suggesting that histologic diversity was associated with tumor invasiveness.

CONCLUSIONS

We demonstrated that lymphatic invasion was the most important and powerful parameter for LNM in early gastric cancers. In addition, tumor invasiveness into the muscularis mucosae was accompanied by tumor histologic diversity.