A randomized trial evaluating the utility of non-targeted biopsies for colorectal neoplasia detection in adults with inflammatory bowel disease: a pilot study protocol

BACKGROUND

Persons with inflammatory bowel diseases are at increased risk of developing colorectal cancer and require frequent colonoscopy surveillance. Guidelines recommend taking 30 to 40 non-targeted biopsies throughout the colorectum to detect "invisible" neoplasia in this setting, despite a lack of evidence supporting this practice. We sought to assess the utility of this practice through a randomized controlled trial. We first propose an internal pilot study to assess recruitment potential, protocol adherence and data capture to guide the full trial.

METHODS

We have designed a multi-centre, parallel-group, non-inferiority randomized controlled trial to test the utility of non-targeted biopsies as an adjunct to colonoscopy surveillance for neoplasia detection in persons with inflammatory bowel disease involving the colorectum in routine clinical practice. Participants are randomized 1:1, stratified by study site, to either standard of care high-definition white-light colonoscopy with 32 to 40 non-targeted biopsies of non-neoplastic-appearing mucosa along with a sampling of abnormal-appearing mucosa (control group) or modified colonoscopy with targeted sampling alone (intervention group). The primary outcome for the full trial will be the proportion of persons with ≥ 1 neoplastic focus detected during colonoscopy. For the pilot phase, we will assess the feasibility of recruiting a minimum of 15% of the estimated sample size within 1 year, under identical conditions as the full trial, while maintaining ≥ 90-95% rate of protocol adherence and data capture. These participants will contribute data to the full trial. The trial is being conducted at 12 centres across Canada, with a total sample size of 1952 persons.

DISCUSSIONS

The trial protocol has been approved by the ethics committees of all participating sites, and the pilot study has received funding through the Canadian Institutes of Health Research (PJT 159607). If feasibility metrics are met during the pilot phase, we will complete the full trial. The trial outcomes will contribute to update the practice guidelines in this area.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04067778.

Interim Analysis of a Trial Evaluating the Utility of Non-Targeted Biopsies for Colorectal Neoplasia Detection in Inflammatory Bowel Disease

Persons with inflammatory bowel disease (IBD) affecting the colorectum (cIBD) have a 1.5- to 2-fold higher risk of developing colorectal cancer (CRC) relative to age- and sex-matched members of the general population.1 Intensive surveillance colonoscopy is recommended in this population to detect and treat early neoplastic lesions before they evolve to incurable cancers.2 Some societies advocate for widespread non-targeted ("random") biopsies throughout the colorectum to screen for "invisible" neoplastic lesions, in addition to targeted biopsies and/or resection of visible lesions.2 Despite the theoretical value of non-targeted biopsies in this setting, there are no high-quality, controlled data to support this practice. In addition to adding significant time and costs to colonoscopy screening, extensive biopsy sampling may also increase the risk of colorectal bleeding and bowel perforation, particularly in elderly patients and those receiving anticoagulant/antiplatelet therapies. With the widespread adoption of disease-modifying biologic and small molecule therapies,3 mucosal healing as a treatment end point,4 high-definition endoscopes,5 and endoscopy quality standards,6 as well as reports of very low neoplasia yield for non-targeted biopsies (0.1%-0.2% of biopsies),7 many experts have started to question the value of non-targeted biopsies as an adjunct for neoplasia surveillance in persons with cIBD.8 However, a recent large French cohort study reported that non-targeted biopsies still identify up to 20% of all neoplastic foci in persons with cIBD,9 albeit primarily in individuals with other major CRC risk factors.

Early Change in Epithelial Neutrophilic Infiltrate Predicts Long-Term Response to Biologics in Ulcerative Colitis

BACKGROUND & AIMS

The prognostic value of histologic scores, grades, and individual histologic subcomponents, alone or in combination with endoscopy, for predicting endoscopic improvement (EI) and histoendoscopic mucosal improvement (HEMI) during maintenance therapy in ulcerative colitis remains uncertain.

