Faculty Bibliography

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreaticobiliary cytology including indications for endoscopic ultrasound (EUS) and fine-needle aspiration (FNA) biopsy, techniques for EUS-FNA, terminology and nomenclature to be used for pancreaticobiliary disease, ancillary testing and postbiopsy management. All documents are based on expertise of the authors, literature review, discussions of the draft document at national and international meetings and synthesis of online comments of the draft document. This document selectively presents the results of these discussions. This document summarizes recommendations for the clinical and imaging work-up of pancreatic and biliary tract lesions along with indications for cytologic study of these lesions. Prebrushing and FNA requirements are also discussed.

The papanicolaou society of cytopathology (PSC) has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) biopsy, techniques of EUS-FNA, terminology and nomenclature for pancreatobiliary cytology, ancillary testing, and postprocedure management. All documents are based on the expertise of the authors, a review of the literature, discussions of the draft document at several national and international meetings over an 18 month period and synthesis of online comments of the draft document on the PSC web site [www.papsociety.org]. This document selectively presents the results of these discussions and focuses on the follow-up and treatment options for patients after procedures performed for obtaining cytology samples for the evaluation of biliary strictures and solid and cystic masses in the pancreas. These recommendations follow the six-tiered terminology and nomenclature scheme proposed by Committee III.

The Papanicolaou Society of Cytopathology (PSC) has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) biopsy, techniques of EUS-FNA, terminology and nomenclature for pancreatobiliary cytology, ancillary testing and post-procedure management. All documents are based on the expertise of the authors, a review of the literature and discussions of the draft document at several national and international meetings over an 18 month period and synthesis of online comments of the draft document on the PSC web site (www.papsociety.org). This document selectively presents the results of these discussions and focuses on the follow-up and treatment options for patients after procedures performed for obtaining cytology samples for the evaluation of biliary strictures and solid and cystic masses in the pancreas. These recommendations follow the six-tiered terminology and nomenclature scheme proposed by committee III.

Membrane bound vesicles, including microvesicles and exosomes, are secreted by both normal and cancerous cells into the extracellular space and in blood circulation. These circulating extracellular vesicles (cirEVs) and exosomes in particular are recognized as a potential source of disease biomarkers. However, to exploit the use of circulatory exosomes as a biomarker, a rapid, high-throughput and reproducible method is required for their isolation and molecular analysis. We have developed a simple, low cost microfluidic-based platform to isolate cirEVs enriched in exosomes directly from blood serum allowing simultaneous capture and quantification of exosomes in a single device. To capture specific exosomes, we employed "ExoChip", a microfluidic device fabricated in polydimethylsiloxane (PDMS) and functionalized with antibodies against CD63, an antigen commonly overexpressed in exosomes. Subsequent staining with a fluorescent carbocyanine dye (DiO) that specifically labels the exosomes, we quantitated exosomes using a standard plate-reader. Ten independent ExoChip experiments performed using serum obtained from five pancreatic cancer patients and five healthy individuals revealed a statistically significant increase (2.34 +/- 0.31 fold, p < 0.001) in exosomes captured in cancer patients when compared to healthy individuals. Exosomal origins of ExoChip immobilized vesicles were further confirmed using immuno-electron-microscopy and Western blotting. In addition, we demonstrate the ability of ExoChip to recover exosomes with intact RNA enabling profiling of exosomal-microRNAs through openarray analysis, which has potential applications in biomarker discovery. Based on our findings, ExoChip is a well suited platform to be used as an exosome-based diagnostic and research tool for molecular screening of human cancers.

PURPOSE OF REVIEW: To appraise the recent literature dealing with important advances in the field of pancreatic surgery. RECENT FINDINGS: Surgical care for pancreatic cancer patients remains fractured, with imperfect patient selection and ongoing bias in referral patterns based on socioeconomic factors. Analysis of readmissions after pancreatectomy reveals it to be a poor quality of care metric. More extensive pancreatic resections lead to higher morbidity. Intraductal papillary mucinous neoplasm and pancreatic neuroendocrine tumor biology affect patient outcomes and suggest the need for better diagnostic approaches for these entities. Perioperative drainage still has a role during Whipple pancreaticoduodenectomy on the basis of the results of a randomized controlled trial. Laparoscopic and robotic approaches married with new emerging technologies have the potential to transform the practice of pancreatic surgery. SUMMARY: Pancreatic surgery is a rapidly evolving field with the promise to significantly improve outcomes for patients with a variety of pancreatic diseases in the future.

OBJECTIVE: Patients with nonfunctional pancreatic neuroendocrine tumors (NF-PNETs) have poorer survival than those with functional PNETs. Our objective was to identify risk factors for recurrence after resection to better define surveillance parameters to improve long-term outcomes. METHODS: A retrospective analysis was performed for NF-PNET patients who underwent resection at the University of Michigan from 1995 to 2012. Immunohistochemical staining of tissues from patients with and without disease recurrence was performed for Ki-67 and the macrophage marker CD68, as tumor-associated macrophages are important for PNET development and progression. Clinicopathological factors and patient outcomes were measured. RESULTS: Ninety-seven NF-PNET patients underwent surgical resection. There was a recurrence rate of 14.4% (14/97). The median time to recurrence was 0.61 years, with 10 (71%) patients recurring within the first 2 years. Six of 7 patients (86%) monitored at 6-month surveillance intervals were diagnosed with recurrence on their first computed tomographic scan or during the intervening intervals. By Cox proportional hazards analysis, the most significant independent risk factors for recurrence were higher grade, stage, and intraoperative blood loss. High CD68 score and Ki-67 index correlated with recurrence risk, and Ki-67 index inversely correlated with time to recurrence. In patients who otherwise had few risk factors, a high CD68 score was a significant prognostic factor for recurrence. CONCLUSIONS: In patients with NF-PNETs, risk factors associated with recurrence were high EBL, grade, stage, CD68 score, and Ki-67 index. The CD68 score was an important prognostic factor in patients who otherwise had few clinicopathological risk factors; therefore, the CD68 score should be considered when planning surveillance strategies. We recommend that NF-PNET patients at high risk of recurrence undergo initial surveillance every 3 months for 2 years after surgery.

