Cancer-associated stroma reveals prognostic biomarkers and novel insights into the tumour microenvironment of colorectal cancer and colorectal liver metastases.

BACKGROUND AND AIMS: Cancer-associated stroma (CAS) is emerging as a key determinant of metastasis in colorectal cancer (CRC); however, little is known about CAS in colorectal liver metastases (CRLM). This study aimed to validate the prognostic significance of stromal protein biomarkers in primary CRC and CRLM. Secondly, this study aimed to describe the transcriptome of the CAS of CRLM and identify novel targetable pathways of metastasis. METHODS: A case-control study design from a prospectively maintained database was adopted. The prognostic value of epithelial and stromal CALD1, IGFBP7, POSTN, FAP, TGF-ß and pSMAD2 expression was assessed by immunohistochemistry (IHC) in multivariate models. Pathway enrichment and sparse partial least square-discriminant analysis (sPLS-DA) were performed on a nested cohort after isolating epithelial tumour and CAS by laser capture microdissection. RESULTS: 110 CRCs with 124 paired CRLMs, and 110 matched non-metastatic control CRCs were included. Median follow-up was 62 and 45 months for primary and CRLM groups, respectively. Stromal FAP and POSTN were independent predictors for the development of CRLM. After CRLM resection, stromal IGFBP7 and POSTN were predictors of poorer survival. sPLS-DA on the nested cohort identified a number of novel targetable stromal genes and pathways that defined poor prognosis CRC and the CAS of CRLM. CONCLUSIONS: This study is the first to describe key differences in stromal gene expression between paired primary CRC and CRLM as well as identifying several targetable biomarkers and transcriptomic pathways whose relevance specifically in the CAS of CRC and CRLM have not been previously described.

Pancreatic adenocarcinoma preferentially takes up and is suppressed by synthetic nanoparticles carrying apolipoprotein A-II and a lipid gemcitabine prodrug in mice.

We hypothesised that synthetic HDL nanoparticles carrying a gemcitabine prodrug and apolipoprotein A-II (sHDLGemA2) would target scavenger receptor-B1 (SR-B1) to preferentially and safely deliver gemcitabine into pancreatic ductal adenocarcinoma (PDAC). We designed, manufactured and characterised sHDLGemA2 nanoparticles sized ~130 nm, incorporating 20 mol% of a gemcitabine prodrug within the lipid bilayer, which strengthens on adding ApoA-II. We measured their ability to inhibit growth in cell lines and cell-derived and patient-derived murine PDAC xenografts. Fluorescent-labelled sHDLGemA2 delivered gemcitabine inside xenografts. Xenograft levels of active gemcitabine after sHDLGemA2 were similar to levels after high-dose free gemcitabine. Growth inhibition in mice receiving 4.5 mg gemcitabine/kg/d, carried in sHDLGemA2, was equivalent to inhibition after high-dose (75 mg/kg/d) free gemcitabine, and greater than inhibition after low-dose (4.5 mg/kg/d) free gemcitabine. sHDLGemA2 slowed growth in semi-resistant cells and a resistant human xenograft. sHDLGemA2 targeted xenografts more effectively than sHDLGemA1. SR-B1 was over-expressed in PDAC cells and xenografts. Targeting by ApoA-II was suppressed by anti-SR-B1. Because sHDLGemA2 provided only ~6% of the free gemcitabine dose for an equivalent response, patient side effects can be greatly reduced, and the sHDLGemA2 concept should be developed through clinical trials.

Biomimetic Gemcitabine-Lipid Prodrug Nanoparticles for Pancreatic Cancer.

