Impact of immunohistochemically identified lymphatic invasion on nodal metastasis in early gastric cancer

Liver metastatic recurrence after curative endoscopic submucosal dissection for slightly submucosal invasive gastric cancer: A case report and literature review

In Japan, differentiated-type early gastric cancer with submucosal invasion <500 µm, tumor diameter <3 cm, no lymphovascular invasion, and negative resection margin are included in pathological curative criteria after endoscopic resection (ER). However, there are a few reports presenting local or metastatic recurrence after ER for the lesions described above. A 72-year-old man was diagnosed with early gastric cancer and underwent endoscopic submucosal dissection (ESD). Pathological diagnosis was well-differentiated tubular adenocarcinoma, 8 × 6 mm, T1b1(SM1; 428 µm below the muscularis mucosae), negative lymphovascular invasion, and negative resection margin, which was included in curative criteria. Eighteen months after ESD, the laboratory studies indicated an increase in carcinoembryonic antigen of 17.6 ng/mL (normal range <5 ng/mL). While endoscopy showed no local recurrence finding, contrast-enhanced computed tomography (CT) showed a metastatic liver tumor in S4. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography/CT revealed metastatic liver tumors in S4, S5, and S8. The liver biopsy specimen showed tubular adenocarcinoma and the findings of immunochemical staining were similar to that of the specimen of prior ESD. Thus, he was diagnosed with multiple liver metastatic recurrences after curative ER. Currently, it has been 3 years and 5 months since ESD and 1 year and 11 months since liver metastatic recurrence, and the patient has survived receiving 5th-line systemic chemotherapy. Here, we report a rare case of liver metastatic recurrence 18 months after curative ESD for early gastric cancer.

Clinical Significance of Lymphatic Involvement in Intramucosal (pT1a) Gastric Cancer Resected by Endoscopic Submucosal Dissection

BACKGROUND AND AIM

Lymphatic involvement is sometimes detected during routine examination of intramucosal (pT1a) gastric cancer resected endoscopically. However, its clinical significance and association with the risk of metastasis remain unknown.

METHODS

This was a retrospective cohort study of 6797 consecutive patients with pT1a gastric cancers treated by endoscopic submucosal dissection (ESD) at three institutions in Japan from January 2005 to August 2023. Patients with 49 uncommon-type gastric cancer types were excluded. The risk of metastasis for pT1a cancers with lymphatic involvement was quantified by comparing lymph node metastasis and/or metastatic recurrence in patient groups who underwent additional surgery post-ESD or did not undergo surgery but were followed up for > 3 years.

RESULTS

Among the 6748 pT1a cancers treated by ESD, 41 lesions (0.6%) had histologically confirmed lymphatic involvement. Among the 41 patients, 1 was excluded from the analysis of metastasis risk because the follow-up period after ESD without additional surgery was ≤ 3 years. Metastasis was identified in 1 of 40 patients analyzed (2.5%; 95% confidence interval [CI] 0.4%-12.9%), and was not detected in any of the 25 patients with pure differentiated-type lesions (0.0%; 95% CI 0.0%-13.7%).

CONCLUSIONS

The low prevalence of metastasis after ESD for pT1a gastric cancer with lymphatic involvement, particularly in patients with pure differentiated-type lesions, suggests a low risk of metastatic recurrence.

Prognostic Implication of Lymphovascular Invasion in Early Gastric Cancer Meeting Endoscopic Submucosal Dissection Criteria: Insights from Radical Surgery Outcomes

BACKGROUND

The management of early gastric cancer (EGC) has witnessed a rise in the utilization of endoscopic submucosal dissection (ESD) as a treatment modality, although prognostic markers are needed to guide management strategies. This study investigates the prognostic implications of lymphovascular invasion (LVI) in ESD-eligible EGC patients, specifically its implications for subsequent radical surgery.

MATERIAL AND METHODS

A retrospective, multicenter study from two primary hospitals analyzed clinicopathological data from 1369 EGC patients eligible for ESD, who underwent gastrectomy at Shanghai Cancer Center and Huashan Hospital between 2009 and 2018. We evaluated the relationship between LVI and lymph node metastasis (LNM), as well as the influence of LVI on recurrence-free survival (RFS) and overall survival (OS).

RESULTS

We found a strong association between LVI and LNM (p < 0.001). Advanced machine learning approaches, including Random Forest, Gradient Boosting Machine, and eXtreme Gradient Boosting, confirmed the pivotal role of LVI in forecasting LNM from both centers. Multivariate analysis identified LVI as an independent negative prognostic factor for both RFS and OS, with hazard ratios of 4.5 (95% CI: 2.4-8.5, p < 0.001) and 4.4 (95% CI: 2.1-8.9, p < 0.001), respectively.

CONCLUSIONS

LVI is crucial for risk stratification in ESD-eligible EGC patients, underscoring the necessity for radical gastrectomy. Future research should explore the potential incorporation of LVI status into existing TNM staging systems and novel therapeutic strategies.

Ensemble Deep Learning Model to Predict Lymphovascular Invasion in Gastric Cancer

Lymphovascular invasion (LVI) is one of the most important prognostic factors in gastric cancer as it indicates a higher likelihood of lymph node metastasis and poorer overall outcome for the patient. Despite its importance, the detection of LVI(+) in histopathology specimens of gastric cancer can be a challenging task for pathologists as invasion can be subtle and difficult to discern. Herein, we propose a deep learning-based LVI(+) detection method using H&E-stained whole-slide images. The ConViT model showed the best performance in terms of both AUROC and AURPC among the classification models (AUROC: 0.9796; AUPRC: 0.9648). The AUROC and AUPRC of YOLOX computed based on the augmented patch-level confidence score were slightly lower (AUROC: -0.0094; AUPRC: -0.0225) than those of the ConViT classification model. With weighted averaging of the patch-level confidence scores, the ensemble model exhibited the best AUROC, AUPRC, and F1 scores of 0.9880, 0.9769, and 0.9280, respectively. The proposed model is expected to contribute to precision medicine by potentially saving examination-related time and labor and reducing disagreements among pathologists.

