Postoperative chemotherapy is beneficial for many pancreatic cancer patients. However, some patients require dose reduction or the discontinuation of adjuvant chemotherapy because of adverse treatment-related effects. In this study, we aimed to evaluate two main outcomes. First, we evaluated the clinicopathological factors affecting patient disease-free survival (DFS) and overall survival (OS) following upfront surgery. Second, we evaluated the factors that influence the continuity of adjuvant chemotherapy. Fifty-four patients with resected pancreatic cancer were enrolled. First, we evaluated the clinicopathological factors affecting postoperative survival using the Kaplan-Meier method and Cox regression method. Next, factors affecting the continuity of adjuvant chemotherapy were analyzed using multiple logistic regression analysis. Univariate and multivariate analyses revealed that positive LN metastasis (HR (95% CI) 6.329 (2.381–16.95); p < 0.001) and relative dose intensity (RDI) < 80% for adjuvant chemotherapy (HR (95% CI) 5.154 (1.761–15.15); p = 0.003) were independent predictive factors for DFS. Regarding OS, extended dissection of the nerve plexus around the superior mesenteric artery (SMA) (HR (95% CI) 4.504 (1.721–11.76); p = 0.002), positive microscopic surgical margin (HR (95% CI) 5.565 (1.724–17.96); p = 0.004), and adjuvant chemotherapy of RDI < 80% (HR (95% CI) 3.534 (1.135–2.667); p = 0.029) were also independent predictive factors. Moreover, the level of RDI significantly correlated with DFS and OS. Multiple logistic regression analysis revealed that low RDI was significantly associated with postoperative body weight loss (BWL) ≥ 10%. The following factors were significantly associated with poor survival: extended dissection of the nerve plexus around the SMA, lymph node metastasis, residual tumor, and RDI of the adjuvant chemotherapy. Patient’s prognosis with adjuvant chemotherapy of RDI < 80% was worse. BWL ≥10% was the most important factor affecting the continuity of adjuvant chemotherapy. Perioperative nutritional intervention is necessary for patients who receive adjuvant chemotherapy for advanced pancreatic cancer.

Background/Aim: We sought to identify the mechanisms of perineural invasion in pancreatic ductal adenocarcinoma (PDAC). Materials and Methods: We utilized in vitro cancer cell-nerve co-culture models comprising human PDAC cell lines (MIA Paca2 and PANC-1) and a dorsal root ganglion (DRG) isolated from neonatal mice. We compared gene expression profiles between cell lines with/without DRG conditioned medium (DRG-CM) using RNA-sequencing (RNA-seq). Results: Migration, invasion, and neurotropism were significantly enhanced in MIA Paca2 but not in PANC-1 cells co-cultured with DRGs. Among 285 genes which showed significant differences in expression levels between cell lines in RNA-seq, we focused on Ephrin receptor A4 (EPHA4), which was upregulated in MIA Paca2 cells treated with DRG-CM. The abilities of migration, invasion, and neurotropism enhanced by DRG co-culture were abolished when EPHA4 was knocked down by siRNA in MIA Paca2 cells. Conclusion: EPHA4 can be a potential target gene to regulate perineural invasion in PDAC cells.

Background: Owing to the lack of definite diagnostic modalities, it is challenging to distinguish malignant cases of cholangiocarcinoma (CCA), which often causes biliary tract obstruction, from benign ones. Here, we investigated a novel lipid biomarker of CCA in bile‐derived small extracellular vesicles (sEVs) and developed a simple detection method for clinical application.Methods: Bile samples from seven patients with malignant diseases (hilar CCA = 4, distal CCA = 3) and eight patients with benign diseases (gallstones = 6, primary sclerosing cholangitis = 1, autoimmune pancreatitis = 1) were collected through a nasal biliary drainage tube. sEVs were isolated via serial ultracentrifugation and characterized using nanoparticle tracking analysis, transmission electron microscopy, and immunoblotting (with CD9, CD63, CD81, and TSG101). Comprehensive lipidomic analysis was performed using liquid chromatography–tandem mass spectrometry. Using a measurement kit, we further confirmed whether lipid concentrations could be used as a potential CCA marker.Results: Lipidomic analysis of bile sEVs in the two groups identified 209 significantly increased lipid species in the malignant group. When focusing on lipid class, phosphatidylcholine (PC) level was 4.98‐fold higher in the malignant group than in the benign group (P = 0.037). The receiver operating characteristic (ROC) curve showed a sensitivity of 71.4%, a specificity of 100%, and an area under the curve (AUC) of 0.857 (95% confidence interval [CI]:0.643–1.000). Using a PC assay kit, the ROC curve showed a cutoff value of 16.1 μg/mL, a sensitivity of 71.4%, a specificity of 100%, and an AUC of 0.839 (95% CI: 0.620–1.000).Conclusion: PC level in sEVs from human bile is a potential diagnostic marker for CCA and can be assessed by a commercially available assay kit.