Gemcitabine (Gem) is a key drug for pancreatic cancer, yet limited by high systemic toxicity, low bioavailability and poor pharmacokinetic profiles. To overcome these limitations, Gem prodrug amphiphiles were synthesised with oleyl, linoleyl and phytanyl chains. Self-assembly and lyotropic mesophase behaviour of these amphiphiles were examined using polarised optical microscopy and Synchrotron SAXS (SSAXS). Gem-phytanyl was found to form liquid crystalline inverse cubic mesophase. This prodrug was combined with phospholipids and cholesterol to create biomimetic Gem-lipid prodrug nanoparticles (Gem-LPNP), verified by SSAXS and cryo-TEM to form liposomes. In vitro testing of the Gem-LPNP in several pancreatic cancer cell lines showed lower toxicity than Gem. However, in a cell line-derived pancreatic cancer mouse model Gem-LPNP displayed greater tumour growth inhibition than Gem using a fraction (<6 %) of the clinical dose and without any systemic toxicity. The easy production, improved efficacy and low toxicity of Gem-LPNP represents a promising new nanomedicine for pancreatic cancer.

SELDI-TOF MS Analysis of Hepatocellular Carcinoma in an Australian Cohort.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common cause of cancer death worldwide. Resection offers the best chance of long-term survival, but a consistent adverse prognostic factor is the presence of microvascular invasion (MVI). In this study, surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS), a high throughput method of analyzing complex samples, was used to explore differentially expressed proteins between HCC and adjacent nontumour liver tissue (ANLT). These findings were correlated with clinical outcomes. MATERIALS AND METHODS: From 2002 to 2011, tumor and ANLT were collected from patients who underwent liver resection and these samples were later prepared for SELDI-TOF MS. Output data were then used to identify proteins capable of discriminating HCC from ANLT. Proteins from the multivariate analysis were then analyzed to determine prognostic factors and the m/z ratios of these proteins were entered into the ExPASy database to infer potential candidates. RESULTS: During the study period, 30 patients had SELDI-TOF MS performed on their HCC and ANLT samples. On multivariate analysis, a panel of four proteins-m/z 5840, m/z 8921, m/z 9961, and m/z 25,872-discriminated HCC from ANLT with an area under the ROC curve of 0.954 (P < 0.001). On prognostic factor assessment, decreased m/z 9961 was significantly associated with the presence of MVI (P = 0.025) and shorter disease-free survival (P = 0.045) in our patients. A potential candidate for this protein was coxsackievirus and adenovirus receptor, isoform 3 (CAR 3/7), which helps maintain tight junction integrity. CONCLUSIONS: Using SELDI TOF-MS, we identified a panel of four proteins with excellent discriminative capacity between HCC and ANLT. Of these, m/z 9961 was the only protein significantly associated with a known poor prognostic factor (presence of MVI) and survival (shorter disease-free survival). While loss of CAR 3/7 could lead to MVI, further research is warranted to validate the identity of protein m/z 9961.

Using patient-derived xenograft models of colorectal liver metastases to predict chemosensitivity.

BACKGROUND: Few in vivo models for colorectal cancer have been demonstrated to show external validity by accurately predicting clinical patient outcomes. Patient-derived xenograft (PDX) models of cancer have characteristics that might provide a form of translational research leading to personalized cancer care. The aim of this pilot study was to assess the feasibility of using PDXs as a platform for predicting patient colorectal liver metastases responses, in this case by correlating PDX and patient tumor responses to either folinic acid, fluorouracil plus oxaliplatin or folinic acid, fluorouracil plus irinotecan-based regimens. METHODS: Sixteen patients underwent potentially curative resection of colorectal liver metastases, and tumors were grafted into NOD.CB17-Prkdcscid/Arc mice. Mice were divided into groups to determine relative tumor growth in response to treatment. Tumors were analyzed by immunohistochemistry for Ki67 and Excision repair cross-complementation group 1. RESULTS: An engraftment rate of 81% was achieved. Overall, there was a 67% positive match rate between eligible patient and PDX chemosensitivity profiles. There was a significant difference in relative decrease in Ki67 expression between sensitive/stable versus resistant PDXs for both treatment regimens. There was no statistically significant correlation between baseline ERCC1 expression and response to Oxaliplatin + 5-Fluorouracil in the PDXs. CONCLUSIONS: This pilot study supports the feasibility of using PDX models of advanced colorectal cancer in larger studies to potentially predict patient chemosensitivity profiles.

Diagnosis and management of pancreatic exocrine insufficiency.

