Mark J. Truty

Total laparoscopic pancreaticoduodenectomy for pancreatic ductal adenocarcinoma: oncologic advantages over open approaches?

Objective:To directly compare the oncologic outcomes of TLPD and OPD in the setting of pancreatic ductal adenocarcinoma. Background:Total laparoscopic pancreaticoduodenectomy (TLPD) has been demonstrated to be feasible and may have several potential advantages over open pancreaticoduodenectomy (OPD), including lower blood loss and shorter hospital stay. Whether potential advantages could allow patients to recover in a timelier manner and pursue adjuvant treatment options remains to be answered. Methods:We reviewed data for all patients undergoing TLPD (N = 108) or OPD (N = 214) for pancreatic ductal adenocarcinoma at our institution between January 2008 and July 2013. Results:Neoadjuvant therapy, tumor size, node positivity, and margin-positive resection were not significantly different between the 2 groups. Median length of hospital stay was significantly longer in the OPD group (9 days; range, 5–73 days) than in the TLPD group (6 days; range, 4–118 days; P < 0.001). There was a significantly higher proportion of patients in the OPD group (12%) who had a delay of greater than 90 days or who did not receive adjuvant chemotherapy at all compared with that in the TLPD group (5%; P = 0.04). There was no significant difference in overall survival between the 2 groups (P = 0.22). A significantly longer progression-free survival was seen in the TLPD group than in the OPD group (P = 0.03). Conclusions:TLPD is not only feasible in the setting of pancreatic ductal adenocarcinoma but also has advantages such as shorter hospital stay and faster recovery, allowing patients to recover in a timelier manner and pursue adjuvant treatment options. This study also demonstrated a longer progression-free survival in patients undergoing TLPD than those undergoing OPD.

Kinetic Growth Rate after Portal Vein Embolization Predicts Posthepatectomy Outcomes: Toward Zero Liver-Related Mortality in Patients with Colorectal Liver Metastases and Small Future Liver Remnant

BACKGROUND Standardized future liver remnant (sFLR) volume and degree of hypertrophy after portal vein embolization (PVE) have been recognized as important predictors of surgical outcomes after major liver resection. However, the regeneration rate of the FLR after PVE varies among individuals and its clinical significance is unknown. STUDY DESIGN Kinetic growth rate (KGR) is defined as the degree of hypertrophy at initial volume assessment divided by number of weeks elapsed after PVE. In 107 consecutive patients who underwent liver resection for colorectal liver metastases with an sFLR volume >20%, the ability of the KGR to predict overall and liver-specific postoperative morbidity and mortality was compared with sFLR volume and degree of hypertrophy. RESULTS Using receiver operating characteristic analysis, the best cutoff values for sFLR volume, degree of hypertrophy, and KGR for predicting postoperative hepatic insufficiency were estimated as 29.6%, 7.5%, and 2.0% per week, respectively. Among these, KGR was the most accurate predictor (area under the curve 0.830 [95% CI, 0.736-0.923]; asymptotic significance, 0.002). A KGR of <2% per week vs ≥2% per week correlates with rates of hepatic insufficiency (21.6% vs 0%; p = 0.0001) and liver-related 90-day mortality (8.1% vs 0%; p = 0.04). The predictive value of KGR was not influenced by sFLR volume or the timing of initial volume assessment when evaluated within 8 weeks after PVE. CONCLUSIONS Kinetic growth rate is a better predictor of postoperative morbidity and mortality after liver resection for small FLR than conventional measured volume parameters (ie, sFLR volume and degree of hypertrophy).

Basics of TGF-β and Pancreatic Cancer

Pancreatic cancer is the 4th leading cause of cancer-related death in the United States. The number of diagnoses per year equals the number of deaths per year, making it the deadliest of all malignancies. Modern advances and breakthroughs in molecular oncology have allowed researchers to gain a better understanding of the mechanisms responsible for the pathogenesis of this disease. The transforming growth factor-β (TGF-β) pathway is one of the signaling systems that has been identified as a major contributor. TGF-β plays a paradoxical role as both a tumor suppressor and a tumor promoter in pancreatic cancer. The purpose of this review is to provide the practicing clinician a thorough review of this molecule and its associated signaling partners in the context of its duplicitous role and behavior in patients with pancreatic cancer.

