The Genomic Landscape of Serrated Lesion of the Colorectum: Similarities and Differences With Tubular and Tubulovillous Adenomas.

Serrated lesions of the colorectum are the precursors of 15-30% of colorectal cancers (CRCs). These lesions have a peculiar morphological appearance, and they are more difficult to detect than conventional adenomatous polyps. In this study, we sought to define the genomic landscape of these lesions using high-depth targeted sequencing. Eight sessile serrated lesions without dysplasia (SSL), three sessile serrated lesions with dysplasia (SSL/D), two traditional serrated adenomas (TSA), and three tubular adenomas (TA) were retrieved from the files of the Institute of Pathology of the University Hospital Basel and from the GILAB AG, Allschwil, Switzerland. Samples were microdissected together with the matched normal counterpart, and DNA was extracted for library preparation. Library preparation was performed using the Oncomine Comprehensive Assay targeting 161 common cancer driver genes. Somatic genetic alterations were defined using state-of-the-art bioinformatic analysis. Most SSLs, as well as all SSL/Ds and TSAs, showed the classical BRAF p.V600E mutation. The BRAF-mutant TSAs showed additional alterations in CTNNB1, NF1, TP53, NRAS, PIK3CA, while TA showed a consistently different profile, with mutations in ARID1A (two cases), SMAD4, CDK12, ERBB3, and KRAS. In conclusion, our results provide evidence that SSL/D and TSA are similar in somatic mutations with the BRAF hotspot somatic mutation as a major driver of the disease. On the other hand, TAs show a different constellation of somatic mutations such as ARID1A loss of function.

Fecal calprotectin and the clinical activity index are both useful to monitor medical treatment in patients with ulcerative colitis.

BACKGROUND: Non-invasive monitoring of inflammatory bowel disease is an unmet clinical need as patients in clinical remission may have residual mucosal inflammation preceding clinical relapse. AIMS: We aimed to assess the value of fecal calprotectin and standardized clinical activity scoring to monitor disease activity in ulcerative colitis under medical treatment. METHODS: Forty-one patients with ulcerative colitis were included in a prospective observational study. Medical treatment was guided by clinical judgement of treating physicians. Fecal calprotectin and the clinical activity index (CAI) were measured blinded to treating physicians every 2 months until the end of follow-up. Twenty-six patients received colonoscopy for clinical reason. RESULTS: As defined by the CAI, patients were in clinical remission (63.4 %), having mild (26.8 %) or moderate (11.2 %) disease activity. Of those in clinical remission (CAI ≤ 4), 86.4 % showed residual endoscopic activity (Mayo Score ≥1). Calprotectin levels were higher in endoscopically active disease (779.0 vs 331.5 µg/g, P = 0.034) and calprotectin testing identified more patients with endoscopic disease activity (86.4 %) than the CAI (45.5 %, P = 0.034). Medical treatment was escalated in 90.2 % during the study. Values of the CAI and calprotectin correlated with therapy escalation (OR 3.94 and 3.22, respectively). Only for calprotectin, changes between two measurements were related to intensified medical treatment (OR 1.39). CONCLUSION: Fecal calprotectin was similarly useful to the CAI to monitor disease activity of ulcerative colitis during medical treatment but identified endoscopic disease activity far more reliably. Changes of calprotectin values between measurements might indicate clinical relapse earlier than the CAI.

Clinical and histopathological correlations of fecal calprotectin release in colorectal carcinoma.