INTRODUCTION: In 2015, the Australasian Pancreatic Club (APC) published the Australasian guidelines for the management of pancreatic exocrine insufficiency (http://pancreas.org.au/2016/01/pancreatic-exocrine-insufficiency-guidelines). Pancreatic exocrine insufficiency (PEI) occurs when normal digestion cannot be sustained due to insufficient pancreatic digestive enzyme activity. This may be related to a breakdown, at any point, in the pancreatic digestive chain: pancreatic stimulation; synthesis, release or transportation of pancreatic enzymes; or synchronisation of secretions to mix with ingested food. Main recommendations: The guidelines provide advice on diagnosis and management of PEI, noting the following: A high prevalence of PEI is seen in certain diseases and conditions, such as cystic fibrosis, acute and chronic pancreatitis, pancreatic cancer and pancreatic surgery. The main symptoms of PEI are steatorrhoea or diarrhoea, abdominal pain, bloating and weight loss. These symptoms are non-specific and often go undetected and untreated. PEI diagnosis is predominantly based on clinical findings and the presence of underlying disease. The likelihood of PEI in suspected patients has been categorised into three groups: definite, possible and unlikely. If left untreated, PEI may lead to complications related to fat malabsorption and malnutrition, and have an impact on quality of life. Pancreatic enzyme replacement therapy (PERT) remains the mainstay of PEI treatment with the recommended adult initial enzyme dose being 25 000-40 000 units of lipase per meal, titrating up to a maximum of 75 000-80 000 units of lipase per meal. Adjunct acid-suppressing therapy may be useful when patients still experience symptoms of PEI on high dose PERT. Nutritional management by an experienced dietitian is essential. Changes in management as a result of these guidelines: These are the first guidelines to classify PEI as being definite, possible or unlikely, and provide a diagnostic algorithm to facilitate the early diagnosis of PEI and appropriate use of PERT.

Upstream and Downstream Co-inhibition of Mitogen-Activated Protein Kinase and PI3K/Akt/mTOR Pathways in Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Extensive cross talk exists between PI3K/Akt/mTOR and mitogen-activated protein kinase (MAPK) pathways, and both are upregulated in pancreatic ductal adenocarcinoma (PDAC). Our previous study suggested that epidermal growth factor receptor inhibitor erlotinib which acts upstream of these pathways acts synergistically with PI3K inhibitors in PDAC. Horizontal combined blockade upstream and downstream of these two pathways is therefore explored. METHODS: Erlotinib paired with PI3K inhibitor (BYL719) was tested against erlotinib plus dual PI3K/mTOR inhibitor BEZ-235, and MEK inhibitor (PD98059) plus BEZ235, on five primary PDAC cell lines and on two pairs of parent and erlotinib-resistant (ER) cell lines. A range of in vitro assays including cell proliferation, Western blotting, migration, clonogenic, cell cycle, and apopotic assays was used to test for the efficacy of combined blockade. RESULTS: Dual downstream blockade of the MAPK and PAM pathways was more effective in attenuating downstream molecular signals. Synergy was demonstrated for erlotinib and BEZ235 and for PD-98059 and BEZ-235. This resulted in a trend of increased growth cell cycle arrest, apoptosis, cell proliferation, and colony and migration suppression. This combination showed more efficacy in cell lines with acquired resistance to erlotinib. CONCLUSIONS: The additional mTOR blockade provided by BEZ235 in combined blockade resulted in increased anticancer effect. The hypersensitivity of ER cell lines to additional mTOR blockade suggested PAM pathway oncogenic dependence via mTOR. Dual downstream combined blockade of MAPK and PAM pathways with MEK and PI3K/mTOR inhibitor appeared most effective and represents an attractive therapeutic strategy against pancreatic cancer and its associated drug resistance.

Apolipoprotein A-II Plus Lipid Emulsion Enhance Cell Growth via SR-B1 and Target Pancreatic Cancer In Vitro and In Vivo.

