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

Value of enhanced computed tomography in differentiating small mesenchymal tumours of the gastrointestinal from smooth muscle tumours

BACKGROUND

Computed tomography (CT) technology has been gradually used in the differentiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.

AIM

To explore the value of enhanced CT in the differentiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.

METHODS

Clinical data of patients with gastric mesenchymal or gastric smooth muscle tumours who were treated in our hospital from May 2018 to April 2023 were retrospectively analysed. Patients were divided into the gastric mesenchymal tumor group and the gastric smooth muscle tumor group respectively (n = 50 cases per group). Clinical data of 50 healthy volunteers who received physical examinations in our hospital during the same period were selected and included in the control group. Serum levels of carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), CA-125 and cytokeratin 19 fragment antigen 21-1 were compared among the three groups. The value of CEA and CA19-9 in the identification of gastric mesenchymal tumours was analysed using the receiver operating characteristic (ROC) curve. The Kappa statistic was used to analyse the consistency of the combined CEA and CA19-9 test in identifying gastric mesenchymal tumours.

RESULTS

CEA levels varied among the three groups in the following order: The gastric mesenchymal tumour group > the control group > the gastric smooth muscle tumour group. CA19-9 levels varied among the three groups in the following order: The gastric mesenchymal group > the gastric smooth muscle group > the control group, the difference was statistically significant (P < 0.05). ROC analysis showed that the area under the curve of CEA and CA19-9 was 0. 879 and 0. 782, respectively.

CONCLUSION

Enhanced CT has shown value in differentiating small mesenchymal tumors of the stomach and intestines from smooth muscle tumors.

The Clinicopathological Features of Mixed Carcinoma in 7,215 Patients with Gastric Cancer in a Tertiary Hospital in South Korea

Background/Aims

There are few reports regarding mixed carcinoma, defined as a mixture of glandular and poorly cohesive components, in patients with gastric cancer (GC). The aim of this study was to evaluate the proportion and characteristics of mixed carcinoma in GC patients.

Methods

A total of 7,215 patients diagnosed with GC at Seoul National University Bundang Hospital were enrolled from March 2011 to February 2020. GC was divided into four groups (well-moderately differentiated GC, poorly differentiated GC, poorly cohesive carcinoma, and mixed carcinoma). The proportion of each GC type and the clinicopathological features were analyzed and divided into early GC and advanced GC.

Results

The proportion of mixed carcinoma was 10.9% (n=787). In early GC, submucosal invasion was the most common in poorly differentiated (53.7%), and mixed carcinoma ranked second (41.1%). Mixed carcinoma showed the highest proportion of lymph node metastasis in early GC (23.0%) and advanced GC (78.3%). In advanced GC, the rate of distant metastasis was 3.6% and 3.9% in well-moderately differentiated GC and mixed carcinoma, respectively, lower than that in poorly differentiated GC (6.4%) and poorly cohesive carcinoma (5.7%), without statistical significance.

Conclusions

Mixed carcinoma was associated with lymph node metastasis compared to other histological GC subtypes. And it showed relatively common submucosal invasion in early GC, but the rates of venous invasion and distant metastasis were lower in advanced GC. Further research is needed to uncover the mechanism underlying these characteristics of mixed carcinoma (Trial registration number: NCT04973631).

Gastric Cancer: Correlation of Histologic Type with Commonly Used Prognostic Variables

Background: Gastric cancer is one of the most common cancers among Iranian men and women. Objectives: The aim here was to investigate different histopathologic types and features of this cancer in association with selected prognostic variables. Methods: A retrospective cross-sectional study was performed to reevaluate the pathologic samples of 100 cases of gastric cancer referred to Shohadaye Tajrish Hospital, Tehran, Iran from 2017 to 2022. Results: We evaluated 100 cases of gastric cancer in this study. They had a mean age of 62.4 ± 13.44 years old (range 28 - 84 years) and were mostly men (n = 66, 66 %). On histopathologic evaluation, tubular carcinoma was the most common type (n = 45, 45%). We found a statistically significant correlation between the histologic type and perineural invasion (P-value = 0.024), lymphovascular invasion (P-value < 0.001), tumoral involvement of surgical margin (P-value = 0.012 ), infiltration depth of the primary tumor (pT) (P-value = 0.049) , number of metastatic lymph nodes (pN) (P-value = < 0.001) , tumor location in the antrum (P-value=0.033) and body (P-value = 0.013) , and tumor size (P-value = 0.002 and P-value = 0.031 in small and large size groups respectively). Conclusions: According to the findings, histologic type of gastric cancer correlates with perineural invasion, lymphovascular invasion, tumoral involvement of the surgical margin, pT, pN, and tumor location and size.

