Identification and validation of fusidic acid and flufenamic acid as inhibitors of SARS-CoV-2 replication using DrugSolver CavitomiX

In this work, we present DrugSolver CavitomiX, a novel computational pipeline for drug repurposing and identifying ligands and inhibitors of target enzymes. The pipeline is based on cavity point clouds representing physico-chemical properties of the cavity induced solely by the protein. To test the pipeline's ability to identify inhibitors, we chose enzymes essential for SARS-CoV-2 replication as a test system. The active-site cavities of the viral enzymes main protease (M^pro) and papain-like protease (Pl^pro), as well as of the human transmembrane serine protease 2 (TMPRSS2), were selected as target cavities. Using active-site point-cloud comparisons, it was possible to identify two compounds-flufenamic acid and fusidic acid-which show strong inhibition of viral replication. The complexes from which fusidic acid and flufenamic acid were derived would not have been identified using classical sequence- and structure-based methods as they show very little structural (TM-score: 0.1 and 0.09, respectively) and very low sequence (~ 5%) identity to M^pro and TMPRSS2, respectively. Furthermore, a cavity-based off-target screening was performed using acetylcholinesterase (AChE) as an example. Using cavity comparisons, the human carboxylesterase was successfully identified, which is a described off-target for AChE inhibitors.

Pre- and Postoperative Levels of Carcinoembryonic Antigen in Microsatellite Stable Versus Instable Colon Cancer: a Retrospective Analysis

PURPOSE

The prognosis of microsatellite stable (MSS) versus instable (MSI) tumors is an ongoing matter of debate, with differences in expression of carcinoembryonic antigen (CEA) in these two tumor subsets being inconsistently reported to date. The aim of this study was to investigate CEA expression in the context of clinical parameters in MSS and MSI tumors.

METHODS

Clinical, pathological, and biochemical parameters of colon cancer patients who underwent curative surgery were documented in a database and compared between MSS and MSI cases. The pre- to postoperative trend of CEA was analyzed. Survival was assessed using the Kaplan-Meier (log rank) test.

RESULTS

One hundred sixty-nine patients were included in the study. Compared to those with MSS tumors, there was a higher proportion of preoperatively elevated CEA among those with MSI tumors (p = 0.067). Median CEA values decreased over the pre- to postoperative course with MSS (p = 0.01) but not MSI (p = 0.093) tumors. The distribution of N classification differed between MSS and MSI tumors (p = 0.014). Patients with MSI tumors had superior survival.

CONCLUSION

Despite the better prognosis, MSI tumors are associated with increases in CEA. Our findings shed light on discrepancies related to the prognostic evaluation of MSI tumors. Furthermore, in follow-up of colorectal cancers, CEA measurements should be interpreted differently for MSI and MSS tumors.

Mixed lymphocytic and collagenous inflammation of the entire gastrointestinal tract under therapy with serotonin and norepinephrine reuptake inhibitors

Drug-induced injury to the gastrointestinal tract has gained growing significance in recent years, and the list of causative medications keeps expanding. Herein, we present the case of a 45-year-old female with major depressive disorder treated with two serotonin and norepinephrine reuptake inhibitors (venlafaxine and duloxetine). She developed nausea and weight loss. Endoscopic evaluation of the upper and lower gastrointestinal tract rendered grossly normal mucosa in all segments. Histological examination, however, revealed lymphocytic esophagitis, collagenous gastritis, celiac disease-like intraepithelial lymphocytosis of the duodenum, and incomplete collagenous colitis. Gastrointestinal side effects of psychoactive drugs are largely underrecognized. This is the first report of a mixed lymphocytic and collagenous pattern of injury affecting esophagus, stomach, duodenum, and colon triggered by combined treatment with venlafaxine and duloxetine. In patients with unclear symptoms, obtaining biopsies from mucosa that is normal upon endoscopic inspection may render decisive clues for clinical management.

Interobserver agreement of estimating the extent of intestinal metaplasia in patients with chronic atrophic gastritis

The extent of gastric intestinal metaplasia (GIM) can be used to determine the risk of gastric cancer. Eleven international gastrointestinal expert pathologists estimated the extent of GIM on haematoxylin and eosin (H&E)- and Alcian blue-Periodic acid Schiff (AB-PAS)-stained slides of 46 antrum biopsies in 5% increments. Interobserver agreement was tested with the intraclass correlation coefficient (ICC). Correlation between standard deviation and extent of GIM was evaluated with the Spearman correlation. The interobserver agreement was very good (ICC = 0.983, 95% confidence interval (CI) 0.975-0.990). The use of AB-PAS did not increase the agreement (ICC = 0.975, 95% CI 0.961-0.985). Cases with a higher amount of metaplastic epithelium demonstrated a higher standard deviation (rs = 0.644; p < 0.01), suggesting lower diagnostic accuracy in cases with extensive GIM. In conclusion, estimating the extent of GIM on H&E-stained slides in patients with chronic atrophic gastritis can be achieved satisfactorily with high interobserver agreement, at least among international expert gastrointestinal pathologists.

Improving tumor budding reporting in colorectal cancer: a Delphi consensus study

Tumor budding is a long-established independent adverse prognostic marker in colorectal cancer, yet methods for its assessment have varied widely. In an effort to standardize its reporting, a group of experts met in Bern, Switzerland, in 2016 to reach consensus on a single, international, evidence-based method for tumor budding assessment and reporting (International Tumor Budding Consensus Conference [ITBCC]). Tumor budding assessment using the ITBCC criteria has been validated in large cohorts of cancer patients and incorporated into several international colorectal cancer pathology and clinical guidelines. With the wider reporting of tumor budding, new issues have emerged that require further clarification. To better inform researchers and health-care professionals on these issues, an international group of experts in gastrointestinal pathology participated in a modified Delphi process to generate consensus and highlight areas requiring further research. This effort serves to re-affirm the importance of tumor budding in colorectal cancer and support its continued use in routine clinical practice.