Reevaluation of lymphovascular invasion in gastric cancer using endothelial markers D2-40 and EVG: Enhanced detection, better predictor of lymph node metastasis and biological aggressiveness

BACKGROUND AND OBJECTIVES

The diagnosis of lymphovascular invasion (LVI) is often inaccurate with routine histology. This study aimed to evaluate the use of immunohistochemistry (IHC) in detecting LVI and reevaluate the clinical implications of LVI in gastric cancer.

METHODS

This prospective unrandomized cohort study analyzed the rates of LVI positivity and its relevance with other clinicopathologic features.

RESULTS

Between November 2017 and April 2018, 558 patients undergoing curative gastrectomy were enrolled and assigned to the IHC group (n = 285) and hematoxylin-eosin group (n = 273). The use of IHC increased the rates of LVI positivity (60.8% vs. 43.3%, p < .001) and decreased the rates of undetermined LVI subtype (7.7% vs. 27.1%, p < .001). The LVI-negative patients identified by IHC had fewer lymph node metastases (16.8% vs. 34.6%, p = .002) and earlier pathological stage (p = .004) than those identified by routine histology. The LVI-positive patients identified by IHC had a higher percentage of perineural invasion (p = .019).

CONCLUSIONS

The use of endothelial markers significantly enhanced the detection of LVI. The LVI detected by IHC could be a better predictor of lymph node metastasis and biological aggressiveness in gastric cancer.

Evaluation of Submucosal or Lymphovascular Invasion Detection Rates in Early Gastric Cancer Based on Pathology Section Interval

PURPOSE

The guidelines for pathological evaluation of early gastric cancer (EGC) recommend wider section intervals for surgical specimens (5-7 mm) than those for endoscopically resected specimens (2-3 mm). Studies in surgically resected EGC specimens showed not negligible lymph node metastasis risks in EGCs meeting the expanded criteria for endoscopic submucosal dissection (ESD).

MATERIALS AND METHODS

This retrospective study included 401 EGC lesions with an endoscopic size of ≤ 30 mm detected in 386 patients. Pathological specimens obtained by ESD or surgery were cut into 2-mm section intervals for reference. Submucosal or lymphovascular invasion (LVI) was evaluated arbitrarily in 4- or 6-mm section intervals. McNemar's tests compared the differences between submucosal and LVI.

RESULTS

Submucosal invasion was detected in 29.2% (117/401) and LVI in 9.5% (38/401) at 2-mm interval. The submucosal invasion detection rates in 4-mm intervals decreased to 88.0% or 90.6% (both P<0.001), while the LVI detection rates decreased to 86.8% or 57.9% (P=0.025 and P<0.001, respectively). In 6-mm intervals, the submucosal and LVI detection rates decreased further to 72.7-80.3% (P<0.001 for all three sets) and 55.3-63.2% (P<0.001 for all three sets), respectively. Among 150 out-of-indication cases at 2-mm interval, 4-10 (2.7%-6.7%) at 4-mm intervals, and 10-17 (6.7%-11.3%) at 6-mm intervals were misclassified as lesions meeting the curative resection criteria due to the underestimation of submucosal or LVI.

CONCLUSIONS

After ESD, the 2-mm wide section interval was suitable for the pathological evaluation of focal submucosal or LVI. Thus, if an EGC lesion meets the expanded criteria for the ESD specimen pathological evaluation, it could be safely followed up.

Lymphovascular invasion in early gastric cancer: impact of ancillary D2-40 and elastin staining on interobserver agreement

AIMS

Lymphatic invasion (LI) and venous invasion (VI) are the strongest risk factors for lymph node metastasis in patients with early gastric cancer, and may predict their prognosis. We aimed to investigate interobserver agreement among pathologists before and after adding ancillary staining for diagnosing LI and VI in this setting.

METHODS AND RESULTS

This retrospective study included 100 specimens of submucosal invasive gastric cancer from 100 patients treated using endoscopic resection. Three pathologists (expert, intermediate and trainee experience levels) independently evaluated individual LI and VI status using haematoxylin and eosin (H&E)-stained slides, and re-evaluated their decisions by reviewing corresponding D2-40-stained and elastin-stained slides. Interobserver agreement was assessed using κ statistics. With the ancillary D2-40 staining, there was an improved agreement for LI diagnoses between the expert and intermediate pathologist (H&E κ = 0.78, D2-40 κ = 0.85) and between the expert and trainee pathologist (H&E κ = 0.37, D2-40 κ = 0.56). With the ancillary elastin staining, there was an improved agreement for VI diagnoses between the expert and intermediate pathologists (H&E κ = 0.25, elastin κ = 0.63) and between the expert and trainee pathologists (H&E κ = 0.29, elastin κ = 0.45).

CONCLUSIONS

With both the ancillary D2-40 and elastin staining there was an improved interobserver agreement for LI and VI diagnoses, regardless of the pathologist's experience. This ancillary staining may be useful in improving the accuracy of LI and VI diagnoses, helping to improve the risk stratification of early gastric cancer patients.

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.