Single amino acid variations are highly associated with many human diseases. The direct detection of peptides containing single amino acid variants (SAAVs) derived from nonsynonymous single nucleotide polymorphisms (SNPs) in serum can provide unique opportunities for SAAV associated biomarker discovery. In the present study, an isobaric labeling quantitative strategy was applied to identify and quantify variant peptides in serum samples of pancreatic cancer patients and other benign controls. The largest number of SAAV peptides to date in serum including 96 unique variant peptides were quantified in this quantitative analysis, of which five variant peptides showed a statistically significant difference between pancreatic cancer and other controls (p-value < 0.05). Significant differences in the variant peptide SDNCEDTPEAGYFAVAVVK from serotransferrin were detected between pancreatic cancer and controls, which was further validated by selected reaction monitoring (SRM) analysis. The novel biomarker panel obtained by combining alpha-1-antichymotrypsin (AACT), Thrombospondin-1 (THBS1) and this variant peptide showed an excellent diagnostic performance in discriminating pancreatic cancer from healthy controls (AUC = 0.98) and chronic pancreatitis (AUC = 0.90). These results suggest that large-scale analysis of SAAV peptides in serum may provide a new direction for biomarker discovery research.

The potential utility of circulating tumor cells (CTCs) to guide clinical care in oncology patients has gained momentum with emerging micro- and nanotechnologies. Establishing the role of CTCs in tumor progression and metastasis depends both on enumeration and on obtaining sufficient numbers of CTCs for downstream assays. The numbers of CTCs are few in early stages of cancer, limiting detailed molecular characterization. Recent attempts in the literature to culture CTCs isolated from metastatic patients using monoculture have had limited success rates of less than 20%. Herein, we have developed a novel in-situ capture and culture methodology for ex-vivo expansion of CTCs using a three dimensional co-culture model, simulating a tumor microenvironment to support tumor development. We have successfully expanded CTCs isolated from 14 of 19 early stage lung cancer patients. Expanded lung CTCs carried mutations of the TP53 gene identical to those observed in the matched primary tumors. Next-generation sequencing further revealed additional matched mutations between primary tumor and CTCs of cancer-related genes. This strategy sets the stage to further characterize the biology of CTCs derived from patients with early lung cancers, thereby leading to a better understanding of these putative drivers of metastasis.

Circulating tumor cells (CTCs) are believed to play an important role in metastasis, a process responsible for the majority of cancer-related deaths. But their rarity in the bloodstream makes microfluidic isolation complex and time-consuming. Additionally the low processing speeds can be a hindrance to obtaining higher yields of CTCs, limiting their potential use as biomarkers for early diagnosis. Here, a high throughput microfluidic technology, the OncoBean Chip, is reported. It employs radial flow that introduces a varying shear profile across the device, enabling efficient cell capture by affinity at high flow rates. The recovery from whole blood is validated with cancer cell lines H1650 and MCF7, achieving a mean efficiency >80% at a throughput of 10 mL h(-1) in contrast to a flow rate of 1 mL h(-1) standardly reported with other microfluidic devices. Cells are recovered with a viability rate of 93% at these high speeds, increasing the ability to use captured CTCs for downstream analysis. Broad clinical application is demonstrated using comparable flow rates from blood specimens obtained from breast, pancreatic, and lung cancer patients. Comparable CTC numbers are recovered in all the samples at the two flow rates, demonstrating the ability of the technology to perform at high throughputs.

PURPOSE: In the current study we examined the ability of diffusion MRI (dMRI) to predict pathologic response in pancreatic cancer patients receiving neoadjuvant chemoradiation. METHODS: We performed a prospective pilot study of dMRI in patients with resectable pancreatic cancer. Patients underwent dMRI prior to neoadjuvant chemoradiation. Surgical specimens were graded according to the percent tumor cell destruction. Apparent diffusion coefficient (ADC) maps were used to generate whole-tumor derived ADC histogram distributions and mean ADC values. The primary objective of the study was to correlate ADC parameters with pathologic and CT response. RESULTS: Ten of the 12 patients enrolled on the study completed chemoradiation and had surgery. Three were found to be unresectable at the time of surgery and no specimen was obtained. Out of the 7 patients who underwent pancreaticoduodenectomy, 3 had a grade III histopathologic response (> 90% tumor cell destruction), 2 had a grade IIB response (51% to 90% tumor cell destruction), 1 had a grade IIA response (11% to 50% tumor cell destruction), and 1 had a grade I response (> 90% viable tumor). Median survival for patients with a grade III response, grade I-II response, and unresectable disease were 25.6, 18.7, and 6.1 months, respectively. There was a significant correlation between pre-treatment mean tumor ADC values and the amount of tumor cell destruction after chemoradiation with a Pearson correlation coefficient of 0.94 (P = .001). Mean pre-treatment ADC was 161 x 10(- 5) mm(2)/s (n = 3) in responding patients (> 90% tumor cell destruction) compared to 125 x 10(- 5) mm(2)/s (n = 4) in non-responding patients (> 10% viable tumor). CT imaging showed no significant change in tumor size in responders or non-responders. CONCLUSIONS: dMRI may be useful to predict response to chemoradiation in pancreatic cancer. In our study, tumors with a low ADC mean value at baseline responded poorly to standard chemoradiation and would be candidates for intensified therapy.