Microscopic colitis: pathophysiology and clinical management

Microscopic colitis is a chronic inflammatory disease of the colon that frequently causes chronic watery diarrhoea that might be accompanied by abdominal pain, nocturnal diarrhoea, urgency, and faecal incontinence. These symptoms lead to poor quality of life and increased health-care costs. Diagnosis relies on histological examination of multiple biopsy samples from the colonic mucosa, which often show no or only few abnormalities on endoscopy. Two major histological subtypes can be distinguished-collagenous colitis and lymphocytic colitis-but incomplete and variant forms with fewer characteristic features have been reported. Here we summarise the latest evidence on epidemiology, pathogenesis, and risk factors, and discuss established and novel therapeutic options for clinical remission. Finally, we propose an updated treatment algorithm. Further prospective studies are needed to clarify the natural history of microscopic colitis, supported by validated criteria for the assessment of disease activity.

Pathology of Fibrosis in Crohn's Disease-Contribution to Understanding Its Pathogenesis

Background: Despite significant progress in the research of fibrosis in various organs, fibrosis remains a poorly understood complication of Crohn's disease (CD). We analyzed pathologic features of fibrosis and inflammation in CD and compared them with the normal bowel, aiming to clarify whether fibrosis in CD pathogenetically resembles fibrosis in other organs.

Methods: Resection specimens from 30 patients with CD were included. Normal bowel from resection specimens of colorectal carcinoma was used for comparison. Trichrome Masson staining, immunohistochemistry for α-smooth muscle actin, fibroblast activation protein, CD34 and erg, in situ hybridization for TGF-β1 and analysis of selected fibrosis-related microRNAs were performed.

Results: In normal bowel, CD34-positive fibroblasts/pericytes were detected in the submucosa and subserosa, particularly around blood vessels. In CD, fibrosis prevailed in the submucosa and subserosa, together with proliferation of myofibroblasts and disappearance of CD34-positive fibroblasts/pericytes. TGF-β1 was present in the lamina propria in normal bowel and CD, and in deeper parts of the bowel wall in CD. MicroRNAs miR-29c, miR-155 miR-150, and miR-155, which have been demonstrated to contribute to fibrosis in various organs, showed significant deregulation in CD.

Conclusions: Distribution of fibroblasts/pericytes in the submucosa and subserosa of normal bowel, their disappearance in fibrosis in CD, together with the appearance of myofibroblasts, suggest that fibroblasts/pericytes are the most likely source of myofibroblasts in CD. Furthemore, fibrosis-related microRNAs showed deregulation in fibrotic areas. Pathogenesis of fibrosis in CD is thus comparable to fibrosis in other organs, in which myofibroblasts are the key effector cells, and pericytes have emerged as the main origin of myofibroblasts. Fibrosis in CD should be regarded as a result of (over)response of the bowel wall to the presence of inflammation in deep structures of the bowel wall, presenting another example of a common pathogenetic pathway of fibrosis development.

Carditis: a relevant marker of gastroesophageal reflux disease. Data from a prospective central European multicenter study on histological and endoscopic diagnosis of esophagitis (histoGERD trial)

The columnar-lined mucosa at the gastroesophageal junction may contain an inflammatory infiltrate, commonly referred to as carditis (or cardia gastritis). The etiology of carditis is not entirely clear since published data are conflicting. Some authors believe it to be secondary to gastroesophageal reflux disease (GERD) and others to Helicobacter pylori gastritis. This prospective study aims at clarifying the relationship between carditis and the histological, clinical, and endoscopic findings of GERD, in a large cohort of individuals negative for H. pylori infection. Eight hundred and seventy-three individuals (477 females and 396 males, median age 53 years) participated in this study. Biopsy material was systematically sampled from above and below the gastroesophageal junction. Reflux-associated changes of the esophageal squamous epithelium were assessed according to the Esohisto consensus guidelines. Grading of carditis was performed according to the Updated Sydney System, known from the histological evaluation of gastritis. In total, 590 individuals (67.5%) had chronic carditis. Of these, 468 (53.6%) had mild chronic inflammation, with 321 individuals (68.6%) showing no or minimal changes on endoscopic examination (Los Angeles Categories N and M). The presence of chronic carditis was associated with several GERD-related parameters of the esophageal squamous epithelium (P < 0.0001), and data retained statistical significance even when analysis was restricted to individuals with mild chronic carditis and/or endoscopically normal mucosa. Chronic carditis was also associated with the presence of intestinal metaplasia (P < 0.0001). In addition, chronic carditis had a statistically significant association with patients' symptoms of GERD (P = 0.0107). This observation remained valid for mild chronic carditis in all patients (P = 0.0038) and in those with mild chronic carditis and normal endoscopic mucosa (P = 0.0217). In conclusion, chronic carditis appears to be the immediate consequence of GERD, correlating with patients' symptoms and endoscopic diagnosis. These results are valid in individuals with nonerosive reflux disease, which indicates a higher sensitivity of histological diagnosis. Our findings may impact the routine assessment of reflux patients.

Involvement of EP2 and EP4 Receptors in Eosinophilic Esophagitis: A Pilot Study

BACKGROUND

The prostaglandin D₂ receptor DP2 has been implicated in eosinophil infiltration and the development of eosinophilic esophagitis (EoE).

AIMS AND METHODS

In this study, we investigated an involvement of PGE₂ (EP1-EP4) and PGD₂ (DP1) receptors in EoE by measuring their expression in peripheral blood eosinophils and esophageal mucosal biopsies of EoE patients and by performing migration and adhesion assays with eosinophils from healthy donors.