Risk Factors Associated with Lymph Node Metastasis for Early Gastric Cancer Patients Who Underwent Non-curative Endoscopic Resection: a Systematic Review and Meta-analysis

BACKGROUND

Recently, increased evidence indicated that additional surgery should be performed in highly selected patients with non-curative endoscopic resection. In this study, we performed a systematic review and meta-analysis to evaluate the risk factors associated with lymph node metastasis for the patients with non-curative endoscopic resection of early gastric cancer.

METHODS

The related studies were identified by searching PubMed and Embase databases. According to the status of lymph node metastasis, all patients were classified into node-negative group and node-positive group. The relevant clinicopathologic factors were extracted, and the pooled odds ratio (OR) and 95% confidence interval (CIs) were assessed using a fixed effects model or random effects model.

RESULTS

A total of nine relevant studies involving 1720 early gastric cancer patients who underwent additional surgery following the non-curative endoscopic resection were included in this meta-analysis. The results indicated that deeper submucosal invasion (SM2) (OR 3.44, 95% CI 1.94-6.10, P < 0.001; I² = 0%), positive vertical margin (OR 2.35, 95% CI 1.57-3.53, P < 0.001; I² = 0%), lymphatic invasion (OR 11.06, 95% CI 5.47-22.36, P < 0.001; I² = 0%), and vascular invasion (OR 2.79, 95% CI 1.68-4.64, P < 0.001; I² = 0%) were significantly associated with lymph node metastasis for these patients. However, horizontal margin, tumor size, differentiation type, and ulceration were not identified as risk factors associated with lymph node metastasis.

CONCLUSION

Lymphatic invasion, vascular invasion, deeper submucosal invasion (SM2), and positive vertical margin should be strongly considered in selecting the candidates for additional surgery treatment.

Exclusive Cerebellar and Leptomeningeal Metastases from Early Gastric Cancer 14 Months after Proximal Gastrectomy: An Autopsy Case Report

We report a rare autopsy case in which the patient received gastrectomy after an endoscopic diagnosis of early gastric cancer, and had deteriorated due to exclusive metastatic cerebellar tumors identified 14 months after surgery. A 65-year-old male was diagnosed as having a 0-IIc-type early gastric cancer on the posterior wall of the upper stomach by gastrointestinal endoscopy in search of a cause of epigastralgia, and thus received proximal gastrectomy and pyloroplasty. Although the tumor was in the early stages and limited within the mucosal layer, adjuvant chemotherapy was started by using S-1 80 mg daily due to evidence of metastasis into lymph node #3 at the lesser curvature. Evidence of both recurrence and metastases was not detected by CT scans of the chest, abdomen, and pelvis, and the chemotherapy was completed 12 months after surgery. However, the patient was admitted to hospital 14 months postoperatively due to dizziness and gait disturbance. Cranial MRI (Magnetic Resonance Imaging) revealed multiple tumors in the bilateral cerebellar hemispheres with additional leptomeningeal involvement. The patient died 2 weeks after admission. An autopsy revealed metastatic cerebellar tumors and leptomeningeal lesions from the early gastric cancer, and obstructive hydrocephalus due to metastatic cerebellar tumors. To our knowledge, this case is the first report of metastasis exclusive to the cerebellum and leptomeninges from early gastric cancer limited to the mucosal layer.

Clinical outcomes of early gastric cancer patients after noncurative endoscopic submucosal dissection in a large consecutive patient series

BACKGROUND

Clinical outcomes of early gastric cancer (EGC) patients after noncurative endoscopic submucosal dissection (ESD) have not been fully elucidated; we therefore aimed to clarify these outcomes.

METHODS

A total of 3058 consecutive patients with 3474 clinically diagnosed EGCs at initial onset underwent ESD with curative intent at our hospital between 1999 and 2010. We retrospectively assessed the following clinical outcomes of noncurative gastric ESD patients with a possible risk of lymph node (LN) metastasis by dividing patients into two groups with different treatment strategies (additional gastrectomy and simple follow-up): presence of LN metastasis at the time of gastrectomy, incidence of LN and distant metastases during the follow-up period, clinicopathological factors associated with metastasis, and 5-year disease-specific survival (DSS).

RESULTS

After exclusion of 75 noncurative ESD patients with only a positive horizontal margin, 569 noncurative ESD patients with a possible risk of LN metastasis were identified. Among the 356 patients undergoing additional gastrectomy, LN metastasis was identified in 18 patients. A positive vertical margin with submucosal invasion (odds ratio 3.6) and lymphovascular invasion (odds ratio 3.5) were significantly associated with LN metastasis. The 5-year DSS rate was 98.8 %. Among the 212 patients who underwent simple follow-up, LN and/or distant metastases were found in eight patients. In this group, lymphovascular invasion (hazard ratio 6.6) was significantly associated with metastasis with a 5-year DSS rate of 96.8 %.

CONCLUSIONS

Additional gastrectomy should be performed particularly in noncurative gastric ESD patients with lymphovascular invasion or a positive vertical margin with submucosal invasion.

Clinical outcomes of endoscopic submucosa dissection for high-grade dysplasia from endoscopic forceps biopsy

BACKGROUND AND STUDY AIMS

Although the Vienna Classification recommends endoscopic resection for gastric high-grade dysplasia (HGD), many resected lesions are diagnosed as gastric cancer after endoscopic resection. This study aims to evaluate the clinical outcomes of gastric HGD identified by endoscopic forceps biopsy (EFB) after endoscopic submucosal dissection (ESD) and factors associated with discrepant results.

PATIENTS AND METHODS

From December 2008 to July 2015, a total of 427 lesions diagnosed as initial HGD by EFB were enrolled. The rate of early gastric cancer (EGC) and factors predicting diagnosis upgrade were analyzed retrospectively.