Clinicopathological characteristics of early gastric cancer with different level of undifferentiated component and nomogram to predict lymph node metastasis

Background

Few studies showed that mixed type early gastric cancer (EGC) relates to higher risk of lymph node metastasis. We aimed to explore the clinicopathological feature of GC according to different proportions of undifferentiated components (PUC) and develop a nomogram to predict status of lymph node metastasis (LNM) in EGC lesions.

Methods

Clinicopathological data of the 4,375 patients who underwent surgically resection for gastric cancer in our center were retrospectively evaluated and finally 626 cases were included. We classified mixed type lesions into five groups (M1:0% < PUC ≤ 20%, M2:20%<PUC ≤ 40%, M3:40%<PUC ≤ 60%, M4:60%<PUC ≤ 80%, M5:80%<PUC < 100%). Lesions with 0% PUC were classified as pure differentiated group (PD) and lesions with 100% PUC were classified as pure undifferentiated group (PUD).

Results

Compared with PD, LNM rate was higher in group M4 and group M5 (p < 0.05 after Bonferroni correction). Differences of tumor size, presence of lymphovascular invasion (LVI), perineural invasion and invasion depth also exist between groups. No statistical difference of LNM rate was found in cases who met the absolute endoscopic submucosal dissection (ESD) indications for EGC patients. Multivariate analysis revealed that tumor size over 2 cm, submucosa invasion to SM2, presence of LVI and PUC level M4 significantly predicted LNM in EGC. With the AUC of 0.899(P < 0.05), the nomogram exhibited a good discrimination. Internal validation by Hosmer-Lemeshow test showed a good fitting effect in model (P > 0.05).

Conclusion

PUC level should be considered as one of the predicting risk factors of LNM in EGC. A nomogram that predicts the risk of LNM in EGC was developed.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

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.

Indications of Endoscopic Submucosal Dissection for Undifferentiated Early Gastric Cancer: Current Status and Future Perspectives for Further Expansion

BACKGROUND

Endoscopic submucosal dissection (ESD) is a widely accepted and minimally invasive treatment for early gastric cancer (EGC) without the risk of lymph node metastasis (LNM). However, undifferentiated-type EGC (UD-EGC) is considered to have a relatively high risk of LNM. Recently, the Japan Clinical Oncology Group conducted a nonrandomized confirmatory trial (JCOG1009/1010) to evaluate the efficacy and safety of ESD for UD-EGC. Herein, we review the results of JCOG1009/1010 and the possibility of further expanding the indications for ESD.

SUMMARY

JCOG1009/1010 showed excellent technical results and 5-year overall survival in patients with UD-EGC. Based on the results, ESD for UD-EGC (cT1a) of ≤2 cm without ulceration was technically feasible and acceptable for standard treatment instead of gastrectomy with lymph node dissection. A review of the EGC of mixed histological type (mixed EGC) suggested that the mixed EGC might have worse biological behavior than the pure histological type. In cases of intramucosal EGC with pure signet-ring cell carcinoma or presenting a double-layer structure, the risk of LNM might be relatively low. Thus, there is a possibility of further expanding the indications or curative evaluations. In the case of UD-EGC after noncurative resection, the data suggest that the eCura system may be applicable to UD-EGC; however, due to the small number of cases, further study is warranted. Key Message: This review summarizes the present knowledge regarding indications for UD-EGC and the possibility of further expanding them.

Lymph node metastasis risk factors and applicability of endoscopic submucosal dissection in mixed-type early gastric cancer in Chinese patients

Background

To analyze the risk factors of lymph node metastasis (LNM) of mixed-type early gastric cancer (EGC), and to explore whether endoscopic submucosal dissection (ESD) is applicable to mixed-type EGC in Chinese patients.

