O. Joe Hines

Evidence for Proteotoxicity in β Cells in Type 2 Diabetes: Toxic Islet Amyloid Polypeptide Oligomers Form Intracellularly in the Secretory Pathway

The islet in type 2 diabetes mellitus (T2DM) is characterized by a deficit in beta cells and islet amyloid derived from islet amyloid polypeptide (IAPP), a protein co-expressed with insulin by beta cells. It is increasingly appreciated that the toxic form of amyloidogenic proteins is not amyloid but smaller membrane-permeant oligomers. Using an antibody specific for toxic oligomers and cryo-immunogold labeling in human IAPP transgenic mice, human insulinoma and pancreas from humans with and without T2DM, we sought to establish the abundance and sites of formation of IAPP toxic oligomers. We conclude that IAPP toxic oligomers are formed intracellularly within the secretory pathway in T2DM. Most striking, IAPP toxic oligomers appear to disrupt membranes of the secretory pathway, and then when adjacent to mitochondria, disrupt mitochondrial membranes. Toxic oligomer-induced secretory pathway and mitochondrial membrane disruption is a novel mechanism to account for cellular dysfunction and apoptosis in T2DM.

Neoadjuvant therapy in pancreatic adenocarcinoma: A meta-analysis of phase II trials

BACKGROUND Neoadjuvant treatment has proven beneficial for many gastrointestinal (GI) malignancies, but no phase III trials have been completed examining this approach in pancreatic cancer. This meta-analysis examines the best available phase II trials using neoadjuvant treatment for resectable and borderline/unresectable pancreatic adenocarcinoma. METHODS Phase II trials were identified using a MEDLINE search, and the Cochrane Central Register of Controlled Trials from 1960 to July 2010. Patients were divided into 2 groups: Patients with initially resectable tumors (group A), and patients with borderline/unresectable tumors (group B). Primary outcome measures were rate of resection and survival. Pooled proportions and 95% confidence intervals (CIs) were calculated using random-effects or fixed-effects models based on the heterogeneity of included studies. RESULTS A total of 14 phase II clinical trials including 536 patients were analyzed. After treatment, resectability was 65.8% (95% CI, 55.4-75.6%) compared with 31.6% in group B (95% CI, 14.0-52.5%). A partial response was observed in patients with borderline/unresectable tumors; 31.8 (95% CI, 24.2-39.8%) in group B and 9.5% (95% CI, 2.9-19.4%) in group A (P = .003). Progressive disease was seen in 17.0% (95% CI, 11.9-22.7) of patients in group A versus 21.8% (95% CI, 10.1-36.5%) in group B (P = .006). Median survival in resected patients was 23 months for group A and 22 months for group B. CONCLUSION Neoadjuvant treatment seems to have some activity in patients with borderline/unresectable pancreatic adenocarcinoma. Nearly one third of tumors initially deemed marginal for operative intervention were able to be ultimately resected after treatment. Until more effective targeted chemotherapeutics are developed, the only group of patients with pancreatic cancer that may benefit from neoadjuvant treatment are those with locally advanced disease.

Early Detection of Sporadic Pancreatic Cancer: Summative Review

Abstract Pancreatic cancer (PC) is estimated to become the second leading cause of cancer death in the United States by 2020. Early detection is the key to improving survival in PC. Addressing this urgent need, the Kenner Family Research Fund conducted the inaugural Early Detection of Sporadic Pancreatic Cancer Summit Conference in 2014 in conjunction with the 45th Anniversary Meeting of the American Pancreatic Association and Japan Pancreas Society. This seminal convening of international representatives from science, practice, and clinical research was designed to facilitate challenging interdisciplinary conversations to generate innovative ideas leading to the creation of a defined collaborative strategic pathway for the future of the field. An in-depth summary of current efforts in the field, analysis of gaps in specific areas of expertise, and challenges that exist in early detection is presented within distinct areas of inquiry: Case for Early Detection: Definitions, Detection, Survival, and Challenges; Biomarkers for Early Detection; Imaging; and Collaborative Studies. In addition, an overview of efforts in familial PC is presented in an addendum to this article. It is clear from the summit deliberations that only strategically designed collaboration among investigators, institutions, and funders will lead to significant progress in early detection of sporadic PC.

