Coordinated single-cell tumor microenvironment dynamics reinforce pancreatic cancer subtype.

Bulk analyses of pancreatic ductal adenocarcinoma (PDAC) samples are complicated by the tumor microenvironment (TME), i.e. signals from fibroblasts, endocrine, exocrine, and immune cells. Despite this, we and others have established tumor and stroma subtypes with prognostic significance. However, understanding of underlying signals driving distinct immune and stromal landscapes is still incomplete. Here we integrate 92 single cell RNA-seq samples from seven independent studies to build a reproducible PDAC atlas with a focus on tumor-TME interdependence. Patients with activated stroma are synonymous with higher myofibroblastic and immunogenic fibroblasts, and furthermore show increased M2-like macrophages and regulatory T-cells. Contrastingly, patients with 'normal' stroma show M1-like recruitment, elevated effector and exhausted T-cells. To aid interoperability of future studies, we provide a pretrained cell type classifier and an atlas of subtype-based signaling factors that we also validate in mouse data. Ultimately, this work leverages the heterogeneity among single-cell studies to create a comprehensive view of the orchestra of signaling interactions governing PDAC.

General Anesthetics in CAncer REsection Surgery (GA-CARES) randomized multicenter trial of propofol vs volatile inhalational anesthesia: protocol description.

BACKGROUND: Studies indicate that patients can be "seeded" with their own cancer cells during oncologic surgery and that the immune response to these circulating cancer cells might influence the risk of cancer recurrence. Preliminary data from animal studies and some retrospective analyses suggest that anesthetic technique might affect the immune response during surgery and hence the risk of cancer recurrence. In 2015, experts called for prospective scientific inquiry into whether anesthetic technique used in cancer resection surgeries affects cancer-related outcomes such as recurrence and mortality. Therefore, we designed a pragmatic phase 3 multicenter randomized controlled trial (RCT) called General Anesthetics in Cancer Resection (GA-CARES). METHODS: After clinical trial registration and institutional review board approval, patients providing written informed consent were enrolled at five sites in New York (NY) State. Eligible patients were adults with known or suspected cancer undergoing one of eight oncologic surgeries having a high risk of cancer recurrence. Exclusion criteria included known or suspected history of malignant hyperthermia or hypersensitivity to either propofol or volatile anesthetic agents. Patients were randomized (1:1) stratified by center and surgery type using REDCap to receive either propofol or volatile agent for maintenance of general anesthesia (GA). This pragmatic trial, which seeks to assess the potential impact of anesthetic type in "real world practice", did not standardize any aspect of patient care. However, potential confounders, e.g., use of neuroaxial anesthesia, were recorded to confirm the balance between study arms. Assuming a 5% absolute difference in 2-year overall survival rates (85% vs 90%) between study arms (primary endpoint, minimum 2-year follow-up), power using a two-sided log-rank test with type I error of 0.05 (no planned interim analyses) was calculated to be 97.4% based on a target enrollment of 1800 subjects. Data sources include the National Death Index (gold standard for vital status in the USA), NY Cancer Registry, and electronic harvesting of data from electronic medical records (EMR), with minimal manual data abstraction/data entry. DISCUSSION: Enrollment has been completed (n = 1804) and the study is in the follow-up phase. This unfunded, pragmatic trial, uses a novel approach for data collection focusing on electronic sources. TRIAL REGISTRATION: Registered (NCT03034096) on January 27, 2017, prior to consent of the first patient on January 31, 2017.

Substituent Effects Impact Surface Charge and Aggregation of Thiophenol-Labeled Gold Nanoparticles for SERS Biosensors.