BACKGROUND: Apolipoprotein A-II (ApoA-II) is down regulated in the sera of pancreatic ductal adenocarcinoma (PDAC) patients, which may be due to increase utilization of high density lipoprotein (HDL) lipid by pancreatic cancer tissue. This study examined the influence of exogenous ApoA-II on lipid uptake and cell growth in pancreatic cancer (PC) both in vitro and in vivo. METHODS: Cryo transmission electron microscopy (TEM) examined ApoA-II's influence on morphology of SMOFLipid emulsion. The influence of ApoA-II on proliferation of cancer cell lines was determined by incubating them with lipid+/-ApoA-II and anti-SR-B1 antibody. Lipid was labeled with the fluorophore, DiD, to trace lipid uptake by cancer cells in vitro by confocal microscopy and in vivo in PDAC patient derived xenograft tumours (PDXT) by fluorescence imaging. Scavenger receptor class B type-1(SR-B1) expression in PDAC cell lines and in PDAC PDXT was measured by western blotting and immunohistochemistry, respectively. RESULTS: ApoA-II spontaneously converted lipid emulsion into very small unilamellar rHDL like vesicles (rHDL/A-II) and enhanced lipid uptake in PANC-1, CFPAC-1 and primary tumour cells as shown by confocal microscopy. SR-B1 expression was 13.2, 10.6, 3.1 and 2.3 fold higher in PANC-1, MIAPaCa-2, CFPAC-1 and BxPC3 cell lines than the normal pancreatic cell line (HPDE6) and 3.7 fold greater in PDAC tissue than in normal pancreas. ApoA-II plus lipid significantly increased the uptake of labeled lipid and promoted cell growth in PANC-1, MIAPaCa-2, CFPAC-1 and BxPC3 cells which was inhibited by anti SR-B1 antibody. Further, ApoA-II increased the uptake of lipid in xenografts by 3.4 fold. CONCLUSION: Our data suggest that ApoA-II enhance targeting potential of lipid in pancreatic cancer which may have imaging and drug delivery potentialities.

Summary and recommendations from the Australasian guidelines for the management of pancreatic exocrine insufficiency.

AIM: Because of increasing awareness of variations in the use of pancreatic exocrine replacement therapy, the Australasian Pancreatic Club decided it was timely to re-review the literature and create new Australasian guidelines for the management of pancreatic exocrine insufficiency (PEI). METHODS: A working party of expert clinicians was convened and initially determined that by dividing the types of presentation into three categories for the likelihood of PEI (definite, possible and unlikely) they were able to consider the difficulties of diagnosing PEI and relate these to the value of treatment for each diagnostic category. RESULTS AND CONCLUSIONS: Recent studies confirm that patients with chronic pancreatitis receive similar benefit from pancreatic exocrine replacement therapy (PERT) to that established in children with cystic fibrosis. Severe acute pancreatitis is frequently followed by PEI and PERT should be considered for these patients because of their nutritional requirements. Evidence is also becoming stronger for the benefits of PERT in patients with unresectable pancreatic cancer. However there is as yet no clear guide to help identify those patients in the 'unlikely' PEI group who would benefit from PERT. For example, patients with coeliac disease, diabetes mellitus, irritable bowel syndrome and weight loss in the elderly may occasionally be given a trial of PERT, but determining its effectiveness will be difficult. The starting dose of PERT should be from 25,000-40,000 IU lipase taken with food. This may need to be titrated up and there may be a need for proton pump inhibitors in some patients to improve efficacy.

Loss of BAP1 Expression Occurs Frequently in Intrahepatic Cholangiocarcinoma.