Predicting Performance on the American Board of Surgery Qualifying and Certifying Examinations: A Multi-institutional Study

BACKGROUND We sought to determine whether US Medical Licensing Examination (USMLE) Step 1 score, American Board of Surgery (ABS) In-Training Examination (ABSITE) score, and other variables are associated with failing the ABS qualifying and certifying examinations. Identifying such factors may assist in the early implementation of an academic intervention for at-risk residents. DESIGN Retrospective review. SETTING Seventeen general surgery training programs in the western United States. PARTICIPANTS Six hundred seven residents who graduated in 2000-2007. MAIN OUTCOME MEASURES First-time pass rates on the qualifying and certifying examinations, US vs non-US medical school graduation, USMLE Steps 1 and 2 scores, ABSITE scores, operative case volume, fellowship training, residency program type, and mandatory research. RESULTS The first-time qualifying and certifying examination pass rates for the 607 graduating residents were 78% and 74%, respectively. On multivariable analysis, scoring below the 35th percentile on the ABSITE at any time during residency was associated with an increased risk of failing both examinations (odds ratio, 0.23 [95% confidence interval, 0.08-0.68] for the qualifying examination and 0.35 [0.20-0.61] for the certifying examination), as was scoring less than 200 on the USMLE Step 1 (0.36 [0.21-0.62] for the qualifying examination and 0.62 [0.42-0.93] for the certifying examination). A mandatory research year was associated with an increased likelihood of passing the certifying examination (odds ratio, 3.3 [95% confidence interval, 1.6-6.8]). CONCLUSIONS Residents who are more likely to fail the ABS qualifying and certifying examinations can be identified by a low USMLE Step 1 score and by poor performance on the ABSITE at any time during residency. These findings support the use of the USMLE Step 1 score in the surgical residency selection process and a formal academic intervention for residents who perform poorly on the ABSITE.

Overexpression of CXCL5 Is Associated With Poor Survival in Patients With Pancreatic Cancer

Epithelial neutrophil-activating peptide-78 (CXCL5), a member of the CXC chemokine family, has been shown to be involved in angiogenesis, tumor growth, and metastasis. The objective of this study was to determine the relationship between CXCL5 expression and tumor progression in human pancreatic cancer and to elucidate the mechanism underlying CXCL5-mediated tumor angiogenesis and cancer growth. We report herein that CXCL5 is overexpressed in human pancreatic cancer compared with paired normal pancreas tissue. Overexpression of CXCL5 is significantly correlated with poorer tumor differentiation, advanced clinical stage, and shorter patient survival. Patients with pancreatic cancer and CXCL5 overexpression who underwent resection of cancer had a mean survival time 25.5 months shorter than that of patients who did not overexpress CXCL5. Blockade of CXCL5 or its receptor CXCR2 by small-interfering RNA knockdown or antibody neutralization attenuated human pancreatic cancer growth in a nude mouse model. Finally, we demonstrated that CXCL5 mediates pancreatic cancer-derived angiogenesis through activation of several signaling pathways, including protein kinase B (Akt), extracellular signal-regulated kinase (ERK), and signal transducer and activator of transcription (STAT) in human endothelial cells. These data suggest that CXCL5 is an important mediator of tumor-derived angiogenesis and that it may serve as a survival factor for pancreatic cancer. Blockade of either CXCL5 or CXCR2 may be a critical adjunct antiangiogenic therapy against pancreatic cancer.

