RNA-Seq-Based Molecular Classification Analyses in Colorectal Cancer and Synchronous Adenoma.

Colorectal cancers (CRC) are classified into consensus molecular subtypes (CMS) based on gene expression profiles. The revised classification system iCMS was proposed by considering intrinsic epithelial status, microsatellite instability (MSI), and fibrosis. This study aimed to provide molecular evidence for the adenoma-carcinoma sequence concept by examining CRC and synchronous adenomas using iCMS. Epithelial CMS cell proportion was estimated using CiberSortx, an in silico cell fractionation method that included CMS cell types among the reference cell types. A random forest (RF) model estimated the posterior probabilities of CMS classes, which were compared with the CiberSortx results. Gene expression profiles of the published iCMS signature panel were retrieved from our dataset and subjected to heatmap clustering for classification. Bulk RNA sequencing data were collected from 29 adenocarcinomas and 11 adenoma samples. CiberSortx showed all CRC contained either CMS2 or CMS3 as the major epithelial cancer cell type. The RF model classified approximately half of the CRC as CMS4, whereas CMS4 was hardly detected by CiberSortx. Because they were enriched with myofibroblasts as per the CiberSortx classification, we tentatively designated them as iCMS2-F/iCMS3-F. iCMS coupled with the application of an in silico cell fractionation method can provide the molecular dissection of CRC and adenoma.

Comparison of different pancreatic anastomosis techniques using the definitions of the International Study Group of Pancreatic Surgery: a single surgeon's experience.

OBJECTIVES: We aimed to compare different techniques using the definitions of the International Study Group of Pancreatic Surgery for postoperative complications after pancreaticoduodenectomy. METHODS: The perioperative data of 119 patients that underwent pancreaticoduodenectomy by a single surgeon were retrospectively analyzed. Pancreaticojejunal anastomosis was performed using the dunking method (n = 39), the duct-to-mucosa anastomosis method (n = 40), and the duct-to-mucosa adaptation (n = 40). RESULTS: The most frequent complication was postoperative pancreatic fistula (POPF; grades A, 21%; B, 8%; and C, 3%), postpancreatectomy hemorrhage (PPH; grades B, 7% and C, 1%), and delayed gastric emptying (DGE; grades A, 1% and B, 6%). No significant differences in POPF were found between patients who underwent different types of pancreatic anastomoses. Only pancreatic ductal adenocarcinoma (P = 0.001) and pancreatic texture (P = 0.012) were potentially related to POPF. Patients with or without POPF grade A had shorter postoperative stays than patients with grade B or C POPF (P < 0.001), and similar findings were obtained for DGE and PPH. CONCLUSIONS: The successful management of pancreatic anastomoses depends more on a meticulous surgical technique and appropriate experience rather than on the type of technique. Furthermore, the International Study Group of Pancreatic Surgery definitions of POPF, DGE, and PPH seem objective and universally acceptable.