Biomarker For Pancreatic Neuroendocrine Tumors Research Articles

Molecular detection of pancreatic neuroendocrine tumors using methylated DNA markers: Discovery and tissue validation.

e16705 Background: The prevalence of pancreatic neuroendocrine tumors (PNETs) has increased in the last decade. Despite being clinically asymptomatic PNETs can be biologically aggressive. There is currently no reliable non-invasive diagnostic biomarker for PNETs. In this study we aimed to identify and validate methylated DNA marker (MDM) candidates that differentiate PNET from normal pancreas. Methods: For discovery, reduced representation bisulfite sequencing (RRBS) was performed on DNA extracted from frozen normal pancreas (n = 13) and PNET (n = 51) tissues. Area under the receiver operator characteristic curve (AUC), fold-change, and p-value criteria selected candidates MDMs for blinded validation in independent FFPE tissues from primary PNET (n = 67; solid = 50, cystic = 17), normal pancreas controls (n = 24), and normal buffy coat (n = 36) using methylation specific PCR. MDM distributions in primary PNETs were compared to primary lung (n = 36) and small bowel (n = 36) NETs and metastatic PNET tissue (n = 25). The discrimination accuracy of candidate markers was summarized as the AUC with corresponding 95% confidence intervals (CI). Results: From the RRBS discovery, 31 candidate MDMs were selected for validation. Four MDMs ( SRRM3, HCN2, SPTBN4 and TMC6) achieved individual AUCs ≥0.95 in the validation set (Table). These MDMs were similarly discriminant in metastatic PNET tissue and in primary lung and small bowel NETs. Three out of these 4 MDMs perfectly differentiated PNET tissue from buffy coat with AUC of 1 and may be ideally suited for further development of a blood-based assay. Conclusions: We identified and validated novel MDMs in tissue that discriminate PNETs from controls with normal pancreas and buffy coat with high accuracy. These MDMs also differentiated metastatic PNETs from normal pancreas tissue. Further exploration of these candidate tissue MDMs in plasma can potentially guide diagnosis and management of PNETs. Funding: P30DK084567. [Table: see text]

Five Novel Genes Related to the Pathogenesis and Progression of Pancreatic Neuroendocrine Tumors by Bioinformatics Analysis With RT-qPCR Verification.

ObjectiveTo explore novel related genes and potential biomarkers of pancreatic neuroendocrine tumors (PanNETs).Materials and MethodsTwo data sets from ICGC and two from the NCBI GEO database were used to identify the differentially expressed genes (DEGs) in PanNETs. The common DEGs among the four sources were analyzed; furthermore, the relationship of these gene expression patterns with different PanNET grades, their mutation status and corresponding impact on prognosis, the interaction network, and the relationship with three known PanNET genes (ATRX, DAXX, and MEN1) were analyzed by two other GEO data and cBioPortal database. Finally, the expressions of novel DEGs were validated in Chinese PanNET tissues by RT-qPCR.ResultsFive new DEGs (ABCC8, PCSK2, IL13RA2, KLKB1, and PART1) and one confirmed DEG-ISL1 were identified. The mutation counts of DEGs increased with the tumor grade increasing from G1 to G3, and PanNET patients present vascular invasion or are deceased. These DEG expression patterns in PanNETs are quite different from that of pancreatic ductal adenocarcinoma and are related to A–D–M (ATRX–DAXX–MEN1) mutation. ABCC8 and KLKB1 are co-occurrence with the A–D–M axis in PanNETs. Importantly, patients with DEG mutations have a lower survival rate. RT-qPCR verification results of KLKB1 (P < 0.01), IL13RA2 (P < 0.01), ABCC8 (P < 0.01), and PART1 (P < 0.0001) expressions in Chinese PanNET tissues are consistent with our database analysis, which were significantly up-regulated. However, the expression of PCSK2 (P < 0.01) was contrary to our bioinformatics analysis, which was significantly down-regulated, suggesting that the expression trend of PCSK2 may be different among different races. These results indicated that these five genes may play an important role in the occurrence and progression of PanNETs.ConclusionFive novel common DEGs identified are related to the development and prognosis of PanNETs and may serve as specific biomarkers and therapeutic targets.