SERS immunoassay biosensors hold immense potential for clinical diagnostics due to their high sensitivity and growing interest in multi-marker panels. However, their development has been hindered by difficulties in designing compatible extrinsic Raman labels. Prior studies have largely focused on spectroscopic characteristics in selecting Raman reporter molecules (RRMs) for multiplexing since the presence of well-differentiated spectra is essential for simultaneous detection. However, these candidates often induce aggregation of the gold nanoparticles used as SERS nanotags despite their similarity to other effective RRMs. Thus, an improved understanding of factors affecting the aggregation of RRM-coated gold nanoparticles is needed. Substituent electronic effects on particle stability were investigated using various para-substituted thiophenols. The inductive and resonant effects of functional group modifications were strongly correlated with nanoparticle surface charge and hence their stability. Treatment with thiophenols diminished the negative surface charge of citrate-stabilized gold nanoparticles, but electron-withdrawing substituents limited the magnitude of this diminishment. It is proposed that this phenomenon arises by affecting the interplay of competing sulfur binding modes. This has wide-reaching implications for the design of biosensors using thiol-modified gold surfaces. A proof-of-concept multiplexed SERS biosensor was designed according to these findings using the two thiophenol compounds with the most electron-withdrawing substitutions: NO2 and CN.

Perioperative chemotherapy versus adjuvant chemotherapy strategies in resectable gastric and gastroesophageal cancer: A Markov decision analysis.

BACKGROUND: Perioperative chemotherapy has been shown to improve overall survival (OS) for operable gastric and gastroesophageal cancer. However, optimal sequence of surgery and chemotherapy has not been clearly identified. Markov models are useful for analyzing the outcomes of different treatment strategies in the absence of adequately powered randomized clinical trials. In this study, we use Markov decision analysis models to compare median OS (mOS), quality-adjusted mOS, life expectancy (LE), and quality-adjusted life expectancy (QALE) of perioperative chemotherapy with adjuvant chemotherapy strategies in resectable gastric and gastroesophageal cancer patients. METHODS: Markov models are constructed to compare two strategies: adjuvant chemotherapy after surgery and preoperative chemotherapy followed by cancer resection and postoperative chemotherapy. LE and QALE are calculated analytically, and mOS are obtained by simulation. Parameters used in the models are computed from prospective clinical trial data published in PUBMED from January 2000 to July 2020. RESULTS: Total of 8088 patients from 25 prospective studies were included in this analysis. Regardless of R0 resection ratio, the analyses of the models show a higher mOS for patients in the perioperative therapy arm compared to adjuvant chemotherapy. For R0 resected patients, the perioperative therapy arm provided an additional 11.0 mOS months (61.3 months vs. 50.3 months). For R1 resected patients, the perioperative therapy arm had mOS of 17.0 months vs. 10.7 months in adjuvant therapy. CONCLUSIONS: The Markov models indicate that perioperative chemotherapy improves mOS, quality-adjusted mOS, LE, and QALE for resectable gastric and gastroesophageal cancer patients compared to adjuvant chemotherapy strategies.

Tumor Biomarker In-Solution Quantification, Standard Production, and Multiplex Detection.

The diagnosis and monitoring of cancer have been facilitated by discovering tumor "biomarkers" and methods to detect their presence. Yet, for certain cancers, we still lack sensitive and specific biomarkers or the means to quantify subtle concentration changes successfully. The identification of new biomarkers of disease and improving the sensitivity of detection will remain key to changing clinical outcomes. Patient liquid biopsies (serum and plasma) are the most easily obtained sources for noninvasive analysis of proteins that tumor cells release directly and via extracellular microvesicles and tumor shedding. Therefore, an emphasis on creating reliable assays using serum/plasma and "direct, in-solution" ELISA approaches has built an industry centered on patient protein biomarker analysis. A need for improved dynamic range and automation has resulted in the application of ELISA principles to paramagnetic beads with chemiluminescent or fluorescent detection. In the clinical testing lab, chemiluminescent paramagnetic assays are run on automated machines that test a single analyte, minimize technical variation, and are not limited by serum sample volumes. This differs slightly from the R&D setting, where serum samples are often limiting; therefore, multiplexing antibodies to test multiple biomarkers in low serum volumes may be preferred. This review summarizes the development of historical biomarker "standards", paramagnetic particle assay principles, chemiluminescent or fluorescent biomarker detection advancements, and multiplexing for sensitive detection of novel serum biomarkers.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Management of Metastatic and/or Unresectable Pheochromocytoma and Paraganglioma.