RESULTS

Tumors ranged between 2 and 65 mm in size (median 12.59). En bloc and complete resection rates were 97.4 and 95.3%, respectively. The diagnostic discrepancy rate was 76.3%. Upgrade and downgrade rates of pathological diagnoses were 66.5 and 9.8%, respectively. Central depression (OR 4.151), nodular surface (OR 5.582), surface redness (OR 2.926), lesion location (upper third of the stomach) (OR 3.894), and tumor size ≥10 mm (OR 2.287) were significantly associated with EGC. Nodular surface (OR 2.746), submucosal fibrosis (OR 3.958), lesion location (upper third of the stomach) (OR 6.652), and tumor size ≥10 mm (OR 4.935) significantly predicted invasive submucosal cancer.

CONCLUSIONS

Central depression, nodular surface, surface redness, lesion location, large tumor size, and submucosal fibrosis were associated with EGC or submucosal cancer. Caution must be used in treating lesions with these features with ESD.

A case of undifferentiated-type mucosal gastric cancer with multiple lymph node metastases fulfilling the curative criteria for endoscopic resection according to routine pathological analysis

BACKGROUND

Endoscopic resection is accepted as the standard treatment for early mucosal gastric cancer, and its indications have recently been expanded while its long-term outcomes are still unclear. Herein, we present a didactic case of undifferentiated-type mucosal gastric cancer fulfilling the expanded indication and curative criteria for endoscopic submucosal dissection (ESD), having synchronous multiple lymph node metastases.

CASE PRESENTATION

A 40-year-old woman was found to have a Helicobacter pylori infection at a standard health check with no abdominal symptoms. She received an upper gastrointestinal endoscopy and found to have an undifferentiated-type mucosal gastric cancer with the size of 15 mm in diameter without ulceration, which fulfilled the expanded indication for ESD. According to patient's preference, we performed laparoscopy-assisted distal gastrectomy with D1+ lymph node dissection, and routine pathological analysis revealed a predominantly signet ring cell carcinoma limited to the mucosa without ulceration or any vessel involvement; on the other hand, 15 lymph node metastases were detected. Then, we added deep sectioning of the whole tumoral area at a thickness of 20 μm and immunohistochemical analyses. As the result, an isolated lymphatic capillary involvement of the extremely superficial submucosa was identified in a single histological section, and pathological diagnosis was corrected to ly1. She received postoperative adjuvant chemotherapy with an S-1 oral agent and had no recurrence under strict surveillance for 1 year postoperatively.

CONCLUSIONS

When we perform ESD for undifferentiated-type gastric cancer, deep sectioning of the whole tumoral area into thin slices and immunohistochemical staining using D2-40 should be practically considered.

Risk Factors of Submucosal or Lymphovascular Invasion in Early Gastric Cancer <2 cm

Although prediction of submucosal (SM) or lymphovascular (LV) invasion is important before endoscopic resection of early gastric cancer (EGC), it can only be confirmed following endoscopic resection. After endoscopic resection, patients with SM or LV invasion may require additional surgery due to high risk of lymph node metastasis.We conducted a retrospective study to identify risk factors for SM or LV invasion before endoscopic submucosal dissection (ESD) of EGC. Between January 2009 and May 2014, we reviewed the data of patients with EGC who met the absolute indications for ESD before procedure: well and/or moderately differentiated adenocarcinomas, tumors ≤ 2 cm in length and absence of ulcer or ulcer-scar.During study period, a total of 308 lesions in 297 patients were included. SM or LV invasion was detected in 34 lesions (34/308, 11.0%). Multivariate analysis revealed that a moderately differentiated adenocarcinoma (odds ratio [OR] 4.157, P = 0.000) and location of the stomach (the upper and middle third; OR 3.100, P = 0.008) were significant risk factors for SM or LV invasion.Careful consideration of endoscopic treatment decision might be necessary for the patients with a moderately differentiated adenocarcinoma and EGC located on the upper and middle third of the stomach.

Prognostic risk factors of early gastric cancer-a western experience

PURPOSE

Lymph node metastasis (LNM) is the leading cause of tumor recurrence in early gastric cancer (EGC). Since endoscopic resection (ER) can be performed in EGC with curative intention when no LNM are present, this study wants to determine the risk factors for LNM in EGC.

METHODS

One hundred twenty-four patients who have had an operative resection because of EGC were analyzed. Histopathological workup included tumor infiltration depth, lymphatic and vascular infiltration, lymph node infiltration, tumor differentiation, and the classification of Ming. A complete follow-up was achieved.

RESULTS

There was no LNM among tumors meeting the standard or extended criteria for an ER. Lymphatic infiltration (p < 0.001) and infiltration of the submucosal layers (p = 0.018) proved to be the strongest risk factors for LNM. Tumors with a deeper infiltration depth (p = 0.015) and a lower grade of differentiation (p = 0.029) presented with a higher grade of lymphatic infiltration. Tumors located in the body of the stomach (p = 0.003) and tumors with infiltrative growth according to Ming (p = 0.021) had a significantly higher risk for lymphatic infiltration. The 5-year overall survival was 84 % in nodal negative patients and 42 % in patients with LNM (p = 0.002).

CONCLUSIONS

ER within the extended criteria with a meticulous histological workup should be performed in EGC to determine whether risk factors for LNM are present. If lymphatic infiltration is observed, surgery with lymphadenectomy is recommended. Tumors exceeding the extended criteria should undergo primary surgery with adequate lymphadenectomy.

Incidence of lymphatic involvement in differentiated-type intramucosal gastric cancers as examined by endoscopic resection

BACKGROUND

Lymphatic involvement may sometimes be detected in differentiated-type intramucosal cancer resected endoscopically during routine examination, but its incidence and clinical significance remain unknown.

