Lewin, David

There is an urgent need for the identification of reliable prognostic biomarkers for patients with intrahepatic cholangiocarcinoma (iCCA) and alterations in N-glycosylation have demonstrated an immense potential to be used as diagnostic strategies for many cancers, including hepatocellular carcinoma (HCC). N-glycosylation is one of the most common post-translational modifications known to be altered based on the status of the cell. N-glycan structures on glycoproteins can be modified based on the addition or removal of specific N-glycan residues, some of which have been linked to liver diseases. However, little is known concerning the N-glycan alterations that are associated with iCCA. We characterized the N-glycan modifications quantitatively and qualitatively in three cohorts, consisting of two tissue cohorts: a discovery cohort (n = 104 cases) and a validation cohort (n = 75), and one independent serum cohort consisting of patients with iCCA, HCC, or benign chronic liver disease (n = 67). N-glycan analysis in situ was correlated to tumor regions annotated on histopathology and revealed that bisected fucosylated N-glycan structures were specific to iCCA tumor regions. These same N-glycan modifications were significantly upregulated in iCCA tissue and serum relative to HCC and bile duct disease, including primary sclerosing cholangitis (PSC) (P < 0.0001). N-glycan modifications identified in iCCA tissue and serum were used to generate an algorithm that could be used as a biomarker of iCCA. We demonstrate that this biomarker algorithm quadrupled the sensitivity (at 90% specificity) of iCCA detection as compared with carbohydrate antigen 19-9, the current “gold standard” biomarker of CCA. Significance: This work elucidates the N-glycan alterations that occur directly in iCCA tissue and utilizes this information to discover serum biomarkers that can be used for the noninvasive detection of iCCA.

Abstract Context. —Establishing adequate interobserver agreement is crucial not only for standardization of patient care but also to ensure validity of findings in multi-institutional trials. Objective. —To evaluate interobserver agreement in assessing chronic hepatitis C (HCV) and acute cellular rejection (ACR) among 17 hepatopathologists involved in the “Hepatitis C 3” trial. Design. —The trial is a randomized multicenter (17 institutions) study involving 312 patients undergoing transplantation for HCV. Patients are randomized to 3 treatment arms. For final data analysis, all biopsy specimens are reviewed by a central pathologist (G.J.N.). Recurrence of HCV is evaluated according to the Batts and Ludwig schema. The 1997 Banff schema is used to evaluate ACR. To assess interobserver agreement, hematoxylin-eosin–stained sections from 11 liver biopsy specimens (6 HCV and 5 ACR) were sent by the central pathologist to 16 local pathologists from 13 institutions. Statistical analysis was performed on raw ACR/HCV data as well as data grouped according to clinically significant primary endpoint cutoffs. Results. —Statistically significant agreement was found among all participating pathologists ( P < .001). On κ analysis, the degree of agreement was rated “moderate” for HCV grade and stage and ACR global grading (κ = 0.30, 0.33, and 0.37, respectively). Interobserver agreement was weaker for rejection activity index scoring of ACR (κ = 0.15). A stronger degree of agreement was found when scores were grouped based on endpoint cutoffs (κ = 0.76 “almost perfect” for HCV and 0.62 “substantial” for ACR). Conclusions. —An overall statistically significant interobserver agreement was found among 17 pathologists using the 1997 Banff schema and the Batts and Ludwig schema.

17077 Background: The overall 5-yr survival for the treatment of lung cancer patients is less than 20% due to the inability to control metastatic disease. Methods: To identify genes that promote the development of metastases in NSCLC and other solid tumors, we first performed three separate microarray analyses using Affymetrix U133A chips whereby expression values of a pool of normal lymph nodes was compared to: lung cancer cell lines (n = 4), and metastatic lymph nodes from breast (n = 3) and pancreatic (n = 3) cancer patients. Separate lists of the 35 most highly overexpressed genes for each cancer type were compiled. Results: We observed that each list contained EpCAM, XAG, CK19, and CK8 (p = 1.1E-18). To search for genes that might regulate expression of these four genes, we queried the CGAP NCI60 gene expression database with the 87 genes contained on the three lists and constructed a connectivity map such that the presence of a gene on the map required: 1) high correlation (p < 8.0E-6) with at least two other genes, and 2), direct or indirect contact to EpCAM or XAG. The map contained two gene clusters (XAG cluster = 6 genes; EpCAM/CK19/CK8 cluster = 7 genes) that were connected to, and potentially regulated by, the Ets transcriptional factor Esx. Genes from both clusters, as well as Esx, were highly overexpressed in metastatic mediastianal lymph nodes obtained from NSCLC patients. To investigate whether Esx might regulate expression of one or more genes in the two clusters, we transfected an NSCLC cell line derived from lymph node metastases with siRNA to Esx and observed: 1) a reduction in expression of EpCAM (4-fold), XAG (7-fold), and the orphan nuclear receptor ESRRα (1,000-fold), and 2), an inhibition of cell growth. Conclusions: Based on our ability to simultaneously inhibit cell growth and expression of multiple metastasis-associated genes with a single siRNA, we conclude that Esx is a major regulator of lymph node metastasis. No significant financial relationships to disclose.

AimsMassive gastric polyposis is a rare entity that is often associated with juvenile polyposis syndrome (JPS). The aim of this study was to evaluate the clinicopathological features of 22 patients with abundant gastric juvenile‐type or hyperplastic‐like polyps.Methods and resultsThe study included 12 males and 10 females with a median age of 48 years (range: 13–79 years). Fourteen (64%) patients carried a diagnosis of JPS, and three had prior gastrointestinal adenocarcinomas. Patients without known JPS presented at an older median age (60 years versus 40 years; P = 0.0068). Clinical symptoms included nausea, vomiting, and abdominal pain; 23% of patients were asymptomatic. Eighteen cases showed complete or near‐complete carpeting of the gastric mucosa by innumerable polyps, ranging from a few millimetres to ~100 mm. Most polyps formed long, bulbous projections and had characteristic histological features, including a smooth outer contour, prominent stromal oedema, and widely spaced, often cystically dilated glands lined by foveolar epithelium; some polyps had less stroma and more hyperplastic foveolar epithelium. All had normal underlying or adjacent mucosa. Four (18%) cases harboured adenocarcinoma, and seven (32%) others showed dysplasia. SMAD4 immunohistochemical staining showed patchy loss in polyps from 19 of 20 cases tested. Five of six (84%) patients tested had a germline SMAD4 mutation.ConclusionsMassive gastric juvenile‐type polyposis can occur in patients with and without known JPS, and may mimic different conditions, such as other polyposis syndromes and Ménétrier disease. Pathologists play an important role in disease classification, as some patients lack a family or personal history of JPS, have few if any colonic polyps, and may not harbour diagnostic germline mutations.