Faculty Bibliography

BACKGROUND AND AIMS/OBJECTIVE:Low-risk branch duct intraductal papillary mucinous neoplasms (BD-IPMN lacking worrisome features (WF) and high-risk stigmata (HRS)), warrant surveillance. However, their optimal duration, especially among cysts with initial five years of size stability, warrants further investigation. We aim to systematically review the surveillance of low-risk BD-IPMNs and investigate incidence of WF/HRS and advanced neoplasia: high-grade dysplasia and pancreatic cancer during the initial (<five-year) and extended surveillance period (≥five-year). METHODS:A systematic search (CRD42020117120) identified studies investigating long-term IPMN surveillance outcomes of low-risk IPMN among Cochrane Library, Embase, Google Scholar, Ovid Medline, PubMed, Scopus, and Web of Science, from inception until July 9, 2021. The outcomes included incidence of WF/HRS and advanced neoplasia, disease-specific mortality, and surveillance-related harm (expressed as % patient-years). The meta-analysis relied on time-to-event plots and utilized random-effects model. RESULTS:Forty-one eligible studies underwent systematic review, and eighteen studies were meta-analyzed. Pooled incidence of WF/HRS among low-risk BD-IPMNs during initial and extended surveillance were 2.2% [95%CI:1.0%-3.7%] and 2.9% [95%CI:1.0%-5.7%] patient-years, respectively, whereas incidence of advanced neoplasia were 0.6%[95%CI:0.2%-1.00%] and 1.0%[95%CI:0.6%-1.5%] patient-years, respectively. Pooled incidence of disease-specific mortality during initial and extended surveillance were 0.3% [95%CI:0.1% - 0.6%] and 0.6% [95%CI: 0.0%-1.6%] patient-years, respectively. Among BD-IPMNs with initial size stability, extended surveillance had WF/HRS and advanced neoplasia incidence of 1.9%[95%CI:1.2%-2.8%] and 0.2%[95%CI:0.1%-0.5%] patient-years, respectively. CONCLUSION/CONCLUSIONS:A lower incidence of advanced neoplasia during extended surveillance among low-risk, stable-sized BD-IPMNs is a key finding of this study. However, the survival benefit of surveillance among this population warrants further exploration through high-quality studies before recommending surveillance cessation with certainty.

Since its emergence as a diagnostic modality in the 1980s, endoscopic ultrasound (EUS) has provided the clinician profound access to gastrointestinal organs to aid in the direct visualization, sampling, and subsequent identification of pancreatic pathology. In recent years, advancements in EUS as an interventional technique have promoted the use of local ablative therapies as a minimally invasive alternative to the surgical management of pancreatic neuroendocrine tumors (pNETs) and pancreatic cystic neoplasms (PCNs), especially for those deemed to be poor operative candidates. EUS-guided local therapies have demonstrated promising efficacy in addressing a spectrum of pancreatic neoplasms, while also balancing local adverse effects on healthy parenchyma. This article serves as a review of the current literature detailing the mechanisms, outcomes, complications, and limitations of EUS-guided local ablative therapies such as chemical ablation and radiofrequency ablation (RFA) for the treatment of pNETs and PCNs, as well as a discussion of future applications of EUS-guided techniques to address a broader scope of pancreatic pathology.

Cholangiocarcinoma remains an aggressive and deadly malignancy that is often diagnosed late. Intrinsic tumour characteristics and the growth pattern of cancer cells contribute to the challenges of diagnosis and chemoresistance. However, establishing an early and accurate diagnosis, and in some instances identifying targetable changes, has the potential to impact survival. Primary sclerosing cholangitis, a chronic cholangiopathy prodromal to the development of a minority of cholangiocarcinomas, poses a particular diagnostic challenge. We present our diagnostic and theranostic approach to the initial evaluation of cholangiocarcinomas, focusing on extrahepatic cholangiocarcinoma. This involves a multipronged strategy incorporating advanced imaging, endoscopic methods, multiple approaches to tissue sampling, and molecular markers. We also provide an algorithm for the sequential use of these tools.