METHODS

We performed a post hoc analysis of participants from the VARSITY trial (n = 734 with histology). Receiver operating characteristic and multivariate logistic regression analyses were performed to assess whether baseline and/or week 14 assessments for the Robarts Histopathology Index, Geboes score, individual histologic subcomponents, and baseline disease characteristics, including endoscopic severity and biomarkers, could predict the achievement of EI and HEMI at week 52.

RESULTS

Changes in epithelial neutrophil involvement from baseline to week 14 had the best performance for predicting week 52 EI (area under the curve, 0.83; 95 % confidence interval [CI], 0.74-0.91) and HEMI (area under the curve, 0.85; 95 % CI, 0.76-0.94). On multivariate analyses, improvement of neutrophils in the epithelium was the only histologic parameter associated with increased odds of week 52 EI (odds ratio, 3.63; 95 % CI, 1.45-9.08; P = .0059) and HEMI (odds ratio, 6.88; 95 % CI, 3.29-14.36; P < .0001). Patients with more than 50 % of crypts involved with neutrophils at week 14 were significantly less likely to achieve week 52 HEMI irrespective of week 14 Mayo endoscopic scores (week 14 Mayo endoscopic score of 2-3: 9.9 % vs 22.4 %; P = .001; week 14 Mayo endoscopic score of 0-1: 33 % vs 62.4 %; P = .044).

CONCLUSIONS

Our results on epithelial neutrophilic infiltrate after induction therapy as the only independent predictor for achievement of maintenance EI or HEMI helps clarify the clinical relevance of measuring histologic disease activity in ulcerative colitis. Epithelial neutrophilic infiltrate poses a means to stratify patients according to their likelihood of response to biologic treatment.

Validation of the 'Inflammatory Bowel Disease-Distribution, Chronicity, Activity [IBD-DCA] Score' for Ulcerative Colitis and Crohn´s Disease

BACKGROUND AND AIMS

Histological scoring plays a key role in the assessment of disease activity in ulcerative colitis [UC] and is also important in Crohn´s disease [CD]. Currently, there is no common scoring available for UC and CD. We aimed to validate the Inflammatory Bowel Disease [IBD]-Distribution [D], Chronicity [C], Activity [A] score [IBD-DCA score] for histological disease activity assessment in IBD.

METHODS

Inter- and intra-rater reliability were assessed by 16 observers on biopsy specimens from 59 patients with UC and 25 patients with CD. Construct validity and responsiveness to treatment were retrospectively evaluated in a second cohort of 30 patients.

RESULTS

Inter-rater reliability was moderate to good for the UC cohort (intraclass correlation coefficients [ICCs] = 0.645, 0.623, 0.767 for D, C, and A, respectively) and at best moderate for the CD cohort [ICC = 0.690, 0.303, 0.733 for D, C, and A, respectively]. Intra-rater agreement ranged from good to excellent in both cohorts. Correlation with the Nancy Histological Index [NHI] was moderate and strong with the Simplified Geboes Score [SGS] and a Visual Analogue Scale [VAS], respectively. Large effect sizes were obtained for all three parameters. External responsiveness analysis revealed correlated changes between IBD-DCA score and NHI, SGS and VAS.

CONCLUSIONS

The IBD-DCA score is a simple histological activity score for UC and CD, agreed and validated by a large group of IBD specialists. It provides reliable information on treatment response. Therefore, it has potential value for use in routine diagnostics as well as clinical studies.

Russell Body Typhlitis: A Case Report and Literature Review

Russell bodies are accumulation of immunoglobulin in plasma cells forming intracytoplasmic inclusions. Russell body colitis is rare with only 3 cases described in the English literature up to date. We report a 78-year-old male with cirrhosis showing prominent cecal infiltration of Russell body containing plasma cells. Plasma cells showed no nuclear atypia or mitoses, and no evidence of light chain restriction. In this article, we report a fourth case of Russell body colitis, that is unique in being localized to the cecum in contrast to the other 3, 1 of which was in an inflammatory polyp in the sigmoid colon, 1 in a rectal tubulovillous adenoma and 1 as part of diffuse gastrointestinal disease. This is therefore the first report of localized Russell body typhlitis, occurring in a cirrhotic patient in whom an adjacent erosion was likely nonsteroidal anti-inflammatory drug-associated, a combination that may have facilitated the formation of Russell bodies.