RESULTS

Expression of EP2 and EP4, but not EP1 and EP3, was decreased in blood eosinophils of patients with EoE vs. control subjects. Adhesion of eosinophils to esophageal epithelial cells was decreased by EP2 receptor agonist butaprost and EP4 agonist ONO-AE1-329, whereas DP1 agonist BW245C increased adhesion. In chemotaxis assays with supernatant from human esophageal epithelial cells, only ONO-AE1-329 but not butaprost or BW245C inhibited the migration of eosinophils. Expression of EP and DP receptors in epithelial cells and eosinophils was detected in sections of esophageal biopsies from EoE patients by immunohistochemistry. qPCR of biopsies from EoE patients revealed that gene expression of EP4 and DP1 was the highest among PGE₂ and PGD₂ receptors. Esophageal epithelial cells in culture showed high gene expression for EP2 and EP4. Activation of EP2 and EP4 receptors decreased barrier integrity of esophageal epithelial cells in impedance assays.

CONCLUSIONS

Activation of EP2 and EP4 receptors may inhibit eosinophil recruitment to the esophageal mucosa. However, their activation could negatively affect esophageal barrier integrity suggesting that eosinophilic rather than epithelial EP2 and EP4 have a protective role in EoE.

Automatic evaluation of tumor budding in immunohistochemically stained colorectal carcinomas and correlation to clinical outcome

Background

Tumor budding, meaning a detachment of tumor cells at the invasion front of colorectal carcinoma (CRC) into single cells or clusters (<=5 tumor cells), has been shown to correlate to an inferior clinical outcome by several independent studies. Therefore, it has been discussed as a complementary prognostic factor to the TNM staging system, and it is already included in national guidelines as an additional prognostic parameter. However, its application by manual evaluation in routine pathology is hampered due to the use of several slightly different assessment systems, a time-consuming manual counting process and a high inter-observer variability. Hence, we established and validated an automatic image processing approach to reliably quantify tumor budding in immunohistochemically (IHC) stained sections of CRC samples.

Methods

This approach combines classical segmentation methods (like morphological operations) and machine learning techniques (k-means and hierarchical clustering, convolutional neural networks) to reliably detect tumor buds in colorectal carcinoma samples immunohistochemically stained for pan-cytokeratin. As a possible application, we tested it on whole-slide images as well as on tissue microarrays (TMA) from a clinically well-annotated CRC cohort.

Results

Our automatic tumor budding evaluation tool detected the absolute number of tumor buds per image with a very good correlation to the manually segmented ground truth (R2 value of 0.86).

Furthermore the automatic evaluation of whole-slide images from 20 CRC-patients, we found that neither the detected number of tumor buds at the invasion front nor the number in hotspots was associated with the nodal status. However, the number of spatial clusters of tumor buds (budding hotspots) significantly correlated to the nodal status (p-value = 0.003 for N0 vs. N1/N2). TMAs were not feasible for tumor budding evaluation, as the spatial relationship of tumor buds (especially hotspots) was not preserved.

Conclusions

Automatic image processing is a feasible and valid assessment tool for tumor budding in CRC on whole-slide images. Interestingly, only the spatial clustering of the tumor buds in hotspots (and especially the number of hotspots) and not the absolute number of tumor buds showed a clinically relevant correlation with patient outcome in our data.

Electronic supplementary material

The online version of this article (10.1186/s13000-018-0739-3) contains supplementary material, which is available to authorized users.

Partial to complete abrogation of the subepithelial macrophage barrier against the gut microbiota in patients with ulcerative colitis and Crohn's colitis

AIMS

The integrity of the band of indigenous macrophages in the subepithelial layer of the lamina propria (SLP) is crucial in preventing the commensal gut microbiota from attacking the host. The breakdown of the SLP macrophage barrier results in microbiota inflow and improper immune responses; this might lead to inflammatory bowel disease (IBD). During inflammation, the SLP macrophage barrier is reinforced by inflammation-elicited macrophages (IEMs), which are derived from blood-circulating monocytes. The aim was to explore the characteristics of the SLP macrophage band in a cohort of biopsies without inflammation, in patients with ulcerative colitis in remission (UCre), and in patients with right-sided Crohn's colitis (RCC).

METHODS AND RESULTS

Endoscopic biopsies were taken from endoscopically normal descending colon in 247 patients; 80 with IBD (27 UCre and 53 RCC), and 167 without IBD [90 had colonic diarrhoea, 63 were enrolled in a colorectal cancer (CRC) surveillance programme, seven had microscopic colitis in remission, and seven had miscellaneous colonic ailments]. Sections showed no inflammatory changes; they were immunostained with CD68. Among patients with UCre and RCC, the SLP band of CD68+ macrophages was fragmented or minute in 59% (47/80) and negative in 9% (7/80). In contrast, only 31% (51/167) of the biopsies from control patients had a fragmented/minute SLP band of CD68+ macrophages, and none had a negative SLP band of CD68+ macrophages (IBD versus controls, P < 0.05).

CONCLUSIONS

The finding that the SLP macrophage barrier was fragmented to totally abrogated in UCre and RCC patients suggests a longlasting defect in the SLP CD68+ macrophage barrier in these patients. The lack of ongoing inflammation in colonic biopsies should rule out the participation of bone marrow-derived IEMs in the abrogation of the SLP macrophage barrier reported here.

