The distinctive gastric fluid proteome in gastric cancer reveals a multi-biomarker diagnostic profile

<p>Abstract</p> <p>Background</p> <p>Overall gastric cancer survival remains poor mainly because there are no reliable methods for identifying highly curable early stage disease. Multi-protein profiling of gastric fluids, obtained from the anatomic site of pathology, could reveal diagnostic proteomic fingerprints.</p> <p>Methods</p> <p>Protein profiles were generated from gastric fluid samples of 19 gastric cancer and 36 benign gastritides patients undergoing elective, clinically-indicated gastroscopy using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry on multiple ProteinChip arrays. Proteomic features were compared by significance analysis of microarray algorithm and two-way hierarchical clustering. A second blinded sample set (24 gastric cancers and 29 clinically benign gastritides) was used for validation.</p> <p>Results</p> <p>By significance analysyis of microarray, 60 proteomic features were up-regulated and 46 were down-regulated in gastric cancer samples (<it>p </it>< 0.01). Multimarker clustering showed two distinctive proteomic profiles independent of age and ethnicity. Eighteen of 19 cancer samples clustered together (sensitivity 95%) while 27/36 of non-cancer samples clustered in a second group. Nine non-cancer samples that clustered with cancer samples included 5 pre-malignant lesions (1 adenomatous polyp and 4 intestinal metaplasia). Validation using a second sample set showed the sensitivity and specificity to be 88% and 93%, respectively. Positive predictive value of the combined data was 0.80. Selected peptide sequencing identified pepsinogen C and pepsin A activation peptide as significantly down-regulated and alpha-defensin as significantly up-regulated.</p> <p>Conclusion</p> <p>This simple and reproducible multimarker proteomic assay could supplement clinical gastroscopic evaluation of symptomatic patients to enhance diagnostic accuracy for gastric cancer and pre-malignant lesions.</p

The Clinical Significance of Incidental Chronic Colitis: A Study of 17 Cases

Introduction: A histologic diagnosis of chronic colitis raises a relatively limited differential diagnosis that includes inflammatory bowel disease, long-standing infections, and chronic ischemia. In routine clinical practice, inflammatory bowel disease accounts for the majority of cases of chronic colitis. Although a variety of drug-induced injury patterns in the colon have been recognized, there are few well-documented examples of drug-induced chronic colitis. In this study, we report the clinical, histologic, and follow-up data on 17 cases of histologically documented cases of chronic colitis in which a definitive etiologic factor could not be identified. Methods: Using our electronic databases we recorded all cases of chronic colitis in adults over an 8-year period. Patients with a history (prior or subsequent) of inflammatory bowel disease were excluded. Cases showing histologic features of ischemic, pseudomembranous, or granulomatous colitis were excluded. The biopsies were evaluated and semiquantitatively scored for established histologic features of activity and chronicity. The clinical, endoscopic, and follow-up data, including drug usage, was recorded. Results: There were 10 males and 7 females and the mean age was 59 years. The majority of cases involved the cecum or ascending colon (16 of 17 cases). A majority of patients were asymptomatic (n=11), and in others, indications for colonoscopy were occult blood (n=3), hematochezia (n=2), and melena (n=1). The most common mucosal abnormality was erythema (n=10), ulcers (n=3), congestion (n=3), and edematous mucosa (n=1). All cases showed histologic features of chronicity and showed either basal plasmacytosis (94%) or crypt architectural distortion (94%). Eight (47%) patients reported nonsteroidal anti-inflammatory drugs (NSAID) use. Withdrawal of NSAIDs in 2 cases resulted in normalization of the colonic mucosa. On follow-up, all 17 patients were asymptomatic (median follow-up 42.8 mo) and did not progress to inflammatory bowel disease. Conclusions: We report a series of 17 histologically documented cases of incidental chronic colitis without a conventional etiology. However, both the frequent usage of NSAIDs, and normalization of mucosal changes after withdrawal of this drug suggest that NSAIDs may account for this cecal-based chronic colitis. The awareness of this histologically dramatic but clinically innocuous form of chronic colitis may avoid errors in mucosal biopsy diagnosis

Australasian Gastrointestinal Pathology Society (AGPS) consensus guidelines for universal defective mismatch repair testing in colorectal carcinoma

Lynch syndrome is the most common hereditary form of colorectal carcinoma caused by a constitutional pathogenic mutation in a DNA mismatch repair gene. Identifying Lynch syndrome is essential to initiate intensive surveillance program for the patient and affected relatives. On behalf of the Australasian Gastrointestinal Pathology Society (AGPS), we present in this manuscript consensus guidelines for Lynch syndrome screening in patients with colorectal carcinoma. The goal of this consensus document is to provide recommendations to pathologists for diagnosis of Lynch syndrome with discussion of the benefits and limitations of each test. Universal screening for defective mismatch repair is recommended, in agreement with the recent endorsement of universal testing by the National Health and Medical Research Council in Australia and the New Zealand Ministry of Health. The value of evaluating defective mismatch repair is acknowledged not only for Lynch syndrome screening but also for therapeutic decision information in patient management. AGPS advocates appropriate government funding for the molecular tests necessary for Lynch syndrome screening (BRAF mutation, MLH1 methylation testing)

More than just counting eosinophils: Proximal oesophageal involvement and subepithelial sclerosis are major diagnostic criteria for eosinophilic oesophagitis