Methods

A total of 812 EGC patients were included. We classified the lesions into four types: pure moderately differentiated (PMD) adenocarcinoma, mixed predominantly moderately differentiated (MMD) type, mixed predominantly poorly differentiated (MPD) type, and pure poorly differentiated (PPD) adenocarcinoma. LNM risk factors in EGC were evaluated by univariate and multivariate analyses, and the feasibility of ESD in mixed-type EGC was estimated.

Results

The LNM rate in mixed-type EGC was 24.7% (68/275). Tumor size [odds ratio (OR) =1.419, P=0.008], MPD (OR =3.278, P=0.002), submucosal invasion ≥500 µm (OR =5.059, P=0.002), and lymphovascular invasion (LVI) (OR =5.836, P<0.001) were independent predictors of LNM in mixed-type EGC. LNM was more common in MMD patients than in PMD patients who met the expanded indications for ESD of differentiated EGC (0.0% vs. 7.84%, P=0.005).

Conclusions

Tumor size, histology, invasion depth, and LVI are independent risk factors for LNM in mixed-type EGC. The absolute indications for ESD are applicable to MMD, and the feasibility of the expanded indications for ESD in MMD and MPD requires further investigation in Chinese patients.

Deep Learning for Automatic Subclassification of Gastric Carcinoma Using Whole-Slide Histopathology Images

Histomorphologic types of gastric cancer (GC) have significant prognostic values that should be considered during treatment planning. Because the thorough quantitative review of a tissue slide is a laborious task for pathologists, deep learning (DL) can be a useful tool to support pathologic workflow. In the present study, a fully automated approach was applied to distinguish differentiated/undifferentiated and non-mucinous/mucinous tumor types in GC tissue whole-slide images from The Cancer Genome Atlas (TCGA) stomach adenocarcinoma dataset (TCGA-STAD). By classifying small patches of tissue images into differentiated/undifferentiated and non-mucinous/mucinous tumor tissues, the relative proportion of GC tissue subtypes can be easily quantified. Furthermore, the distribution of different tissue subtypes can be clearly visualized. The patch-level areas under the curves for the receiver operating characteristic curves for the differentiated/undifferentiated and non-mucinous/mucinous classifiers were 0.932 and 0.979, respectively. We also validated the classifiers on our own GC datasets and confirmed that the generalizability of the classifiers is excellent. The results indicate that the DL-based tissue classifier could be a useful tool for the quantitative analysis of cancer tissue slides. By combining DL-based classifiers for various molecular and morphologic variations in tissue slides, the heterogeneity of tumor tissues can be unveiled more efficiently.

ALOX5-5-HETE promotes gastric cancer growth and alleviates chemotherapy toxicity via MEK/ERK activation

Background

Recent studies highlight the regulatory role of arachidonate lipoxygenase5 (Alox5) and its metabolite 5‐hydroxyeicosatetraenoic acid (5‐HETE) in cancer tumorigenesis and progression. In this study, we analyzed the expression, biological function and the downstream signaling of Alox5 in gastric cancer.

Methods

Alox5 protein levels were measured using IHC and ELISA. Growth, migration and survival assays were performed. Phosphorylation of molecules involved in growth and survival signaling were analyzed by WB. Analysis of variance and t‐test were used for statistic analysis.

Results

Alox5 and 5‐HETE levels were upregulated in gastric cancer patients. ALOX5 overexpression or 5‐HETE addition activates gastric cancer cells and reduces chemotherapy’s efficacy. In contrast, ALOX5 inhibition via genetic and pharmacological approaches suppresses gastric cancer cells and enhances chemotherapy’s efficacy. In addition, Alox5 inhibition led to suppression of ERK‐mediated signaling pathways whereas ALOX5‐5‐HETE activates ERK‐mediated signaling in gastric cancer cells.

Conclusions

Our work demonstrates the critical role of ALOX5‐5‐HETE in gastric cancer and provides pre‐clinical evidence to initialize clinical trial using zileuton in combination with chemotherapy for treating gastric cancer.

