Mitochondrial morphology controls fatty acid utilization by changing CPT1 sensitivity to malonyl-CoA.

Changes in mitochondrial morphology are associated with nutrient utilization, but the precise causalities and the underlying mechanisms remain unknown. Here, using cellular models representing a wide variety of mitochondrial shapes, we show a strong linear correlation between mitochondrial fragmentation and increased fatty acid oxidation (FAO) rates. Forced mitochondrial elongation following MFN2 over-expression or DRP1 depletion diminishes FAO, while forced fragmentation upon knockdown or knockout of MFN2 augments FAO as evident from respirometry and metabolic tracing. Remarkably, the genetic induction of fragmentation phenocopies distinct cell type-specific biological functions of enhanced FAO. These include stimulation of gluconeogenesis in hepatocytes, induction of insulin secretion in islet ß-cells exposed to fatty acids, and survival of FAO-dependent lymphoma subtypes. We find that fragmentation increases long-chain but not short-chain FAO, identifying carnitine O-palmitoyltransferase 1 (CPT1) as the downstream effector of mitochondrial morphology in regulation of FAO. Mechanistically, we determined that fragmentation reduces malonyl-CoA inhibition of CPT1, while elongation increases CPT1 sensitivity to malonyl-CoA inhibition. Overall, these findings underscore a physiologic role for fragmentation as a mechanism whereby cellular fuel preference and FAO capacity are determined.

HCF-1 Regulates De Novo Lipogenesis through a Nutrient-Sensitive Complex with ChREBP.

Carbohydrate response element binding protein (ChREBP) is a key transcriptional regulator of de novo lipogenesis (DNL) in response to carbohydrates and in hepatic steatosis. Mechanisms underlying nutrient modulation of ChREBP are under active investigation. Here we identify host cell factor 1 (HCF-1) as a previously unknown ChREBP-interacting protein that is enriched in liver biopsies of nonalcoholic steatohepatitis (NASH) patients. Biochemical and genetic studies show that HCF-1 is O-GlcNAcylated in response to glucose as a prerequisite for its binding to ChREBP and subsequent recruitment of OGT, ChREBP O-GlcNAcylation, and activation. The HCF-1:ChREBP complex resides at lipogenic gene promoters, where HCF-1 regulates H3K4 trimethylation to prime recruitment of the Jumonji C domain-containing histone demethylase PHF2 for epigenetic activation of these promoters. Overall, these findings define HCF-1's interaction with ChREBP as a previously unappreciated mechanism whereby glucose signals are both relayed to ChREBP and transmitted for epigenetic regulation of lipogenic genes.

WSB1 promotes tumor metastasis by inducing pVHL degradation.

The von Hippel-Lindau tumor suppressor pVHL is an E3 ligase that targets hypoxia-inducible factors (HIFs). Mutation of VHL results in HIF up-regulation and contributes to processes related to tumor progression such as invasion, metastasis, and angiogenesis. However, very little is known with regard to post-transcriptional regulation of pVHL. Here we show that WD repeat and SOCS box-containing protein 1 (WSB1) is a negative regulator of pVHL through WSB1's E3 ligase activity. Mechanistically, WSB1 promotes pVHL ubiquitination and proteasomal degradation, thereby stabilizing HIF under both normoxic and hypoxic conditions. As a consequence, WSB1 up-regulates the expression of HIF-1α's target genes and promotes cancer invasion and metastasis through its effect on pVHL. Consistent with this, WSB1 protein level negatively correlates with pVHL level and metastasis-free survival in clinical samples. This work reveals a new mechanism of pVHL's regulation by which cancer acquires invasiveness and metastatic tendency.

Minimally Invasive Versus Open Pancreatectomy for Right-Sided and Left-Sided G1/G2 Nonfunctioning Pancreatic Neuroendocrine Tumors: A Multicenter Matched Analysis with an Inverse Probability of Treatment-Weighting Method.

