Feasibility for the application of expanded endoscopic resection criteria in mucosal undifferentiated gastric cancer.

BACKGROUND & AIM: The indication of endoscopic submucosal dissection (ESD) for mucosal undifferentiated early gastric cancer (EGC) remains controversial because of risk of lymph node metastasis (LNM). The aim of this study was to identify risk factors for lymph node metastasis (LNM) in mucosal undifferentiated EGC, and further to confirm feasibility of the ESD for the treatment of mucosal undifferentiated EGC. METHODS: We retrospectively reviewed data of patients who underwent surgical resection with lymph node dissection of T1a stage primary gastric adenocarcinoma at three medical centers between 2012 and 2022. We evaluated the frequency of lymph node metastasis and the associated risk factors, as well as the lymph node metastasis rate in the expanded indication of mucosal undifferentiated EGC. RESULTS: A total of 100 surgically treated patients with mucosal undifferentiated EGC were enrolled. LNM was irrelevant to the age, tumor size, location, and macroscopic type (all P > 0.05), while it was significantly associated with lymphovascular invasion (LVI, P ＜0.001). And logistic regression analysis showed that the LVI was the only significant risk factors for LNM (OR: 0.34, 95%CI: 0.06-0.204; P ＜0.001). Of 44 mucosal undifferentiated EGC patients satisfying the expanded indication of ESD, 3 patients (6.8%) showed LN metastasis, all of them with undifferentiated cancer without ulceration, less than 2.0 cm in size. CONCLUSIONS: Because LNM is present in mucosal undifferentiated EGC patients who satisfied the expanded indication of ESD, ESD cannot be considered a better choice than surgery for all undifferentiated EGC patients. LVI was significant risk factors for LNM in patients with mucosal undifferentiated EGC.

Prognostic significance of microRNA-141 expression and its tumor suppressor function in human pancreatic ductal adenocarcinoma.

Increasing evidence shows that dysregulation of microRNAs is correlated with tumor development. This study was performed to determine the expression of miR-141 and investigate its clinical significance in pancreatic ductal adenocarcinoma (PDAC). Taqman quantitative RT-PCR was used to detect miR-141 expressions in 94 PDAC tissues and 16 nontumorous pancreatic tissues. Correlations between miR-141 expression and clinicopathologic features and prognosis of patients were statistically analyzed. The effects of miR-141 expression on growth and apoptosis of PDAC cell line (PANC-1) were determined by MTT, colony formation, and flow cytometry assays. Potential target genes were identified by luciferase reporter and Western blot assays. The expression level of miR-141 in PDAC tissues was significantly lower than that in corresponding nontumorous tissues. Downregulation of miR-141 correlated with poorer pT and pN status, advanced clinical stage, and lymphatic invasion. Also, low miR-141 expression in PDAC tissues was significantly correlated with shorter overall survival, and multivariate analysis showed that miR-141 was an independent prognostic factor for PDAC patients. Further, functional researches suggested that miR-141 inhibits growth and colony formation, and enhances caspase-3-dependent apoptosis in PANC-1 cells by targeting Yes-associated protein-1 (YAP1). Therefore, miR-141 is an independent prognostic factor for PDAC patients, and functions as a tumor suppressor gene by targeting YAP1.