Limited role of Chromogranin A as clinical biomarker for pancreatic neuroendocrine tumors

BackgroundSerum Chromogranin A (CgA) is widely used as a biomarker for pancreatic neuroendocrine tumors (PanNETs). The aim of this study was to investigate the value of CgA as a diagnostic and prognostic marker for well-differentiated PanNETs. MethodsPatients with well-differentiated PanNET and a baseline CgA measurement, between 2011 and 2016 were reviewed. The diagnostic value was determined by comparing CgA values from patients with PanNETs to those with other pancreatic neoplasms and healthy controls. The Kaplan–Meier method was used to investigate the CgA prognostic significance. ResultsNinety-nine patients met inclusion criteria. As a diagnostic marker, CgA had a sensitivity of 66%, specificity of 95%, and overall accuracy of 71%. The use of PPIs was associated with a higher CgA level (p = 0.015). When excluding patients on PPIs, CgA accuracy in distinguishing PanNETs from other pancreatic neoplasms was 66%, the sensitivity and specificity were 60% and 75% respectively. Elevated CgA (p = 0.004), Ki67% (p < 0.001), tumor grade (p < 0.001) and stage of disease (p = 0.036) were associated with disease-specific survival. ConclusionCgA has a limited role as a diagnostic biomarker for well-differentiated PanNETs. An elevated CgA level may have prognostic value but its role should be further investigated with respect to other known pathological factors.

Prognostic relevance of UCH-L1 and \u03b1-internexin in pancreatic neuroendocrine tumors

Prognostic biomarkers for the pancreatic neuroendocrine tumors are needed. Proteomic study on insulinoma has been rarely reported. We identified the differential expression of proteins between insulinoma and their paired tissues by proteomic analysis, and evaluated the prognostic significance of specific proteins in pancreatic neuroendocrine tumors including insulinoma. The differential expression of select proteins was validated in more than 300 tumors using immunohistochemical staining and western blot. Methylation of UCH-L1 promoter in tumors was examined by methylation specific PCR and validated by sequencing. The concurrent expression of UCH-L1 and α-internexin was correlated with the prognosis in 2 independent collectives of patients with tumors. Sixty-two and 219 proteins were significantly down-regulated and up-regulated in insulinomas, respectively. Demethylation of UCH-L1 promoter was associated with UCH-L1 expression in tumors (p = 0.002). The concurrent expression of UCH-L1 and α-internexin in pancreatic neuroendocrine tumors was significantly associated with better overall survival and disease-free survival in the combination of both cohorts (log rank p = 3.90 × 10−4 and p = 3.75 × 10−5, respectively) and in each of cohorts. The prognostic value of both proteins was also validated in patients with stage II and III tumors (p = 0.017 and p = 0.006, respectively). The proteins UCH-L1 and α-internexin could be independent prognostic biomarkers of pancreatic neuroendocrine tumors.

Utility of chromogranin B compared with chromogranin A as a biomarker in Japanese patients with pancreatic neuroendocrine tumors.