BACKGROUND: Limited evidence exists for the safety and oncologic efficacy of minimally invasive surgery (MIS) for nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) according to tumor location. This study aimed to compare the surgical outcomes of MIS and open surgery (OS) for right- or left-sided NF-PNETs. METHODS: The study collected data on patients who underwent surgical resection (pancreatoduodenectomy, distal/total/central pancreatectomy, duodenum-preserving pancreas head resection, or enucleation) of a localized NF-PNET between January 2000 and July 2017 at 14 institutions. The inverse probability of treatment-weighting method with propensity scores was used for analysis. RESULTS: The study enrolled 859 patients: 478 OS and 381 MIS patients. A matched analysis by tumor location showed no differences in resection margin, intraoperative blood loss, or complications between MIS and OS. However, MIS was associated with a longer operation time for right-sided tumors (393.3 vs 316.7 min; P < 0.001) and a shorter postoperative hospital stay for left-sided tumors (8.9 vs 12.9 days; P < 0.01). The MIS group was associated with significantly higher survival rates than the OS group for right- and left-sided tumors, but survival did not differ for the patients divided by tumor grade and location. Multivariable analysis showed that MIS did not affect survival for any tumor location. CONCLUSION: The short-term outcomes offered by MIS were comparable with those of OS except for a longer operation time for right-sided NF-PNETs. The oncologic outcomes were not compromised by MIS regardless of tumor location or grade. These findings suggest that MIS can be performed safely for selected patients with localized NF-PNETs.

Risk Factors for Recurrence in Pancreatic Neuroendocrine Tumor and Size as a Surrogate in Determining the Treatment Strategy: A Korean Nationwide Study.

INTRODUCTION: The prognostic factors of pancreatic neuroendocrine tumor (PNET) are unclear, and the treatment guidelines are insufficient. This study aimed to suggest a treatment algorithm for PNET based on risk factors for recurrence in a large cohort. METHODS: Data of 918 patients who underwent curative intent surgery for PNET were collected from 14 tertiary centers. Risk factors for recurrence and survival analyses were performed. RESULTS: The 5-year disease-free survival (DFS) rate was 86.5%. Risk factors for recurrence included margin status (R1, hazard ratio [HR] 2.438; R2, HR 3.721), 2010 WHO grade (G2, HR 3.864; G3, HR 7.352), and N category (N1, HR 2.273). A size of 2 cm was significant in the univariate analysis (HR 8.511) but not in the multivariate analysis (p = 0.407). Tumor size was not a risk factor for recurrence, but strongly reflected 2010 WHO grade and lymph node (LN) status. Tumors ≤2 cm had lower 2010 WHO grade, less LN metastasis (p < 0.001), and significantly longer 5-year DFS (77.9 vs. 98.2%, p < 0.001) than tumors >2 cm. The clinicopathologic features of tumors <1 and 1-2 cm were similar. However, the LN metastasis rate was 10.3% in 1-2-cm sized tumors and recurrence occurred in 3.0%. Tumors <1 cm in size did not have any LN metastasis or recurrence. DISCUSSION/CONCLUSION: Radical surgery is needed in suspected LN metastasis or G3 PNET or tumors >2 cm. Surveillance for <1-cm PNETs should be sufficient. Tumors sized 1-2 cm require limited surgery with LN resection, but should be converted to radical surgery in cases of doubtful margins or LN metastasis.

WIP1, a homeostatic regulator of the DNA damage response, is targeted by HIPK2 for phosphorylation and degradation.

WIP1 (wild-type p53-induced phosphatase 1) functions as a homeostatic regulator of the ataxia telangiectasia mutated (ATM)-mediated signaling pathway in response to ionizing radiation (IR). Here we identify homeodomain-interacting protein kinase 2 (HIPK2) as a protein kinase that targets WIP1 for phosphorylation and proteasomal degradation. In unstressed cells, WIP1 is constitutively phosphorylated by HIPK2 and maintained at a low level by proteasomal degradation. In response to IR, ATM-dependent AMPKα2-mediated HIPK2 phosphorylation promotes inhibition of WIP1 phosphorylation through dissociation of WIP1 from HIPK2, followed by stabilization of WIP1 for termination of the ATM-mediated double-strand break (DSB) signaling cascade. Notably, HIPK2 depletion impairs IR-induced γ-H2AX foci formation, cell-cycle checkpoint activation, and DNA repair signaling, and the survival rate of hipk2+/- mice upon γ-irradiation is markedly reduced compared to wild-type mice. Taken together, HIPK2 plays a critical role in the initiation of DSB repair signaling by controlling WIP1 levels in response to IR.