AIM: To determine calprotectin release before and after colorectal cancer operation and compare it to tumor and histopathological parameters. METHODS: The study was performed on patients with diagnosed colorectal cancer admitted for operation. Calprotectin was measured in a single stool sample before and three months after the operation using an enzyme-linked immunosorbent assay (ELISA). Calprotectin levels greater than or equal to 50 µg/g were considered positive. The compliance for collecting stool samples was assessed and the value of calprotectin was correlated to tumor and histopathological parameters of intra- and peri-tumoral inflammation. Surgical specimens were fixed in neutral buffered formalin and stained with hematoxylin and eosin. Staging was performed according to the Dukes classification system and the 7(th) edition tumor node metastasis classification system. Intra- and peri-tumoral inflammation was graded according to the Klintrup criteria. Immunohistochemical quantification was performed for MPO, CD45R0, TIA-1, CD3, CD4, CD8, CD57, and granzyme B. Statistical significance was measured using Wilcoxon signed rank test, Kruskal Wallis test and Spearman's rank correlation coefficient as appropriate. RESULTS: Between March 2009 and May 2011, 80 patients with colorectal cancer (46 men and 34 women, with mean age of 71 ± 11.7 years old) were enrolled in the study. Twenty-six patients had rectal carcinoma, 29 had left-side tumors, 23 had right-side tumors, and 2 had bilateral carcinoma. In total, 71.2% of the patients had increased levels of calprotectin before the operation (median 205 µg/g, range 50-2405 µg/g) and experienced a significant decrease three months after the operation (46 µg/g, range 10-384 µg/g, P < 0001). The compliance for collecting stool samples was 89.5%. Patients with T3 and T4 tumors had significantly higher values than those with T1 and T2 cancers (P = 0.022). For all other tumor parameters (N, M, G, L, V, Pn) and location, no significant difference in calprotectin concentration was found. Furthermore, the calprotectin levels and histological grading of both peri- and intra-tumoral inflammation was not correlated. Additional testing with specific markers for lymphocytes and neutrophils also revealed no statistically significant correlation. CONCLUSION: Fecal calprotectin decreases significantly after colorectal cancer operation. Its value depends exclusively on the individual T-stage, but not on other tumor or histopathological parameters.

Diagnostic yield of endoscopy in patients with abdominal complaints: incremental value of faecal calprotectin on guidelines of appropriateness.

BACKGROUND: European Panel on the Appropriateness of Gastrointestinal Endoscopy (EPAGE) criteria have been developed to increase diagnostic yield, but their predictive value is limited. We investigated the incremental diagnostic value of faecal calprotectin to EPAGE criteria. METHODS: In a post-hoc analysis of a prospective study, EPAGE criteria were applied to 298 of 575 (51.8%) patients who had undergone esophagogastroduodenoscopy (EGD), colonoscopy or both for abdominal complaints at the Division of Gastroenterology & Hepatology at the University Hospital Basel in Switzerland. Faecal calprotectin was measured in stool samples collected within 24 hours before the investigation using an enzyme-linked immunosorbent assay. Final endoscopic diagnoses were blinded to calprotectin values. RESULTS: Of 149 EGDs and 224 colonoscopies, 17.6% and 14.7% respectively were judged inappropriate by EPAGE criteria. Appropriate or uncertain indications revealed more endoscopic findings in both EGD (46.3% vs. 23.1%, P = 0.049) and colonoscopy (23.6% vs. 6.1%, P = 0.041) than inappropriate indications. Median calprotectin levels were higher (81.5 µg/g, interquartile range 26-175, vs. 10 µg/g, IQR 10-22, P < 0.001) and testing was more often positive (>50 µg/g) in patients with endoscopic findings, both in EGD (58.2% vs. 33.0%, P = 0.005) and in colonoscopy (57.3% vs. 7.4%, P < 0.001). The use of faecal calprotectin in addition to EPAGE criteria improved the risk reclassification of patients by endoscopic findings. The calculated net reclassification index was 37.8% (P = 0.002) for EGD and 110.9% (P <0.001) for colonoscopy, thus improving diagnostic yield to 56.8% and 70.2%, respectively. CONCLUSIONS: The use of faecal calprotectin in addition to EPAGE criteria improved diagnostic yield in patients with abdominal complaints.

Monoclonal antibody testing for fecal calprotectin is superior to polyclonal testing of fecal calprotectin and lactoferrin to identify organic intestinal disease in patients with abdominal discomfort.

