Micropapillary early gastric carcinoma with distinct clinicopathological features, high risk for lymph node metastasis, and dismal prognosis: a multicenter clinicopathological study of 29 cases identified in 1890 early gastric carcinoma radical gastrectomies

Risk Factors of Lymph Node Metastasis and Prognosis in 891 Chinese Patients With Submucosal Early Gastric Carcinoma, Emphasizing Differences Between Gastric Cardiac and Noncardiac Origins

Differences in risk factors (RF) of lymph node metastasis (LNM) and prognosis between submucosal early gastric cardiac (SEGCC) and noncardiac (SEGNCC) carcinomas remain unclear. In this study, we investigated and compared RF of LNM and prognosis in 891 patients with radical gastrectomy for SEGCC (n=217) or SEGNCC (n=674). Compared with SEGNCC, SEGCC displayed significantly higher proportion of elderly patients (70 y or above), the elevated macroscopic type, well/moderately differentiated tubular and low-grade papillary adenocarcinomas, as well as low-grade tumor budding, but lower prevalence of the depressed macroscopic type, poorly differentiated tubular adenocarcinoma, mixed adenocarcinoma, poorly cohesive carcinoma, lymphovascular invasion (LVI), perineural invasion, and high-grade tumor budding. By univariate analysis, significant RF for LNM of the cohort included female sex, poor differentiation, SM2 invasion, LVI, intermediate-grade and high-grade tumor budding, whereas tumor size, histology type, and perineural invasion were the significant RF for LNM in SEGNCC. By multivariate analysis, significant independent RF for LNM included female sex and LVI in SEGCC but were female sex, mixed adenocarcinoma, LVI, and high-grade tumor budding in SEGNCC. The 5-year overall survival was significantly worse in SEGCC than in SEGNCC for patients with LNM, but not for those without. For overall survival, LNM was the only significant independent RF in SEGCC, whereas age 70 years or above and LNM were independent RF in SEGNCC. The results of our study provided the clinicopathologic evidence for individualized clinical management strategies for these 2 groups of patients and suggested different pathogenesis mechanisms between SEGCC and SEGNCC.

Application of preoperative CT texture analysis in papillary gastric adenocarcinoma

Background

This study aimed to analyze the ability of computed tomography (CT) texture analysis to discriminate papillary gastric adenocarcinoma (PGC) and to explore the diagnostic efficacy of multivariate models integrating clinical information and CT texture parameters for discriminating PGCs.

Methods

This retrospective study included 20 patients with PGC and 80 patients with tubular adenocarcinoma (TAC). The clinical data and CT texture parameters based on the arterial phase (AP) and venous phase (VP) of all patients were collected and analyzed. Two CT signatures based on the AP and VP were built with the optimum features selected by the least absolute shrinkage and selection operator method. The performance of CT signatures was tested by regression analysis. Multivariate models based on regression analysis and the support vector machine (SVM) algorithm were established. The diagnostic performance of the established nomogram based on regression analysis was evaluated by receiver operating characteristic curve analysis.

Results

Thirty-two and fifteen CT texture parameters extracted from AP and VP CT images, respectively, differed significantly between PGCs and TACs (all p < 0.05). The diagnostic performance of CT signatures based on the AP and VP achieved AUCs of 0.873 and 0.859 in distinguishing PGCs. Multivariate models that integrated two CT signatures and age based on regression analysis and the SVM algorithm showed favorable performance in preoperatively predicting PGCs (AUC = 0.922 and 0.914, respectively).

Conclusion

CT texture analysis based multivariate models could preoperatively predict PGCs with satisfactory diagnostic efficacy.

Metastatic Neoplasms Involving the Stomach

OBJECTIVES

Metastatic neoplasms involving the stomach are rare and diagnostically challenging if clinical history of malignancy is absent or unavailable. This study was designed to identify the tumors that most frequently metastasize to the stomach and the morphologic features that can provide clues to investigate the possibility of metastasis and predict the primary sites.

METHODS

All patients with metastatic neoplasms involving the stomach were included in the study. The H&E- and immunohistochemical-stained slides were reviewed, and all clinical, endoscopic, and radiologic information was recorded.