Improved Survival Following Pancreaticoduodenectomy to Treat Adenocarcinoma of the Pancreas: The Influence of Operative Blood Loss

HYPOTHESIS Although the safety of pancreaticoduodenectomy has notably improved over the past several decades, the reported survival of patients with pancreatic cancer remains poor. We hypothesized that, in recent years, the survival of patients with pancreatic adenocarcinoma following pancreaticoduodenectomy has substantially improved. DESIGN Retrospective case series. SETTING Major academic medical and pancreatic surgery center. PATIENTS A total of 182 consecutive patients underwent pancreaticoduodenectomy for various diagnoses between 1987 and 2005. Patients from 1987-1995 were compared with patients from 1996-2005. INTERVENTIONS Pancreaticoduodenectomy for patients with a diagnosis of pancreatic adenocarcinoma. MAIN OUTCOME MEASURES Survival after pancreaticoduodenectomy and patient outcomes. RESULTS During the time period analyzed, 182 patients underwent pancreaticoduodenectomy to treat ductal adenocarcinoma. There were no operative deaths, and 86.3% of patients had an R0 resection. The 5-year survival rate for the entire group was 27.4%. However, survival improved from 15.8% to 35.5% during the study period. Both groups had equivalent demographic and pathological characteristics, and the only predictors of poor survival in multivariate analysis were operative blood loss of more than 400 mL (hazard ratio, 2.17), poorly differentiated tumors (3.03), lymph node metastases (1.92), perineural invasion (2.66), and undergoing an operation before 1996 (1.42). CONCLUSIONS The survival rate for patients undergoing pancreaticoduodenectomy to treat pancreatic cancer has substantially improved. This finding is partially owing to improved operative technique and limited operative blood loss.

An Orthotopic Nude Mouse Model for Evaluating Pathophysiology and Therapy of Pancreatic Cancer

Introduction Orthotopic, clinically relevant animal models are necessary for the study of pathophysiology and therapy for pancreatic cancer. Aims To develop a minimally traumatic technique of orthotopic tumor induction, to develop a scoring system to quantify local and systemic tumor spread, and to provide a model with a broad range of well-differentiated to undifferentiated pancreatic cancers. Methodology Orthotopic tumors were induced in nude mice by atraumatic pancreatic implantation of two fragments from subcutaneous donor tumors or intrapancreatic injection of human tumor cells (MIAPaCa-2, AsPC-1, HPAF-2, Capan-1). Animals were monitored for 14 weeks or until death. Primary tumor volume, local infiltration, and systemic metastasis were assessed and analyzed at autopsy. Macroscopic findings were confirmed by histologic evaluation. Results Tumor take rate in the implantation group was 100% for all four cell lines. Marked differences with regard to tumor size, metastatic spread, and survival were found depending on the grade of differentiation. Less differentiated cells (MIAPaCa-2, AsPC-1) caused higher dissemination scores and mortality than better-differentiated cells (HPAF-2, Capan-1). Clinical features included cachexia, jaundice, and malignant ascites. Orthotopic tumor cell injection resulted in an incomplete tumor take rate. Moreover, early artificial abdominal tumor spread was found in injected animals due to microscopic cell loss during the injection procedure. Conclusions Orthotopic implantation of donor tumor fragments into nude mice is technically feasible and is superior to the cell injection technique. It results in reproducible local and systemic development of pancreatic cancer that mimics the human disease. A dissemination score may help to better quantify therapeutic effects in future studies.

Survival After Resection of Ampullary Carcinoma: A National Population-Based Study