BACKGROUND AND AIMS: Fecal calprotectin and lactoferrin are sensitive markers of mucosal inflammation. We compared three different assays in their ability to identify patients with organic intestinal disease. METHODS: In a post-hoc analysis of a prospective study, we examined 405 unselected patients with abdominal complaints referred for endoscopy to the University Hospital Basel, Switzerland. Calprotectin (EK-CAL, Bühlmann Laboratories, Switzerland; PhiCal, Calpro AS, Norway) and lactoferrin (IBD-Scan, Techlab, USA) were measured using enzyme-linked immunosorbent assays. The presence of a clinically significant endoscopic finding was the primary endpoint of the study. Final diagnoses were adjudicated blinded to calprotectin values. RESULTS: The prevalence of organic intestinal disease was 35.3%. Receiver operating characteristics analysis calculated an area under the curve (AUC) for EK-CAL of 0.918, which was significantly better than for PhiCal (AUC 0.842, P<0.001) and IBD-Scan (AUC 0.830, P=0.003) to identify patients with organic intestinal disease. Overall test accuracy was 88.1% for EK-CAL, 83.7% for PhiCal, and 81.3% for IBD-Scan. Optimal cut-off value calculated for PhiCal and IBD-Scan were lower than recommended by the manufacturer. CONCLUSIONS: Monoclonal testing of calprotectin is superior to both polyclonal calprotectin testing and fecal lactoferrin in identifying symptomatic patients with organic intestinal disease.

Monitoring of therapy for inflammatory bowel disease.

The monitoring of inflammatory bowel disease (IBD) based on clinical symptoms and activity scores alone has major drawbacks. Despite clinical remission, in many patients with ongoing low-grade inflammation and activity scores, there is a tendency to underestimate IBD activity as parameters depend on the subjective symptoms of the patients. C-reactive protein might identify patients with low-grade inflammation, especially in Crohn's disease, but sensitivity remains limited. Recently, fecal markers of inflammation have been shown to correlate well with endoscopic disease activity and to predict relapse. However, data on serial measurements to guide therapy are scarce. The role of anti-TNF-α antibodies and plasma TNF-α concentrations in IBD therapy is currently unclear and needs to be defined further. The goal of improving disease outcome has not been demonstrated for any noninvasive biomarker so far.

Value of fecal calprotectin in the evaluation of patients with abdominal discomfort: an observational study.

BACKGROUND: The evaluation of patients with abdominal discomfort is challenging and patient selection for endoscopy based on symptoms is not reliable. We evaluated the diagnostic value of fecal calprotectin in patients with abdominal discomfort. METHODS: In an observational study, 575 consecutive patients with abdominal discomfort referred for endoscopy to the Department of Gastroenterology & Hepatology at the University Hospital Basel in Switzerland, were enrolled in the study. Calprotectin was measured in stool samples collected within 24 hours before the investigation using an enzyme-linked immunosorbent assay. The presence of a clinically significant finding in the gastrointestinal tract was the primary endpoint of the study. Final diagnoses were adjudicated blinded to calprotectin values. RESULTS: Median calprotectin levels were higher in patients with significant findings (N = 212, median 97 µg/g, IQR 43-185) than in patients without (N = 326, 10 µg/g, IQR 10-23, P < 0.001). The area under the receiver operating characteristics curve (AUC) to identify a significant finding was 0.877 (95% CI, 0.85-0.90). Using 50 µg/g as cut off yielded a sensitivity of 73% and a specificity of 93% with good positive and negative likelihood ratios (10.8 and 0.29, respectively). Fecal calprotectin was useful as a diagnostic parameter both for findings in the upper intestinal tract (AUC 0.730, 0.66-0.79) and for the colon (AUC 0.912, 0.88-0.94) with higher diagnostic precision for the latter (P < 0.001). In patients > 50 years, the diagnostic precision remained unchanged (AUC 0.889 vs. 0.832, P = 0.165). CONCLUSION: In patients with abdominal discomfort, fecal calprotectin is a useful non-invasive marker to identify clinically significant findings of the gastrointestinal tract, irrespective of age.

Impact of COX-2 inhibitors in common clinical practice a gastroenterologist's perspective.

