Molecular profiling of gastric neuroendocrine carcinomas.

Gastric neuroendocrine carcinoma (G-NEC) usually has NEC and adenocarcinoma components and is considered to have a common origin in gastric adenocarcinoma because common pathogenic mutations are shared. However, G-NEC without adenocarcinoma also exists, and it may have a different mechanism of tumorigenesis. We aimed to elucidate the tumorigenesis of G-NEC by focusing on the proportion of NEC components. Thirteen patients with G-NEC were included in this study. Comprehensive genetic analysis using whole-exome sequencing was performed. G-NEC without an adenocarcinoma component was defined as pure NEC. TP53 was detected as the most frequent gene mutation (85% of the patients), independent of classification. RB1, KMT2C, LTBP1, and RYR2 mutations were identified in two of three pure NEC patients but were not detected in other G-NEC patients. Pure NEC has different somatic mutation profile than other NECs. This study provides insights into the mechanism of tumorigenesis in G-NEC.

The Effect of Minimally Invasive Gastrectomy for Gastric Cancer on Postoperative Gallstone Formation.

BACKGROUND: Gallstones are known to occur quite frequently after gastrectomy. Most of the studies about postoperative cholelithiasis have focused on open gastrectomy, whereas laparoscopic gastrectomy has recently gained popularity as a type of minimally invasive surgery (MIS). Hence, the efficacy of MIS in preventing post-gastrectomy gallstone formation remains to be elucidated. This study aimed to evaluate the risk of gallstone formation after MIS for clinical stage I/IIA gastric cancer. METHODS: A total of 1166 patients undergoing gastrectomy for clinical stage I/IIA gastric cancer between 2009 and 2016 were included in this study. Gallstones were detected on abdominal ultrasound and/or computed tomography. Multivariate logistic regression analysis was used to determine factors associated with postoperative gallstone formation. RESULTS: Gallstone formation was observed in 174 patients (15%), of whom 22 (2%) experienced symptomatic cholelithiasis. In multivariate analysis, the following were identified as risk factors for post-gastrectomy gallstone formation: open approach with an odds ratio (OR) of 1.670 and a 95% confidence interval (CI) of 1.110-2.510 (P = 0.014), older age (OR 1.880; 95% CI 1.290-2.730; P < 0.001), high body mass index (OR 1.660; 95% CI 1.140-2.420; P = 0.008), Roux-en-Y (RY) reconstruction (OR 1.770; 95% CI 1.230-2.530; P = 0.002), hepatic branch vagotomy (OR 1.600; 95% CI 1.050-2.440; P = 0.029), and intra-abdominal infectious complications (OR 3.040; 95% CI 1.680-5.490; P < 0.001). CONCLUSION: Our study suggested that MIS along with the preservation of the hepatic vagus nerve and non-RY reconstruction could help prevent post-gastrectomy gallstone development.

[Perioperative Chemotherapy for Gastric Cancer].

Radical surgery is the mainstay for the treatment for advanced gastric cancer. However, the results are still not satisfactory. Various kind of perioperative chemotherapy has been evaluated to improve the therapeutic results. In Japan, adjuvant chemotherapy is regarded as a standard treatment. Japanese gastric cancer treatment guidelines have recommended the adjuvant chemotherapy with S-1 for 1 year in patients with pStageⅡor Ⅲgastric cancer. Meanwhile, the efficacy of S-1 plus docetaxel has been demonstrated in Stage Ⅲ gastric cancer, and it is recommended as a standard treatment for Stage Ⅲ gastric cancer in the guidelines. On the contrary, neoadjuvant chemotherapy(NAC)is regarded as a standard treatment for advanced gastric cancer in the West. The FLOT regimen is recommended for patients with good performance status. As the patient background and operative results are significantly different between the West and the East, extrapolation of the Western evidences seems to be difficult. We have to establish our own evidence of NAC.

Laparoscopic approach to early gastric cancer in a patient with a prior history of open right hepatectomy: a case report.

BACKGROUND: Laparoscopic gastrectomy is regarded a standard treatment procedure for early gastric cancer and is widely used in clinical practice. However, the feasibility of laparoscopic gastrectomy for patients with a prior history of open surgery, especially in the case of a complicated operation, remains unclear. Here, we report a laparoscopic gastrectomy case with a prior history of right hepatectomy. CASE PRESENTATION: A 70-year-old man was diagnosed with early gastric cancers preceding a right hepatectomy for a solitary hepatocellular carcinoma at risk of rupture. An additional gastrectomy, after non-curative endoscopic submucosal dissection, was planned after the hepatectomy. Extensive adhesions were found around the liver. Rigid adherence of the duodenum to the adjacent hepatoduodenal ligament had formed. In addition, identification of the hepatic artery was difficult due to stiffening of the mesentery. Peeling off the adhesions from the ventral side of the duodenum revealed the supra-pyloric vessels and enabled us to transect the duodenum safely. Further, exposing the proper hepatic artery via the dorsal side of the mesentery and subsequent supra-pancreatic dissection on the outermost layer allowed effective identification of the right gastric artery. The postoperative course was uneventful. CONCLUSIONS: We successfully performed total laparoscopic distal gastrectomy on a patient with a prior history of major hepatectomy.