ABSTRACT: This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management and surveillance of metastatic and unresectable pheochromocytoma and paraganglioma held on October 2 and 3, 2019. The panelists consisted of endocrinologists, medical oncologists, surgeons, radiologists/nuclear medicine physicians, nephrologists, pathologists, and radiation oncologists. The panelists performed a literature review on a series of questions regarding the medical management of metastatic and unresectable pheochromocytoma and paraganglioma as well as questions regarding surveillance after resection. The panelists voted on controversial topics, and final recommendations were sent to all panel members for final approval.

Development of cancer after bariatric surgery.

BACKGROUND: Although bariatric surgery has been associated with a reduction in risk of obesity-related cancer, data on the effect of bariatric interventions on other cancers are limited. OBJECTIVES: This study aimed to examine the relationship between bariatric interventions and the incidence of various cancers after bariatric surgery. SETTING: Administrative statewide database. METHODS: The New York Statewide Planning and Research Cooperative System database was used to identify all adult patients diagnosed with obesity between 2006 and 2012 and patients who underwent bariatric procedures without preexisting cancer diagnosis and alcohol or tobacco use. Subsequent cancer diagnoses were captured up to 2016. Multivariable proportional subdistribution hazard regression analysis was performed to compare the risk of having cancer among obese patients with and without bariatric interventions. RESULTS: We identified 71,000 patients who underwent bariatric surgery and 323,197 patients without a bariatric intervention. Patients undergoing bariatric surgery were less likely to develop both obesity-related cancer (hazard ratio.91; 95% confidence interval, .85-.98; P = .013) and other cancers (hazard ratio .81; 95% confidence interval, .74-.89; P < .0001). Patients undergoing Roux-en-Y gastric bypass had a lower risk of developing cancers that are considered nonobesity related (hazard ratio .59; 95% confidence interval, .42-.83; P = .0029) compared with laparoscopic sleeve gastrectomy. CONCLUSIONS: Bariatric surgery is associated with a decreased risk of obesity-related cancers. More significantly, we demonstrated the relationship between bariatric surgery and the reduction of the risk of some previously designated nonobesity-related cancers, as well. Reclassification of nonobesity-related cancers and expansion of bariatric indications for reducing the risk of cancer may be warranted.

Correction: Direct therapeutic targeting of immune checkpoint PD-1 in pancreatic cancer.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Comparative single-cell RNA sequencing (scRNA-seq) reveals liver metastasis-specific targets in a patient with small intestinal neuroendocrine cancer.

Genomic analysis of a patient's tumor is the cornerstone of precision oncology, but it does not address whether metastases should be treated differently. Here we tested whether comparative single-cell RNA sequencing (scRNA-seq) of a primary small intestinal neuroendocrine tumor to a matched liver metastasis could guide the treatment of a patient's metastatic disease. Following surgery, the patient was put on maintenance treatment with a somatostatin analog. However, the scRNA-seq analysis revealed that the neuroendocrine epithelial cells in the liver metastasis were less differentiated and expressed relatively little SSTR2, the predominant somatostatin receptor. There were also differences in the tumor microenvironments. RNA expression of vascular endothelial growth factors was higher in the primary tumor cells, reflected by an increased number of endothelial cells. Interestingly, vascular expression of the major VEGF receptors was considerably higher in the liver metastasis, indicating that the metastatic vasculature may be primed for expansion and susceptible to treatment with angiogenesis inhibitors. The patient eventually progressed on Sandostatin, and although consideration was given to adding an angiogenesis inhibitor to her regimen, her disease progression involved non-liver metastases that had not been characterized. Although in this specific case comparative scRNA-seq did not alter treatment, its potential to help guide therapy of metastatic disease was clearly demonstrated.

A Comparative Analysis of Survival and Funding Discrepancies in Cancers With High Mortality.