Optimal stapler cartridge selection to reduce post-operative pancreatic fistula according to the pancreatic characteristics in stapler closure distal pancreatectomy.

BACKGROUND: Postoperative pancreatic fistula (POPF) is associated with potentially fatal complications, but there is lack of data on relationship between pancreas thickness, and stapler size and the POPF rate. This study aimed to suggest optimal stapler that reduces POPF rate according to the pancreas thickness. METHODS: This retrospective cohort study was conducted in two tertiary high-volume pancreas centers. 599 patients who underwent distal pancreatectomy were assessed for stump reinforcement methods, pathology findings, pancreas thickness, and cartridge used. The cartridges were grouped as I, II, III according to the closed height ≤1.5 mm, 1.8 mm, and ≥2.0 mm, respectively. RESULTS: The POPF rate increased according to the thickness. The stapler Groups I, II, and III had an overall POPF rate of 66.4% vs. 61.7% vs. 57.8%, but Group II stapler cartridge showed a significant reduction in the POPF rate than other cartridges in pancreas with thickness <13 mm (53.5% vs. 21.7% vs. 36.0%, p = 0.031). There was no significant difference between the POPF rate according to stapler groups when the pancreas was thicker than 13 mm. CONCLUSION: Thickness is the strongest risk factor in predicting POPF. Use of Group II stapler cartridge for pancreas with a thickness of <13 mm can help reduce POPF.

The deubiquitinating enzyme USP20 stabilizes ULK1 and promotes autophagy initiation.

Autophagy begins with the formation of autophagosomes, a process that depends on the activity of the serine/threonine kinase ULK1 (hATG1). Although earlier studies indicated that ULK1 activity is regulated by dynamic polyubiquitination, the deubiquitinase involved in the regulation of ULK1 remained unknown. In this study, we demonstrate that ubiquitin-specific protease 20 (USP20) acts as a positive regulator of autophagy initiation through stabilizing ULK1. At basal state, USP20 binds to and stabilizes ULK1 by removing the ubiquitin moiety, thereby interfering with the lysosomal degradation of ULK1. The stabilization of basal ULK1 protein levels is required for the initiation of starvation-induced autophagy, since the depletion of USP20 by RNA interference inhibits LC3 puncta formation, a marker of autophagic flux. At later stages of autophagy, USP20 dissociates from ULK1, resulting in enhanced ULK1 degradation and apoptosis. Taken together, our findings provide the first evidence that USP20 plays a crucial role in autophagy initiation by maintaining the basal expression level of ULK1.

Prognostic Impact of Intra-Ampullary Papillary-Tubular Neoplasm versus Flat Dysplasia as Precursor Lesions of Ampullary Adenocarcinoma.

BACKGROUND: The aim of this study is to compare the prognostic impact of 2 precursor lesions of ampullary adenocarcinoma, intra-ampullary papillary-tubular neoplasm (IAPN) and flat dysplasia (FD). METHODS: From December 1994 to December 2012, a total of 359 patients underwent curative surgery for ampullary adenocarcinoma. RESULTS: The precursor lesions were IAPNs in 134 (37.3%) patients and FD in the other 225 (62.7%) patients. The FD group had more aggressive tumor biology with advanced T stage (p = 0.002), nodal involvement (p < 0.001), poor differentiation (p < 0.001), perineural and lymphovascular invasion (p < 0.001), and pancreatobiliary or mixed subtype (p < 0.001). Five-year overall survival rates were 71.1% in the IAPN group and 51.4% in the FD group (p = 0.002), respectively. Five-year disease-free survival rates were 69.7% in the IAPN group and 49.6% in the FD group (p < 0.001), respectively. The recurrence rate was also higher in the FD group (49.8 vs. 30.6%; p < 0.001). On multivariate analysis, higher levels of tumor markers including CEA and CA19-9, lymph node metastasis, poorly differentiated histology, and perineural invasion were negative predictive factors for survival. Higher levels of CEA and CA19-9, lymphovascular invasion, and FD were independent prognostic factors for recurrence. CONCLUSION: FD was significantly associated with worse prognosis and a greater tendency toward advanced disease. Further studies are needed to clarify the impacts of these precursor lesions.

The Beneficial Effects of Morusin, an Isoprene Flavonoid Isolated from the Root Bark of Morus.