BRCA1-associated protein 1 (BAP1) is a deubiquitinating enzyme that functions as a tumor suppressor gene. Double hit BAP1 inactivation has been reported in a range of tumor types, including intrahepatic cholangiocarcinoma (ICC), sometimes in association with germline mutation.We performed immunohistochemistry for BAP1 on a well-characterized cohort of 211 ICC patients undergoing surgical resection with curative intent at 3 institutions based in 3 different countries. The median age at diagnosis was 65 years (range, 36.5-86) and 108 (51%) were men. Negative staining for BAP1 (defined as completely absent nuclear staining in the presence of positive internal controls in nonneoplastic cells) occurred in 55 ICCs (26%). BAP1 loss predicted a strong trend toward improved median survival of 40.80 months (95% CI, 28.14-53.46) versus 24.87 months (95% CI, 18.73-31.01), P = 0.059). In a multivariate model including age, sex, BAP1 status, tumor stage, tumor grade, lymphovascular invasion, and tumor size, female sex was associated with improved survival (hazard ratio [HR] 0.54; 95% CI, 0.34-0.85), while advanced tumor stage and lymphovascular invasion (HR 1.89; 95% CI, 1.09-3.28) correlated with decreased survival. In a multivariate analysis, high grade tumors were associated with BAP1 loss (odds ratio [OR] 3.32; 95% CI, 1.29-8.55), while lymphatic invasion was inversely associated with BAP1 loss (OR 0.36; 95% CI, 0.13-0.99).In conclusion, we observed a trend toward improved prognosis in ICC associated with absent expression of BAP1 and an association of BAP1 loss with higher histological grade and absent lymphatic invasion. Female sex was associated with improved survival while advanced tumor stage and lymphatic invasion were associated with decreased survival.

A patient-derived subrenal capsule xenograft model can predict response to adjuvant therapy for cancers in the head of the pancreas.

BACKGROUND: Although gemcitabine is commonly used as adjuvant therapy for pancreatic adenocarcinoma and pancreaticobiliary-type periampullary cancers, not all patients appear to benefit. This translational study evaluates the potential of a patient-derived subrenal capsule pancreatic cancer xenograft (SRCPCX) model to identify within eight weeks after surgery those tumours which will respond to gemcitabine. METHODS: SRCPCXs from 32 pancreatectomy patients were established in six to ten NOD/SCID mice per patient. After four weeks the mice were randomly assigned to receive gemcitabine or saline for four more weeks. After eight weeks, gemcitabine response in the grafts was evaluated by the percentage of tumour growth inhibition (%TGI), histological morphology and immunohistochemical markers (Ki-67, CK7 and cleaved caspase-3). These were collated into an Overall Response. Survival was assessed by Kaplan-Meier and Cox multivariate analyses. RESULTS: 375 of 450 pieces of tissue from 27 of 31 patients were evaluable. In 90% of patients, histopathological and immunostaining features of saline-treated control grafts were concordant with their original tumours. At follow up, six of 15 patients whose tumours had an Overall Response to gemcitabine died, compared with ten of 12 whose tumours did not respond (P = 0.025, Fisher's exact test). This was associated with improved survival on Kaplan-Meier analysis (P = 0.013). Cox multivariate analysis indicated that Overall Response, stage and grade were independent predictors of survival. CONCLUSION: This SRCPCX model retains major histopathological and immunohistochemical characteristics of the original tumour and when a combination of measures is used, enables early assessment of tumour sensitivity to gemcitabine in pancreatic cancers.

Serum CA19-9 is significantly upregulated up to 2 years before diagnosis with pancreatic cancer: implications for early disease detection.

PURPOSE: Biomarkers for the early detection of pancreatic cancer are urgently needed. The primary objective of this study was to evaluate whether increased levels of serum CA19-9, CA125, CEACAM1, and REG3A are present before clinical presentation of pancreatic cancer and to assess the performance of combined markers for early detection and prognosis. EXPERIMENTAL DESIGN: This nested case-control study within the UKCTOCS included 118 single and 143 serial serum samples from 154 postmenopausal women who were subsequently diagnosed with pancreatic cancer and 304 matched noncancer controls. Samples were split randomly into independent training and test sets. CA19-9, CA125, CEACAM1, and REG3A were measured using ELISA and/or CLIA. Performance of markers to detect cancers at different times before diagnosis and for prognosis was evaluated. RESULTS: At 95% specificity, CA19-9 (>37 U/mL) had a sensitivity of 68% up to 1 year, and 53% up to 2 years before diagnosis. Combining CA19-9 and CA125 improved sensitivity as CA125 was elevated (>30 U/mL) in approximately 20% of CA19-9-negative cases. CEACAM1 and REG3A were late markers adding little in combined models. Average lead times of 20 to 23 months were estimated for test-positive cases. Prediagnostic levels of CA19-9 and CA125 were associated with poor overall survival (HR, 2.69 and 3.15, respectively). CONCLUSIONS: CA19-9 and CA125 have encouraging sensitivity for detecting preclinical pancreatic cancer, and both markers can be used as prognostic tools. This work challenges the prevailing view that CA19-9 is upregulated late in the course of pancreatic cancer development.