OBJECTIVE: Comparative analyses of survival and funding statistics in cancers with high mortality were performed to quantify discrepancies and identify areas for intervention. BACKGROUND: Discrepancies in research funding may contribute to stagnant survival rates in pancreatic ductal adenocarcinoma (PDAC). METHODS: The Surveillance, Epidemiology, and End Results database was queried for survival statistics. Funding data were obtained from the National Cancer Institute (NCI). Clinical trial data were obtained from www.clinicaltrials.gov. Cancers with high mortality were included for analyses. RESULTS: Since 1997, PDAC has received lesser funding ($1.41 billion) than other cancers such as breast ($10.52 billion), prostate ($4.93 billion), lung ($4.80 billion), and colorectal ($4.50 billion). Similarly, fewer clinical trials have been completed in PDAC (n = 608) compared with breast (n = 1904), lung (n = 1629), colorectal (n = 1080), and prostate (n = 1055) cancer. Despite this, since 1997, dollars invested in PDAC research produced a greater return on investment with regards to 5-year overall survival (5Y-OS) compared with breast, prostate, uterine, and ovarian cancer. Incremental cost-effectiveness analysis demonstrates that millions (liver, non-Hodgkin lymphoma, and melanoma) and billions (colorectal and lung) of dollars were required for each additional 1% increase in 5Y-OS compared with PDAC. Funding of research towards early diagnosis of PDAC has decreased by 19% since 2007. For nearly all cancers, treatment-related research receives the highest percentage of NCI funding. CONCLUSIONS: Funding of PDAC research is significantly less than other cancers, despite its higher mortality and greater potential to improve 5Y-OS. Increased awareness and lobbying are required to increase funding, promote research, and improve survival.

Phase I trial of concurrent stereotactic body radiotherapy and nelfinavir for locally advanced borderline or unresectable pancreatic adenocarcinoma.

INTRODUCTION: The HIV protease inhibitor nelfinavir (NFV) displays notable radiosensitizing effects. There have been no studies evaluating combined stereotactic body radiotherapy (SBRT) and NFV for borderline/unresectable pancreatic cancer. The primary objective of this phase I trial (NCT01068327) was to determine the maximum tolerated SBRT/NFV dose, and secondarily evaluate outcomes. METHODS: Following initial imaging, pathologic confirmation, and staging laparoscopy, subjects initially received three 3-week cycles of gemcitabine/leucovorin/fluorouracil; patients without radiologic progression received 5-fraction SBRT/NFV. Dose escalation was as follows: (1) 25 Gy/625 mg BID ×3wks; (2) 25 Gy/1250 mg BID ×3wks; (3) 30 Gy/1250 mg BID ×3wks; (4) 35 Gy/1250 mg BID ×3wks; (5) 35 Gy/1250 mg BID ×5wks; and (6) 40 Gy/1250 mg BID ×5wks. Pancreaticoduodenectomy was performed thereafter if resectable; if not, gemcitabine/leucovorin/fluorouracil was administered. RESULTS: Forty-six patients enrolled (10/2008-5/2013); 39 received protocol-directed therapy. Sixteen (41%) experienced any grade ≥2 event during and 1 month after SBRT. Four grade 3 and both grade 4 events occurred in a single patient at the initial dose level. 40 Gy/1250 mg BID ×5wks was the maximum tolerated dose. Five patients had late gastrointestinal bleeding (n = 2 superior mesenteric artery pseudo-aneurysm, n = 1 disease progression, n = 1 lower GI tract, n = 1 unknown location). The median overall survival was 14.4 months. Six (15%) patients recurred locally; median local failure-free survival was not reached. The median distant failure-free survival was 11 months, and median all failure-free survival was 10 months. CONCLUSIONS: Concurrent SBRT (40 Gy)/NFV (1250 mg BID) for locally advanced pancreatic cancer is feasible and safe, although careful attention to treatment planning parameters is recommended to reduce the incidence of late gastrointestinal bleeding.

Direct therapeutic targeting of immune checkpoint PD-1 in pancreatic cancer.

