High methylation levels of PCDH10 predict poor prognosis in patients with pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and is not a clinically homogeneous disease, but subsets of patients with distinct prognosis and response to therapy can be identified by genome-wide analyses. Mutations in major PDAC driver genes were associated with poor survival. By bioinformatics analysis, we identified protocadherins among the most frequently mutated genes in PDAC suggesting an important role of these genes in the biology of this tumor. Promoter methylation of protocadherins has been suggested as a prognostic marker in different tumors, but in PDAC this epigenetic modification has not been extensively studied. Thus, we evaluated whether promoter methylation of three frequently mutated protocadherins, PCDHAC2, PCDHGC5 and PCDH10 could be used as survival predictors in PDAC patients. METHODS: DNA extracted from 23 PDACs and adjacent non-neoplastic pancreatic tissues were bisulfite treated. Combined Bisulfite Restriction Analysis (COBRA) coupled to denaturing high-performance liquid chromatography (dHPLC) detection and bisulfite genomic sequencing (BGS) were used to determine the presence of methylated CpG dinucleotides in the promoter amplicons analyzed. RESULTS: In an exploratory analysis, two protocadherins showed the same pattern of CpG methylation in PDAC and adjacent non-neoplastic pancreatic tissues: lack of methylation for PCDHAC2, complete methylation for PCDHGC5. Conversely, the third protocadherin analyzed, PCDH10, showed a variable degree of CpG methylation in PDAC and absence of methylation in adjacent non-neoplastic pancreatic tissues. At Kaplan-Meier analysis, high levels of PCDH10 methylation defined according to the receiver operating characteristic (ROC) curve analysis were significantly associated with worse progression-free survival (PFS) rates (P = 0.008), but not with overall survival (OS). High levels of PCDH10 methylation were a prognostic factor influencing PFS (HR = 4.0: 95% CI, 1.3-12.3; P = 0.016), but not the OS. CONCLUSIONS: In this study, we show for the first time that the methylation status of PCDH10 can predict prognosis in PDAC patients with a significant impact on the outcome in terms of progression-free survival. High levels of PCDH10 promoter methylation could be useful to identify patients at high risk of disease progression, contributing to a more accurate stratification of PDAC patients for personalized clinical management.

A tumour score with multidetector spiral CT for venous infiltration in pancreatic cancer: influence on borderline resectable.

PURPOSE: A tumour score for venous invasion in patients with pancreatic adenocarcinoma was evaluated by means of computed tomography (CT), in order to improve the assessment of medical treatment and clinical outcome with special attention to borderline resectable disease. MATERIALS AND METHODS: Fifty-six consecutive patients who underwent curative surgical resection for pancreatic cancer were analysed. On the basis of CT criteria, tumour involvement of the portal vein (PV) and superior mesenteric vein (SMV) was graded according to an adapted 4-point scale: score 1, definite absence of invasion; score 2, probable absence of invasion; score 3, probable presence of invasion; score 4, definite presence of invasion. Correlations between the venous infiltration scores and the patients' clinical features were also evaluated. RESULTS: After radiological evaluation of PV and SMV grades of infiltration, 21/56 (37 %) and 37/56 (66 %) patients, respectively, were found to have borderline resectable disease. The 4-point scale achieved a sensitivity of 80 %, a specificity of 96 % and an accuracy of 93 % in the evaluation of the PV, and a sensitivity of 100 %, a specificity of 94 % and an accuracy of 95 % in the evaluation of the SMV. Analysis of the distribution of clinical characteristics by PV and SMV infiltration showed that both scores correlated with the presence of distal metastasis (p = 0.016 and p = 0.028, respectively), and resection margins status (p = 0.015 and p = 0.006, respectively). CONCLUSIONS: This adapted tumour score is reliable for assessing venous invasion and might improve preoperative staging in patients with borderline resectable pancreatic cancer.

Changes in miR-143 and miR-21 expression and clinicopathological correlations in pancreatic cancers.

OBJECTIVES: Despite advances in clinical management of pancreatic cancer (PC), there is still room for improvement in early detection, diagnosis, and treatment strategies. The role of microRNAs (miRNAs) in tumor biology might pinpoint an alteration in expression of miRNAs as new diagnostic/prognostic biomarkers. METHODS: Expression levels of miR-143 and miR-21 and correlations with clinicopathological features were analyzed in 26 matched pairs of tumor and adjacent noncancerous tissue samples collected from patients with PCs, including 18 pancreatic ductal adenocarcinomas (PDACs) and 8 adenocarcinomas of Vater's papilla (PVACs). RESULTS: Compared to normal tissues, miR-143 was up-regulated in both PDAC and PVAC tumor samples (P = 0.0028 and P = 0.039, respectively). Conversely, alterations in miR-21 expression were significantly different in PDAC versus PVAC samples (P = 0.0049). Tumor levels of miR-21 were associated with preoperative serum levels of CA 19-9 (r = 0.63, P = 0.0022), whereas miR-143 expression was negatively correlated to lymph node spreading (r = -0.64; P = 0.0004). Correlation between miR-143 and miR-21 expression levels in patients with PDAC was observed (r = 0.53, P = 0.023). CONCLUSIONS: Deregulation of miR-143 and miR-21 may reflect histological features and biological behavior of different PCs. Association data with clinical parameters might indicate a prognostic significance for miR-143 and miR-21 in PCs.