Background: According to American Gastroenterological Association Institute criteria, the diagnosis of eosinophilic oesophagitis (EOE) requires clinicopathological correlation. In the appropriate clinical context, a high eosinophil count (HEC, defined as ≥15/HPF) is considered pathological evidence of EOE. However, HEC may not always be identified in biopsies given its patchy distribution, and there may be histological overlap between EOE and gastro-oesophageal reflux disease (GORD) in the distal oesophagus. Aims: To evaluate the utility of subepithelial sclerosis and HEC in proximal oesophageal biopsies as additional diagnostic criteria. Methods: Cases between 2004 and 2008 with paired proximal and distal oesophageal biopsies and the mention of eosinophils in the reports were retrieved from PathWest Queen Elizabeth II Medical Centre archives. Biopsies were reviewed and assessed for eosinophilic count and presence of subepithelial stroma and sclerosis. A final diagnosis was made after review of both biopsy and clinical details. Results: There were 23 cases of EOE and 20 cases of GORD in an adult cohort. In comparison to GORD, cases of EOE had significantly higher eosinophil counts in proximal (39.4 vs 0.6 eosinophils/HPF) and distal biopsies (35.6 vs 1.9), with HEC in proximal biopsies a feature exclusive to EOE (83% vs 0%). Subepithelial sclerosis was identified in at least one biopsy in 74% of EOE and in only a single case of GORD. Conclusions: HEC in proximal oesophageal biopsies and subepithelial sclerosis should be considered major diagnostic findings in EOE

Divergent Expression of MUC5AC, MUC6, MUC2, CD10, and CDX-2 in Dysplasia and Intramucosal Adenocarcinomas With Intestinal and Foveolar Morphology: Is This Evidence of Distinct Gastric and Intestinal Pathways to Carcinogenesis in Barrett Esophagus?

Dysplasia in Barrett esophagus has been recognized to be morphologically heterogenous, featuring adenomatous, foveolar, and hybrid phenotypes. Recent studies have suggested a tumor suppressor role for CDX-2 in the metaplasia-dysplasia-carcinoma sequence. The phenotypic stability and role of CDX-2 in the neoplastic progression of different types of dysplasias have not been evaluated. Thirty-eight endoscopic mucosal resections with dysplasia and/or intramucosal carcinoma (IMC) arising in Barrett esophagus were evaluated for the expression of MUC5AC, MUC6, MUC2, CD10, and CDX-2. The background mucosa was also evaluated. The results were correlated with morphologic classification and clinicopathologic parameters. Of 38 endoscopic mucosal resections, 23 had IMC and dysplasia, 8 had IMC only, and 7 had dysplasia only. Among dysplastic lesions, 73% were foveolar, 17% were adenomatous, and 10% were hybrid. Twenty of 23 cases with dysplasia and adjacent IMC showed an identical immunophenotype of dysplasia and IMC comprising 16 gastric, 3 intestinal, and 1 mixed immunophenotype. Three cases showed discordance of dysplasia and IMC immunophenotype. These findings suggest that most Barrett-related IMC cases are either gastric or intestinal, with phenotypic stability during progression supporting separate gastric and intestinal pathways of carcinogenesis. CDX-2 showed gradual downregulation of expression during progression in adenomatous dysplasia but not in foveolar or hybrid dysplasia, supporting a tumor suppressor role, at least in the intestinal pathway. CDX-2 was also found to be expressed to a greater degree in intestinal metaplasia compared with nonintestinalized columnar metaplasia. Consistent with CDX-2 as a tumor suppressor, this suggests that nonintestinalized columnar metaplasia may be an unstable intermediate state at risk for neoplastic progression

RET gene rearrangements occur in a subset of pancreatic acinar cell carcinomas.

Pancreatic acinar cell carcinoma is relatively rare (1 to 2% of pancreatic malignancies) but may be under-recognized. In contrast to pancreatic ductal adenocarcinoma, most acinar cell carcinomas lack mutations in KRAS, DPC, CDKN2A or TP53, but appear to have a high incidence of gene rearrangements, with up to 20% reported to be driven by BRAF fusions. With the development of a new class of RET-specific tyrosine kinase inhibitors, which appear to have particularly strong activity against RET gene rearranged tumours, there is now considerable interest in identifying RET gene rearrangements across a wide range of cancers. RET rearrangements have been reported to occur at a very low incidence (<1%) in all pancreatic carcinomas. We postulated that given its unique molecular profile, RET gene rearrangements may be common in acinar cell carcinomas. We performed fluorescent in-situ hybridization (FISH) studies on a cohort of 40 acinar cell spectrum tumours comprising 36 pure acinar cell carcinomas, three pancreatoblastomas and one mixed acinar-pancreatic neuroendocrine tumour. RET gene rearrangements were identified in 3 (7.5%) cases and BRAF gene rearrangements in 5 (12.5%). All gene rearranged tumours were pure acinar cell carcinomas. Our findings indicate that amongst all pancreatic carcinomas, acinar carcinomas are highly enriched for potentially actionable gene rearrangements in RET or BRAF. FISH testing is inexpensive and readily available in the routine clinical setting and may have a role in the assessment of all acinar cell carcinomas-at this stage to recruit patients for clinical trials of new targeted therapies, but perhaps in the near future as part of routine care