Transport properties of pancreatic cancer describe gemcitabine delivery and response

BACKGROUND The therapeutic resistance of pancreatic ductal adenocarcinoma (PDAC) is partly ascribed to ineffective delivery of chemotherapy to cancer cells. We hypothesized that physical properties at vascular, extracellular, and cellular scales influence delivery of and response to gemcitabine-based therapy. METHODS We developed a method to measure mass transport properties during routine contrast-enhanced CT scans of individual human PDAC tumors. Additionally, we evaluated gemcitabine infusion during PDAC resection in 12 patients, measuring gemcitabine incorporation into tumor DNA and correlating its uptake with human equilibrative nucleoside transporter (hENT1) levels, stromal reaction, and CT-derived mass transport properties. We also studied associations between CT-derived transport properties and clinical outcomes in patients who received preoperative gemcitabine-based chemoradiotherapy for resectable PDAC. RESULTS Transport modeling of 176 CT scans illustrated striking differences in transport properties between normal pancreas and tumor, with a wide array of enhancement profiles. Reflecting the interpatient differences in contrast enhancement, resected tumors exhibited dramatic differences in gemcitabine DNA incorporation, despite similar intravascular pharmacokinetics. Gemcitabine incorporation into tumor DNA was inversely related to CT-derived transport parameters and PDAC stromal score, after accounting for hENT1 levels. Moreover, stromal score directly correlated with CT-derived parameters. Among 110 patients who received preoperative gemcitabine-based chemoradiotherapy, CT-derived parameters correlated with pathological response and survival. CONCLUSION Gemcitabine incorporation into tumor DNA is highly variable and correlates with multiscale transport properties that can be derived from routine CT scans. Furthermore, pretherapy CT-derived properties correlate with clinically relevant endpoints. TRIAL REGISTRATION Clinicaltrials.gov NCT01276613. FUNDING Lustgarten Foundation (989161), Department of Defense (W81XWH-09-1-0212), NIH (U54CA151668, KCA088084).

Preoperative Modified FOLFIRINOX Treatment Followed by Capecitabine-Based Chemoradiation for Borderline Resectable Pancreatic Cancer: Alliance for Clinical Trials in Oncology Trial A021101

IMPORTANCE Although consensus statements support the preoperative treatment of borderline resectable pancreatic cancer, no prospective, quality-controlled, multicenter studies of this strategy have been conducted. Existing studies are retrospective and confounded by heterogeneity in patients studied, therapeutic algorithms used, and outcomes reported. OBJECTIVE To determine the feasibility of conducting studies of multimodality therapy for borderline resectable pancreatic cancer in the cooperative group setting. DESIGN, SETTING, AND PARTICIPANTS A prospective, multicenter, single-arm trial of a multimodality treatment regimen administered within a study framework using centralized quality control with the cooperation of 14 member institutions of the National Clinical Trials Network. Twenty-nine patients with biopsy-confirmed pancreatic cancer preregistered, and 23 patients with tumors who met centrally reviewed radiographic criteria registered. Twenty-two patients initiated therapy (median age, 64 years [range, 50-76 years]; 55% female). Patients registered between May 29, 2013, and February 7, 2014. INTERVENTIONS Patients received modified FOLFIRINOX treatment (85 mg/m2 of oxaliplatin, 180 mg/m2 of irinotecan hydrochloride, 400 mg/m2 of leucovorin calcium, and then 2400 mg/m2 of 5-fluorouracil for 4 cycles) followed by 5.5 weeks of external-beam radiation (50.4 Gy delivered in 28 daily fractions) with capecitabine (825 mg/m2 orally twice daily) prior to pancreatectomy. MAIN OUTCOMES AND MEASURES Feasibility, defined by the accrual rate, the safety of the preoperative regimen, and the pancreatectomy rate. RESULTS The accrual rate of 2.6 patients per month was superior to the anticipated rate. Although 14 of the 22 patients (64% [95% CI, 41%-83%]) had grade 3 or higher adverse events, 15 of the 22 patients (68% [95% CI, 49%-88%]) underwent pancreatectomy. Of these 15 patients, 12 (80%) required vascular resection, 14 (93%) had microscopically negative margins, 5 (33%) had specimens that had less than 5% residual cancer cells, and 2 (13%) had specimens that had pathologic complete responses. The median overall survival of all patients was 21.7 months (95% CI, 15.7 to not reached) from registration. CONCLUSIONS AND RELEVANCE The successful completion of this collaborative study demonstrates the feasibility of conducting quality-controlled trials for this disease stage in the multi-institutional setting. The data generated by this study and the logistical elements that facilitated the trials completion are currently being used to develop cooperative group trials with the goal of improving outcomes for this subset of patients. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01821612.