METHODS

We examined 300 endoscopically resected lesions obtained from 238 patients diagnosed with differentiated-type intramucosal gastric cancer. All sections were subjected to D2-40 monoclonal-based immunohistochemistry.

RESULTS

The incidence of lymphatic involvement in differentiated-type intramucosal cancer was 2.0% (6/300). An incidence of 1.8% (5/279) was determined in lesions that were ≤ 3 cm in size and 2.2% (6/276) in those without an ulcer or ulcer scar. Of the six lesions presenting lymphatic involvement, three were determined to be histologically mixed with a predominance of differentiated type, while the other three lesions were pure differentiated type.

CONCLUSIONS

We determined that the incidence of lymphatic involvement in differentiated-type intramucosal cancer was 2.0%. To clarify the clinical significance of such lymphatic involvement, it is necessary to detect it with this incidence in mind and to gather and follow up the clinical courses of such cases.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients' desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Clinical significance of a papillary adenocarcinoma component in early gastric cancer: a single-center retrospective analysis of 628 surgically resected early gastric cancers

BACKGROUND

We recently reported that the presence of a papillary adenocarcinoma (pap) component was an independent risk factor for lymphatic involvement in endoscopically resected early gastric cancer (EGC). This study aimed to investigate the potential association between the presence of a pap component in EGC and lymph node metastasis (LNM).

METHODS

In order to evaluate the association between LNM and clinicopathological features, including a pap component, we reviewed 628 surgically resected EGCs at our institution between 2009 and 2012. Clinicopathological features included age, gender, tumor location, macroscopic type, tumor size, histological type, depth, ulcerative findings, and lymphatic and venous involvement. In addition, the association between clinicopathological features and lymphatic involvement was also evaluated.

RESULTS

LNM was observed in 52 cases (8.3%). Univariate analyses revealed a significant correlation between a pap component and LNM as well as tumor size, depth, macroscopic type, a poorly differentiated adenocarcinoma component, and lymphatic and venous involvement. The percentage of positive LNM among the EGC cases with a pap component was significantly higher than in those without the component (18.2 vs. 7.3%, P = 0.010). Via multivariate analyses lymphatic involvement was identified as the strongest risk factor for LNM [odds ratio (OR) 14.1] and a pap component was revealed as an independent risk factor for lymphatic involvement (OR 3.1).

CONCLUSION

Our study revealed that EGC cases with a pap component were at higher risk of lymphatic involvement and showed a higher percentage of positive LNM. More attention should be paid to a pap component in EGC.

Potential prognostic, diagnostic and therapeutic markers for human gastric cancer

The high incidence of gastric cancer (GC) and its consequent mortality rate severely threaten human health. GC is frequently not diagnosed until a relatively advanced stage. Surgery is the only potentially curative treatment. Thus, early screening and diagnosis are critical for improving prognoses in patients with GC. Gastroscopy with biopsy is an appropriate method capable of aiding the diagnosis of specific early GC tumor types; however, the stress caused by this method together with it being excessively expensive makes it difficult to use it as a routine method for screening for GC on a population basis. The currently used tumor marker assays for detecting GC are simple and rapid, but their use is limited by their low sensitivity and specificity. In recent years, several markers have been identified and tested for their clinical relevance in the management of GC. Here, we review the serum-based tumor markers for GC and their clinical significance, focusing on discoveries from microarray/proteomics research. We also review tissue-based GC tumor markers and their clinical application, focusing on discoveries from immunohistochemical research. This review provides a brief description of various tumor markers for the purposes of diagnosis, prognosis and therapeutics, and we include markers already in clinical practice and various forthcoming biomarkers.

Early gastric cancer with mixed histology predominantly of differentiated type is a distinct subtype with different therapeutic outcomes of endoscopic resection

BACKGROUND

Safety of endoscopic resection (ER) for early gastric cancers (EGC) with mixed histology predominantly of differentiated type has not been securely established, since those lesions tend to exhibit lymph node metastasis, compared to pure differentiated type. The purpose of this study was to evaluate clinicopathologic characteristics, therapeutic outcomes, and risk for lymph node metastasis in predominantly differentiated mixed EGC treated by ER.

METHODS

A total of 1,016 patients with 1,039 EGCs underwent ER between January 2007 and June 2013. Enrolled lesions were divided into groups of either pure differentiated (n = 1,011) or predominantly differentiated mixed (n = 28), according to the presence of mixed histology predominantly of differentiated type in ER specimen.

RESULTS

Mixed histology predominantly of differentiated type was diagnosed in 2.7% of lesions. Larger size, mid-third location, and moderately differentiated histology on forceps biopsy were independent risk factors for the predominantly differentiated mixed histologic type of EGC in multivariate analysis. En bloc resection rate tended to be lower, and complete and curative resection rates were significantly lower in the predominantly differentiated mixed group. The rate of lymph node metastasis in the lesions with additional operation tended to be higher, in this mixed histology group.

CONCLUSIONS

Larger size, mid-third location, and moderately differentiated histology on forceps biopsy carry the significant risk for mixed histology predominantly of differentiated type. EGC with predominantly differentiated mixed histologic type affects therapeutic outcomes and consequent clinical course accompanied by possibly higher risk for lymph node metastasis. The safety of ER for predominantly differentiated mixed EGC should be validated by further prospective investigation.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients' desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Assessment of vascular invasion in gastric cancer: A comparative study

AIM: To evaluate and compare detection of lymphatic and blood vessel invasion (LVI and BVI) by hematoxylin-eosin (HE) and immunohistochemistry (IHC) in gastric cancer specimens, and to correlate with lymph node status.

