Faculty Bibliography

Introduction: World Health Organization (WHO) grading system is prognostic in pancreatic neuroendocrine tumors (PanNETs). Concordance between WHO-grade on cytology (c-grade) of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and histopathological analysis (h-grade) of surgical specimen is reported between 60% and 80%. Factors associated with concordance and trends of utilization of EUS-FNA remain poorly understood.
Method(s): A multicenter retrospective study was performed on patients undergoing resection for PanNETs at four high-volume centers. Patients with functional or syndrome-associated tumors, and those receiving neoadjuvant therapy were excluded. Factors associated with concordance and trends of utilization of EUS-FNA were assessed.
Result(s): Of 1,329 patients, 682 (51.1%) underwent EUS-FNA; 567(83.1%) were diagnostic of PanNETs and WHO-grade was reported for 293 (51.7%) patients. The concordance between c-grade and h-grade was 78.2% with moderate inter-rater agreement (Kc=0.48,p<0.001). Significantly higher rates of concordance were observed in patients with smaller tumors (<2 vs. >=2 cm, 88.9% vs. 72.7%,p=0.001). The highest concordance of 97.9% was observed in patients with small tumors undergoing assessment between 2015-2019 with near perfect inter-rater agreement (Kc=0.88, p<0.001) An increase in utilization of EUS-FNA (46.7% to 62.1%) was observed over the last 2 decades (p<0.001). EUS-FNA was more frequently diagnostic of PanNETs (p<0.001), and WHO-grade was more frequently reported (<0.001). Concordance between c-grade and h-grade did not change significantly (p=0.056).
Conclusion(s): Recently, a trend towards increasing utilization and improved diagnostic accuracy of EUS-FNA has been observed in PanNETs. Concordance between c-grade and h-grade is associated with tumor size with strong agreement when assessing PanNETs >2cm in size.
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Although the natural history of recurrence/progression in patients with intraductal papillary mucinous neoplasms (IPMN) of the pancreas has not been studied thoroughly, the three principal mechanisms have been identified: (a) presence of residual disease at the transection margin, (b) presence of intraductal/intraparenchymal metastases and (c) development of new primary lesions. Mechanisms (a) and (b) result in metastatic lesions that are genetically related to the primary, while new primary lesions (mechanism c) are genetically distinct. Interestingly, recurrence/progression in IPMN displays conceptual parallels with the well-established paradigm of disease recurrence in patients with hepatocellular carcinoma (HCC). Specifically, patients with HCC may also develop recurrent tumors due to microscopic residual disease/intrahepatic metastasis which are genetically similar to the primary while the development of genetically unrelated, de novo HCC after curative-intent resection is also common. The latter has been attributed to the presence of a widespread genetic abnormality ("field defect") in the liver (ie, cirrhosis). Given the conceptual similarities between IPMN and HCC, a pancreatic "field defect"may also be hypothesized to exist. This review does not suggest that HCC and IPMN have identical pathogeneses, but rather that they have conceptual similarities in tumor recurrence/progression; thus, lessons learned from HCC could be applied to IPMN research and subsequent management. Conceptual similarities in tumor progression and recurrence may also be observed between IPMN and other malignancies. However, HCC was selected because it is well studied and can serve as a paradigm.