BACKGROUND: Pancreatic cancer (PC) hijacks innate cellular processes to promote cancer growth. We hypothesized that PC exploits PD-1/PD-L1 not only to avoid immune responses, but to directly enhance growth. We also hypothesized that immune checkpoint inhibitors (ICIs) have direct cytotoxicity in PC. We sought to elucidate therapeutic targeting of PD-1/PD-L1. METHODS: PD-1 was assessed in PC cells, patient-derived organoids (PDOs), and clinical tissues. Then, PC cells were exposed to PD-L1 to evaluate proliferation. To test PD-1/PD-L1 signaling, cells were exposed to PD-L1 and MAPK was examined. Radio-immunoconjugates with anti-PD-1 drugs were developed to test uptake in patient-derived tumor xenografts (PDTXs). Next, PD-1 function was assessed by xenografting PD-1-knockdown cells. Finally, PC models were exposed to ICIs. RESULTS: PD-1 expression was demonstrated in PCs. PD-L1 exposure increased proliferation and activated MAPK. Imaging PDTXs revealed uptake of radio-immunoconjugates. PD-1 knockdown in vivo revealed 67% smaller volumes than controls. Finally, ICI treatment of both PDOs/PDTXs demonstrated cytotoxicity and anti-MEK1/2 combined with anti-PD-1 drugs produced highest cytotoxicity in PDOs/PDTXs. CONCLUSIONS: Our data reveal PCs innately express PD-1 and activate druggable oncogenic pathways supporting PDAC growth. Strategies directly targeting PC with novel ICI regimens may work with adaptive immune responses for optimal cytotoxicity.

Development of Patient-Derived Gastric Cancer Organoids from Endoscopic Biopsies and Surgical Tissues.

BACKGROUND: Organoids are three-dimensional in vitro models of human disease developed from benign and malignant gastrointestinal tissues with tremendous potential for personalized medicine applications. We sought to determine whether gastric cancer patient-derived organoids (PDOs) could be safely established from endoscopic biopsies for rapid drug screening. METHODS: Patients underwent esophagogastroduodenoscopy (EGD) for surveillance or staging and had additional forceps biopsies taken for PDO creation. Cancer tissues from operative specimens were also used to create PDOs. To address potential tumor heterogeneity, we performed low-coverage whole-genome sequencing of endoscopic-derived PDOs with paired surgical PDOs and whole-tumor lysates. The stability of genomic alterations in endoscopic organoids was assessed by next-generation sequencing and nested polymerase chain reaction (PCR) assay. The feasibility and potential accuracy of drug sensitivity screening with endoscopic-derived PDOs were also evaluated. RESULTS: Gastric cancer PDOs (n = 15) were successfully established from EGD forceps biopsies (n = 8) and surgical tissues (n = 7) from five patients with gastric adenocarcinoma. Low-coverage whole-genomic profiling of paired EGD and surgical PDOs along with whole-tumor lysates demonstrated absence of tumor heterogeneity. Nested PCR assay identified similar KRAS alterations in primary tumor and paired organoids. Drug sensitivity testing of endoscopic-derived PDOs displayed standard dose-response curves to current gastric cancer cytotoxic therapies. CONCLUSIONS: Our study results demonstrate the feasibility of developing gastric cancer PDOs from EGD biopsies. These results also indicate that endoscopic-derived PDOs are accurate surrogates of the primary tumor and have the potential for drug sensitivity screening and personalized medicine applications.

Organoid Profiling Identifies Common Responders to Chemotherapy in Pancreatic Cancer.

Pancreatic cancer is the most lethal common solid malignancy. Systemic therapies are often ineffective, and predictive biomarkers to guide treatment are urgently needed. We generated a pancreatic cancer patient-derived organoid (PDO) library that recapitulates the mutational spectrum and transcriptional subtypes of primary pancreatic cancer. New driver oncogenes were nominated and transcriptomic analyses revealed unique clusters. PDOs exhibited heterogeneous responses to standard-of-care chemotherapeutics and investigational agents. In a case study manner, we found that PDO therapeutic profiles paralleled patient outcomes and that PDOs enabled longitudinal assessment of chemosensitivity and evaluation of synchronous metastases. We derived organoid-based gene expression signatures of chemosensitivity that predicted improved responses for many patients to chemotherapy in both the adjuvant and advanced disease settings. Finally, we nominated alternative treatment strategies for chemorefractory PDOs using targeted agent therapeutic profiling. We propose that combined molecular and therapeutic profiling of PDOs may predict clinical response and enable prospective therapeutic selection.Significance: New approaches to prioritize treatment strategies are urgently needed to improve survival and quality of life for patients with pancreatic cancer. Combined genomic, transcriptomic, and therapeutic profiling of PDOs can identify molecular and functional subtypes of pancreatic cancer, predict therapeutic responses, and facilitate precision medicine for patients with pancreatic cancer. Cancer Discov; 8(9); 1112-29. ©2018 AACR.See related commentary by Collisson, p. 1062This article is highlighted in the In This Issue feature, p. 1047.