The root bark of Morus has long been appreciated as an antiphlogistic, diuretic and expectorant drug in Chinese herbal medicine, albeit with barely known targets and mechanisms of action. In the 1970s, the development of analytic chemistry allowed for the discovery of morusin as one of 7 different isoprene flavonoid derivatives in the root bark of Morus. However, the remarkable antioxidant capacity of morusin with the unexpected potential for health benefits over the other flavonoid derivatives has recently sparked scientific interest in the biochemical identification of target proteins and signaling pathways and further clinical relevance. In this review, we discuss recent advances in the understanding of the functional roles of morusin in multiple biological processes such as inflammation, apoptosis, metabolism and autophagy. We also highlight recent in vivo and in vitro evidence on the clinical potential of morusin treatment for multiple human pathologies including inflammatory diseases, neurological disorders, diabetes, cancer and the underlying mechanisms.

Stress Granule Formation Attenuates RACK1-Mediated Apoptotic Cell Death Induced by Morusin.

Stress granules are membraneless organelles composed of numerous components including ribonucleoproteins. The stress granules are characterized by a dynamic complex assembly in response to various environmental stressors, which has been implicated in the coordinated regulation of diverse biological pathways, to exert a protective role against stress-induced cell death. Here, we show that stress granule formation is induced by morusin, a novel phytochemical displaying antitumor capacity through barely known mechanisms. Morusin-mediated induction of stress granules requires activation of protein kinase R (PKR) and subsequent eIF2α phosphorylation. Notably, genetic inactivation of stress granule formation mediated by G3BP1 knockout sensitized cancer cells to morusin treatment. This protective function against morusin-mediated cell death can be attributed at least in part to the sequestration of receptors for activated C kinase-1 (RACK1) within the stress granules, which reduces caspase-3 activation. Collectively, our study provides biochemical evidence for the role of stress granules in suppressing the antitumor capacity of morusin, proposing that morusin treatment, together with pharmacological inhibition of stress granules, could be an efficient strategy for targeting cancer.

Clinicopathologic analysis of intraductal papillary neoplasm of bile duct: Korean multicenter cohort study.

BACKGROUND: IPNB is very rare disease and most previous studies on IPNB were case series with a small number due to low incidence. The aim of this study is to validate previously known clinicopathologic features of intraductal papillary neoplasm of bile duct (IPNB) based on the first largest multicenter cohort. METHODS: Among 587 patients previously diagnosed with IPNB and similar diseases from each center in Korea, 387 were included in this study after central pathologic review. We also reviewed all preoperative image data. RESULTS: Of 387 patients, 176 (45.5%) had invasive carcinoma and 21 (6.0%) lymph node metastasis. The 5-year overall survival was 80.9% for all patients, 88.8% for IPNB with mucosal dysplasia, and 70.5% for IPNB with invasive carcinoma. According to the "Jang & Kim's modified anatomical classification," 265 (68.5%) were intrahepatic, 103 (26.6%) extrahepatic, and 16 (4.1%) diffuse type. Multivariate analysis revealed that tumor invasiveness was a unique predictor for survival analysis. (p = 0.047 [hazard ratio = 2.116, 95% confidence interval 1.010-4.433]). CONCLUSIONS: This is the first Korean multicenter study on IPNB through central pathologic and radiologic review process. Although IPNB showed good long-term prognosis, relatively aggressive features were also found in invasive carcinoma and extrahepatic/diffuse type.

Effect of Hyperbilirubinemia on Hepatic Hypertrophy after Portal Vein Embolization and Liver Failure after Hepatectomy in Primary Biliary Malignancy.