Currently, serum chromogranin A is a well-established biomarker for pancreatic neuroendocrine tumors; however, other pancreatic diseases, oral use of a proton pump inhibitor and renal impairment can affect chromogranin A. Meanwhile, chromogranin B, belonging to the same granin family as chromogranin A, is not fully examined in these conditions. The present study aimed to evaluate the utility of chromogranin B as a pancreatic neuroendocrine tumor biomarker. Serum chromogranin B levels were determined by radioimmunoassay and serum chromogranin A levels by enzyme-linked immunosorbent assay in pancreatic neuroendocrine tumor (n = 91) and other pancreatic conditions, and in healthy people (n = 104), to assess the relationships with clinical features. The diagnostic ability of chromogranin B was as good as chromogranin A. The area under the curve was 0.79 for chromogranin B (sensitivity/specificity: 72%/77%), and 0.78 for chromogranin A (sensitivity/specificity: 79%/64%). Chromogranin B was not affected by proton pump inhibitor use and age, which affected chromogranin A. The number of cases without liver metastases was larger in pancreatic neuroendocrine tumor patients with positive chromogranin B and negative chromogranin A. Though chromogranin A significantly elevated cases with proton pump inhibitor treatment and had positive correlation with age, chromogranin B did not have the tendencies. However, both chromogranin B and chromogranin A elevated in the case with renal impairment. In addition, the logistic regression analysis showed that chromogranin B was superior to chromogranin A in differentiation of pancreatic neuroendocrine tumor from other pancreatic diseases. Compared with chromogranin A, chromogranin B may be more useful during proton pump inhibitor treatment and can detect tumors without liver metastases. In addition, chromogranin B may be an excellent biomarker when differentiation of pancreatic neuroendocrine tumor from other pancreatic diseases is required.

Comparison of Tumor Markers for Predicting Disease-Free Survival in Surgically Resected Pancreatic Neuroendocrine Tumors.

Identification of biomarkers of pancreatic neuroendocrine tumors (PNETs) is important for stratification of the prognosis. Ki-67 index was the significant prognostic factor for PNETs. Recently, MMP-9, DJ-1, and α-1-B glycoprotein (A1BG) were shown to be the prognostic markers in some malignant tumors except for PNETs. The aim of this study was to compare these tumor markers for predicting disease-free survival in surgically resected PNETs. A retrospective review of patients pathologically diagnosed with PNETs at our institution from January 2012 to January 2014 was conducted. Tumor specimens were stained by immunochemistry for MMP-9, DJ-1, A1BG, and Ki-67. Clinicopathologic findings and these 4 tumor markers of patients with PNETs were analyzed. Prognostic factors were determined by univariate and multivariate analyses. A total of 40 patients were selected. Of 40 tumors, 19 (47.5%) were positive for MMP-9, 21 (52.5%) for DJ-1, 18 (45%) for A1BG, and 24 (60%) for Ki-67 > 2%. Four (10%) tumors expressed none of the markers. MMP-9 and DJ-1 expression were more frequently observed in distant metastasis, higher WHO grade, and lymph node metastasis. Similarly, those with Ki-67 > 2% had larger tumor, higher WHO grade, lymph node invasion and larger surgical procedures. A1BG had no substantial effect on distant metastasis. Univariate analyses revealed that grade 2/3 histology, distant metastasis, lymph nodes metastasis, high expression of MMP-9, high expression of DJ-1, and Ki-67 > 2% were predictive of inferior disease-free survival for PNETs (all p < 0.05). In multivariable analysis, the significant poor factors associated with disease-free survival were grade 2/3 histology, distant metastasis, lymph node metastasis, and Ki-67 > 2% (all p < 0.05). Of the 4 markers studied, only Ki-67 was the independent prognostic factor. Expression of MMP-9 and DJ-1 correlated with invasion, metastasis, disease progression, and poor prognosis in PNETs, while A1BG had no prognostic value in PNETs. It is anticipated that these findings can serve as useful clinical survival predictors, especially in the setting of resected disease.

Pancreatic polypeptide as a biomarker for pancreatic neuroendocrine tumors.