Secondary tumours of the ampulla of Vater: Case report and review of the literature

Secondary tumours of the ampulla of Vater are rare. Underlying primary tumours, clinical presentation, macroscopic appearance, treatment strategies and outcome of secondary ampullary lesions have not been systematically analysed. The present case study reported a 57-year old patient with an ampullary metastasis from renal cancer and a literature review was performed in which a further 32 patients were included. The most common responsible primary tumours were malignant melanoma and renal clear cell carcinoma, followed by breast cancer. The time interval between the diagnosis of the primary tumour and the ampullary metastasis was highly variable, and may be as long as 10 years, particularly for renal cancer. Patients may present with unspecific abdominal discomfort, jaundice or upper gastrointestinal bleeding. The gross appearance was largely indistinguishable from that of a primary tumour. Lesions may present as polypoid or irregular, soft and friable tumour mass, in certain cases with superficial ulceration. In ~50% of cases, the ampullary metastasis was the only metastatic lesion, while in the remaining cases, the cancer had spread to one or more organs. The prognosis was generally poor. The management requires a multi-modal approach, including endoscopic, surgical and oncological procedure.

Autoimmune enteropathies

Autoimmune enteropathy (AIE) is a rare condition characterized by intractable diarrhea and immune-mediated injury of the intestinal mucosa. As the clinical and histopathologic manifestations of this disease are highly variable, its diagnosis is challenging for both clinicians and pathologists. In fact, the term autoimmune enteropathies is likely more appropriate since the clinicopathologic manifestations are observed in association with a heterogeneous group of disorders. The pathophysiology of AIE has not been fully elucidated. It appears to result from dysregulation of intestinal immunity and particularly in children, often presents in association with immunodeficiency. The overarching histopathologic changes seen in AIE include mucosal inflammation and epithelial injury, although this can manifest in the form of different patterns. Recognition of the clinical settings and of the various histologic patterns can aid the pathologist in establishing the correct diagnosis.

Recommendations for reporting tumor budding in colorectal cancer based on the International Tumor Budding Consensus Conference (ITBCC) 2016

Tumor budding is a well-established independent prognostic factor in colorectal cancer but a standardized method for its assessment has been lacking. The primary aim of the International Tumor Budding Consensus Conference (ITBCC) was to reach agreement on an international, evidence-based standardized scoring system for tumor budding in colorectal cancer. The ITBCC included nine sessions with presentations, a pre-meeting survey and an e-book covering the key publications on tumor budding in colorectal cancer. The 'Grading of Recommendation Assessment, Development and Evaluation' method was used to determine the strength of recommendations and quality of evidence. The following 10 statements achieved consensus: tumor budding is defined as a single tumor cell or a cell cluster consisting of four tumor cells or less (22/22, 100%). Tumor budding is an independent predictor of lymph node metastases in pT1 colorectal cancer (23/23, 100%). Tumor budding is an independent predictor of survival in stage II colorectal cancer (23/23, 100%). Tumor budding should be taken into account along with other clinicopathological features in a multidisciplinary setting (23/23, 100%). Tumor budding is counted on H&E (19/22, 86%). Intratumoral budding exists in colorectal cancer and has been shown to be related to lymph node metastasis (22/22, 100%). Tumor budding is assessed in one hotspot (in a field measuring 0.785 mm2) at the invasive front (22/22, 100%). A three-tier system should be used along with the budding count in order to facilitate risk stratification in colorectal cancer (23/23, 100%). Tumor budding and tumor grade are not the same (23/23, 100%). Tumor budding should be included in guidelines/protocols for colorectal cancer reporting (23/23, 100%). Members of the ITBCC were able to reach strong consensus on a single international, evidence-based method for tumor budding assessment and reporting. It is proposed that this method be incorporated into colorectal cancer guidelines/protocols and staging systems.

Antibiotic-Associated Apoptotic Enterocolitis in the Absence of a Defined Pathogen: The Role of Intestinal Microbiota Depletion

Supplemental Digital Content is available in the text.

Objective:

Antibiotic therapy is a major risk factor for the development of diarrhea and colitis with varying severity. Often the origin of antibiotic-associated gastrointestinal deterioration remains elusive and no specific infectious agents could be discerned.

Patients:

We represent three cases of intractable high-volume diarrhea associated with combined antibiotic and steroid therapy in critically ill patients not fitting into established disease entities. Cases presented with severe apoptotic enterocolitis resembling acute intestinal graft-versus-host-disease. Microbiologic workup precluded known enteropathogens, but microbiota analysis revealed a severely depleted gut microbiota with concomitant opportunistic pathogen overgrowth.

Interventions:

Fecal microbiota transplantation, performed in one patient, was associated with correction of dysbiosis, rapid clinical improvement, and healing of enterocolitis.

Conclusions:

Our series represents a severe form of antibiotic-associated colitis in critically ill patients signified by microbiota depletion, and reestablishment of a physiologic gastrointestinal microbiota might be beneficial for this condition.

Genetic Biopsy for Prediction of Surveillance Intervals after Endoscopic Resection of Colonic Polyps: Results of the GENESIS Study

Background and objective

Current surveillance strategies for colorectal cancer following polypectomy are determined by endoscopic and histopathological factors. Such a distinction has been challenged. The present study was designed to identify molecular parameters in colonic polyps potentially defining new sub-groups at risk.

Methods

One hundred patients were enrolled in this multicentre study. Polyps biopsies underwent formalin-free processing (PAXgene, PreAnalytiX) and targeted next generation sequencing (38 genes (QIAGEN), NextSeq 500 platform (Illumina)). Genetic and histopathological analyses were done blinded to other data.

Results

In 100 patients, 224 polyps were removed. Significant associations of genetic alterations with endoscopic or histological polyp characteristics were observed for BRAF, KRAS, TCF7L2, FBXW7 and CTNNB1 mutations. Multivariate analysis revealed that polyps ≥ 10 mm have a significant higher relative risk for harbouring oncogene mutations (relative risk 3.467 (1.742-6.933)). Adenomas and right-sided polyps are independent risk factors for CTNNB1 mutations (relative risk 18.559 (2.371-145.245) and 12.987 (1.637-100.00)).