Advanced pancreatic cancer: a meta-analysis of clinical trials over thirty years.

BACKGROUND: In contrast to other cancers, survival rates for pancreatic ductal adenocarcinoma (PDAC) patients have improved but minimally over the past thirty years. The aim of this study was to perform a meta-analysis of clinical trials published since 1986 to determine trends in median overall survival in primarily metastatic PDAC. MATERIALS AND METHODS: All Phase 2-4 clinical trials published during or after 1986 investigating first-line systemic chemotherapy in metastatic PDAC were included in the meta-analysis. Publications obtained through PubMed and www.ClinicalTrials.gov were cross-referenced to identify additional trials. Trials enrolling fewer than 50% of study participants with metastatic disease were excluded. RESULTS: Of 19,488 patients enrolled in 151 clinical trials, 84% had metastatic disease and 16% had locally advanced pancreatic cancer. In clinical trials published from 1986 to 2016, the weighted median overall survival (wMOS) increased by 3.0 months. The median wMOS was higher in combination therapy (7.31 months, IQR 5.4 to 8.5) compared to non-gemcitabine, single-agent therapy (4.76 months, IQR 3.5 to 6.0), gemcitabine monotherapy (6.48 months, IQR 5.9 to 7.2), and gemcitabine plus single-agent therapy (7.09 months, IQR 6.3 to 8.2). Of all regimens used in more than one study arm, FOLFIRINOX had the highest wMOS (10.9 months). CONCLUSIONS: Regardless of treatment regimen, survival rates in PDAC have minimally improved over time. Of drugs used in two or more study arms, only FOLFIRINOX has a wMOS greater than ten months. Emphasis should, therefore, be placed on identification of novel targets that promote early diagnosis and intervention. FUNDING: The authors on this manuscript are in parts, supported by grants from the National Institutes of Health (EDRN U01 CA200466, SPORE P50 CA127297, R01 CA183459, R21 AA026428 and R01 CA 195586).

Successful creation of pancreatic cancer organoids by means of EUS-guided fine-needle biopsy sampling for personalized cancer treatment.

BACKGROUND AND AIMS: Pancreatic cancer organoids are tumor models of individualized human pancreatic ductal adenocarcinoma (PDA), created from surgical specimens and used for personalized treatment strategies. Unfortunately, most patients with PDA are not operative candidates. Creation of human PDA organoids at the time of initial tumor diagnosis is therefore critical. Our aim was to assess the feasibility of creating human PDA organoids by EUS fine-needle biopsy (EUS-FNB) sampling in patients with PDA. METHODS: In this prospective clinical trial in patients referred to evaluate a pancreatic mass, EUS-FNA was performed for initial onsite diagnosis. Two additional needle passes were performed with a 22-gauge FNB needle for organoid creation. Primary outcome was successful isolation of organoids within 2 weeks of EUS-FNB sampling (P0, no passages), confirmed by organoid morphology and positive genotyping. RESULTS: Thirty-seven patients with 38 PDA tumors were enrolled. Successful isolation of organoids (P0) was achieved in 33 of 38 tumors (87%). Establishment of PDA organoid lines for ≥5 passages of growth (P5, five passages) was reached in 25 of 38 tumors (66%). In the single patient with successful P5 FNB sampling-derived and P5 surgically derived organoids, there was identical matching of specimens. There were no serious adverse events. Two patients developed bleeding at the EUS-FNB puncture site requiring hemostasis clips. CONCLUSIONS: Pancreatic cancer organoids can be successfully and rapidly created by means of EUS-FNB sampling using a 22-gauge needle at the time of initial diagnosis. Successful organoid generation is essential for precision medicine in patients with pancreatic cancer in whom most are not surgically resectable. (Clinical trial registration number: NCT03140592.).

