A Combined DNA/RNA-based Next-Generation Sequencing Platform to Improve the Classification of Pancreatic Cysts and Early Detection of Pancreatic Cancer Arising From Pancreatic Cysts.

OBJECTIVE: We report the development and validation of a combined DNA/RNA next-generation sequencing (NGS) platform to improve the evaluation of pancreatic cysts. BACKGROUND AND AIMS: Despite a multidisciplinary approach, pancreatic cyst classification, such as a cystic precursor neoplasm, and the detection of high-grade dysplasia and early adenocarcinoma (advanced neoplasia) can be challenging. NGS of preoperative pancreatic cyst fluid improves the clinical evaluation of pancreatic cysts, but the recent identification of novel genomic alterations necessitates the creation of a comprehensive panel and the development of a genomic classifier to integrate the complex molecular results. METHODS: An updated and unique 74-gene DNA/RNA-targeted NGS panel (PancreaSeq Genomic Classifier) was created to evaluate 5 classes of genomic alterations to include gene mutations (e.g., KRAS, GNAS, etc.), gene fusions and gene expression. Further, CEA mRNA ( CEACAM5 ) was integrated into the assay using RT-qPCR. Separate multi-institutional cohorts for training (n=108) and validation (n=77) were tested, and diagnostic performance was compared to clinical, imaging, cytopathologic, and guideline data. RESULTS: Upon creation of a genomic classifier system, PancreaSeq GC yielded a 95% sensitivity and 100% specificity for a cystic precursor neoplasm, and the sensitivity and specificity for advanced neoplasia were 82% and 100%, respectively. Associated symptoms, cyst size, duct dilatation, a mural nodule, increasing cyst size, and malignant cytopathology had lower sensitivities (41-59%) and lower specificities (56-96%) for advanced neoplasia. This test also increased the sensitivity of current pancreatic cyst guidelines (IAP/Fukuoka and AGA) by >10% and maintained their inherent specificity. CONCLUSIONS: PancreaSeq GC was not only accurate in predicting pancreatic cyst type and advanced neoplasia but also improved the sensitivity of current pancreatic cyst guidelines.

Longer Course of Induction Chemotherapy Followed by Chemoradiation Favors Better Survival Outcomes for Patients With Locally Advanced Pancreatic Cancer.

OBJECTIVES: At diagnosis, 30% of patients with pancreatic cancer are unresectable stage 3 locally advanced. The standard treatment for locally advanced pancreatic cancer (LAPC) is not defined. The current study was conducted to assess the roles of chemotherapy and chemoradiation for LAPC treatment. MATERIALS AND METHODS: Between June 2006 and March 2011, 100 patients with LAPC were treated at the Johns Hopkins Hospital. Retrospective analysis was performed to compare cumulative incidence of progression (CIP) and overall survival (OS) among different subgroups. RESULTS: For the 100 patients, the median OS was 15.8 months and the median CIP was 8.4 months. The combination of chemotherapy and chemoradiation before disease progression was significantly associated with improved CIP (P=0.001) and improved OS when compared with chemoradiation alone (median OS: 16.4 vs. 11.1 mo, P=0.03). Among patients receiving combination treatment, patients who received chemotherapy first followed by chemoradiation had a trend toward lower CIP (P=0.09) and improved OS (median OS: 18.1 vs. 11.0 mo, P=0.09). Patients who received >2 cycles of chemotherapy before chemoradiation had a significantly decreased CIP (P=0.008) and a trend toward better OS (median OS: 19.4 vs. 15.7 mo, P=0.10). On multivariate analysis, receiving >2 cycles of chemotherapy before chemoradiation was associated with improved CIP. CONCLUSIONS: Although combination chemotherapy and chemoradiation is favored in the treatment of LAPC, longer induction chemotherapy may play a more important role in sensitization of tumors to subsequent chemoradiation. Our results support treating patients with induction chemotherapy for at least 3 cycles followed by consolidative chemoradiation. These results merit further validation by a prospective study.

A single institution's 26-year experience with nonfunctional pancreatic neuroendocrine tumors: a validation of current staging systems and a new prognostic nomogram.