Factors that may influence the willingness of cancer patients to consent for biobanking.

BACKGROUND: Broad or general consent given by cancer patients for their tissue, blood, and clinical information to be stored in institutional biorepositories is fundamental to enable future ethical translational cancer research. The decision to consent for biobanking will contribute to the development of advanced diagnostic and prognostic tests, as well as new therapies to improve patient outcomes. While the rate of patient participation in biobanking programs is generally reported as high worldwide, few studies have investigated factors that may influence this decision. Biobanking at our medical research institute, an associated public (government-run) university hospital, and private hospital has been established for over 20 years, with collection of certain tumor types embedded in the research culture of these institutions. In this study, we investigated factors that may influence a cancer patient's decision to give broad consent for biobanking of their specimens. METHODS: Data on patient consent were collected over a 6-month period from both government and private hospitals associated with our medical research institute. Factors considered included gender, patient age at surgery, type of malignancy (breast, duodenal, cervical, endometrial, gastric, liver, esophageal, ovarian, pancreatic, pelvic, uterine, or vulval), type of institution where surgery was performed, and timing of consent. RESULTS: Of 171 cancer patients, 159 (93%) gave broad consent for biobanking of their tissue and blood specimens for future cancer research projects receiving ethical and scientific approval. None of the factors analyzed was shown to influence a patient's decision to contribute biological specimens and clinical data to a biorepository for future medical research. CONCLUSION: Biobanking for future ethically and scientifically approved research projects in an established institution is an initiative that receives strong support from patients undergoing cancer surgery, independent of factors including gender, age, type of tumor, type of institution where surgery was performed, or timing of consent.

Cotargeting of epidermal growth factor receptor and PI3K overcomes PI3K-Akt oncogenic dependence in pancreatic ductal adenocarcinoma.

PURPOSE: PI3K-Akt is overexpressed in 50% to 70% of pancreatic ductal adenocarcinoma (PDAC). The hypothesis of this study is that PI3K and EGFR coinhibition may be effective in PDAC with upregulated PI3K-Akt signaling. EXPERIMENTAL DESIGN: Multiple inhibitors were tested on five PDAC cell lines. EGFR inhibitor (EGFRi)-resistant cell lines were found to have significantly overexpressed AKT2 gene, total Akt, and pAkt. In vitro erlotinib-resistant (ER) cell models (BxPC-ER and PANC-ER) with highly constitutively active PI3K-Akt were developed. These and their respective parent cell lines were tested for sensitivity to erlotinib, IGFIR inhibitor NVP-AEW541 (AEW), and PI3K-alpha inhibitor NVP-BYL719 (BYL), alone or in combination, by RTK-phosphoarray, Western blotting, immunofluorescence, qRT-PCR, cell proliferation, cell cycle, clonogenic, apoptosis, and migration assays. Erlotinib plus BYL was tested in vivo. RESULTS: Erlotinib acted synergistically with BYL in BxPC-ER (synergy index, SI = 1.71) and PANC-ER (SI = 1.44). Treatment of ER cell lines showing upregulated PI3K-Akt with erlotinib plus BYL caused significant G1 cell-cycle arrest (71%, P < 0.001; 58%, P = 0.003), inhibition of colony formation (69% and 72%, both P < 0.001), and necrosis and apoptosis (75% and 53%, both P < 0.001), more so compared with parent cell lines. In primary patient-derived tumor subrenal capsule (n = 90) and subcutaneous (n = 22) xenografts, erlotinib plus BYL significantly reduced tumor volume (P = 0.005). Strong pEGFR and pAkt immunostaining (2+/3+) was correlated with high and low responses, respectively, to both erlotinib and erlotinib plus BYL. CONCLUSION: PDAC with increased expression of the PI3K-Akt pathway was susceptible to PI3K-EGFR coinhibition, suggesting oncogenic dependence. Erlotinib plus BYL should be considered for a clinical study in PDAC; further evaluation of pEGFR and pAkt expression as potential positive and negative predictive biomarkers is warranted.