Non-selective NSAIDs enhance the risk of serious ulcer complications (bleeding, perforation, obstruction), hospitalization and death about 3-10-fold. The gastrointestinal side effects of NSAIDs have a considerable economical burden, since they are responsible for 5-10 billion dollars in hospitalization charges and lost work time. NSAIDs cause gastrointestinal damage by both topical and systemic effects. COX-1-mediated inhibition of prostaglandin synthesis is probably the most relevant mechanism, but NSAIDs can cause gastrointestinal injury also by COX-independent pathways. COX-2-selective inhibitors (Coxibs) such as celecoxib, rofecoxib or valdecoxib have been developed to achieve an equal relief of pain and inflammation as classical NSAIDs but without their risk of gastrointestinal side effects. Within the first three months, celecoxib became the fastest selling drug in history. The gastrointestinal safety of classical NSAIDs and Coxibs has been compared in a variety of endoscopic investigations, meta-analyses and outcome studies. In conclusion, these studies have clearly shown, that Coxibs are associated with significantly less dyspeptic symptoms, erosions, ulcers and ulcer complications. In contrast, Coxibs seem to delay gastric ulcer healing to the same extent as traditional NSAIDs. Besides their effects on the upper gastrointestinal tract, NSAIDs can cause small intestinal inflammation, ulcers of the small and large intestine, ileal dysfunction, intestinal strictures, colitis and NSAID enteropathy. In addition, NSAIDs increase the risk of lower gastrointestinal complications including bleeding, perforation and obstruction. Current data suggest, that Coxibs are associated with a significantly lower risk of serious lower GI events than traditional NSAIDs. It is now under debate, who should receive COX-2-selective inhibitors instead of classical NSAIDs, since Coxibs are much more expensive. Data from cost-effectiveness studies suggest, that Coxibs should currently be used only in patients with high risks of GI complications.

Role of pantoprazole in the treatment of gastro-oesophageal reflux disease.

The diagnosis and treatment of gastro-oesophageal reflux disease (GERD) presents many problems, despite the fact that significant advances have been made in recent years in the understanding of its pathogenesis and symptomatology. GERD affects many people and has a significant negative impact on patient quality of life. Heartburn is the most common symptom of GERD which occurs with and without oesophagitis. The predominant causative factor for symptoms is prolonged contact of oesophageal mucosa with refluxed acid and pepsin. Proton pump inhibitors (PPIs) are the most effective treatment for GERD: overall proportions of patients with healing and complete heartburn relief are markedly higher with PPIs than with alternative treatment strategies. Furthermore, the speed of healing and heartburn relief with PPIs is almost twice as rapid as with any other form of therapy. The present review focuses on the effectiveness and safety of the PPI, pantoprazole. The data show that the compound is highly effective in GERD patients with and without oesophagitis. Pantoprazole has an excellent safety record and shows only minor interaction with other drugs.

Current role of Helicobacter pylori stool tests.

Helicobacter pylori stool tests are an accurate and noninvasive tool to assess H. pylori status before and after treatment. We are convinced that the current technical shortcomings of H. pylori stool tests, i.e. inter-test variability and reduced specificity after treatment, can be overcome in the near future. The availability of an office-based stool test would offer a considerable advantage since it could be performed in any private practice without further delay. However, it remains to be seen whether the reluctance of patients to collect stool specimens will have an impact on its general use.

In situ correlation of cytokine secretion and apoptosis in Helicobacter pylori-associated gastritis.

Tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) are important for the pathogenesis of Helicobacter pylori-associated gastritis and peptic ulcer disease. Gastric biopsies from H. pylori-positive and -negative patients were used to examine the in situ correlation of TNF-alpha and IFN-gamma with epithelial cell apoptosis, bacterial load, and histological parameters of gastritis. From the same patients, we isolated H. pylori-specific T cell lines and clones and examined their ex vivo release of proinflammatory cytokines. We found a highly significant correlation of TNF-alpha and IFN-gamma production with activity and grade of gastritis (P < 0.01), H. pylori density (P = 0.01), epithelial cell apoptosis (P < 0.001), and Fas/Fas-ligand expression (P < 0.001). T cell lines and clones were all TCR-alphabeta(+) and showed T helper 1 functional phenotype. With the use of serial histological sections, this study showed for the first time the in situ correlation of TNF-alpha and IFN-gamma with epithelial cell apoptosis, bacterial load, and histological severity of disease and emphasizes the role of these cytokines in the pathophysiology of H. pylori-associated disease.