Case report of intestinal non-rotation, heterotaxy, and polysplenia in a patient with pancreatic cancer.

RATIONALE: Heterotaxy with polysplenia is an extremely rare congenital condition resulting from abnormal arrangement of organs in the abdominal and thoracic cavities during embryologic development. When a malignancy such as pancreatic cancer develops under these conditions, surgical resection becomes particularly complex. This case report demonstrates successful pancreatic cancer resection despite the patient's complicated anatomy. PATIENT CONCERNS: An 82-year-old female presented to our institution with complaints of mild right upper quadrant pain radiating to the mid-epigastric region. DIAGNOSES: Physical examination revealed jaundice with scleral icterus consistent with obstructive jaundice. Radiographic imaging revealed hepatic duct dilation with several anatomic anomalies including small bowel location in the right upper abdomen, cecum, and appendix in the left lower quadrant, reversed superior mesenteric artery and superior mesenteric vein positions, and right-sided duodenal-jejunal flexture as well as an entirely right-sided pancreas, and left lower pelvis with ≥6 separate splenules. These findings resulted in a diagnosis of heterotaxy syndrome with polysplenia. INTERVENTIONS: Careful preoperative planning and total pancreatectomy was performed without complication. OUTCOMES: The patient recovered well. Pathologic examination of the pancreatic mass revealed moderately/poorly differentiated invasive pancreatic duct adenocarcinoma. The patient remains alive and well without signs of recurrent disease at the 2-year follow-up. LESSONS: Given the wide range of anatomical variants observed in patients with heterotaxy syndrome, a thorough radiologic assessment is necessary before engaging in any surgical procedure. In our case, preoperative identification of the various anatomic anomalies, such as the short and vertically oriented pancreas, the porta hepatis position anterior to the duodenum, the nonrotation of the intestines and the anomalous origin of the right hepatic artery allowed us to perform a safe and uncomplicated total pancreatectomy.

De Novo Lipid Synthesis Facilitates Gemcitabine Resistance through Endoplasmic Reticulum Stress in Pancreatic Cancer.

Pancreatic adenocarcinoma is moderately responsive to gemcitabine-based chemotherapy, the most widely used single-agent therapy for pancreatic cancer. Although the prognosis in pancreatic cancer remains grim in part due to poor response to therapy, previous attempts at identifying and targeting the resistance mechanisms have not been very successful. By leveraging The Cancer Genome Atlas dataset, we identified lipid metabolism as the metabolic pathway that most significantly correlated with poor gemcitabine response in pancreatic cancer patients. Furthermore, we investigated the relationship between alterations in lipogenesis pathway and gemcitabine resistance by utilizing tissues from the genetically engineered mouse model and human pancreatic cancer patients. We observed a significant increase in fatty acid synthase (FASN) expression with increasing disease progression in spontaneous pancreatic cancer mouse model, and a correlation of high FASN expression with poor survival in patients and poor gemcitabine responsiveness in cell lines. We observed a synergistic effect of FASN inhibitors with gemcitabine in pancreatic cancer cells in culture and orthotopic implantation models. Combination of gemcitabine and the FASN inhibitor orlistat significantly diminished stemness, in part due to induction of endoplasmic reticulum (ER) stress that resulted in apoptosis. Moreover, direct induction of ER stress with thapsigargin caused a similar decrease in stemness and showed synergistic activity with gemcitabine. Our in vivo studies with orthotopic implantation models demonstrated a robust increase in gemcitabine responsiveness upon inhibition of fatty acid biosynthesis with orlistat. Altogether, we demonstrate that fatty acid biosynthesis pathway manipulation can help overcome the gemcitabine resistance in pancreatic cancer by regulating ER stress and stemness. Cancer Res; 77(20); 5503-17. ©2017 AACR.