METHODS: IHC using D2-40 (a lymphatic endothelial marker) and CD34 (a pan-endothelial marker) was performed to study LVI and BVI in surgical specimens from a consecutive series of 95 primary gastric cancer cases. The results of the IHC study were compared with the detection by HE using McNemar test and kappa index. The morphologic features of the tumors and the presence of LVI and BVI were related to the presence of lymph node metastasis. A χ² test was performed to obtain associations between LVI and BVI and other prognostic factors for gastric cancer.

RESULTS: The detection rate of LVI was considerably higher than that of BVI. The IHC study identified eight false-positive cases and 13 false-negative cases for LVI, and 24 false-positive cases and 10 false-negative cases for BVI. The average Kappa value determined was moderate for LVI (κ = 0.50) and low for BVI (κ = 0.20). Both LVI and BVI were statistically associated with the presence of lymph node metastasis (HE: P = 0.001, P = 0.013, and IHC: P = 0.001, P = 0.019). The morphologic features associated with LVI were location of the tumor in the distal third of the stomach (P = 0.039), Borrmann’s macroscopic type (P = 0.001), organ invasion (P = 0.03) and the depth of tumor invasion (P = 0.001). The presence of BVI was related only to the depth of tumor invasion (P = 0.003).

CONCLUSION: The immunohistochemical identification of lymphatic and blood vessels is useful for increasing the accuracy of the diagnosis of vessel invasion and for predicting lymph node metastasis.

Risk factors for lymphatic and venous involvement in endoscopically resected gastric cancer

BACKGROUND

Lymphatic and venous involvement is a critical factor in the curability assessment of endoscopically resected gastric cancers; however, the risk factors for lymphatic and venous involvement in endoscopically resected gastric cancers remain unknown.

METHODS

To identify risk factors for lymphatic and venous involvement in endoscopically resected gastric cancers, we retrospectively reviewed a consecutive series of 1229 endoscopically resected gastric cancers in 1083 patients treated between January 2009 and December 2011.

RESULTS

Lymphatic and venous involvement was detected in 57 (4.6%) and 32 (2.6%) lesions, respectively. A multivariate analysis identified a larger tumor size, deeper invasion (submucosal invasion or deeper), and the presence of a papillary or an undifferentiated-type adenocarcinoma component as independent risk factors for lymphatic involvement. As for venous involvement, deeper invasion (≥500 μm submucosal invasion), a macroscopically elevated type, and the presence of an undifferentiated-type adenocarcinoma component were identified as independent risk factors.

CONCLUSIONS

The present study identified the independent risk factors for lymphatic and venous involvement in endoscopically resected gastric cancers. The recognition of these risk factors would help in the selection of lesions that may require a particularly careful histological evaluation.

A case of mucosal cancer of the stomach treated by endoscopic submucosal dissection after which nodal metastasis became evident

An 82-year-old male was referred to our institution for evaluation and treatment of a protruding lesion in the stomach. Esophagogastroduodenoscopy (EGD) showed a small protruding lesion and a large superficial elevated lesion on the lesser curvature of the stomach (macroscopic type: 0-I and 0-IIa, resp.). CT and endoscopic ultrasonography (EUS) visualized a small round lymph node (LN) 11 mm in size near the lesser curvature, although submucosal invasion was not evident. These two lesions were resected en bloc by endoscopic submucosal dissection (ESD). Pathological examination of the resected specimen showed moderately differentiated tubular adenocarcinoma (tub2) and well-differentiated tubular adenocarcinoma (tub1), respectively, which were limited to the mucosal layer. Because lymphatic-vascular involvement was not detected by hematoxylin and eosin (HE) staining, additional gastrectomy was not performed. Two months after ESD, follow-up EUS and CT showed an enlarged LN. EUS-guided fine needle aspiration (EUS-FNA) for the LN revealed metastasis. Therefore, total gastrectomy with LN dissection was performed. His postoperative course was uneventful. After discharge, he has been followed up at the outpatient department without any sign of recurrence for 5 years. Histological reexamination of the ESD specimen using immunohistochemistry showed lymphatic invasion of cancer cells in the lamina propria of the 0-I lesion 13 mm in size.

Pathological evaluation of gastrointestinal endoscopic submucosal dissection materials based on Japanese guidelines

Endoscopic surgery first started as snare polypectomy and then progressed to endoscopic mucosal resection (EMR). In order to resect a lesion that is more than 2 cm, endoscopic submucosal dissection (ESD) was developed. ESD therapy has now been established and is being used for early stage neoplastic lesions in the stomach, colon, esophagus, larynx and pharynx. In ESD specimens, we deal with relatively small lesions; therefore, more meticulous and precise pathological diagnosis is required compared to that in surgically resected specimens. In addition, we should be expert in the eligibility criteria of the different organs for ESD therapy. Here, we explain the biopsy diagnosis, including the Japanese group classification as well as the Vienna classification, handling the specimen, including fixation, photography, cutting and paraffin embedding, histological type, depth, vascular invasion and evaluation of the surgical margins, based on the latest Japanese guidelines. Japanese histopathology diagnostic criteria for the stomach, colon and esophagus are also described. We also demonstrate some examples of those mentioned above.

Does immunohistochemical staining have a clinical impact in early gastric cancer conducted endoscopic submucosal dissection?

AIM: To evaluate clinicopathologic parameters and the clinical significance related lymphovascular invasion (LVI) by immunohistochemical staining (IHCS) in endoscopic submucosal dissection (ESD).