BACKGROUND:Nonfunctional pancreatic neuroendocrine tumors display a wide range of biological behavior, and nodal disease is associated with metastatic disease and poorer survival. The aim of this study was to develop a tool to predict nodal disease in patients with small (≤2 cm) nonfunctional pancreatic neuroendocrine tumors. METHODS:A multicenter retrospective study was performed on patients undergoing resection for small nonfunctional pancreatic neuroendocrine tumors. Patients with genetic syndromes, metastatic disease at diagnosis, neoadjuvant therapy, or positive resection margin were excluded. Factors associated with nodal disease were identified to develop a predictive model. Internal validation was performed using bootstrap with 1,000 resamples. RESULTS:Nodal disease was observed in 39 (11.1%) of the 353 patients included. Presence of nodal disease was significantly associated with lower 5-year disease-free survival (71.6% vs 96.2%, P < .001). Two predictors were strongly associated with nodal disease: G2 grade (odds ratio: 3.51, 95% confidence interval: 1.71-7.22, P = .001) and tumor size (per mm increase, odds ratio: 1.14, 95% confidence interval: 1.03-1.25, P = .009). Adequate discrimination was observed with an area under the curve of 0.71 (95% confidence interval: 0.63-0.80). Based on risk distribution, 3 risk groups of nodal disease were identified; low (<5%), intermediate (≥5% to <20%), and high (≥20%) risk. The observed mean risk of nodal disease was 3.7% in the low-risk patients, 9.6% in the intermediate-risk patients, and 30.4% in the high-risk patients (P < .001). The 10-year disease-free survival in the low, intermediate, and high-risk groups was 100%, 88.8%, and 50.1%, respectively. CONCLUSION/CONCLUSIONS:Our model using tumor grade and size can predict nodal disease in small nonfunctional pancreatic neuroendocrine tumors. Integration of this tool into clinical practice could help guide management of these patients.

BACKGROUND:Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare with low-grade malignancy and unclarified clinicopathological features. This study aimed to examine their characteristics and re-evaluate current treatments. METHODS:Databases from three sources were screened for patients with SPNs. We compared the perioperative variables, clinical data, overall survival (OS), and prognostic factors for recurrence among the three corresponding cohorts. RESULTS:We identified 286 patients diagnosed with SPNs between 1988 and 2020. Patients were mostly women (81%; median age: 38 years), and peak incidence was observed in women of 20-29 years of age. SPNs had a peak incidence in Asian men at 50-59 years of age (p = 0.002) and a delayed peak incidence in Asian women at 30-39 years of age (p < 0.001). Treatment strategies differed significantly across the institutions and included variations in the number of harvested lymph nodes and rates of vascular resection. Lymph node positivity was the only predictor of postoperative recurrence (odds ratio, 2.2; 95% confidence interval, 1.38-2.99; p = 0.007). Higher rates of lymphovascular invasion (p = 0.02), perineural invasion (p < 0.001), and R1 margin involvement (p < 0.001), as seen in one institution, did not result in poorer long-term survival in terms of the overall (p = 0.43), SPN-specific (p = 0.69), and recurrence-free survivals (p = 0.067). CONCLUSIONS:In contrast to previous findings that SPNs are prevalent in young women, a racial predilection for middle-aged Asian men and a delayed female peak incidence were noted. Parenchyma-preserving pancreatectomy may be an acceptable treatment. Non-radical surgery may be appropriate in patients with multiple comorbidities.

Background/UNASSIGNED:Recent literature suggests wide variations exist in the international management of locally advanced pancreatic cancer. This study sought to evaluate how geography contributes to variations in management of locally advanced pancreatic cancer. Methods/UNASSIGNED:An electronic survey investigating preferences for the evaluation and management of locally advanced pancreatic cancer was distributed to an international cohort of pancreatic surgeons. Surgeons were classified according to geographic location of practice, and survey responses were compared across locations. Results/UNASSIGNED:A total of 153 eligible responses were received from 4 continents: North and South America (n = 94, 61.4%), Europe (n = 25, 16.3%), and Asia (n = 34, 22.2%). Preferences for the use and duration of neoadjuvant chemotherapy and radiotherapy varied widely. For example, participants in Asia commonly preferred 2 months of neoadjuvant chemotherapy (61.8%), whereas North and South American participants preferred 4 months (52.1%), and responses in Europe were mixed (P = .006). Participants in Asia were less likely to consider isolated liver or lung metastases contraindications to exploration and consequently had a greater propensity to consider exploration in a vignette of oligometastatic disease (56.7% vs North and South America: 25.6%, Europe: 43.5%; P = .007). Conclusion/UNASSIGNED:In an international survey of pancreatic surgeons, attitudes regarding locally advanced pancreatic cancer and metastatic disease management varied widely across geographic locations. Better evidence is needed to define optimal management of locally advanced pancreatic cancer.