RESULTS

One hundred fifty patients, including 84 (56%) women and 66 (44%) men (mean age, 64 years), were identified. Gastric metastases were the initial presentation in 15% cases. Epithelial tumors (73.3%) comprised the largest group, followed by melanoma (20.6%), sarcomas (4%), germ cell tumors (1.3%), and hematolymphoid neoplasms (0.7%). Lobular breast carcinoma was the most common neoplasm overall in women, while in men, it was melanoma. Solid/diffuse growth pattern (75%) was more common compared with glandular morphology. The solid/diffuse category included lobular breast carcinoma (21.3%), melanoma (20.6%), and renal cell carcinoma (10.6%), while the glandular category was dominated by gynecologic serous carcinomas (7.3%) with papillary/micropapillary architecture.

CONCLUSIONS

Metastatic neoplasms should be considered in the differential diagnosis of gastric neoplasms, particularly those with a diffuse/solid growth pattern. Glandular neoplasms are difficult to differentiate from gastric primaries except for Müllerian neoplasms, which frequently show a papillary/micropapillary architecture.

High-grade Papillary Early Gastric Carcinoma With High Risk for Lymph Node Metastasis and Poor Prognosis: A Clinicopathologic Study of 96 Cases Among 1136 Consecutive Radical Gastrectomies

Papillary early gastric carcinoma (EGC) is believed to have a low risk of lymph node metastasis (LNM) and thus can be resected endoscopically. We observed anecdotally that some papillary EGC tumors showed conspicuous high-grade dysplastic features, but the significance of these observations is unknown. In this bicenter study we investigated papillary EGCs that were divided into high-grade (n=96) and low-grade (n=118) groups among 1136 consecutive EGC radical resection cases. Concurrent 464 well-moderately differentiated tubular EGCs were served as the control group. Compared with low-grade papillary and well-moderately differentiated tubular EGCs, high-grade papillary EGC displayed significantly larger sizes (mean 2.51 cm), higher frequencies of the elevated macroscopic type (51%), lymphovascular invasion (LVI) (38.5%), and LNM (31.2%). Low-grade papillary EGCs exhibited a higher prevalence of the elevated macroscopic type, but not LVI nor LNM, compared with tubular EGC. Independent risk factors for LNM included high-grade histology, female sex, distal location, submucosal invasion, and LVI. The 5-year overall survival rate was significantly lower in high-grade (79.6%) papillary than in low-grade (88.9%) papillary or tubular (92.8%) EGCs, while no significant difference in prognosis was observed in the latter 2 groups. Age of 66 years or older and LNM were independent risk factors for overall survival. In conclusions, high-grade papillary EGC was associated with high frequencies of LVI, LNM, and poor prognosis, and thus unsuitable for endoscopic therapy, while low-grade papillary EGC showed clinicopathologic features and prognosis similar to well-moderately differentiated tubular EGC and may be treated endoscopically in appropriate clinical settings.

Aberrant activation of Rho/ROCK signaling in impaired polarity switching of colorectal micropapillary carcinoma

Micropapillary carcinoma (MPC) is a morphologically distinctive form of carcinoma, composed of small nests of cancer cells surrounded by lacunar spaces. Invasive MPC is associated with poor prognosis. The nests of tumor cells in MPC reportedly exhibit reverse polarity, although the molecular mechanisms underlying MPC patterns are poorly understood. Using the cancer tissue-originated spheroid (CTOS) method, we previously reported polarity switching in colorectal cancer (CRC). When cultured in suspension, the apical membrane promptly switches from the outside surface of the CTOSs to the surface of the lumen inside the CTOSs under extracellular matrix (ECM)-embedded conditions, and vice versa. Here, we investigated two CTOS lines from CRC patient tumors with MPC lesions. Xenograft tumors from the CTOSs exhibited the MPC phenotype. The MPC-CTOSs did not switch polarity in vitro. Time-course analysis of polarity switching using real-time imaging of the apical membrane revealed that local switching was continually propagated in non-MPC-CTOSs, while MPC-CTOSs were unable to complete the process. Integrin β4 translocated to the outer membrane when embedded in ECM in both MPC and non-MPC-CTOSs. Protein levels, as well as the active form of RhoA, were higher in MPC-CTOSs. The suppression of RhoA activity by GAP overexpression enabled MPC-CTOSs to complete polarity switching both in vitro and in vivo, while overexpression of active RhoA did not affect polarity switching in non-MPC-CTOSs. Pretreatment with a ROCK inhibitor enabled MPC-CTOSs to complete polarity switching both in vitro and in vivo, although delayed treatment after becoming embedded in ECM failed to do so. Thus, the inability to switch polarity might be a cause of MPC, in which the aberrant activation of RhoA plays a critical role. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

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

Background

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

Methods

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

Results

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

Conclusions

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