PURPOSE: To retrospectively investigate the impact of hyperbilirubinemia on future liver remnant (FLR) volume after percutaneous transhepatic portal vein embolization (PVE) and incidence of post-hepatectomy liver failure in primary biliary malignancy. MATERIALS AND METHODS: Eighty-seven patients (62 men, overall mean age 66.9 y) who underwent PVE, using Gelfoam and coils before major hepatectomy between January 2004 and June 2016, were included in this study and divided into a hyperbilirubinemia (serum total bilirubin level at PVE 5.80 ± 2.44 mg/dL; n = 41) group and a control group (1.09 ± 0.73 mg/dL; n = 46). Liver volume was measured from computerized tomographic data before and 18.5 days, on average, after PVE. Correlation between FLR hypertrophy (degree of hypertrophy and percentage increase in future liver remnant [%FLR]) and total bilirubin were analyzed. FLR hypertrophy and incidence of post-hepatectomy liver failure were compared. Simple and multiple regressions were used for univariable and multivariable analyses, respectively. RESULTS: Mean FLR volumes before and after PVE were 529.1 cm3 and 640.5 cm3, respectively. Degree of hypertrophy and %FLR were 7.64 ± 4.22 and 21.77 ± 13.34, respectively. There was no significant correlation between FLR hypertrophy and total bilirubin (P > .5). FLR hypertrophy was not significantly different between the 2 groups. Planned major hepatectomy was performed in 73 patients (83.9%). Grade 3 post-hepatectomy liver failure occurred in 6 patients (8.2%; 2 in the hyperbilirubinemia group and 4 in the control group), and its incidence was not significantly different between the groups (P = .354). CONCLUSIONS: Hyperbilirubinemia at the time of PVE seems to have no effect on FLR hypertrophy. The incidence of grade 3 post-hepatectomy liver failure is not likely to be influenced, either.

Laparoscopic versus open distal pancreatectomy for nonfunctioning pancreatic neuroendocrine tumors: a large single-center study.

BACKGROUND: Pancreatic neuroendocrine tumors (PNETs) account for 1-2% of all pancreatic neoplasms. Nonfunctioning PNETs (NF-PNETs) account for 60-90% of all PNETs. Laparoscopic distal pancreatectomy (LDP) is becoming the treatment of choice for benign lesions in the body and tail of the pancreas. However, LDP has not yet been widely accepted as the gold standard for NF-PNETs. The purpose of this study is to evaluate the clinical and oncologic outcomes after laparoscopic versus open distal pancreatectomy (ODP) for NF-PNETs. METHODS: Between April 1995 and September 2016, 94 patients with NF-PNETs underwent open or laparoscopic distal pancreatectomy at Samsung Medical Center. Patients were divided into two groups: those who underwent LDP and those who underwent ODP. Both groups were compared in terms of clinical and oncologic variables. RESULTS: LDP patients had a significantly shorter hospital stay compared with ODP patients, amounting to a mean difference of 2 days (p < 0.001). Overall complication rates did not differ significantly between the ODP and LDP groups (p = 0.379). The 3-year overall survival rates in the ODP and LDP groups were 93.7 and 100%, respectively (p = 0.069). CONCLUSIONS: In this study, LDP for NF-PNETs had similar oncologic outcomes compared with ODP. In addition, LDP was associated with a shorter hospital stay compared with ODP. Therefore, LDP is a safe and effective procedure for patients with NF-PNETs. A multicenter study and a randomized controlled trial are needed to better assess the clinical and oncologic outcomes.

Surgical Strategy for T2 Gallbladder Cancer: Nationwide Multicenter Survey in Korea.

BACKGROUND: Although all guidelines suggest that T2 gallbladder (GB) cancer should be treated by extended cholecystectomy (ECx), high-level scientific evidence is lacking because there has been no randomized controlled trial on GB cancer. METHODS: A nationwide multicenter study between 2000 and 2009 from 14 university hospitals enrolled a total of 410 patients with T2 GB cancer. The clinicopathologic findings and long-term follow-up results were analyzed after consensus meeting of Korean Pancreas Surgery Club. RESULTS: The 5-year cumulative survival rate (5YSR) for the patients who underwent curative resection was 61.2%. ECx group showed significantly better 5YSR than simple cholecystectomy (SCx) group (65.4% vs. 54.0%, P = 0.016). For N0 patients, there was no significant difference in 5YSR between SCx and ECx groups (68.7% vs. 73.6%, P = 0.173). Systemic recurrence was more common than locoregional recurrence (78.5% vs. 21.5%). Elevation of cancer antigen 19-9 level preoperatively and lymph node (LN) metastasis were significantly poor prognostic factors in a multivariate analysis. CONCLUSION: ECx including wedge resection of GB bed should be recommended for T2 GB cancer. Because systemic recurrence was more common and recurrence occurred more frequently in patients with LN metastasis, postoperative adjuvant therapy should be considered especially for the patients with LN metastasis.