PURPOSE/OBJECTIVE:A wide array of benign and malignant lesions of the pancreas can be cystic and these cystic lesions can have overlapping imaging appearances. The purpose of this study is to compare the diagnostic accuracy of a radiomics-based pancreatic cyst classifier to an experienced academic radiologist. METHODS:In this IRB-approved retrospective single-institution study, patients with surgically resected pancreatic cysts who underwent preoperative abdominal CT from 2003 to 2016 were identified. Pancreatic cyst(s) and background pancreas were manually segmented, and 488 radiomics features were extracted. Random forest classification based on radiomics features, age, and gender was evaluated with fourfold cross-validation. An academic radiologist blinded to the final pathologic diagnosis reviewed each case and provided the most likely diagnosis. RESULTS:214 patients were included (64 intraductal papillary mucinous neoplasms, 33 mucinous cystic neoplasms, 60 serous cystadenomas, 24 solid pseudopapillary neoplasms, and 33 cystic neuroendocrine tumors). The radiomics-based machine learning approach showed AUC of 0.940 in pancreatic cyst classification, compared with AUC of 0.895 for the radiologist. CONCLUSION/CONCLUSIONS:Radiomics-based machine learning achieved equivalent performance as an experienced academic radiologist in the classification of pancreatic cysts. The high diagnostic accuracy can potentially maximize the efficiency of healthcare utilization by maximizing detection of high-risk lesions.

Background: Pancreatectomy remains the only potentially curative therapy for patients with pancreatic ductal adenocarcinoma (PDAC). Existing literature reports that 27-68% of patients require perioperative allogeneic blood transfusion (PBT). An historical practice of liberal PBT use is being questioned as data emerges documenting a detrimental long-term oncologic effect. The impact of transfusion in an era of restrictive PBT is incompletely described. Methods: Single-institution, prospectively maintained databases identified 546 patients who underwent resection for PDAC from 2009 to 2015. Patients were stratified by PBT and clinicopathological variables and outcomes were analyzed by multivariable Cox regression to determine risk-adjusted hazard ratios (HR). Results: The 238 patients (43.0%) who received PBT, were more likely to be elderly or have a history of coagulopathy and anemia. PBT was also more common with rising American Society of Anesthesiologist (ASA) class, neoadjuvant therapy, higher estimated blood loss, positive margins, and need for vascular resection. The median overall survival (OS) for the entire cohort was 24.8 months. PBT was associated with a poorer median OS (17.2 vs. 27.4 months, P<0.001). On multivariable analysis, PBT was independently associated with poorer OS (HR =1.45, P=0.006). Receipt of two or more blood units was associated with a shorter survival (15.9 vs. 26.8 months, P<0.001). Conclusions: Patients are more apt to require PBT with increasing comorbidities, locally-advanced/borderline-resectable tumors, and neoadjuvant therapy. After risk adjustment, PBT is associated with decreased survival, while increasing transfusion requirements are associated with poorer outcome. This is the largest single-institution study confirming the effects of PBT on long-term outcomes after pancreatectomy for PDAC.

OBJECTIVES/OBJECTIVE:To identify predictors, patterns, and timing of recurrence after resection of invasive carcinomas arising in association with an IPMN. BACKGROUND:Postoperative management of an invasive carcinoma arising in association with an intraductal papillary mucinous neoplasm (IPMN), a biologically distinct entity from PanIN-derived pancreatic ductal adenocarcinoma (PDAC), remains largely based on guidelines for PanIN-derived PDAC. To minimize treatment failure and inform disease-specific management, cancer recurrence must be better characterized. METHODS:Patients were identified from a prospectively maintained registry between 1996 and 2018. Predictors of recurrence were evaluated by employing Cox regression models to determine risk-adjusted hazard ratios (HR) with 95% confidence intervals (95%CI). The patterns and timing of recurrence were recognized and compared utilizing a log-rank test, respectively. RESULTS:Of the 213 patients included, 92 (43.2%) recurred with a median RFS of 23.7 months (16.7-30.7). The predominant pattern of recurrence included any systemic (65.2%). The median time to local recurrence was longer than systemic (21.6 versus 11.4 months, p = 0.05). Poor differentiation [HR: 3.01, 95%CI (1.06-8.61)] and nodal disease [N1, HR: 2.23, 95%CI (1.12-4.60); and N2, HR: 5.67 95%CI (2.93-10.99)] emerged as independent predictors of systemic recurrence. For local-specific recurrences, poor differentiation [HR: 3.73, 95%CI (1.04-13.45)] and an R1 margin [high-grade dysplasia or invasive carcinoma; HR: 2.66, 95%CI (1.14-6.21)] emerged as independent predictors. CONCLUSIONS:The predominant pattern of recurrence after resection of invasive carcinomas arising in association with IPMNs is systemic, and occurs earlier than local recurrence. Poor differentiation and nodal disease are associated with systemic recurrence while poor differentiation and an R1 margin are associated with local recurrence. Future studies should investigate the role of systemic (chemotherapy) versus local (radiation) therapies and surveillance strategies in a personalized manner.