The Poor Prognosis of Patients with Stage III Gastric Cancer after D2 Dissection Is Mainly due to Lymphatic Metastasis, Especially the Metastasis of No.12a LN: A Nested Case-Control Study

BACKGROUND

The prognosis of stage III gastric cancer (GC) patients based on the 8th edition TNM staging system after D2 dissection was still heterogeneous. We aimed to explore clinicopathological reasons that led to the poor prognosis of these patients, especially from a surgical aspect.

METHODS

We divided 320 stage III GC patients who underwent distal or total gastrectomy with D2 lymphadenectomy into group 1 and group 2, according to the disease-free survival (DFS), and compared the clinicopathological features between these 2 groups. Then, we divided group 1 into group 1D and group 1T and group 2 into group 2D and group 2T, according to distal or total gastrectomy. Finally, we compared the status of lymph node (LN) metastasis in each group of perigastric LN between the subgroups, respectively.

RESULTS

Univariate analyses revealed that patients' LN metastasis was the only significant difference between group 1 and group 2 (p < 0.05). Compared with group 1D, the percentage of patients who had metastatic LN in all groups of the perigastric LN (included No.1, 3, 4sb, 4d, 5, 6, 7, 8a, 9, 11p and 12a) increased in group 2D. A similar tendency was found in group 2T (included No.1, 2, 3, 4sa, 4sb, 4d, 5, 6, 7, 8a, 9, 10, 11p, 11d and 12a) compared with group 1T. Further multivariate regression analyses revealed that the increases of group No.12a and 5 LN were significant (p < 0.05) in group 2D, the increases of group No.12a, 8a and 6 LN were significant (p < 0.05) in group 2T, respectively. Among these, the increases of group No.12a LNs were the most significant (p < 0.01).

CONCLUSIONS

The poor prognosis of patients with stage III GC after D2 dissection is mainly due to lymphatic metastasis. The status of LN metastasis in the prognostic value of GC needs to be further enhanced in present staging systems. Maybe the metastasis of No.12a LN is the most significant poor prognostic factor of these patients. It points out that the dissection of No.12a LN should be carefully performed in radical gastrectomy.

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.

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.

Histological Differentiated/Undifferentiated Mixed Type Should Not Be Considered as a Non-Curative Factor of Endoscopic Resection for Patients With Early Gastric Cancer

Background

Histological differentiated/undifferentiated mixed-type adenocarcinomas are frequently found in patients with early gastric cancer (EGC). Yet it is unclear whether these mixed-type adenocarcinomas can be treated by endoscopic resection (ER) in EGC patients.

Aims

To evaluate the lymph node metastasis (LNM) rate and long-term outcomes in mixed-type EGC patients and assess the feasibility of ER in these patients.

Methods

Clinicopathological features, risk factors of LNM, and overall survival (OS) and progression-free survival (PFS) rates of EGC patients were analyzed according to different histological types.

Results

Patients with mixed-type EGC had higher LNM rates than patients with non-mixed-type EGC (11.4 vs. 6.2%, P = 0.044). In the multivariate analysis, larger tumor diameter, presence of an ulcer, submucosal invasion, histological undifferentiated type, histological mixed type, and lymphovascular invasion resulted as independent risk factors for LNM in EGC patients (all P < 0.05). The LNM rate in mixed-type patients who met the Japanese ER criteria was 3.3%, including fulfilling the absolute criteria 0%. The 5-year OS and PFS rates in mixed-type patients were 94.59 and 91.47%, respectively. There was no statistical significance in the OS (P = 0.870) and PFS (P = 0.705) between mixed-type and non-mixed-type EGC patients fulfilling the Japanese ER criteria.

Conclusion

Histological differentiated/undifferentiated mixed type in EGC patients meeting the Japanese absolute criteria for ER are associated with low risk of LNM and favorable prognosis, and thus, it should not be considered as a non-curative factor for ER.

