Advances in the diagnosis and treatment of gastric neuroendocrine neoplasms

Clinical outcomes of gastroduodenal neuroendocrine tumors according to their WHO grade: A single-institutional retrospective analysis

The management of gastroduodenal neuroendocrine tumor (NET) has been controversial between radical surgical resection and local excision including endoscopic resection. A gastroduodenal NET grade (G), measured by their mitotic rate and Ki67 proliferation index, is important to predict prognosis. In this study, we aimed to compare the clinical outcomes of gastroduodenal NET according to grades in order to identify poor prognostic factors of gastroduodenal NETs. Fifty-four gastroduodenal NETs diagnosed between December 2008 and December 2020 in a tertiary referral hospital were retrospectively reviewed. The clinical outcomes of gastroduodenal NETs, according to tumor grades and factors associated with NET G2-3, were analyzed. A total of 52 gastroduodenal NET patients was enrolled. The mean follow-up period was 56.2 ± 40.1 months. The mean size of gastric and duodenal NET was 7.9 ± 11.0 mm and 9.8 ± 7.6 mm, respectively. During the study period, 72.7% (16/22) of gastric NETs and 83.3% (25/30) of duodenal NETS were G1. All G1 gastroduodenal NETs showed no lymph node or distant metastasis during the study periods. All G3 gastroduodenal NETs showed metastasis (one lymph node metastasis and 3 hepatic metastases). Among metastatic NETs, the smallest tumor size was a 13 mm gastric G3 NET. Factors associated with G2-3 NETs were larger tumor size, mucosal ulceration, proper muscle or deeper invasion, and lymphovascular invasion. A small-sized gastroduodenal NET confined to submucosa without surface ulceration may be suitable for endoscopic resection. After local resection of a gastroduodenal NET (G1) without lymphovascular and muscle proper invasion, follow-up examination without radical surgical resection can be recommended. G3 NETs may be treated by radical surgical resection, regardless of tumor size.

Long intergenic noncoding RNA 01296 aggravates gastric cancer cells progress through miR-122/MMP-9

Long non-coding RNAs (lncRNAs) play important roles on tumor development and progression in gastric cancer (GC). However, the biological function and regulatory mechanisms of LINC01296 in GC still remain unknown. The objective of this study is to investigate the clinical significance and pathological roles of LINC01296 in GC. Results showed that LINC01296 was up-regulated in GC tissue and correlated with poor prognosis. In vitro, LINC01296 knockdown was up-regulated in GC cells and LINC01296 knockdown suppressed GC cells proliferation, migration and invasion, and promoted apoptosis. In vivo xenograft assays, results showed LINC01296 knockdown significantly inhibited GC tumor growth. Bioinformatics analysis revealed that LINC01296 sponged miR-122, which was proved to target MMP-9. Western blot and RT-PCR showed that LINC01296 was positively correlated with MMP-9 expression, while miR-122 was negatively correlated to it. Overall, results indicate that LINC01296 acts as oncogenic lncRNA in GC carcinogenesis, suggesting the LINC01296/miR-122/MMP-9 regulatory pathway in GC tumorigenesis.