Conclusions

Assessment of the mutational landscape of polyps can be integrated in the workflow of current colonoscopy practice. There are distinct genetic patterns related to polyp size and location. These results suffice to optimise individual risk calculation and may help to better define surveillance intervals.

Regulation of apoptosis is impaired in atrophic gastritis associated with gastric cancer

BACKGROUND

Gastric premalignant conditions, atrophic gastritis (AG) and intestinal metaplasia (IM) are characterized by an increase of proliferation and a reduction of apoptosis in epithelial cells. The epithelial cell kinetics in AG and IM in gastric mucosa adjacent to gastric cancer is still unclear. The aim of this study was to evaluate the epithelial cell turnover and expression of proliferation and apoptosis-related genes in gastric cancer (GC) and adjacent mucosa with atrophic gastritis or intestinal metaplasia (AG/IM GC+), as well as in atrophic gastritis or intestinal metaplasia mucosa of patients without GC (AG/IM GC-) and in control biopsy samples of non-transformed gastric mucosa (Control).

METHODS

We selected 58 patients (M: F = 34:24; age range 20-84 years, median 61.06 years) with 4 well defined histological conditions: 20 controls with histological finding of non-transformed gastric mucosa, 20 patients with AG or IM (AG/IM GC-), and 18 patients with intestinal type gastric adenocarcinoma (GC) and AG or IM in the adjacent mucosa (3 cm from the macroscopic tumour margin, AG/IM GC+). We performed an immunohistochemical staining of Ki67 and TUNEL and quantitative RT-PCR to determine the expression of PCNA and Bax/Bcl-2.

RESULTS

The immunohistochemical expression of Ki67 and TUNEL in AG/IM GC- was significantly increased compared to not transformed gastric mucosa (p < 0.0001) but not compared to AG/IM in gastric mucosa adjacent to GC. Levels of Bcl-2 were reduced in GC and AG/IM GC- compared to controls as well as in AG/IM GC- compared to AG/IM in mucosa adjacent to GC+ (p < 0.05). Proliferation and apoptosis markers did not correlate with H.pylori status in our study population.

CONCLUSIONS

In AG/IM associated with GC, no significant changes in the epithelial cell turnover were detected. Decreased Bcl-2 gene expression signified atrophic gastritis and IM in presence of cancer, as well as intestinal type gastric adenocarcinoma.

[Pathology of the R1 classification in visceral cancer surgery]

The completeness of tumor removal is described in the residual tumor classification (R classification). The R category of a surgical specimen reflects the effects of treatment, influences further treatment decisions and is associated with patient survival. Thorough pathological examination of all resection planes, including the circumferential margin, is necessary for accurate classification.

Colorectal polypectomy and endoscopic mucosal resection (EMR): European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline

1 ESGE recommends cold snare polypectomy (CSP) as the preferred technique for removal of diminutive polyps (size ≤ 5 mm). This technique has high rates of complete resection, adequate tissue sampling for histology, and low complication rates. (High quality evidence, strong recommendation.) 2 ESGE suggests CSP for sessile polyps 6 - 9 mm in size because of its superior safety profile, although evidence comparing efficacy with hot snare polypectomy (HSP) is lacking. (Moderate quality evidence, weak recommendation.) 3 ESGE suggests HSP (with or without submucosal injection) for removal of sessile polyps 10 - 19 mm in size. In most cases deep thermal injury is a potential risk and thus submucosal injection prior to HSP should be considered. (Low quality evidence, strong recommendation.) 4 ESGE recommends HSP for pedunculated polyps. To prevent bleeding in pedunculated colorectal polyps with head ≥ 20 mm or a stalk ≥ 10 mm in diameter, ESGE recommends pretreatment of the stalk with injection of dilute adrenaline and/or mechanical hemostasis. (Moderate quality evidence, strong recommendation.) 5 ESGE recommends that the goals of endoscopic mucosal resection (EMR) are to achieve a completely snare-resected lesion in the safest minimum number of pieces, with adequate margins and without need for adjunctive ablative techniques. (Low quality evidence; strong recommendation.) 6 ESGE recommends careful lesion assessment prior to EMR to identify features suggestive of poor outcome. Features associated with incomplete resection or recurrence include lesion size > 40 mm, ileocecal valve location, prior failed attempts at resection, and size, morphology, site, and access (SMSA) level 4. (Moderate quality evidence; strong recommendation.) 7 For intraprocedural bleeding, ESGE recommends endoscopic coagulation (snare-tip soft coagulation or coagulating forceps) or mechanical therapy, with or without the combined use of dilute adrenaline injection. (Low quality evidence, strong recommendation.)An algorithm of polypectomy recommendations according to shape and size of polyps is given (Fig. 1).

Anal verrucous carcinoma is not related to infection with human papillomaviruses and should be distinguished from giant condyloma (Buschke-Löwenstein tumour)

AIMS

Verrucous carcinoma (VC) is a variant of well-differentiated squamous cell carcinoma and in the anal region is regarded as synonymous with giant condyloma (Buschke-Löwenstein tumour) (BLT). Aetiology, diagnostic criteria and clinical behaviour of both lesions are controversial. Recent studies suggest that VC at other sites is not associated with human papillomaviruses (HPV). We hypothesized that anal VC is also not related to HPV, while BLT is a HPV-induced lesion.

METHODS AND RESULTS

Ten cases of VC and four cases of BLT were included. Several techniques were used for HPV detection: in-situ hybridization for HPV6, 11, 16 and 18, six different polymerase chain reaction (PCR) protocols for detection of at least 89 HPV types from alpha-, beta-, gamma- and mu-PV genera and in-situ hybridization for high-risk HPV E6/E7 mRNA; p16 immunohistochemistry and morphometric analysis were also performed. Alpha-, gamma- and mu-PVs were not found in any case of VC, while HPV6 was detected in all cases of BLT. p16 overexpression was not present in any of the lesions. Among microscopic features, only the absence of koilocytosis and enlarged spinous cells seem to be useful to distinguish VC from BLT.