An expert consensus to standardise the assessment of histological disease activity in Crohn's disease clinical trials

BACKGROUND

Targeting histological remission or response in Crohn's disease (CD) is not recommended in clinical practice guidelines or as an outcome in clinical trials due to uncertainties regarding index validity and prognostic relevance.

AIMS

To conduct a modified RAND/University of California Los Angeles appropriateness process with the goal of producing a framework to standardise histological assessment of CD activity in clinical trials.

METHODS

A total of 115 statements generated from literature review and expert opinion were rated on a scale of 1-9 by a panel of 11 histopathologists and 6 gastroenterologists. Statements were classified as inappropriate, uncertain or appropriate based upon the median panel rating and degree of disagreement.

RESULTS

The panellists considered it important to measure histological activity in clinical trials to determine efficacy and that absence of neutrophilic inflammation is an appropriate histological target. They were uncertain whether the Global Histological Activity Score was an appropriate instrument for measuring histological activity. The Geboes Score and Robarts Histopathology Index were considered appropriate. Two biopsies from five segments should be biopsied, and the colon and the ileum should be analysed separately for all indices. Endoscopic mucosal appearance should guide biopsy procurement site with biopsies taken from the ulcer edge, or the most macroscopically inflamed area in the absence of ulcers.

CONCLUSION

We evaluated the appropriateness of items for assessing histological disease activity in CD clinical trials. These items will be used to develop a novel histological index.

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.

Active Margins, Plexitis, and Granulomas Increase Postoperative Crohn's Recurrence: Systematic Review and Meta-analysis

BACKGROUND & AIMS

Rates of postoperative Crohn's disease recurrence remain high, although the ability to predict this risk of recurrence remains limited. As such, we aimed to determine the association of histologic features at the time of resection with postoperative recurrence.

METHODS

Electronic databases were searched through February 2020 for studies that reported risk of clinical, endoscopic, or surgical postoperative recurrence in patients with positive resection margins, plexitis, or granulomas in the index specimen. Pooled risk ratios (RRs) with 95% CIs were calculated for this risk in patients with and without these histologic features.

RESULTS

Twenty-one studies (2481 patients) assessed positive resection margins, 10 studies (808 patients) assessed plexitis, and 19 studies (1777 patients) assessed granulomas. Positive resection margins increased the risk of clinical (RR, 1.26; 95% CI, 1.06-1.49; I² = 41%) and surgical (RR, 1.87; 95% CI, 1.14-3.08; I² = 71%) recurrence, with a trend toward endoscopic recurrence (RR, 1.56; 95% CI, 0.79-3.05; I² = 85%). Granulomas increased the risk of clinical (RR, 1.31; 95% CI, 1.05-1.64; I² = 36%) and endoscopic (RR, 1.37; 95% CI, 1.00-1.87; I² = 49%) recurrence, with a trend toward surgical recurrence (RR, 1.58; 95% CI, 0.89-2.80; I² = 75%). Plexitis increased the risk of endoscopic recurrence (RR, 1.31; 95% CI, 1.00-1.72; I² = 20%), with a trend toward clinical recurrence (RR, 1.34; 95% CI, 0.95-1.91; I² = 46%).

CONCLUSIONS

Positive resection margins, granulomas, and plexitis are predictive of postoperative Crohn's disease recurrence and should be recorded at the time of index resection.

Most colitis associated carcinomas lack expression of LGR5: a preliminary study with implications for unique pathways of carcinogenesis compared to sporadic colorectal carcinoma

Background

Leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), a component of the Wnt receptor complex, is thought to lineage label gastric and intestinal stem cells. LGR5 expression is increased in colorectal carcinoma (CRC) compared to normal tissue. Colitis associated colorectal adenocarcinoma (CAC) often shows distinct morphologic and molecular phenotypes compared to sporadic cases. However, the expression profile of LGR5, and by extension the potential role of an intestinal stem cell phenotype, has not been well described in a series of human CAC.