OBJECTIVE: To validate the 2010 American Joint Committee on Cancer (AJCC) and 2006 European Neuroendocrine Tumor Society (ENETS) tumor staging systems for pancreatic neuroendocrine tumors (PanNETs) using the largest, single-institution series of surgically resected patients in the literature. BACKGROUND: The natural history and prognosis of PanNETs have been poorly defined because of the rarity and heterogeneity of these neoplasms. Currently, there are 2 main staging systems for PanNETs, which can complicate comparisons of reports in the literature and thereby hinder progress against this disease. METHODS: Univariate and multivariate analyses were conducted on the prognostic factors of survival using 326 sporadic, nonfunctional, surgically resected PanNET patients who were cared for at our institution between 1984 and 2011. Current and proposed models were tested for survival prognostication validity as measured by discrimination (Harrel's c-index, HCI) and calibration. RESULTS: Five-year overall-survival rates for AJCC stages I, II, and IV are 93% (88%-99%), 74% (65%-83%), and 56% (42%-73%), respectively, whereas ENETS stages I, II, III, and IV are 97% (92%-100%), 87% (80%-95%), 73% (63%-84%), and 56% (42%-73%), respectively. Each model has an HCI of 0.68, and they are no different in their ability to predict survival. We developed a simple prognostic tool just using grade, as measured by continuous Ki-67 labeling, sex, and binary age that has an HCI of 0.74. CONCLUSIONS: Both the AJCC and ENETS staging systems are valid and indistinguishable in their survival prognostication. A new, simpler prognostic tool can be used to predict survival and decrease interinstitutional mistakes and uncertainties regarding these neoplasms.

Grading of well-differentiated pancreatic neuroendocrine tumors is improved by the inclusion of both Ki67 proliferative index and mitotic rate.

The grading system for pancreatic neuroendocrine tumors (PanNETs) adopted in 2010 by the World Health Organization (WHO) mandates the use of both mitotic rate and Ki67/MIB-1 index in defining the proliferative rate and assigning the grade. In cases when these measures are not concordant for grade, it is recommended to assign the higher grade, but specific data justifying this approach do not exist. Thus, we counted mitotic figures and immunolabeled, using the Ki67 antibody, 297 WHO mitotic grade 1 and 2 PanNETs surgically resected at a single institution. We quantified the Ki67 proliferative index by marking at least 500 cells in "hot spots" and by using digital image analysis software to count each marked positive/negative cell and then compared the results with histologic features and overall survival. Of 264 WHO mitotic grade 1 PanNETs, 33% were WHO grade 2 by Ki67 proliferative index. Compared with concordant grade 1 tumors, grade-discordant tumors were more likely to have metastases to lymph node (56% vs. 34%) (P<0.01) and to distant sites (46% vs. 12%) (P<0.01). Discordant mitotic grade 1 PanNETs also showed statistically significantly more infiltrative growth patterns, perineural invasion, and small vessel invasion. Overall survival was significantly different (P<0.01), with discordant mitotic grade 1 tumors showing a median survival of 12 years compared with 16.7 years for concordant grade 1 tumors. Conversely, mitotic grade 1/Ki67 grade 2 PanNETs showed few significant differences from tumors that were mitotic grade 2 and either Ki67 grade 1 or 2. Our data demonstrate that mitotic rate and Ki67-based grades of PanNETs are often discordant, and when the Ki67 grade is greater than the mitotic grade, clinical outcomes and histopathologic features are significantly worse than concordant grade 1 tumors. Patients with discordant mitotic grade 1/Ki67 grade 2 tumors have shorter overall survival and larger tumors with more metastases and more aggressive histologic features. These data strongly suggest that Ki67 labeling be performed on all PanNETs in addition to mitotic rate determination to define more accurately tumor grade and prognosis.

Progression of gene hypermethylation in gallstone disease leading to gallbladder cancer.

BACKGROUND: Aberrant methylation of tumor-suppressor genes is associated with a loss of gene function that can afford selective growth advantages to sporadic neoplastic cells arising during gallbladder inflammation. METHODS: Fifty-four gallbladder neoplasms were selected from tumor banks in the United States and Chile. Each of the neoplasms was subjected to methylation-specific polymerase chain reaction to detect promoter methylation associated with six candidate tumor-suppressor genes (p16, APC, methylguanine methyltransferase, hMLH1, retinoic acid receptor beta-2, and p73) implicated in multiple human cancer types. RESULTS: Aberrant methylation of any of the six candidate tumor-suppressor genes was detected in 72% of the gallbladder neoplasms, 28% of the cases of chronic cholecystitis, and in only 1 of the 15 normal gallbladder controls. The four most commonly methylated genes in the gallbladder cancers were p16 (56%), p73 (28%), APC (27%), and hMLH1 (14%). Significant differences in gene methylation were discovered between US gallbladder cancers and those from Chile, where gallbladder cancer is one of the leading causes of cancer-related deaths. APC methylation was present in 42% of the US cases but in only 14% of the Chilean tumors (P =.028). p73 methylation was common among the Chilean cancers (40%) compared with those from the United States (13%; P =.034). CONCLUSIONS: The acquisition of hypermethylation at multiple tumor-suppressor gene-promoter sites may contribute to tumor formation and progression within the chronically inflamed gallbladder. The apparent differences in methylation patterns among the Chilean and US gallbladder cases may indicate a unique biology associated with this cancer in different parts of the world.