CONCLUSIONS

Our results suggest that anal VC, similarly to VC at other sites, is not associated with HPV infection, and must be distinguished from BLT, which is associated with low-risk HPV. Only with well-set diagnostic criteria will it be possible to ascertain clinical behaviour and optimal treatment for both lesions.

MUC1, MUC2, MUC5AC, and MUC6 in colorectal cancer: expression profiles and clinical significance

Mucin glycoprotein expression can be altered during the carcinogenic process. The impact on the prognosis of patients with colorectal cancer (CRC) is controversial. We analyzed tumors from 381 patients for MUC1, MUC2, MUC5AC, and MUC6 expression by immunohistochemical staining, using tissue microarrays. Progression-free and cancer-specific survival were determined using the Kaplan-Meier method. Expression of intestinal mucin MUC2 was lost in 85 (23 %) CRCs, and patients with MUC6-negative tumors showed shorter progression-free survival (PFS, p = 0.043). Gastric mucins MUC5AC and MUC6 showed high (>50 %) aberrant expression in 28 (8 %) and 9 (2 %) cases, respectively. High expression of MUC5AC was associated with longer PFS (p = 0.055). High expression of MUC6 was associated with 100 % PFS (p = 0.024) and longer cancer-specific survival (CSS, p = 0.043). MUC1 was expressed in 238 (64 %) tumors and had no impact on outcome. When analysis was restricted to stages II and III, loss of MUC2 was associated with adverse outcome. Overexpression of both MUC5AC and MUC6 significantly predicted favorable PFS and CSS. In conclusion, loss of MUC2 expression proved to be a predictor of adverse outcome, while the gain of aberrant expression of MUC5AC and particularly of MUC6 was associated with favorable outcome in CRC, notably in intermediate stages II and III.

Immunohistochemical and molecular characterizations in urothelial carcinoma of bladder in patients less than 45 years

Bladder tumours in early-onset patients are rare and seem to exhibit unique clinicopathological features. Only few studies have investigated somatic alterations in this specific age of onset group and evidence is accumulating of a distinct molecular behaviour of early-onset bladder tumours. We collected the largest cohort of early-onset tumours of patients 45 years old or younger and aimed to test genomic alterations typically found in bladder cancer. Tumours of 118 early-onset patients were compared with a consecutive group of 113 cases. Immunohistochemistry of TP53, CK20 and Ki-67 was carried out. Molecular analysis was conducted to test for loss of heterozygosity of chromosome 9 and 17, as well as TP53 and FGFR3 mutations. Fisher´s exact and chi-squared test were appropriately used. No differences in grade/stage characteristics were observed. Overexpressed TP53 was differentially distributed between the two groups. TP53 nuclear accumulation was significantly more frequent in early-onset papillomas, PUNLMPs and pTa low-grade tumours compared to the consecutive cohort (p=0.005). Moreover, chromosome 9 deletions (29.5% vs. 44.6%) and FGFR3 mutations (34.5% vs. 63.7%) were less often detected in early-onset patients (p=0.05 and p<0.0001). By comparing the largest cohort of early-onset bladder cancer patients with an unselected group, we demonstrated that the typical molecular features are not independent of age at diagnosis. Our study supports the hypothesis of a distinct biological behaviour in early-onset tumours.

Propionibacterium acnes overabundance and natural killer group 2 member D system activation in corpus-dominant lymphocytic gastritis

Corpus‐dominant lymphocytic gastritis (LyG) is characterized by CD8⁺ T‐cell infiltration of the stomach epithelium by a so far uncharacterized mechanism. Although Helicobacter pylori is typically undetectable in LyG, patients respond to H. pylori antibiotic eradication therapy, suggesting a non‐H. pylori microbial trigger for the disease. Comparative microbiota analysis of specimens from LyG, H. pylori gastritis and healthy controls precluded involvement of H. pylori in LyG but identified Propionibacterium acnes as a possible disease trigger. In addition, the natural killer group 2 member D (NKG2D) system and the proinflammatory cytokine interleukin (IL)‐15 are significantly upregulated in the gastric mucosa of LyG patients, and gastric epithelial cells respond to microbe‐derived stimuli, including live P. acnes and the microbial products short‐chain fatty acids, with induction of NKG2D ligands. In contrast, H. pylori infection does not activate or even repress NKG2D ligands. Together, our findings identify P. acnes as a possible causative agent for LyG, which is dependent on the NKG2D system and IL‐15 activation. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Diagnostic reproducibility of tumour budding in colorectal cancer: a multicentre, multinational study using virtual microscopy

AIMS

Despite the established prognostic relevance of tumour budding in colorectal cancer, the reproducibility of the methods reported for its assessment has not yet been determined, limiting its use and reporting in routine pathology practice.

METHODS AND RESULTS

A morphometric system within telepathology was devised to evaluate the reproducibility of the various methods published for the assessment of tumour budding in colorectal cancer. Five methods were selected to evaluate the diagnostic reproducibility among 10 investigators, using haematoxylin and eosin (H&E) and AE1-3 cytokeratin-immunostained, whole-slide digital scans from 50 pT1-pT4 colorectal cancers. The overall interobserver agreement was fair for all methods, and increased to moderate for pT1 cancers. The intraobserver agreement was also fair for all methods and moderate for pT1 cancers. Agreement was dependent on the participants' experience with tumour budding reporting and performance time. Cytokeratin immunohistochemistry detected a higher percentage of tumour budding-positive cases with all methods compared to H&E-stained slides, but did not influence agreement levels.