Method

RNA in situ hybridization (ISH) for LGR5 expression on 30 CACs (12 cases with conventional morphology and 18 cases with non-conventional type morphology) from 29 inflammatory bowel disease (IBD) patients was performed and compared the expression profile to a control group of 10 sporadic CRCs. Immunohistochemistry for beta-catenin and SATB2 was performed on the 30 CACs.

Result

LGR5 was positive in 30% (9/30) of CAC cases and 90% (9/10) of sporadic CRCs (p = 0.002). A large majority (89%) of LGR5 positive CACs were of the conventional histologic type, and conventional type CAC showed a significantly higher LGR5 score (median 3.0; interquartile range 1.75–3.25) than non-conventional type CAC (median 1.5; interquartile range 1.00–2.00) (p = 0.034). CAC with conventional morphology did have a lower level of LGR5 expression than sporadic CRC. Sporadic CRCs showed a significantly higher LGR5 level score than non-conventional type CACs (p < 0.001). Nuclear translocation of beta-catenin was strongly associated with LGR5 expression (p = 0.003), however no significant association was identified between SATB2 expression and LGR5 expression status in CACs.

Conclusion

These findings suggest that the wider spectrum of tumor morphology in CAC may be associated with absence of a LGR5-expressing intestinal stem cell phenotype.

Tumor regression grading after neoadjuvant treatment of esophageal and gastroesophageal junction adenocarcinoma: results of an international Delphi consensus survey

Complete histopathologic tumor regression after neoadjuvant treatment is a well-known prognostic factor for survival among patients with adenocarcinomas of the esophagus and gastroesophageal junction. The aim of this international Delphi survey was to reach a consensus regarding the most useful tumor regression grading (TRG) system that could represent an international standard for histopathologic TRG grading of gastroesophageal carcinomas. Fifteen pathologists with special interest in esophageal and gastric pathology participated in the online survey. The initial questionnaire contained of 43 statements that addressed the following topics: (1) specimen processing, (2) gross examination, (3) cross sectioning, (4) staining, (5) Barrett's esophagus, (6) TRG systems, and (7) TRG in lymph node (LN). Participants rated the items using a 5-point Likert style scale and were encouraged to write comments for each statement. The expert panel recommended a 4-tiered TRG system for assessing the primary tumor: grade 1: No residual tumor (complete histopathologic tumor regression), grade 2: less than 10% residual tumor (near-complete regression), grade 3: 10%-50% residual tumor (partial regression), grade 4: greater than 50% residual tumor (minimal/no regression), combined with a 3-tiered system for grading therapeutic response in metastatic LNs: grade a: no residual tumor (complete histopathologic TRG), grade b: partial regression (tumor cells and regression), grade c: no regression (no sign of tumor response). This TRG grading system can be recommended as an international standard for histopathologic TRG grading in esophageal and gastroesophageal junction adenocarcinoma.

Alpha-Fetoprotein-Producing Early Gastric Cancer with Intramucosal Hepatoid and Fetal Enteric Differentiation

Alpha-fetoprotein (AFP)-producing gastric carcinomas (AFPGCs) are relatively rare tumors known to have a poor prognosis and commonly found as advanced lesions. Histologically, AFPGCs have been described as having hepatoid and fetal enteric (enteroblastic) morphology and are associated with conventional adenocarcinomas. Prior studies reported a hepatoid component present only in invasive areas and hypothesized that AFPGCs may develop hepatoid features during the process of tumor invasion. We report three cases of AFP-producing early gastric cancer which had an intramucosal hepatoid component. Immunohistochemistry showed that the hepatoid component was diffusely immunoreactive for SALL4, AFP, arginase-1, and HepPar1, and focally for CDX2 and PDX1. An intramucosal transition between the hepatoid component and conventional intramucosal adenocarcinoma was identified. Two patients also had a coexistent fetal enteric component, which was admixed with a hepatoid component. Although at an early stage one patient subsequently developed liver metastasis and a second patient was suspected of having liver metastasis, these were not biopsy-proven. The latter patient had a previous history of hepatocellular carcinoma (HCC) and SALL4 was used on the HCC to distinguish metastatic/further HCC from a gastric metastatic primary with hepatoid differentiation.