Survival, mortality and morbidity outcomes after oesophagogastric cancer surgery in New South Wales, 2001-2008.

OBJECTIVES: To examine the relationship between hospital volume and patient outcomes for New South Wales hospitals performing oesophagectomy and gastrectomy for oesophagogastric cancer. DESIGN, SETTING AND PATIENTS: A retrospective, population-based cohort study of NSW residents diagnosed with a new case of invasive oesophageal or gastric cancer who underwent oesophagectomy or gastrectomy between 2001 and 2008 in NSW hospitals using linked de-identified data from the NSW Central Cancer Registry, the National Death Index and the NSW Admitted Patient Data Collection. A higher-volume hospital was defined as one performing > 6 relevant procedures per year. MAIN OUTCOME MEASURES: Odds ratios for > 21-day length of stay, 28-day unplanned readmission, 30-day mortality and 90-day mortality, and hazard ratios (HRs) for 5-year absolute and conditional survival. RESULTS: Oesophagectomy (908 patients) and gastrectomy (1621 patients) were undertaken in 42 and 84 hospitals, respectively, between 2001 and 2008. Median annual hospital volume ranged from 2 to 4 for oesophagectomies and ranged from 2 to 3 for gastrectomies. Controlling for known confounders, no associations between hospital volume and > 21-day length of stay and 28-day unplanned readmission were found. Overall 30-day mortality was 4.1% and 4.4% for oesophagectomy and gastrectomy, respectively. Five-year absolute survival was significantly better for patients who underwent oesophagectomy in higher-volume hospitals (adjusted HR for lower-volume hospitals, 1.28 [95% CI, 1.10-1.49]; P = 0.002) and for those with localised gastric cancer who underwent gastrectomy in higher-volume hospitals (adjusted HR for lower-volume hospitals, 1.83 [95% CI, 1.28-2.61]; P = 0.001). CONCLUSIONS: These data support initial surgery for oesophagogastric cancer in higher-volume hospitals.

Identification of potential serum peptide biomarkers of biliary tract cancer using MALDI MS profiling.

BACKGROUND: The aim of this discovery study was the identification of peptide serum biomarkers for detecting biliary tract cancer (BTC) using samples from healthy volunteers and benign cases of biliary disease as control groups. This work was based on the hypothesis that cancer-specific exopeptidases exist and that their activities in serum can generate cancer-predictive peptide fragments from circulating proteins during coagulation. METHODS: This case control study used a semi-automated platform incorporating polypeptide extraction linked to matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) to profile 92 patient serum samples. Predictive models were generated to test a validation serum set from BTC cases and healthy volunteers. RESULTS: Several peptide peaks were found that could significantly differentiate BTC patients from healthy controls and benign biliary disease. A predictive model resulted in a sensitivity of 100% and a specificity of 93.8% in detecting BTC in the validation set, whilst another model gave a sensitivity of 79.5% and a specificity of 83.9% in discriminating BTC from benign biliary disease samples in the training set. Discriminatory peaks were identified by tandem MS as fragments of abundant clotting proteins. CONCLUSIONS: Serum MALDI MS peptide signatures can accurately discriminate patients with BTC from healthy volunteers.

Discovery of diagnostic biomarkers for pancreatic cancer in immunodepleted serum by SELDI-TOF MS.