Mixed Type Histology as a Predictive Factor for Esophagojejunostomy Leak in Advanced Gastric Cancer

Since esophagojejunostomy leak (EJL) after gastrectomy is a potentially fatal complication and may impact the survival of patients with advanced gastric cancer (GC), it is important to establish risk factors for the EJL and to prevent this surgical complication. The aim of this study was analysis of predictors for the postoperative clinically apparent EJL. All patients operated for advanced GC between October 2016 and December 2019 were analyzed from a prospectively maintained database. The evaluation of the EJL and postoperative complications according to the demographic and clinical (categorized) variables was performed with odds ratio test (multivariate analysis was performed with the use of logistic regression method). Among the 114 patients included in the study, 71.1% received neoadjuvant chemotherapy and 19.3% underwent gastrectomy followed by the hyperthermic intraperitoneal chemotherapy (HIPEC). Postoperative EJL was found in 4.6% patients. The risk of EJL was significantly higher for mixed-type GC (OR = 12.45, 95% CI: 1.03-150.10; p = 0.0472). The risk of other postoperative complications was significantly higher in patients undergoing HIPEC (OR = 3.88, 95% CI: 1.40-10.80, p = 0.0094). The number of lymph nodes removed (>38) was characterized by 80% sensitivity and 79.6% specificity in predicting EJL (AUC = 0.80, 95% CI: 0.72-0.87; p < 0.0001). Mixed histological type of GC is a tumor-related risk factor for the EJL. HIPEC was confirmed to be a risk factor for postoperative complications after gastrectomy.

A subset of diffuse-type gastric cancer is susceptible to mTOR inhibitors and checkpoint inhibitors

Background

Mechanistic target of rapamycin (mTOR) pathway is essential for the growth of gastric cancer (GC), but mTOR inhibitor everolimus was not effective for the treatment of GCs. The Cancer Genome Atlas (TCGA) researchers reported that most diffuse-type GCs were genomically stable (GS). Pathological analysis suggested that some diffuse-type GCs developed from intestinal-type GCs.

Methods

We established patient-derived xenograft (PDX) lines from diffuse-type GCs, and searched for drugs that suppressed their growth. Diffuse-type GCs were classified into subtypes by their gene expression profiles.

Results

mTOR inhibitor temsirolimus strongly suppressed the growth of PDX-derived diffuse-type GC-initiating cells, which was regulated via Wnt-mTOR axis. These cells were microsatellite unstable (MSI) or chromosomally unstable (CIN), inconsistent with TCGA report. Diffuse-type GCs in TCGA cohort could be classified into two clusters, and GS subtype was major in cluster I while CIN and MSI subtypes were predominant in cluster II where PDX-derived diffuse-type GC cells were included. We estimated that about 9 and 55% of the diffuse-type GCs in cluster II were responders to mTOR inhibitors and checkpoint inhibitors, respectively, by identifying PIK3CA mutations and MSI condition in TCGA cohort. These ratios were far greater than those of diffuse-type GCs in cluster I or intestinal-type GCs. Further analysis suggested that diffuse-type GCs in cluster II developed from intestinal-type GCs while those in cluster I from normal gastric epithelial cells.

Conclusion

mTOR inhibitors and checkpoint inhibitors might be useful for the treatment of a subset of diffuse-type GCs which may develop from intestinal-type GCs.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1121-3) contains supplementary material, which is available to authorized users.

Evaluation of Gastric Carcinomas Histological Patterns in Relation to Tumors Aggressiveness Parameters

Gastric carcinomas are frequent tumors with variable growth patterns that may interfere with the evaluation of histopathological prognostic parameters of the lesions. In this study we analyzed the incidence and statistical relation of histological growth patterns depending on the prognostic parameters of gastric carcinomas for 95 cases. Pure forms were present in 82.2% of cases, from which more frequent subtypes were low grade tubular carcinomas and poorly cohesive with signet-ring cells carcinomas. Mixed forms were present in 17.8% of cases, with the highest incidence of tumors containing well differentiated tubular carcinoma and poorly differentiated papillary carcinoma areas. Analysis of the identified types and subtypes in relation to the histological prognostic parameters indicated significant differences regarding the tumor stage, the mixed subtypes being more frequent in advanced stages. Although mixed subtypes were more commonly associated with vascular and perineural invasion, the aspects were statistically insignificant. Together with tumor stage, the lymphovascular and/or perineural invasion should be taken into consideration as prognostic indicators in the postoperative management of gastric cancer.

Expansion of lymph node metastasis in mixed-type submucosal invasive gastric cancer

BACKGROUND/OBJECTIVE

Mixed-type early gastric cancer (differentiated and undifferentiated components) incurs a higher risk of lymph node metastasis than pure-type early gastric cancer (only differentiated or only undifferentiated components). Therefore, we investigated the expansion of lymph node metastasis in mixed-type submucosal invasive gastric cancer in order to establish the most appropriate treatment for mixed-type cancer.