Histological Markers of Clinical Relapse in Endoscopically Quiescent Ulcerative Colitis

BACKGROUND

In ulcerative colitis (UC) patients who have achieved mucosal healing, active microscopic colonic mucosal inflammation is commonly observed. We aimed to assess the association between histological activity and disease relapse in endoscopically quiescent UC.

METHODS

Ulcerative colitis patients with endoscopically quiescent disease and ≥12 months of follow-up were included. Biopsies were reviewed for the presence of basal plasmacytosis (BPC) and active histological inflammation, defined as a Geboes score (GS) ≥3.2. Primary outcome measures were disease relapse at 18 months and time to first relapse after index colonoscopy.

RESULTS

Seventy-six UC patients (51% male; mean age, 38.6 years; median follow-up [range], 75.2 [2-118] months) were included. Sixty-two percent had an endoscopic Mayo score of 0 at index colonoscopy. Basal plasmacytosis was present in 46% and active histological inflammation in 30% of subjects. Presence of BPC was associated with a significantly shorter time to disease relapse (P = 0.01). Active histological inflammation was significantly associated with clinical relapse at 18 months (P = 0.0005) and shorter time to clinical relapse (P = 0.0006). Multivariate analysis demonstrated active histological inflammation to be independently associated with clinical relapse at 18 months and time to clinical relapse.

CONCLUSIONS

In endoscopically quiescent UC, active histological inflammation and the presence of BPC are adjunctive histological markers associated with increased likelihood of disease relapse. Although prospective studies are required, the presence of these histological markers should be a factor considered when making therapeutic decisions in UC.

Impact of Referral Center Pathology Review on Diagnosis and Management of Patients With Appendiceal Neoplasms

Context.—

Data regarding the clinical impact of subspecialist pathology review of appendiceal neoplasms are limited.

Objective.—

To determine whether pathology review by gastrointestinal pathologists at a tertiary-care referral center resulted in significant changes in the diagnosis and clinical management of appendiceal neoplastic lesions.

Design.—

We conducted a retrospective review of all patients with an initial diagnosis of appendiceal neoplasm referred to a tertiary-care referral center in Ontario, Canada, from 2010–2016. The discordance rate between original and review pathology reports, the nature of discordances, and the impact of any discordance on patient management were recorded.

Results.—

A total of 145 patients with appendiceal lesions were identified (low-grade mucinous appendiceal neoplasm [n = 79], invasive mucinous adenocarcinoma [n = 12], “colorectal type” adenocarcinoma [n = 12], goblet cell carcinoid and adenocarcinomas ex goblet cell carcinoid [n = 24], and other lesions/neoplasms [n = 20]). One or more changes in diagnoses were found in 36 of 145 cases (24.8%), with changes within the same category of interpretation (n = 10), stage (n = 7), grade (n = 6), and categoric interpretation (n = 5) being the most common. In 10 of 36 patients (28%), the diagnostic change led to a significant change in management, including recommendation for additional surveillance, systemic chemotherapy, additional surgery, or discontinuation of surveillance.

Conclusions.—

Subspecialist pathology review of appendiceal neoplastic lesions led to a change in diagnosis in 36 of 145 cases (24.8%), of which nearly 30% (10 of 36 cases) led to a change in clinical management. The overall rate of clinically significant discordances was 7% (10 of 145). Our findings suggest that subspecialist pathology review of appendiceal neoplasms referred to specialized centers is justified.

Colitis-associated colorectal adenocarcinomas are frequently associated with non-intestinal mucin profiles and loss of SATB2 expression

