Faculty Bibliography

BACKGROUND:The purpose of this study was to investigate the prognostic significance of early (30-day) hospital readmission (EHR) on mortality after pancreatectomy. METHODS:Using a prospectively collected institutional database linked with a statewide dataset, we evaluated the association between EHR and overall mortality in all patients undergoing pancreatectomy at our tertiary institution (2005 to 2010). RESULTS:Of 595 pancreatectomy patients, EHR occurred in 21.5%. Overall mortality was 29.4% (median follow-up 22.7 months). Patients with EHR had decreased survival compared with those who were not readmitted (P = .011). On multivariate analysis adjusting for baseline group differences, EHR for gastrointestinal-related complications was a significant independent predictor of mortality (hazard ratio 2.30, P = .001). CONCLUSIONS:In addition to known risk factors, 30-day readmission for gastrointestinal-related complications following pancreatectomy independently predicts increased mortality. Additional studies are necessary to identify surgical, medical, and social factors contributing to EHR, as well as interventions aimed at decreasing postpancreatectomy morbidity and mortality.

Our neoadjuvant clinical trial of a GM-CSF secreting allogeneic pancreas tumor vaccine (GVAX) revealed the development of tertiary lymphoid aggregates (TLAs) within the pancreatic ductal adenocarcinoma (PDA) tumor microenvironment 2 weeks after GVAX treatment. Microarray studies revealed that multiple components of the TGF-β pathway were suppressed in TLAs from patients who survived greater than 3 years and who demonstrated vaccine-enhanced mesothelin-specific T cell responses. We tested the hypothesis that combining GVAX with TGF-β inhibitors will improve the anti-tumor immune response of vaccine therapy. In a metastatic murine model of pancreatic cancer, combination therapy with GVAX vaccine and a TGF-β blocking antibody improved the cure rate of PDA-bearing mice. TGF-β blockade in combination with GVAX significantly increased the infiltration of effector CD8+ T lymphocytes, specifically anti-tumor-specific IFN-g producing CD8+ T cells, when compared to monotherapy controls (all p < 0.05). TGF-β blockade alone did not deplete T regulatory cells (Tregs), but when give in combination with GVAX, GVAX induced intratumoral Tregs were depleted. Therefore, our PDA preclinical model demonstrates a survival advantage in mice treated with an anti-TGF-β antibody combined with GVAX therapy and provides strong rational for testing this combinational therapy in clinical trials.

Pancreatic resection has become a feasible treatment of pancreatic neoplasms, and with improvements in surgical techniques and perioperative management, mortality associated with pancreatic surgery has decreased considerably. Despite this improvement, a high rate of complications is still associated with these procedures. Among these complications, delayed gastric emptying (DGE) and postoperative pancreatic fistula (POPF) have a substantial impact on patient outcomes and burden our healthcare system. Technical modifications and postoperative approaches have been proposed to reduce rates of both POPF and DGE in patients undergoing pancreatectomy; however, to date, their rates have remained unchanged. In the present study, we summarize the findings of the most significant studies that have investigated these complications. In particular, several studies focused on technical modifications including extent of dissection, stent placement, nature of anastomosis, type of reconstruction, and application of biological or non-biological agents to site of anastomosis. Moreover, postoperatively, drain placement, duration of drain usage, postoperative feeding, and use of pharmacological agents were studied to reduce rates of POPF and DGE. In this review, we summarize the most relevant literature on this fundamental aspect of pancreatic surgery. Despite studies identifying the potential benefit of technical modifications and postoperative approaches, these findings remain controversial and suggest need for further extensive investigation. Most importantly, we recommend that all surgeons performing these procedures base their practice on the most updated and highest available level of evidence.