Proposed Nomogram Predicting the Individual Risk of Malignancy in the Patients With Branch Duct Type Intraductal Papillary Mucinous Neoplasms of the Pancreas.

OBJECTIVES: This study evaluated individual risks of malignancy and proposed a nomogram for predicting malignancy of branch duct type intraductal papillary mucinous neoplasms (BD-IPMNs) using the large database for IPMN. BACKGROUND: Although consensus guidelines list several malignancy predicting factors in patients with BD-IPMN, those variables have different predictability and individual quantitative prediction of malignancy risk is limited. METHODS: Clinicopathological factors predictive of malignancy were retrospectively analyzed in 2525 patients with biopsy proven BD-IPMN at 22 tertiary hospitals in Korea and Japan. The patients with main duct dilatation >10 mm and inaccurate information were excluded. RESULTS: The study cohort consisted of 2258 patients. Malignant IPMNs were defined as those with high grade dysplasia and associated invasive carcinoma. Of 2258 patients, 986 (43.7%) had low, 443 (19.6%) had intermediate, 398 (17.6%) had high grade dysplasia, and 431 (19.1%) had invasive carcinoma. To construct and validate the nomogram, patients were randomly allocated into training and validation sets, with fixed ratios of benign and malignant lesions. Multiple logistic regression analysis resulted in five variables (cyst size, duct dilatation, mural nodule, serum CA19-9, and CEA) being selected to construct the nomogram. In the validation set, this nomogram showed excellent discrimination power through a 1000 times bootstrapped calibration test. CONCLUSION: A nomogram predicting malignancy in patients with BD-IPMN was constructed using a logistic regression model. This nomogram may be useful in identifying patients at risk of malignancy and for selecting optimal treatment methods. The nomogram is freely available at http://statgen.snu.ac.kr/software/nomogramIPMN.

Predictive factors of gastroduodenal bleeding after postoperative radiotherapy in biliary tract cancer.

OBJECTIVE: To identify predictive factors for gastroduodenal bleeding after postoperative radiation therapy in patients with biliary tract cancer. METHODS: We identified 186 patients with biliary tract cancer who completed scheduled postoperative radiation therapy from March 2000 to August 2013. To isolate the effects of radiation on gastroduodenal bleeding, patients with pylorus-preserving pancreaticoduodenectomy, pylorus-resecting pancreaticoduodenectomy or Whipple surgery (n = 67) were excluded from this analysis. Postoperative radiation therapy was started at a median 5 weeks (range: 4-12 weeks) after surgery with a median dose of 44 Gy (range: 44-54), and chemotherapy was also concurrently administered to 102 patients. RESULTS: The median age of the patients was 59 years (range: 36-76 years). Of the 119 patients, 26 had intrahepatic cholangiocarcinoma, 29 had hilar cholangiocarcinoma, while 64 had extrahepatic tumors (gallbladder cancer, n = 53; proximal bile duct cancer, n = 10; choledochal cyst cancer, n = 1). Of all, 11 patients (9%) developed gastroduodenal bleeding. In univariate analyses, hepatic artery resection and gastroduodenal wall thickening on postoperative radiation therapy simulation computed tomography were statistically significant factors for gastroduodenal bleeding. Multivariate analysis by a logistic regression model using those two variables revealed that both parameters were independent predictors for gastroduodenal bleeding. CONCLUSIONS: Concomitant hepatic artery resection and presence of gastroduodenal wall thickening on postoperative radiation therapy simulation computed tomography were predictive factors for gastroduodenal bleeding after postoperative radiation therapy in biliary tract cancer. In such cases, patients should be informed of the high risk of gastroduodenal bleeding, and should be closely observed during and after postoperative radiation therapy.

Intratumoral heterogeneity of (18)F-FDG uptake predicts survival in patients with pancreatic ductal adenocarcinoma.