MOTIVATION: Reports of serum pancreatic cancer (PC) biomarkers using SELDI-TOF MS have been inconsistent because different chip surfaces and interference with high-abundant proteins. This study examines the influence of these factors on the detection of discriminating diagnostic biomarkers. METHODS: Serum from fourteen from patients with PC, disease controls (DC, n = 14) and healthy volunteers (HV, n = 14) were evaluated by SELDI using H50, IMAC, Q10 and CM10 chips. A further evaluation was undertaken after depletion of seven high-abundant proteins using spin cartridges. RESULTS: More protein peaks were detected in whole serum than in depleted serum for IMAC, H50 and Q10 chips: 60 vs 39, 56 vs 48 and 69 vs 65, respectively, while the CM10 found less peaks in serum (27 vs 47 peaks). However, there were more differentially expressed peaks in the depleted serum samples for PC vs DC and PC vs HV samples using the H50, Q10 and CM10 ProteinChip arrays, whereas for IMAC arrays, more discriminating peaks were seen in non-depleted serum. The highly significant peaks observed on Q10, CM10 and H50 are consistent with the previous finding of ApoA-I (m/z 27,910-28000) and ApoA-II (m/z 8758 and 17,240). In addition, a number of new discriminating protein peaks were found on different ProteinChip arrays, notably peaks at m/z 4280 and 7763 on IMAC arrays. CONCLUSION: This study confirms the diagnostic value of ApoA-I&II and identifies further potential diagnostic biomarkers for pancreatic cancer when multiple chip surfaces are used with depletion of the most highly-abundant proteins.

Long-term changes in body composition after pancreaticoduodenectomy.

BACKGROUND: The Whipple's procedure (WP) is a major operation that adds a further demand on the body's nutritional reserves and therefore body composition after the effect of pancreatic cancer. The aim was to document changes in body composition changes that occur during the first six months after a WP for a pancreatic cancer malignancy. METHODS: Twenty-seven (14 males, 13 females) consecutive WP patients had body composition measured at baseline and then at 2, 5, 14 and 26 weeks after surgery. These included; anthropometric measure (weight, skin folds and arm muscle area (AMA)), total body measures of protein (TBP), potassium (TBK), water (TBW) and fat mass (FM). Changes were compared using repeated measures analysis of variance. RESULTS: Hospital nutritional care maintained TBP and TBK but at 2 weeks there was a loss of FM (P= 0.037). The nadir of weight loss (P < 0.001) occurred at 5 weeks because of losses of protein (P= 0.007), fat (P < 0.001) and potassium (P= 0.045) but not water. Although weight and FM were still significantly less than baseline measures at 26 weeks weight, TBP, TBK and AMA were not significantly different to preoperative values. CONCLUSIONS: Although at 6 months, important measures of the metabolically functioning tissue, TBP and TBK, have returned to preoperative values significant losses occurred during the first 3 weeks after discharge from hospital and FM did not return to preoperative values. These results suggest the need to improve post-discharge nutritional care.

Pyogenic liver abscess: an audit of 10 years' experience.

AIM: To describe our own experience with pyogenic liver abscesses over the past 10 years and investigate the risk factors associated with failure of initial percutaneous therapy. METHODS: A retrospective study of records of 63 PLA patients presenting between 1998 and 2008 to Australian tertiary referral centre, were reviewed. Amoebic and hydatid abscesses were excluded. Demographic, clinical, radiological, and microbiological characteristics, as well as surgical/radiological interventions, were recorded. RESULTS: Sixty-three patients (42 males, 21 females) aged 65 (± 14) years [mean ± (SD)] had prodromal symptoms for a median (interquartile range; IQR) of 7 (5-14) d. Only 59% of patients were febrile at presentation; however, the serum C-reactive protein was elevated in all 47 in whom it was measured. Liver function tests were non-specifically abnormal. 67% of patients had a solitary abscess, while 32% had > 3 abscesses with a median (IQR) diameter of 6.3 (4-9) cm. Causative organisms were: Streptococcus milleri 25%, Klebsiella pneumoniae 21%, and Escherichia coli 16%. A presumptive cryptogenic cause was most common (34%). Four patients died in this series: one from sepsis, two from advanced cancer, and one from acute myocardial infarction. The initial procedure was radiological aspiration ± drainage in 54 and surgery in two patients. 17% underwent surgical management during their hospitalization. Serum hypoalbuminaemia [mean (95% CI): 32 (29-35) g/L vs 28 (25-31) g/L, P = 0.045] on presentation was found to be the only factor related to failure of initial percutaneous therapy on univariate analysis. CONCLUSION: PLA is a diagnostic challenge, because the presentation of this condition is non-specific. Intravenous antibiotics and radiological drainage in the first instance allows resolution of most PLAs; However, a small proportion of patients still require surgical drainage.