OBJECTIVE:The study aim was to quantify the burden of complications of pancreatoduodenectomy (PD). BACKGROUND:The Postoperative Morbidity Index (PMI) is a quantitative measure of the average burden of complications of a procedure. It is based on highly validated systems--ACS-NSQIP and the Modified Accordion Severity Grading System. METHODS:Nine centers contributed ACS-NSQIP complication data for 1589 patients undergoing PD from 2005 to 2011. Each complication was assigned a severity weight ranging from 0.11 for the least severe complication to 1.00 for postoperative death, and PMI was derived. Contribution to total burden by each complication grade was used to generate a severity profile ("spectrogram") for PD. Associations with PMI were determined by regression analysis. RESULTS:ACS-NSQIP complications occurred in 528 cases (33.2%). The non-risk-adjusted PMI was 0.115 (SD = 0.023) for all centers and 0.113 (SD = 0.005) for the 7 centers that contributed at least 100 cases. Grade 2 complications were predominant in frequency, and the most common complication was postoperative bleeding/transfusion. Frequency and burden of complications differed markedly. For instance, severe complications (grades 4/5/6) accounted for only about 20% of complications but for more than 40% of the burden of complications. Organ space infection had the highest burden of any complication. The average burden in cases in which a complication actually occurred was 0.346. CONCLUSIONS:This study develops a quantitative non-risk-adjusted benchmark for postoperative morbidity of PD. The method quantifies the burden of types and grades of postoperative complications and should prove useful in identifying areas that require quality improvement.

BACKGROUND:While contemporary studies demonstrate decreasing complication rates following total pancreatectomy (TP), none have quantified the impact of post-TP complications. The Postoperative Morbidity Index (PMI)-a quantitative measure of postoperative morbidity-combines ACS-NSQIP complication data with severity weighting derived from Modified Accordion Grading System. We establish the PMI for TP in a multi-institutional cohort. METHODS:Nine institutions contributed ACS-NSQIP data for 64 TPs (2005-2011). Each complication was assigned an Accordion severity weight ranging from 0.110 (grade 1/mild) to 1.00 (grade 6/death). PMI equals the sum of complication severity weights ("Total Burden") divided by total number of patients. RESULTS:Overall, 29 patients (45.3 %) suffered 55 ACS-NSQIP complications; 15 (23.4 %) had >1 complication. Thirteen patients (20.3 %) were readmitted and one death (1.6 %) occurred within 30 days. Non-risk adjusted PMI was 0.151, while PMI for complication-bearing cases rose to 0.333. Bleeding/Transfusion and Sepsis were the most common complications. Discordance between frequency and burden of complications was observed. While grades 4-6 comprised only 18.5 % of complications, they contributed 37.1 % to the series' total burden. CONCLUSION/CONCLUSIONS:This multi-institutional series is the first to quantify the complication burden following TP using the rigor of ACS-NSQIP. A PMI of 0.151 indicates that, collectively, patients undergoing TP have an average burden of complications in the mild to moderate severity range, although complication-bearing patients have a considerable reduction in health utility.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with a dismal prognosis. However, while most patients die within the first year of diagnosis, very rarely, a few patients can survive for >10 years. Better understanding the molecular characteristics of the pancreatic adenocarcinomas from these very-long-term survivors (VLTS) may provide clues for personalized medicine and improve current pancreatic cancer treatment. To extend our previous investigation, we examined the proteomes of individual pancreas tumor tissues from a group of VLTS patients (survival >/=10 years) and short-term survival patients (STS, survival <14 months). With a given analytical sensitivity, the protein profile of each pancreatic tumor tissue was compared to reveal the proteome alterations that may be associated with pancreatic cancer survival. Pathway analysis of the differential proteins identified suggested that MYC, IGF1R and p53 were the top three upstream regulators for the STS-associated proteins, and VEGFA, APOE and TGFbeta-1 were the top three upstream regulators for the VLTS-associated proteins. Immunohistochemistry analysis using an independent cohort of 145 PDAC confirmed that the higher abundance of ribosomal protein S8 (RPS8) and prolargin (PRELP) were correlated with STS and VLTS, respectively. Multivariate Cox analysis indicated that 'High-RPS8 and Low-PRELP' was significantly associated with shorter survival time (HR=2.69, 95% CI 1.46-4.92, P=0.001). In addition, galectin-1, a previously identified protein with its abundance aversely associated with pancreatic cancer survival, was further evaluated for its significance in cancer-associated fibroblasts. Knockdown of galectin-1 in pancreatic cancer-associated fibroblasts dramatically reduced cell migration and invasion. The results from our study suggested that PRELP, LGALS1 and RPS8 might be significant prognostic factors, and RPS8 and LGALS1 could be potential therapeutic targets to improve pancreatic cancer survival if further validated.