EUS-guided pancreatic duct intervention: outcomes of a single tertiary-care referral center experience.

BACKGROUND EUS can provide access to the main pancreatic duct (MPD) for therapeutic intervention. The long-term clinical success of EUS-guided MPD interventions is unknown. OBJECTIVE To determine technical and clinical success rates, predictors of success, and long-term outcomes of EUS-guided MPD intervention. DESIGN Retrospective, single-center study. SETTING Tertiary-care referral center. PATIENTS Forty-five patients. INTERVENTION EUS-guided MPD stent retrieval or placement. MAIN OUTCOME MEASUREMENTS Technical and clinical success rates, adverse events, and long-term clinical outcomes. RESULTS Among the 45 patients, 37 had undergone failed ERCP, and 29 had surgically altered anatomy. Median follow-up after initial EUS-guided intervention was 23 months. Two patients underwent EUS for stent removal, and EUS-guided MPD stent placement was attempted in 43 patients. Technical success was achieved in 32 of 43 patients (74%) with antegrade (n = 18) or retrograde (n = 14) stent insertion. Serious adverse events occurred in 3 patients (6%). Patients underwent a median of 2 (range 1-6) follow-up procedures for revision or removal of stents, without adverse events. Complete symptom resolution occurred in 24 of 29 patients (83%) while stents were in place, including all 6 with nondilated ducts. Stents were removed in 23 patients, who were then followed for an additional median of 32 months; 4 patients had recurrent symptoms. Among the 11 failed cases, most had persistent symptoms or required surgery. LIMITATIONS Retrospective study design, individualized patient management. CONCLUSION EUS-guided MPD intervention is feasible and safe, with long-term clinical success in the majority of patients. EUS provides important treatment options, particularly in patients who would otherwise undergo surgery.

Multi-color palette of fluorescent proteins for imaging the tumor microenvironment of orthotopic tumorgraft mouse models of clinical pancreatic cancer specimens

Pancreatic‐cancer‐patient tumor specimens were initially established subcutaneously in NOD/SCID mice immediately after surgery. The patient tumors were then harvested from NOD/SCID mice and passaged orthotopically in transgenic nude mice ubiquitously expressing red fluorescent protein (RFP). The primary patient tumors acquired RFP‐expressing stroma. The RFP‐expressing stroma included cancer‐associated fibroblasts (CAFs) and tumor‐associated macrophages (TAMs). Further passage to transgenic nude mice ubiquitously expressing green fluorescent protein (GFP) resulted in tumors that acquired GFP stroma in addition to their RFP stroma, including CAFs and TAMs as well as blood vessels. The RFP stroma persisted in the tumors growing in the GFP mice. Further passage to transgenic nude mice ubiquitously expressing cyan fluorescent protein (CFP) resulted in tumors acquiring CFP stroma in addition to persisting RFP and GFP stroma, including RFP‐ and GFP‐expressing CAFs, TAMs and blood vessels. This model can be used to image progression of patient pancreatic tumors and to visually target stroma as well as cancer cells and to individualize patient therapy. J. Cell. Biochem. 113: 2290–2295, 2012.

Silencing of the Transforming Growth Factor-β (TGFβ) Receptor II by Krüppel-like Factor 14 Underscores the Importance of a Negative Feedback Mechanism in TGFβ Signaling

The role of non-Smad proteins in the regulation of transforming growth factor-β (TGFβ) signaling is an emerging line of active investigation. Here, we characterize the role of KLF14, as a TGFβ-inducible, non-Smad protein that silences the TGFβ receptor II (TGFβRII) promoter. Together with endocytosis, transcriptional silencing is a critical mechanism for down-regulating TGFβ receptors at the cell surface. However, the mechanisms underlying transcriptional repression of these receptors remain poorly understood. KLF14 has been chosen from a comprehensive screen of 24 members of the Sp/KLF family due to its TGFβ inducibility, its ability to regulate the TGFβRII promoter, and the fact that this protein had yet to be functionally characterized. We find that KLF14 represses the TGFβRII, a function that is augmented by TGFβ treatment. Mapping of the TGFβRII promoter, in combination with site-directed mutagenesis, electromobility shift, and chromatin immunoprecipitation assays, have identified distinct GC-rich sequences used by KLF14 to regulate this promoter. Mechanistically, KLF14 represses the TGFβRII promoter via a co-repressor complex containing mSin3A and HDAC2. Furthermore, the TGFβ pathway activation leads to recruitment of a KLF14-mSin3A-HDAC2 repressor complex to the TGFβRII promoter, as well as the remodeling of chromatin to increase histone marks that associate with transcriptional silencing. Thus, these results describe a novel negative-feedback mechanism by which TGFβRII activation at the cell surface induces the expression of KLF14 to ultimately silence the TGFβRII and further expand the network of non-Smad transcription factors that participate in the TGFβ pathway.