CONCLUSION

An overall fair level of diagnostic agreement for tumour budding in colorectal cancer was demonstrated, which was significantly higher in early cancer and among experienced gastrointestinal pathologists. Cytokeratin immunostaining facilitated detection of budding cancer cells, but did not result in improved interobserver agreement.

Mixed adenoneuroendocrine carcinoma of the ampulla of Vater: A case report

Mixed adenoneuroendocrine carcinomas (MANECs) are rare biphasic tumour types, which are morphologically recognisable as both gland-forming and neuroendocrine neoplasms. Within the gastrointestinal tract, MANECs occur predominantly in the stomach or colorectum. The present study described a case of a MANEC originating from the ampullary region. The patient presented with widespread metastatic disease. Biopsy samples obtained from the ampullary primary tumour disclosed a complex lesion with adenocarcinoma and neuroendocrine small cell carcinoma components, positive for the intestinal transcription factor caudal type homeobox-2 and for neuroendocrine markers, including chromogranin A, synaptophysin, cluster of differentiation 56/neural cell adhesion molecule. By contrast, biopsy samples obtained from metastatic tissue revealed pure neuroendocrine carcinoma. As exemplified by this true mixed tumour, tumour heterogeneity evolves as the major challenge in oncology today, with potentially severe implications for the choice of chemotherapy. The assessment of metastatic sites may render valuable diagnostic information that is crucial for clinical decision-making and patient management.

Inclusion of cytological features in tumor grading improves prognostic stratification of patients with colorectal cancer

PURPOSE

Tumor grade is a traditional prognostic parameter in colorectal cancer. Remarkably, however, there is still no generally accepted consensus how to perform tumor grading. In this study, we systematically compared the prognostic value of traditional grading based upon histological features, that is, gland formation alone with grading based upon both histological and cytological features, such as nuclear pleomorphism and anaplasia ("alternative grade").

METHODS

Three hundred eighty-one tumors of randomly selected patients were retrospectively reviewed. Traditional and alternative tumor grades were related to various clinicopathological features and to progression-free and cancer-specific survival applying both univariate and multivariate testing.

RESULTS

Traditional and alternative tumor grades were significantly associated with T and N classification, tumor size, lymphovascular invasion, as well as both progression-free and cancer-specific survival. In Cox's proportional hazards regression models, the alternative grade was superior to the traditional tumor grade and was significantly associated with progression-free survival (hazard ratio 1.57, 95% confidence interval 1.04-2.35; p = 0.031), independent of patients' age and gender, T and N classification, and lymphovascular invasion. Likewise, patients with tumors with high alternative grade were more likely to die of disease (hazard ratio 1.30, 95% confidence interval 0.85-2.00), but this difference was not statistically significant (p = 0.22).

CONCLUSIONS

Tumor grade based upon both histological and cytological features was superior to grade based upon histological features alone and proved to be an independent prognostic parameter. Thus, tumor grade based upon both histological and cytological features may help to improve prognostic stratification and may thereby affect clinical decision-making and patient management.

Reproducibility of histological assessments of disease activity in UC

OBJECTIVE

Histopathology is potentially an important outcome measure in UC. Multiple histological disease activity (HA) indices, including the Geboes score (GS) and modified Riley score (MRS), have been developed; however, the operating properties of these instruments are not clearly defined. We assessed the reproducibility of existing measures of HA.

DESIGN

Five experienced pathologists with GI pathology fellowship training and expertise in IBD evaluated, on three separate occasions at least two weeks apart, 49 UC colon biopsies and scored the GS, MRS and a global rating of histological severity using a 100 mm visual analogue scale (VAS). The reproducibility of each grading system and for individual instrument items was quantified by estimates of intraclass correlation coefficients (ICCs) based on two-way random effects models. Uncertainty of estimates was quantified by 95% two-sided CIs obtained using the non-parametric cluster bootstrap method. Biopsies responsible for the greatest disagreement based on the ICC estimates were identified. A consensus process was used to determine the most common sources of measurement disagreement. Recommendations for minimising disagreement were subsequently generated.

RESULTS

Intrarater ICCs (95% CIs) for the total GS, MRS and VAS scores were 0.82 (0.73 to 0.88), 0.71 (0.63 to 0.80) and 0.79 (0.72 to 0.85), respectively. Corresponding inter-rater ICCs were substantially lower: 0.56 (0.39 to 0.67), 0.48 (0.35 to 0.66) and 0.61 (0.47 to 0.72). Correlation between the GS and VAS was 0.62 and between the MRS and VAS was 0.61.

CONCLUSIONS

Although 'substantial' to 'almost perfect' ICCs for intrarater agreement were found in the assessment of HA in UC, ICCs for inter-rater agreement were considerably lower. According to the consensus process results, standardisation of item definitions and modification of the existing indices is required to create an optimal UC histological instrument.

Photodynamic therapy downregulates the function of regulatory T cells in patients with esophageal squamous cell carcinoma

Photodynamic therapy (PDT) by selective photosensitization of cancer cells and subsequent laser application results in local tumor necrosis. However, the effects of PDT on immune function, which may depend on the type of immune response, are controversial. We investigated the immunological changes induced by PDT and the effect of PDT on level and function of regulatory T cells (Treg) in patients with invasive esophageal squamous cell carcinoma (ESCC). We analyzed patient's blood samples before and after PDT. Blood CD4+CD25+CD127-FoxP3+ Treg levels were quantified by FACS, and Treg function was evaluated by coculture proliferation assays with T effector (Teff) cells. We found that PDT abrogated the suppressive capacity of peripheral Treg (Days 7 and 14, p = 0.016) but had no effect on Treg levels. The effect of PDT on Treg function at Day 7 was accompanied by slight but statistically significant increases in peripheral neutrophil granulocytes (p = 0.035) and monocytes (p = 0.013) and a statistically significant increase (approximately 18-fold) in serum IL-6 levels (p = 0.008). In conclusion, PDT abolished Treg function, possibly due to increased IL-6 levels in treated ESCC patients. This may be crucial for an improved therapeutic outcome.