The special AT-rich sequence binding protein 2 (SATB2) is a sensitive and specific diagnostic marker for colorectal adenocarcinoma and reduced expression of SATB2 is associated with a poor prognosis. Colitis-associated colorectal adenocarcinoma often shows distinct morphologic and molecular phenotypes compared to sporadic cases. However, the SATB2 expression profile in colitis-associated carcinoma has not been defined. We performed immunohistochemistry for SATB2 as well as CDX2, MUC5AC, MUC6 and mismatch repair proteins on 60 consecutive colitis-associated carcinomas from 58 inflammatory bowel disease patients and compared the expression profile to a control group of 32 sporadic colorectal carcinomas. Only 26 (43%) colitis-associated carcinomas expressed SATB2, compared to 29 (91%) sporadic colorectal carcinomas (p < 0.0001). MUC5AC expression was more frequently observed in colitis-associated carcinomas than sporadic colorectal caracinomas (52% and 25% respectively; p = 0.013). Eight (13%) cases of colitis-associated carcinoma showed loss of CDX2 expression, which was retained in all of the sporadic controls (p = 0.047). In colitis-associated carcinoma, 50% of SATB2 negative cases had lymph node metastasis compared to only 15% of SATB2 positive cases (p = 0.007). Loss of SATB2 was particularly frequent in mucinous-type tumors, occurring in 83% of these cases. There was no significant association between SATB2 expression and mismatch repair protein status. These data show that the immunoprofile of colitis-associated carcinoma is different than that seen in sporadic cases. In particular, SATB2 is significantly less sensitive in colitis-associated carcinoma and it should be interpreted cautiously as a marker of colorectal origin in colitis patients. The association between loss of SATB2 and lymph node metastasis suggests that it may have similar prognostic value in the setting of inflammatory bowel disease as in sporadic cases.

Development of an index to define overall disease severity in IBD

BACKGROUND AND AIM

Disease activity for Crohn's disease (CD) and UC is typically defined based on symptoms at a moment in time, and ignores the long-term burden of disease. The aims of this study were to select the attributes determining overall disease severity, to rank the importance of and to score these individual attributes for both CD and UC.

METHODS

Using a modified Delphi panel, 14 members of the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) selected the most important attributes related to IBD. Eighteen IOIBD members then completed a statistical exercise (conjoint analysis) to create a relative ranking of these attributes. Adjusted utilities were developed by creating proportions for each level within an attribute.

RESULTS

For CD, 15.8% of overall disease severity was attributed to the presence of mucosal lesions, 10.9% to history of a fistula, 9.7% to history of abscess and 7.4% to history of intestinal resection. For UC, 18.1% of overall disease severity was attributed to mucosal lesions, followed by 14.0% for impact on daily activities, 11.2% C reactive protein and 10.1% for prior experience with biologics. Overall disease severity indices were created on a 100-point scale by applying each attribute's average importance to the adjusted utilities.

CONCLUSIONS

Based on specialist opinion, overall CD severity was associated more with intestinal damage, in contrast to overall UC disease severity, which was more dependent on symptoms and impact on daily life. Once validated, disease severity indices may provide a useful tool for consistent assessment of overall disease severity in patients with IBD.

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.

Tumor budding is a strong predictor of disease-free survival in stage II colorectal cancer: Validation study based on the International Tumor Budding Consensus Conference (ITBCC) recommendations

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Background: Tumor budding, defined as single tumor cells or small clusters of four or less tumor cells at the invasive front, has been shown to be a strong and independent prognostic factor in colorectal cancer (CRC). However, widespread reporting of tumor budding has been held back largely due to a lack of consensus on scoring methods. 23 experts from the United States, Canada, Japan and Europe participated at the International Tumor Budding Consensus Conference (ITBCC), held in April 2016 in Bern, Switzerland, and agreed on a set of recommendations for assessing and reporting tumor budding in CRC. The aim of this study was to validate the method proposed by ITBCC in the clinically relevant scenario of Stage II CRC. Methods: In 151 Stage II CRC patients, tumor budding was assessed on scanned H&E-stained slides in a single hot spot measuring 0.785mm2. Cutoffs as defined by ITBCC were used: Low (Bd1): 0-4 buds, intermediate (Bd2): 5-9 buds, high (Bd3): ≥ 10 buds. Statistical analysis for associations with clinicopathological features, disease free survival (DFS) and overall survival (OS) was performed. Results: The average number of buds/hotspot was 6.8 (median 5.0). 43.1% of cases were Bd1, 27.2% Bd2 and 29.8% Bd3. Tumor budding as a continuous variable was associated with extramural venous invasion (EMVI) (p = 0.05). Tumor budding was associated with poorer OS in univariate analysis (p = 0.0386, HR 1.048, 95%CI 1.002-1.095). For 3- and 5- year DFS, Bd3 was associated with significantly worse survival in comparison with Bd1/2 (p = 0.0031 and p = 0.0025, respectively). In multivariate analysis adjusting for pT, tumor grade and EMVI, tumor budding retained its adverse prognostic effect for DFS (p = 0.006, HR 3.293, 95%CI 1.66-6.53). Conclusions: This study provides promising data on tumor budding assessed by the ITBCC method in the Stage II scenario. Especially Bd3 shows a detrimental adverse impact on DFS in comparison to Bd1/Bd2. Based on the ITBCC, tumor budding has the potential to strongly affect the management of Stage II CRC patients and should be therefore included in reporting guidelines and staging systems in CRC.