Pancreatic cancer-derived exosomes cause paraneoplastic β-cell dysfunction

Purpose: Pancreatic cancer frequently causes diabetes. We recently proposed adrenomedullin as a candidate mediator of pancreatic β-cell dysfunction in pancreatic cancer. How pancreatic cancer–derived adrenomedullin reaches β cells remote from the cancer to induce β-cell dysfunction is unknown. We tested a novel hypothesis that pancreatic cancer sheds adrenomedullin-containing exosomes into circulation, which are transported to β cells and impair insulin secretion. Experimental Methods: We characterized exosomes from conditioned media of pancreatic cancer cell lines (n = 5) and portal/peripheral venous blood of patients with pancreatic cancer (n = 20). Western blot analysis showed the presence of adrenomedullin in pancreatic cancer-exosomes. We determined the effect of adrenomedullin-containing pancreatic cancer exosomes on insulin secretion from INS-1 β cells and human islets, and demonstrated the mechanism of exosome internalization into β cells. We studied the interaction between β-cell adrenomedullin receptors and adrenomedullin present in pancreatic cancer-exosomes. In addition, the effect of adrenomedullin on endoplasmic reticulum (ER) stress response genes and reactive oxygen/nitrogen species generation in β cells was shown. Results: Exosomes were found to be the predominant extracellular vesicles secreted by pancreatic cancer into culture media and patient plasma. Pancreatic cancer-exosomes contained adrenomedullin and CA19-9, readily entered β cells through caveolin-mediated endocytosis or macropinocytosis, and inhibited insulin secretion. Adrenomedullin in pancreatic cancer exosomes interacted with its receptor on β cells. Adrenomedullin receptor blockade abrogated the inhibitory effect of exosomes on insulin secretion. β cells exposed to adrenomedullin or pancreatic cancer exosomes showed upregulation of ER stress genes and increased reactive oxygen/nitrogen species. Conclusions: Pancreatic cancer causes paraneoplastic β-cell dysfunction by shedding adrenomedullin+/CA19-9+ exosomes into circulation that inhibit insulin secretion, likely through adrenomedullin-induced ER stress and failure of the unfolded protein response. Clin Cancer Res; 21(7); 1722–33. ©2014 AACR. See related commentary by Korc, p. 1508

Extracellular lumican inhibits pancreatic cancer cell growth and is associated with prolonged survival after surgery.

Purpose: To evaluate the relevance between lumican expression patterns and the clinical course of patients with pancreatic ductal adenocarcinoma (PDAC), and to investigate the role of lumican in PDAC progression. Experimental Design: One hundred thirty-one patient tumors were chosen for tissue microarray staining, and Cox regression analysis was used to test the associations between lumican expression and clinical, pathologic, and oncologic outcomes in all patients. Primary PDAC cells and recombinant human lumican protein were used to establish a working model to mimic the in vivo interactions between stromal lumican and PDAC cells. Using this model, we tested the effects of lumican on EGFR signaling via Akt and hypoxia-inducible factor-1α (HIF1α) and its subsequent influence on glucose consumption, lactate production, intracellular ATP, and apoptotic cell death. Results: Lumican was present in the stroma surrounding PDAC cells in roughly one-half of primary tumors and the direct xenografts. Patients with stromal lumican were associated with a profound reduction in metastatic recurrence after surgery and 3-fold longer survival than patients without stromal lumican. In PDAC cells, extracellular lumican reduced EGFR expression and phosphorylation through enhanced dimerization and internalization of EGFR and the resultant inhibition of Akt kinase activity. Lumican also reduced HIF1α expression and activity via Akt. PDAC cells with enhanced HIF1α activity were resistant to lumican-induced inhibition of glucose consumption, lactate production, intracellular ATP, and apoptosis. Conclusions: There is a positive association between stromal lumican in primary PDAC tumors and prolonged survival after tumor resection. Lumican plays a restrictive role in EGFR-expressing pancreatic cancer progression. Clin Cancer Res; 20(24); 6529–40. ©2014 AACR.