Mirna expression profiles identify drivers in colorectal and pancreatic cancers.

BACKGROUND AND AIM: Altered expression of microRNAs (miRNAs) hallmarks many cancer types. The study of the associations of miRNA expression profile and cancer phenotype could help identify the links between deregulation of miRNA expression and oncogenic pathways. METHODS: Expression profiling of 866 human miRNAs in 19 colorectal and 17 pancreatic cancers and in matched adjacent normal tissues was investigated. Classical paired t-test and random forest analyses were applied to identify miRNAs associated with tissue-specific tumors. Network analysis based on a computational approach to mine associations between cancer types and miRNAs was performed. RESULTS: The merge between the two statistical methods used to intersect the miRNAs differentially expressed in colon and pancreatic cancers allowed the identification of cancer-specific miRNA alterations. By miRNA-network analysis, tissue-specific patterns of miRNA deregulation were traced: the driving miRNAs were miR-195, miR-1280, miR-140-3p and miR-1246 in colorectal tumors, and miR-103, miR-23a and miR-15b in pancreatic cancers. CONCLUSION: MiRNA expression profiles may identify cancer-specific signatures and potentially useful biomarkers for the diagnosis of tissue specific cancers. miRNA-network analysis help identify altered miRNA regulatory networks that could play a role in tumor pathogenesis.

R2 resection in pancreatic cancer--does it make sense?

BACKGROUND: The goal of surgical treatment in patients with pancreatic cancer is the complete resection of tumor tissue; however, the intraoperative appraisal of resectability can be difficult. Extensive surgical exploration for definitive clear resectability may lead to R2 resections in single cases. PATIENTS: We analyzed 38 patients with pancreatic cancer with remaining macroscopic tumor tissue after pancreatic resection, as R0 resection was not possible. Patients were compared to 46 patients with unresectable cancer without distant metastases or peritoneal carcinomatosis, in which a bypass procedure was performed. RESULTS: Operating time and hospital stay were significantly longer after R2 resection. Intraoperative blood loss was significantly higher; and severe surgical complications and the need for relaparotomy were significantly more frequent after R2 resection. The 30-day mortality rate was higher after R2 resection; this difference was not statistically significant. Median survival was comparable in both groups. Two years after surgery, 22.6% of the patients after R2 resection were still alive compared to 10.9% after bypass surgery. CONCLUSION: Tumor debulking is not a treatment option in patients with advanced pancreatic cancer, but the patient is not at a disadvantage compared to bypass procedures if tumor tissue remains and R0 resection cannot be achieved after surgical exploration.

Up-regulation of p75 neurotrophin receptor (p75NTR) is associated with apoptosis in chronic pancreatitis.

Activation of apoptosis in chronic pancreatitis has been demonstrated. The low-affinity neurotrophin receptor p75 (p75NTR) mediates apoptosis in many cell types in vivo and in vitro. The aim of this study was to examine whether p75NTR is involved in the apoptotic process in chronic pancreatitis. The quantity and localization of the receptor was evaluated using northern blot analysis, in situ hybridization, immunohistochemistry, and western blot analysis. Apoptosis was determined by TUNEL assay. By northern blot analysis, p75NTR mRNA levels were increased 40-fold in chronic pancreatitis compared with normal pancreas (P < 0.01). In situ hybridization revealed weak p75NTR mRNA expression in some ductal cells in the normal pancreas. In contrast in chronic pancreatitis moderate p75NTR expression was present in acinar cells next to fibrosis, ductal cells, and cells of ductular structures as well as in some islet cells. Immunostaining of p75NTR in normal pancreas and chronic pancreatitis tissue samples showed a similar intensity and distribution pattern as found by in situ hybridization. Higher p75NTR protein levels could be confirmed by western blot analysis, which revealed an 8.6-fold increase of p75NTR in chronic pancreatitis. TUNEL staining showed, in chronic pancreatitis samples, positivity in some acinar cells next to fibrosis, some ductal cells, and cells of ductular structures. Also some islet cells were positive by TUNEL staining. The presence of p75NTR immunoreactivity was positively correlated (P < 0.05) with the apoptotic index in the exocrine and endocrine pancreas. In conclusion, p75NTR, the low-affinity receptor of neurotrophins which mediates apoptosis, is up-regulated in CP and is involved in the apoptotic process of the exocrine and endocrine pancreas.