The tumor microenvironment (TME) in pancreatic ductal adenocarcinoma (PDAC) is a complex ecosystem that drives tumor progression; however, in-depth single cell characterization of the PDAC TME and its role in response to therapy is lacking. Here, we perform single-cell RNA sequencing on freshly collected human PDAC samples either before or after chemotherapy. Overall, we find a heterogeneous mixture of basal and classical cancer cell subtypes, along with distinct cancer-associated fibroblast and macrophage subpopulations. Strikingly, classical and basal-like cancer cells exhibit similar transcriptional responses to chemotherapy and do not demonstrate a shift towards a basal-like transcriptional program among treated samples. We observe decreased ligand-receptor interactions in treated samples, particularly between TIGIT on CD8 + T cells and its receptor on cancer cells, and identify TIGIT as the major inhibitory checkpoint molecule of CD8 + T cells. Our results suggest that chemotherapy profoundly impacts the PDAC TME and may promote resistance to immunotherapy.

Introduction: Pancreatic cancer continues to carry a dismal prognosis due to the high failure rates of conventional first line treatments. There is growing interest in the molecular profiling of tumors to guide early initiation of targeted therapies. Nearly all patients undergo endoscopic ultrasound (EUS) fine needle aspiration or biopsy as the initial diagnostic procedure. Therefore, we sought to assess the yield of EUS biopsies in obtaining samples for molecular profiling of pancreatic tumors and investigated the endoscopic factors associated with successful EUS sampling.
Method(s): We performed a search for all EUS-guided needle biopsies done for the indication of suspected pancreatic mass on imaging between January 2017 and January 2022. We then limited our cases to those diagnosed with pancreatic adenocarcinoma and had EUS samples sent for molecular profiling. Molecular profiling was done with next-generation sequencing with either a targeted panel of 648 genes or 324 genes. Differences in tumor size, number of needle passes, and needle gauge size between the successful sampling and non-successful sampling groups were determined by Mann-Whitney U Test using SPSS Statistics.
Result(s): We identified 309 consecutive cases where the diagnosis of pancreatic adenocarcinoma was established by EUS. Fifty-nine EUS biopsies were sent for molecular profiling and of these, fifty-three were sufficient for molecular testing (89.5% success rate). No procedural factors were significantly associated with successful sampling though we observed larger mean tumor sizes (31.3 vs 28 mm) and greater mean number of needle passes (3.4 vs 2.7 mean passes) in the successful sampling group. In Figure, we show the most commonly identified mutations and identify those that at the time had potential clinical impact on therapies. The yield of actionable mutations was 14% in the 53 patients who were successfully tested. (Figure)
Conclusion(s): Our results support that yield of somatic mutation testing is high from standard of care EUS biopsies and no obvious procedural factors were associated with failure of testing. We found that 14% of patients had actionable mutations. As the number of available targeted therapies improve, we expect the impact of this highly technically successful approach to grow (Table)

BACKGROUND:Genetic testing is recommended for all pancreatic ductal adenocarcinoma (PDAC) patients. Prior research demonstrates that multidisciplinary pancreatic cancer clinics (MDPCs) improve treatment- and survival-related outcomes for PDAC patients. However, limited information exists regarding the utility of integrated genetics in the MDPC setting. We hypothesized that incorporating genetics in an MDPC serving both PDAC patients and high-risk individuals (HRI) could: (1) improve compliance with guideline-based genetic testing for PDAC patients, and (2) optimize HRI identification and PDAC surveillance participation to improve early detection and survival. METHODS:Demographics, genetic testing results, and pedigrees were reviewed for PDAC patients and HRI at one institution over 45 months. Genetic testing analyzed 16 PDAC-associated genes at minimum. RESULTS:Overall, 969 MDPC subjects were evaluated during the study period; another 56 PDAC patients were seen outside the MDPC. Among 425 MDPC PDAC patients, 333 (78.4%) completed genetic testing; 29 (8.7%) carried a PDAC-related pathogenic germline variant (PGV). Additionally, 32 (9.6%) met familial pancreatic cancer (FPC) criteria. These PDAC patients had 191 relatives eligible for surveillance or genetic testing. Only 2/56 (3.6%) non-MDPC PDAC patients completed genetic testing (p < 0.01). Among 544 HRI, 253 (46.5%) had a known PGV or a designation of FPC, and were eligible for surveillance at baseline; of the remainder, 15/291 (5.2%) were eligible following genetic testing and PGV identification. CONCLUSION/CONCLUSIONS:Integrating genetics into the multidisciplinary setting significantly improved genetic testing compliance by reducing logistical barriers for PDAC patients, and clarified cancer risks for their relatives while conserving clinical resources. Overall, we identified 206 individuals newly eligible for surveillance or genetic testing (191 relatives of MDPC PDAC patients, and 15 HRI from this cohort), enabling continuity of care for PDAC patients and at-risk relatives in one clinic.