BackgroundAmpullary cancer is the second most common periampullary cancer, with a resection and survival rate more favorable than that for pancreatic cancer. However, most reports have been conducted at single institutions with small sample sizes, and results may not reflect the practices and outcomes in the community. Our objective was to complete a population-based analysis of patients undergoing resection for ampullary carcinoma and compare it with outcomes in the published literature.MethodsPatients diagnosed with ampullary cancer reported in the Surveillance, Epidemiology, and End Results program (1988–2003) were collected. Primary outcome was survival (5-year), and secondary outcome was stage at presentation. Comparisons were made with outcomes reported in the literature (resection rate, perioperative mortality, and 5-year survival).ResultsOf the 3292 ampullary cancer patients, 1301 (40%) underwent resection. Thirty-seven percent presented with stage I tumors. Perioperative mortality (30 day) was 7.6% after resection, and 5-year survival was 36.8%. Few patients died if they survived at least 5 years. The cancer registry data showed less early stage disease, higher perioperative mortality, and lower 5-year survival compared with published reports.ConclusionsThis is the largest population-based analysis of ampullary carcinoma. Resection rates and survival at the national level are lower, in general, compared with cancer center reports, which may have implications for regionalizing these procedures. Many patients surviving at least 5 years seem to be cured by surgical resection.

Pancreatic Cyst Disease: A Review

IMPORTANCE Cystic lesions of the pancreas are common and increasingly detected in the primary care setting. Some patients have a low risk for developing a malignancy and others have a high risk and need further testing and interventions. OBSERVATIONS Pancreatic cysts may be intraductal mucinous neoplasms, mucinous cystic neoplasms, serous cystadenomas, solid pseudopapillary neoplasms, cystic variations of pancreatic neuroendocrine tumors, pancreatic ductal adenocarcinomas, or 1 of several types of nonneoplastic cysts. Mucinous (intraductal mucinous neoplasm or mucinous cystic neoplasm) lesions have malignant potential and should be distinguished from serous lesions (serous cystadenomas) that are nearly always benign. Symptomatic patients or those having high-risk features on initial imaging (eg, main pancreatic duct dilatation, a solid component, or mural nodule) require further evaluation with advanced imaging, possibly followed by surgical resection. Advanced imaging includes endoscopic ultrasound with cyst fluid analysis and cytology to confirm the type of cyst and determine the risk of malignancy. Small cysts (size <3 cm) in asymptomatic patients without any suspicious features may be observed with serial imaging because the risk for malignancy is low. CONCLUSIONS AND RELEVANCE The management of pancreatic cysts requires risk stratification for malignant potential based on the presence or absence of symptoms and high-risk features on cross-sectional imaging. Because pancreatic cysts are becoming more frequently diagnosed, clinicians should have a systematic approach for establishing a diagnosis and determining which patients require treatment.

Pancreatic–pleural fistula is best managed by early operative intervention

BACKGROUND Pancreatic-pleural fistula is an uncommon complication of chronic pancreatitis occurring as a result of disruption of the main pancreatic duct and tracking of pancreatic fluid through the retroperitoneum into 1 or both thoracic cavities. The optimal treatment strategy for pancreatic-pleural fistula is unknown; it has traditionally been medical management followed by operative therapy for patients who fail to respond to conservative treatment. Our objective was to compile the case reports of pancreatic-pleural fistula in the literature in order to better define clinical management strategy. METHODS The case management of pancreatic-pleural fistula was reviewed and a structured MEDLINE search for published studies was performed. Descriptive statistical analysis was performed on compiled data. RESULTS Review of the literature revealed 63 adult patients with pancreatic-pleural fistula published in English between 1970 and 2008. The majority of patients were male (71%) and there was a predominance of alcohol-associated chronic pancreatitis (51%). There were 10 complications (16%) and 2 deaths (3%) reported. Most patients were treated initially with medical therapy (87%). Medical therapy was deemed to have failed after an average period of 35+/-5 days. Total duration of therapy for patients in whom operative intervention was required after attempted medical management was 40+/-6 days, which was greater than the surgery alone cohort. In total, operative treatment was successful more often than medical therapy (94% vs 31%). CONCLUSION Analysis from this series indicates that a majority of patients recover from pancreatic-pleural fistula without sequelae (81%). Attempts at prolonged periods of medical therapy tend to delay the resolution of the fistula compared with patients who undergo definitive operative intervention early in the course of treatment.