METHODS

We retrospectively analyzed 279 consecutive patients with submucosal invasive gastric cancer who underwent curative gastrectomy for gastric cancer between 1996 and 2015. We classified the patients into the mixed-type and pure-type groups according to histologic examination and evaluated the expansion of lymph node metastasis.

RESULTS

The rate of lymph node metastasis was 23.7% (66/279) in the total patients, 36.4% (36/99) in the mixed-type group, and 16.6% (30/180) in the pure-type group. The significant independent risk factors for lymph node metastasis were tumor size ≥2.0 cm (P = 0.014), mixed-type gastric cancer (P < 0.001), and lymphatic invasion (P < 0.001). Lymphatic invasion and lymph node metastasis had a strong relationship in mixed-type group. The rates of no. 7 lymph node metastasis in the total patients and mixed-type group were 2.9% (8/279) and 5.1% (5/99), respectively; the rates of no. 8a lymph node metastasis were 1.4% (4/279) and 4.0% (4/99), respectively.

CONCLUSION

Mixed histological type is an independent risk factor for lymph node metastasis. Lymph node metastasis in mixed-type gastric cancer involves expansion to the no. 7 and no. 8a lymph nodes. Therefore, lymphadenectomy for mixed-type submucosal invasive gastric cancer requires D1+ or D2 dissection.

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.

Feasibility study on expanded indication for endoscopic submucosal dissection of intramucosal poorly differentiated early gastric cancer

AIM: To identify clinicopathological factors predictive of lymph node metastasis (LNM) in intramucosal poorly differentiated early gastric cancer (EGC), and further to expand the possibility of using endoscopic submucosal dissection (ESD) for the treatment of intramucosal poorly differentiated EGC.

METHODS: Data for 81 surgically treated patients with intramucosal poorly differentiated EGC were collected, and the association between the clinicopathological factors and the presence of LNM was retrospectively analyzed by univariate and multivariate logistic regression analyses. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Several clinicopathologic factors were investigated to identify predictive factors for lymph nodes metastasis, including gender, age, family history of gastric cancer, number of tumors, tumor location, ulceration, tumor size, macroscopic type, lymphatic vessel involvement, and signet-ring-cell component.

RESULTS: Tumor size (OR = 7.273, 95%CI: 1.246-29.918, P = 0.042), lymphatic vessel involvement (OR = 42.219, 95%CI: 1.923-97.052, P = 0.018) and signet-ring-cell component (OR = 17.513, 95%CI: 1.647-77.469, P = 0.034) that were significantly associated with LNM by univariate analysis, were found to be significant and independent risk factors for LNM by multivariate analysis. However, gender, age, family history of gastric cancer, number, location, ulceration and macroscopic type of tumor were found not to be associated with LNM. Of these 81 patients diagnosed with intramucosal poorly differentiated EGC, 7 (8.6%) had LNM. The LNM rates were 9.1%, 22.2% and 57.1%, respectively, in cases with one, two and three of the risk factors. There was no LNM in 54 patients without the three risk clinicopathological factors.

CONCLUSION: Tumor size, lymphatic vessel involvement and signet-ring-cell component are independently associated with the presence of LNM in intramucosal poorly differentiated EGC. Thus, these three risk factors may be used as a simple criterion to expand the possibility of using ESD for the treatment of intramucosal poorly differentiated EGC.

Risk of lymph node metastasis in mixed-type early gastric cancer determined by the extent of the poorly differentiated component

AIM: To predict the rate of lymph node (LN) metastasis in diffuse- and mixed-type early gastric cancers (EGC) for guidelines of the treatment.

METHODS: We reviewed 550 cases of EGC with diffuse- and mixed-type histology. We investigated the clinicopathological factors and histopathological components that influence the probability of LN metastasis, including sex, age, site, gross type, presence of ulceration, tumour size, depth of invasion, perineural invasion, lymphovascular invasion, and LN metastasis status. We reviewed all slides and estimated the proportions of each tumour component; pure diffuse type, mixed-predominantly diffuse type (diffuse > intestinal type), mixed-predominantly intestinal type (intestinal > diffuse type), and mixed diffuse = intestinal type. We calculated the extents of the respective components.