METHODS: Between May 2005 and May 2010, a total of 348 lesions from 321 patients (mean age 63 ± 10 years, men 74.6%) with early gastric cancer (EGC) who met indication criteria after ESD were analyzed retrospectively. The 348 lesions were divided into the absolute (n = 100, differentiated mucosal cancer without ulcer ≤ 20 mm) and expanded (n = 248) indication groups after ESD. The 248 lesions were divided into four subgroups according to the expanded ESD indication. The presence of LVI was determined by factor VIII-related antigen and D2-40 assessment. We compared LVI IHCS-negative group with LVI IHCS-positive in each group.

RESULTS: LVI by hematoxylin-eosin staining (HES) and IHCS were all negative in the absolute group, while was observed in only the expanded groups. The positive rate of LVI by IHCS was higher than that of LVI by HES (n = 1, 0.4% vs n = 11, 4.4%, P = 0.044). LVI IHCS-positivity was observed when the cancer invaded to the mucosa 3 (M3) or submucosa 1 (SM1) levels, with a predominance of 63.6% in the subgroup that included only SM1 cancer (P < 0.01). In a univariate analysis, M3 or SM1 invasion by the tumor was significantly associated with a higher rate of LVI by IHCS, but no factor was significant in a multivariate analysis. There were no cases of tumor recurrence or metastasis during the median 26 mo follow-up.

CONCLUSION: EGCs of the absolute group are immunohistochemically stable. The presence of LVI may be carefully examined by IHCS in an ESD expanded indication group with an invasion depth of M3 or greater.

Lymphatic invasion in small differentiated-type mucosal gastric cancer

Endoscopic resection for early gastric cancer is indicated for patients who are at negligible risk of lymph node metastasis. A 71-year-old female underwent endoscopic resection for a 15-mm differentiated-type mucosal gastric tumor, as recommended in the Japanese treatment guidelines. A histological examination revealed lymphatic invasion. Therefore, we performed laparoscopy-assisted distal gastrectomy and D1+ lymph node dissection. A histological examination detected no.3 lymph node metastasis, but no residual cancer cells were observed at the site of the endoscopic resection. This case is rare as lymphatic invasion and lymph node metastasis are highly unusual in small differentiated-type mucosal gastric cancer. Having experienced this case, we consider that en-bloc endoscopic resection of such lesions is extremely important, as it allows precise histological examinations to be performed, which can determine the necessity of additional treatment.

A case of small undifferentiated intramucosal gastric cancer with lymph node metastasis

Early gastric cancer (EGC) has a favorable prognosis after surgical gastrectomy. For intramucosal EGC with little risk of lymph node metastasis, endoscopic mucosal resection (EMR) is an accepted treatment method. Herein we document a noteworthy case of small undifferentiated gastric cancer with nodal metastasis. A 60-year-old Japanese woman underwent gastrectomy with D2 lymph node dissection for the treatment of EGC in the lower gastric body. Histological examination revealed that signet-ring cell carcinoma was located in approximately one-third of the superficial portion of the mucosal layer, with a tumor size of 13 mm. No lymphatic invasion, venous invasion, or fibrosis was observed in the submucosal layer. This case had nodal metastasis and was finally diagnosed as stage IB (T1N1M0) according to the Japanese Classification of Gastric Carcinoma (JCGC). The patient is alive without recurrence 6 years after treatment.

Lymph node metastasis from undifferentiated-type mucosal gastric cancer satisfying the expanded criteria for endoscopic resection based on routine histological examination

A 58-year-old woman was found to have a 45-mm abdominal mass adjacent to the pancreas on screening ultrasonography, and subsequent esophagogastroduodenoscopy revealed a small gastric cancer (13 mm in diameter). We initially performed endoscopic submucosal dissection (ESD), and routine histological examination of the specimen sectioned at 2-mm intervals revealed a poorly differentiated adenocarcinoma and signet ring cell carcinoma confined to the mucosa without lymphatic-vascular capillary involvement or ulceration. These findings satisfied the expanded criteria for ESD we reported recently. We next performed laparoscopic excisional biopsy of the abdominal mass, and histological examination with immunohistochemical staining revealed a metastatic lymph node (LN) resulting from the gastric cancer. Distal gastrectomy with extended lymphadenectomy was then performed and histological examination indicated no residual cancer cells or any additional LN metastases. After the above-described clinical course, further analysis was conducted because of the highly unusual nature of this case; 60 additional deep-cut sections from the resected specimen were performed, with one section showing lymphatic involvement in the mucosa on hematoxylin and eosin staining. This case suggests practical limitations in determining lymphatic involvement through routine histological examination, which may not always be able to detect LN metastasis.

Study on lymph node metastasis correlated to lymphangiogenesis, lymphatic vessel invasion, and lymph node micrometastasis in gastric cancer

BACKGROUND

This study aimed to evaluate the clinical significance of lymphangiogenesis, lymph vessel invasion (LVI), and lymph node (LN) micrometastasis (LNMM) in patients with gastric cancer.

METHODS

The influences of the expression levels of LVI, lymph vessel density (LVD) by D2-40 immunohistochemical (IHC) staining (n=68), LNMM (including CK 20 and CK pan immunostainings, n=51) on the clinicopathologic profiles and the prognosis were analyzed.