Endoscopic submucosal dissection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system 1 2 was adopted to define the strength of recommendations and the quality of evidence.

MAIN RECOMMENDATIONS

1 ESGE recommends endoscopic en bloc resection for superficial esophageal squamous cell cancers (SCCs), excluding those with obvious submucosal involvement (strong recommendation, moderate quality evidence). Endoscopic mucosal resection (EMR) may be considered in such lesions when they are smaller than 10 mm if en bloc resection can be assured. However, ESGE recommends endoscopic submucosal dissection (ESD) as the first option, mainly to provide an en bloc resection with accurate pathology staging and to avoid missing important histological features (strong recommendation, moderate quality evidence). 2 ESGE recommends endoscopic resection with a curative intent for visible lesions in Barrett's esophagus (strong recommendation, moderate quality evidence). ESD has not been shown to be superior to EMR for excision of mucosal cancer, and for that reason EMR should be preferred. ESD may be considered in selected cases, such as lesions larger than 15 mm, poorly lifting tumors, and lesions at risk for submucosal invasion (strong recommendation, moderate quality evidence). 3 ESGE recommends endoscopic resection for the treatment of gastric superficial neoplastic lesions that possess a very low risk of lymph node metastasis (strong recommendation, high quality evidence). EMR is an acceptable option for lesions smaller than 10 - 15 mm with a very low probability of advanced histology (Paris 0-IIa). However, ESGE recommends ESD as treatment of choice for most gastric superficial neoplastic lesions (strong recommendation, moderate quality evidence). 4 ESGE states that the majority of colonic and rectal superficial lesions can be effectively removed in a curative way by standard polypectomy and/or by EMR (strong recommendation, moderate quality evidence). ESD can be considered for removal of colonic and rectal lesions with high suspicion of limited submucosal invasion that is based on two main criteria of depressed morphology and irregular or nongranular surface pattern, particularly if the lesions are larger than 20 mm; or ESD can be considered for colorectal lesions that otherwise cannot be optimally and radically removed by snare-based techniques (strong recommendation, moderate quality evidence).

Grading lymph node metastasis: a feasible approach for prognostication of patients with stage III colorectal cancer

This study aimed to assess the clinicopathological significance of tumour differentiation of metastatic lymph node tissue in patients with American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) stage III colorectal cancer. In a cohort of 145 patients, lymph node grades were G1 in 77 (53.1%), G2 in 41 (28.3%) and G3 in 27 (18.6%) cases, respectively. Despite differences in 77 (53.1%) cases, primary tumour and lymph node grade correlated significantly (Somer's D=0.639; p<0.001). Lymph node grade was significantly associated with N classification (p=0.009), tumour size (p=0.024) and lymphovascular invasion (p=0.004). Patients with lymph node grade G1 had better progression-free survival (p=0.031) and cancer-specific survival (p=0.008). Multivariable analysis identified lymph node grade as independent predictor of cancer-specific survival in this cohort. In conclusion, lymph node grade emerged as a promising novel prognostic variable for patients with AJCC/UICC stage III disease. Additional studies are warranted to validate this new finding.

TP53 Mutational Status and Prediction of Benefit from Adjuvant 5-Fluorouracil in Stage III Colon Cancer Patients

We investigated the hypothesis that the varying treatment efficacy of adjuvant 5-fluorouracil (5FU) in stage III colon cancer is linked to the TP53 mutational status.

ABCSG-90 was a prospective randomized trial in which effect of adjuvant 5FU was studied in stage III colon cancer patients. Tumor material of 70% of these patients (389/572) was available for analysis of the biomarker TP53 using a TP53-gene-specific Sanger sequencing protocol.

Median follow-up was 88 months. TP53 mutation frequency was 33%. A significant interaction between TP53 status, outcomes and nodal category was found (P = 0.0095). In the N1 category, TP53 wildtype patients had significantly better overall survival than TP53 mutated (81.0% vs. 62.0% overall survival at 5 years; HR = 2.131; 95% CI: 1.344–3.378; P = 0.0010). In the N2 category, the TP53 status did not affect survival (P = 0.4992). In TP53 wildtype patients, the prognostic significance of N category was significantly enhanced (P = 0.0002). In TP53 mutated patients, survival curves of N1 and N2 patients overlapped and nodal category was no longer prognostic.

The biomarker TP53 independently predicted effect of adjuvant 5FU in N1 colon cancer patients. TP53 was not predictive in N2 patients, in whom 5FU is known to have no effect.

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The TP53 status was found to be an independent predictive marker for the effect of adjuvant 5FU in stage III colon cancer.

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In the N1 category, patients with wildtype TP53 experienced a significant survival benefit from adjuvant 5FU.

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In TP53 mutant patients survival curves of N1 and N2 patients overlapped and nodal category was no longer prognostic.

Postoperative chemotherapy is recommended for all patients with lymph node positive colon cancer. In colon cancer, mutations in the TP53 gene are present in more than 30% of tumors. We found that the most commonly used postoperative chemotherapy resulted in a marked survival benefit for patients with normal TP53 status while it was associated with significant survival disadvantage in TP53 mutant patients. Overall the survival disadvantage of the mutated patients almost balanced the survival benefit of the TP53 normal patients. This might be an explanation why chemotherapy resulted in less progress in survival of colon cancer than we would have expected.