RESULTS: LN metastasis was observed in 12.9% (71/550) of early gastric cancers cases [15/288 mucosal EGCs (5.2%) and 56/262 submucosal EGCs (21.4%)]. Of 550 cases, 302 were diffuse-type and 248 were mixed-type EGCs. Of 248 mixed-type EGCs, 163 were mixed-predominantly diffuse type, 82 were mixed-predominantly intestinal type, and 3 were mixed diffuse = intestinal type. Mixed-type cases with predominantly diffuse type histology showed a higher frequency of LN metastasis (20.2%) than cases of pure diffuse type (9.3%) and predominantly intestinal type (12.2%) histology. We measured the dimensions of each component (intestinal and diffuse type) to determine the association of the extent of each component with LN metastasis in mixed-type gastric carcinoma. The total tumour size and the extent of poorly differentiated components was associated with LN metastasis, while that of signet ring cell components was not.

CONCLUSION: We recommend careful identification and quantitative evaluation of mixed-type early gastric cancer components after endoscopic resection to determine the intensity of the treatment.

Relevant risk factors for positive lateral margin after en bloc endoscopic submucosal dissection for early gastric adenocarcinoma

OBJECTIVE

This study aimed to systematically assess the relevant risk factors of positive lateral margin (LM) after en bloc resection of early gastric adenocarcinoma.

METHODS

A total of 242 patients who had undergone endoscopic submucosal dissection (ESD) due to early gastric lesions from January 2009 to March 2015 were included in the study. Clinicopathological features of the lesions and the risk factors related to positive LM were analyzed.

RESULTS

The curative rate was 82.2% and positive LM was found in 12.4% of the lesions. Univariate analysis showed that positive LM was significantly associated with the tumor location (at the upper third of the stomach), size (>3 cm), histological findings, the presence of lymphovascular invasion and deeper invasion depth. Moreover, positive LM had a higher incidence of recurrent or residual tumors. A multivariate analysis showed that the location, tumor size and histological classification of tumors were independent risk factors for positive LM.

CONCLUSIONS

Positive LM is closely related to the upper third of stomach, a tumor larger than 3 cm and a mixed-type carcinoma. Additionally, positive LM has a predilection for recurrent or residual tumors.

Clinicopathological Variation of Lauren Classification in Gastric Cancer

The investigation of prognostic factor for gastric cancer is still desirable because of dismal prognosis in gastric cancer. Lauren's classification is currently a useful histological classification. There are few large series evaluating the prognostic significance of Lauren's classification in gastric cancer. From January 1987 to December 2013, a total of 3071 patients received gastrectomy for gastric cancer. According Lauren's classification, 1423(46.3%) patients were intestinal type, 1000 patients (32.6%) were diffuse type, and 648 patients (21.1%) were mixed type. The clinicopathological characteristics and prognosis in Lauren's classification were analyzed in these patients. Our results showed that patients with intestinal type gastric cancer (57.7%) had a better 5-year overall survival than diffuse type (45.6%) and mixed type (43.4%, P < 0.001). The clinicopathological characteristics showed that gastric cancer patients with intestinal type were older (P < 0.001), male predominant (P < 0.001), smaller tumor size (P < 0.001), distal stomach predominant (P < 0.001), relative well differentiated (P < 0.001), less advanced Borrmann type (P < 0.001), less scirrhous type stromal reaction(P < 0.001), less infiltrating type of Ming's histology type(P < 0.001), less tumor invasion depth and less lymphovascular invasion (P < 0.001). Multivariate analysis with overall survival as an endpoint showed that age (P = 0.005), Borrmann classification (P < 0.001), pathological T category (P = 0.023), pathological N category (P < 0.001) and Lauren's classification (P = 0.003) were significant correlated in gastric cancer. Lauren's classification is an independent prognostic factor in gastric cancer patient undergoing gastrectomy. Lauren's classification can serve as a prognostic marker for gastric cancer patient receiving gastrectomy. The clinicopathological appearance and prognosis of mixed type gastric cancer is similar to diffuse type gastric cancer.

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.