RESULTS

The higher positive rate of LVI-IHC was related to deeper invasion (P=0.044), later TNM stage (P=0.003), and more extensive LN metastasis (LNM, P=0.000). The level of LVD was significantly associated with venous invasion (P=0.037), later TNM stage (P=0.020), positive LVI-HE (P=0.040), positive LVI-IHC status (P=0.001), and severer LNM (P=0.001). Better prognosis in LVI negative group than LVI positive group has been identified. The survival rate of the group with LVD≥15/field was significantly lower than that in the group with LVD≤14/field (P=0.032). Invasion depth, N stage, LNM, blood vessel invasion, or LVI was respectively an independent prognostic factor to 3-y survival rate. The incidence of patients with LNM and metastasized LNs increased respectively from 74.5% (38/51) by HE staining to 88.2% (45/51) by CK immunostaining and from 32.0% (253/791) to 41.5% (328/791) (P=0.001). The increment of LNMM was correlated to larger tumor diameter (P=0.001), deeper invasion (P=0.018), LNM (P=0.001) and later TNM stage (P=0.012), positive LVI (P=0.04). Meanwhile, the evaluation on LNMM revealed the migration of LN stage (N(0)→N(1) in seven patients, N(1)→N(2) in six patients, and N(2)→N(3) in one patient), and TNM stage (I(b)→II in four patients, II→III(a) in 4 patients, III(a)→III(b) in 3 patients, and III(b)→IV in one patient). Survival analysis demonstrated that better prognosis in patients without LNM and/or LNMM.

CONCLUSION

Our immunohistochemical analyses using antibodies of D2-40 and CK, including both CK 20 and CK pan, detected a higher incidence of LVIs and LNMs in gastric cancer specimens. This study shows close correlations among lymphangiogenesis related factors, such as LVI, LVD, and LNMM, and patients' prognosis after surgery. Therefore, immunohistochemical evaluations of these factors could be used for the accurate determination of tumor aggressiveness.

Increased intratumoral lymphatic vessel density correlates with lymph node metastasis in early gastric carcinoma

BACKGROUND

Prediction of lymph node metastasis in early gastric carcinoma (EGC) is important for management and follow-up of EGC patients. Increased lymphangiogenesis has been suggested to correlate with lymphatic invasion and lymph node metastasis in various tumors.

METHODS

Lymphatic vessel density (LVD) and microvessel density (MVD) of 141 EGCs were determined by double immunohistochemical staining for D2-40 and CD31. The mean values of three to five hotspots were calculated in intratumoral and peritumoral areas in digital images.

RESULTS

The mean value of intratumoral LVD in a lymph-node-positive EGC group was 28.24/field, which was significantly higher than in a lymph-node-negative EGC group (19.43/field, P = 0.005). Peritumoral LVD, intratumoral MVD, and peritumoral MVD did not correlate with lymph node metastasis in EGCs (P > 0.05). Intratumoral LVD did not show significant differences according to lymphatic invasion and differentiation, which were positive predictors for lymph node metastasis in EGC. Using multivariate logistic regression, intratumoral LVD was an independent factor, with the above two factors and depth of invasion, for the prediction of lymph node metastasis in EGC with a relative risk of 3.570 in high-intratumoral-LVD group compared with low-intratumoral-LVD group (P = 0.022).

CONCLUSION

Intratumoral LVD may be a useful, independent predictor for lymph node metastasis, especially in combination with previously established predictors in EGC.

Clinical significance of immunohistochemically-identified lymphatic and/or blood vessel tumor invasion in gastric cancer

BACKGROUND

Tumor invasion and lymph node metastasis are significant prognostic factors for gastric cancer, and lymphatic and vascular tumor invasion are also significant risk factors for gastric cancer recurrence. Recently, the immunohistochemical detection of lymphatic and blood vessel tumor invasion (LBVI) has been shown to have a higher sensitivity and specificity than hematoxylin-eosin staining methods.

MATERIALS AND METHODS

One hundred forty-nine gastric cancer patients who underwent curative resection at Korea University Hospital between November 2003 and December 2006 served as the study subjects. Lymphatic vessel invasion was evaluated by immunostaining with the new selective marker, D2-40, and blood vessel invasion was assessed with anti-CD31 antibody. Patients were divided according to the presence of LBVI, clinicopathologic factors were compared, and postoperative surgical outcomes were analyzed.

RESULTS

LBVI was present in 66 patients (44.3%). LBVI was significantly correlated with depth of tumor invasion (P < 0.001), lymph node stage (P < 0.001), and lymph node micrometastasis (P = 0.013). Cancer recurrence was more common in the LBVI group (P = 0.007), and peritoneal seeding was the most prevalent type of recurrence (P = 0.028). Univariate analysis showed tumor size, depth of tumor invasion, lymph node stage, and LBVI to have a significant impact on survival. Based on multivariate analysis, however, depth of tumor invasion and lymph node stage were correlated with survival.

CONCLUSION

Immunohistochemical demonstration of LBVI is an additional prognostic marker, and provides useful information for planning treatment strategies in gastric cancer patients.

Histopathological predictor for regional lymph node metastasis in gastric cancer

Regional lymph node metastasis in gastric cancer is a definitive indicator of the patient's prognosis. The goal of this study was to identify the predictors for lymph node metastasis among all the possible histopathological parameters, especially by conducting an objective discrimination of the lymphatic and blood vessels. A total of 210 resected primary gastric cancers with or without lymph node metastasis were evaluated based on the conventional histopathological parameters together with immunohistochemistry using antisera-recognizing lymphatic endothelial hyaluronan receptor-1 (LYVE-1), von Willebrand factor, and lymphangiogenesis promoter vascular endothelial growth factor-C (VEGF-C) antibodies. A multivariate regression analyses of the results indicated that only lymphatic invasion was a significant independent predictor of lymph node metastasis at any stage of cancer invasion. VEGF-C expression was partially related to lymph node metastasis in early gastric cancer. The identification of lymphatic invasion by LYVE-1 antibody is therefore useful to predict regional lymph node metastasis in gastric cancer.