BACKGROUND AND AIMS/OBJECTIVE:Pancreatic ductal adenocarcinoma is an aggressive disease most often diagnosed after local progression or metastatic dissemination, precluding resection and resulting in a high mortality rate. For individuals with elevated personal risk of the development of pancreatic cancer, EUS is a frequently used advanced imaging and diagnostic modality. However, there is variability in the expertise and definition of EUS findings among gastroenterologists, as well as lack of standardized reporting of relevant findings at the time of examination. Adoption of standardized EUS reporting, using a universally accepted and agreed upon terminology, is needed. METHODS:A consensus statement designed to create a standardized reporting template was authored by a multidisciplinary group of experts in pancreatic diseases that includes gastroenterologists, radiologists, surgeons, oncologists, and geneticists. This statement was developed using a modified Delphi process as part of the Pancreatic Cancer Early Detection Consortium (PRECEDE) and >75% agreement was required to reach consensus. RESULTS:We identified reporting elements and present standardized reporting templates for EUS indications, procedural data, EUS image capture, and descriptors of findings, tissue sampling, and for postprocedural assessment of adequacy. CONCLUSIONS:Adoption of this standardized EUS reporting template should improve consistency in clinical decision making for individuals with elevated risk of pancreatic cancer by providing complete and accurate reporting of pancreatic abnormalities. Standardization will also help to facilitate research and clinical trial design by using clearly defined and consistent imaging descriptions, thus allowing for comparison of results across different centers.

BACKGROUND:Identifying branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) at lowest risk of progression may allow for a reduced intensity of surveillance. OBJECTIVE:We aimed to externally validate the previously developed Dutch-American Risk stratification Tool (DART-1; https://rtools.mayo.edu/DART/), which identifies cysts at low risk of developing worrisome features (WFs) or high-risk stigmata (HRS). METHODS:Three prospective cohorts of individuals under surveillance for BD-IPMNs were combined, independent from the original development cohort. We assessed the performance (discrimination and calibration) of DART-1, a multivariable Cox-proportional logistic regression model with five predictors for the development of WFs or HRS. RESULTS:Of 832 individuals (mean age 77 years, SD 11.5) under surveillance for a median of 40 months (IQR 44), 163 (20%) developed WFs or HRS. DART-1's discriminative ability (C-statistic 0.68) was similar to that in the development cohort (0.64-0.72) and showed moderate calibration. DART-1 adequately estimated the risk for patients in the middle risk quintile, and slightly underestimated it in the lowest quintiles. Their range of predicted versus observed 3-year risk was 0%-0% versus 0%-3.7% for Q1; 0.3%-0.4% versus 3%-11% for Q2; and 2.6%-3% versus 2.4%-9.8% for Q3. The development of WFs or HRS was associated with pancreatic cancer (p < 0.001). Vice versa, in absence of WFs or HRS, the risk of malignancy was low (0.3%). CONCLUSIONS:The performance of DART-1 to predict the development of WFs or HRS in BD-IPMN was validated in an external international cohort, with a discriminative ability equal as in the development cohort. Risk estimations were most accurate for patients with BD-IPMNs in the middle risk quintile and slightly underestimated in the lowest quintiles.