BACKGROUND:Postoperative chemotherapy following pancreatic cancer resection is the standard of care. The utility of postoperative chemotherapy for patients who receive neoadjuvant therapy (NAT) is unclear. METHODS:Patients who underwent pancreatectomy after NAT with FOLFIRINOX or gemcitabine-based chemotherapy for non-metastatic pancreatic adenocarcinoma (2015-2019) were identified. Patients who received less than 2 months of neoadjuvant chemotherapy or died within 90 days from surgery were excluded. RESULTS:A total of 427 patients (resectable, 22.2%; borderline resectable, 37.9%; locally advanced, 39.8%) were identified with the majority (69.3%) receiving neoadjuvant FOLFIRINOX. Median duration of NAT was 4.1 months. Following resection, postoperative chemotherapy was associated with an improved median overall survival (OS) (28.7 vs. 20.4 months, P = 0.006). Risk-adjusted multivariable modeling showed negative nodal status (N0), favorable pathologic response (College of American Pathologists score 0 & 1), and receipt of postoperative chemotherapy to be independent predictors of improved OS. Regimen, duration, and number of cycles of NAT were not significant predictors. Thirty-four percent (60/176) of node-positive and 50.1% (126/251) of node-negative patients did not receive postoperative chemotherapy due to poor functional status, postoperative complications, and patient preference. Among patients with node-positive disease, postoperative chemotherapy was associated with improved median OS (27.2 vs. 10.5 months, P < 0.001). Among node-negative patients, postoperative chemotherapy was not associated with a survival benefit (median OS, 30.9 vs. 36.9 months; P = 0.406). CONCLUSION/CONCLUSIONS:Although there is no standard NAT regimen for patients with pancreatic cancer, postoperative chemotherapy following NAT and resection appears to be associated with improved OS for patients with node-positive disease.

Pancreatic ductal adenocarcinoma is the third-leading cause of all cancer-related deaths in the US. While 20% of patients have resectable disease at diagnosis, improved control of systemic disease using effective chemotherapeutic regimens allows for aggressive operations involving complex vascular resection and reconstruction. A pancreas protocol computed tomography (PPCT) is the gold standard imaging modality in determining local resectability (degree of tumor-vessel involvement), however, it is limited by the inter-operator variability. While post-processing-3D-rendering helps, it does not allow for real-time dynamic assessment of resectability. A recent development in post-process-rendering called cinematic rendering (CR) overcomes this by utilizing advanced light modeling to generate photorealistic 3D images with enhanced details. Cinematic rendering allows for nuanced visualization of areas of interest. Our preliminary experience, as one of the first centers to incorporate the routine use of CR, has proven very useful in surgical planning. For local determination of resectability, vascular mapping allows for accurate assessment of major arteries and the portovenous system. For the portovenous anatomy it assists in determining the optimal surgical approach (extent of resection, appropriate technique for reconstruction, and need for mesocaval shunting). For arterial anatomy, vessel encasement either represents dissectible involvement via periadventitial dissection or true vessel invasion that is unresectable. CR could potentially provide superior ability than traditional PPCT to discern between the two. Additionally, CR allows for better 3D visualization of arterial anatomic variants which, if not appreciated preoperatively, increases risk of intraoperative ischemia and postoperative complications. Lastly, CR could help avoid unnecessary surgery by enhanced identification of occult metastatic disease that is metastatic disease that is otherwise not appreciated on a standard PPCT.