e21109 Background: Pancreatic neuroendocrine tumors (PNETs) represent tumors that secrete numerous proteins that could be used as biomarkers. We present a retrospective analysis of patients with PNETs who have had Pancreatic Polypeptide (PP) testing in an attempt to better define PP producing tumors as an entity and the role of PP as a biomarker. To our knowledge, this is the first single center comprehensive review of Pancreatic Polypeptide producing tumors. Methods: A retrospective study of patients with PNETs seen at Mount Sinai from 1980 to 2011. All patients that have had PP concentrations measured at least once were evaluated. Data relating to diagnosis, pathology, surgery, liver directed therapies, chemotherapy and survival outcome were noted. 71 patients with PNETs fulfilled the inclusion criteria. The 71 patients formed 4 subgroups. The 4 subgroups were evaluated and compared for survival: all 71 PP tested patients, 30 patients with PP producing tumors, 8 patients with PPomas, 22 patients with PP producing tumors that were non PP-omas and 41 patients with PP non-producing tumors Results: We identified a trend towards better survival for PNETs patients with PP producing tumors vs. non- PP producing tumors (p=0.19). There was no correlation between survival and a diagnosis of PPoma in relation to other PP producing tumors (p= 0.59) or non-PP producing tumors (p=0.58). Conclusions: Pancreatic Polypeptide is a biomarker that is worth prospective investigation and a standardized assay. Our analysis investigating Pancreatic Polypeptide as a prognostic and or predictive biomarker reveals a trend towards showing these characteristics. Using a standardized test and investigating this biomarker prospectively could lead to the validation of Pancreatic Polypeptide as a biomarker.

Biomarkers in pancreatic neuroendocrine tumors.

166 Background: This study was designed to determine the role of Chromogranin A (CGA) and serotonin as prognostic biomarkers in relation with cytoreductive surgery for pancreatic neuroendocrine tumors (PNETs).The role of CGA and serotonin as biomarkers for PNETs is not fully established. Clinicians use CGA to monitor progression of disease and response to treatment; however this hasn’t been fully validated. There is no definitive data for serotonin as prognostic biomarker in PNETs. Methods: A retrospective study of patients with PNETs seen at Mount Sinai from 1980 to 2011 was performed. All patients (142) that have had CGA and serotonin concentrations measured at least once were evaluated. Data relating to diagnosis, therapies and survival outcome were noted Results: We evaluated the probability of survival post cytoreductive surgery among patients characterized by their postoperative CGA and serotonin values. 27 patients have had CGA level measured early post-op (0 to 3 months) and 30 patients have had CGA measurement late post-op (3-12 months). We identified no correlation between survival and a normal CGA early post-op (p = 0.5895). We identified a trend (p=0.1369) towards increase in survival for patients with a normal CGA late post-op with a probability in survival of 92.86% vs 65.12% at 3 years and median months to death of 80.265 for normal CGA vs 50.39 months for high CGA late post-op. For the 22 patients that had both a CGA early and late post-op the probability of survival by their change from early to late post- surgery CgA values was not statistically significant (p=0.2903). Serotonin did not correlate with survival in any of the 3 analyses: early post op, late postop or change in serotonin level. Conclusions: The role of CGA as a predictive or prospective biomarker for PNETs is worth prospective investigation. Our study shows that late post-op CGA may predict clinical outocome while CGA early postop and serotonin early, late and change post op did not have value in predicting survival.

Non-Functioning Pancreatic Neuroendocrine Tumors—A Case Report and Review of Literature

Neuroendocrine tumors of pancreas (PNET) are rare pancreatic neoplasms comprising 1-2% of all pancreatic tumors. The overall prognosis and long-term survival for PNET patients is far better than for patients with exocrine pancreatic cancer. PNETs are classified as functional or nonfunctional based on the presence or absence of a specific clinical syndrome associated with hormone oversecretion. We present the case of a 36-year-old female with epigastric and right upper quadrant abdominal pain for 3months associated with decreased appetite, early satiety and a 20-lb weight loss. On examination, she was cachectic with hepatomegaly. Laboratory assays showed elevated liver and pancreatic enzymes. On computed tomography (CT) scan of the abdomen and pelvis, there was a low-attenuation mass in the distal pancreatic tail measuring 4.7 × 2.4cm with multiple liver masses, omental implants, left ovarian mass, and a small amount of ascites. CT-guided liver biopsy on pathology was consistent with a well-differentiated pancreatic neuroendocrine carcinoma with metastasis to the liver. Assays for biomarkers of pancreatic neuroendocrine tumors showed an elevated chromogranin A with normal to non-specific elevations of the rest. The patient and her family declined palliative chemoembolization of the liver lesions or palliative chemotherapy and desired home hospice. We describe here the presentation and course of the case as well as a literature review of PNET with particular emphasis on nonfunctioning PNETs.