PURPOSE: To assess whether intratumoral heterogeneity measured by (18)F-FDG PET texture analysis has potential as a prognostic imaging biomarker in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: We evaluated a cohort of 137 patients with newly diagnosed PDAC who underwent pretreatment (18)F-FDG PET/CT from January 2008 to December 2010. First-order (histogram indices) and higher-order (grey-level run length, difference, size zone matrices) textural features of primary tumours were extracted by PET texture analysis. Conventional PET parameters including metabolic tumour volume (MTV), total lesion glycolysis (TLG), and standardized uptake value (SUV) were also measured. To assess and compare the predictive performance of imaging biomarkers, time-dependent receiver operating characteristic (ROC) curves for censored survival data and areas under the ROC curve (AUC) at 2 years after diagnosis were used. Associations between imaging biomarkers and overall survival were assessed using Cox proportional hazards regression models. RESULTS: The best imaging biomarker for overall survival prediction was first-order entropy (AUC = 0.720), followed by TLG (AUC = 0.697), MTV (AUC = 0.692), and maximum SUV (AUC = 0.625). After adjusting for age, sex, clinical stage, tumour size and serum CA19-9 level, multivariable Cox analysis demonstrated that higher entropy (hazard ratio, HR, 5.59; P = 0.028) was independently associated with worse survival, whereas TLG (HR 0.98; P = 0.875) was not an independent prognostic factor. CONCLUSION: Intratumoral heterogeneity of (18)F-FDG uptake measured by PET texture analysis is an independent predictor of survival along with tumour stage and serum CA19-9 level in patients with PDAC. In addition, first-order entropy as a measure of intratumoral metabolic heterogeneity is a better quantitative imaging biomarker of prognosis than conventional PET parameters.

Transduodenal Ampullectomy for the Treatment of Early-Stage Ampulla of Vater Cancer.

BACKGROUND: Transduodenal ampullectomy (TDA) is a less invasive procedure than pancreaticoduodenectomy (PD). However, the outcomes of TDA and PD have been compared rarely in early ampullary cancer. METHODS: From September 1994 to June 2013, the patients who underwent curative surgery for Tis or T1 ampulla of Vater neoplasm were identified. The patients were divided into two groups according to the types of surgery; TDA group and PD group. The patient characteristics and survival outcomes were retrospectively investigated between the two groups. RESULTS: Total 137 patients were included in this study. The 18 patients underwent TDA and 119 patients underwent PD for Tis or T1 ampullary cancer. There was no lymph node metastasis in the patients with Tis tumor although 10 of 104 patients had lymph node metastasis in T1 cancer. After a median follow-up of 50 months (range, 6-148), there were no recurrence after TDA for Tis tumor. However, the TDA was associated with higher local recurrence rate than PD in the patients with T1 ampullary cancer on Kaplan-Meier survival analysis (p = 0.007). CONCLUSION: The TDA is feasible treatment for Tis ampulla of Vater neoplasm. However, TDA is unsuitable for the treatment of T1 ampulla of Vater cancer.

Recurrence-associated pathways in hepatitis B virus-positive hepatocellular carcinoma.

BACKGROUND: Despite the recent identification of several prognostic gene signatures, the lack of common genes among experimental cohorts has posed a considerable challenge in uncovering the molecular basis underlying hepatocellular carcinoma (HCC) recurrence for application in clinical purposes. To overcome the limitations of individual gene-based analysis, we applied a pathway-based approach for analysis of HCC recurrence. RESULTS: By implementing a permutation-based semi-supervised principal component analysis algorithm using the optimal principal component, we selected sixty-four pathways associated with hepatitis B virus (HBV)-positive HCC recurrence (p < 0.01), from our microarray dataset composed of 142 HBV-positive HCCs. In relation to the public HBV- and public hepatitis C virus (HCV)-positive HCC datasets, we detected 46 (71.9%) and 18 (28.1%) common recurrence-associated pathways, respectively. However, overlap of recurrence-associated genes between datasets was rare, further supporting the utility of the pathway-based approach for recurrence analysis between different HCC datasets. Non-supervised clustering of the 64 recurrence-associated pathways facilitated the classification of HCC patients into high- and low-risk subgroups, based on risk of recurrence (p < 0.0001). The pathways identified were additionally successfully applied to discriminate subgroups depending on recurrence risk within the public HCC datasets. Through multivariate analysis, these recurrence-associated pathways were identified as an independent prognostic factor (p < 0.0001) along with tumor number, tumor size and Edmondson's grade. Moreover, the pathway-based approach had a clinical advantage in terms of discriminating the high-risk subgroup (N = 12) among patients (N = 26) with small HCC (<3 cm). CONCLUSIONS: Using pathway-based analysis, we successfully identified the pathways involved in recurrence of HBV-positive HCC that may be effectively used as prognostic markers.