Development and validation of a histological index for UC

OBJECTIVE

Although the Geboes score (GS) and modified Riley score (MRS) are commonly used to evaluate histological disease activity in UC, their operating properties are unknown. Accordingly, we developed an alternative instrument.

DESIGN

Four pathologists scored 48 UC colon biopsies using the GS, MRS and a visual analogue scale global rating. Intra-rater and inter-rater reliability for each index and individual index items were measured using intraclass correlation coefficients (ICCs). Items with high reliability were used to develop the Robarts histopathology index (RHI). The responsiveness/validity of the RHI and multiple histological, endoscopic and clinical outcome measures were evaluated by analyses of change scores, standardised effect size (SES) and Guyatt's responsiveness statistic (GRS) using data from a clinical trial of an effective therapy.

RESULTS

Inter-rater ICCs (95% CIs) for the total GS and MRS scores were 0.79 (0.63 to 0.87) and 0.80 (0.69 to 0.87). The correlation estimates between change scores in RHI and change score in GS and MRS were 0.75 (0.67 to 0.82) and 0.84 (0.79 to 0.88), respectively. The SES and GRS estimates for GS, MRS and RHI were: 1.87 (1.54 to 2.20) and 1.23 (0.97 to 1.50), 1.29 (1.02 to 1.56) and 0.88 (0.65 to 1.12), and 1.05 (0.79 to 1.30) and 0.88 (0.64 to 1.12), respectively.

CONCLUSIONS

The RHI is a new histopathological index with favourable operating properties.

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.

Canadian Association of Pathologists-Association canadienne des pathologistes National Standards Committee for High Complexity Testing/Immunohistochemistry: guidelines for the preparation, release, and storage of unstained archived diagnostic tissue sections for immunohistochemistry

OBJECTIVES

Formalin-fixed, paraffin-embedded unstained archived diagnostic tissue sections are frequently exchanged between clinical laboratories for immunohistochemical staining. The manner in which such sections are prepared represents a type of preanalytical variable that must be taken into account given the growing importance of immunohistochemical assays, especially predictive and prognostic tests, in personalized medicine.

METHODS

Recommendations were derived from review of the literature and expert consensus of the Canadian Association of Pathologists-Association canadienne des pathologists National Standards Committee for High Complexity Testing/Immunohistochemistry.

RESULTS

Relevant considerations include the type of glass slide on which to mount the unstained sections; the thickness of the tissue sections; the time from slide preparation to testing; the environment, particularly the temperature at which the unstained sections will be maintained prior to testing; the inclusion of on-slide positive control tissue where possible; and whether patient identifier(s) should be included on slide labels.

CONCLUSIONS

Clear communication between requesting and releasing laboratories will facilitate the proper preparation of unstained sections and also ensure that applicable privacy considerations are addressed.

Gastrointestinal stromal tumours: etiology, pathology and clinical management

Investigation of the regulation of cell growth, differentiation and death by signalling pathways has led to a greater understanding of how alterations in these pathways play a critical role in the development of some cancers, and has opened new opportunities for their treatment. In the present review, results with the prototype drug of this class, imatinib (Gleevec, Glivec [formerly STI571]; Novartis, Switzerland), in metastatic gastrointestinal stromal tumours are presented. The present review originated from a conference of the authors held in Montreal, Quebec in June 2003, under the sponsorship of Novartis.

Agreement in interpreting villous elements and dysplasia in adenomas less than one centimetre in size

BACKGROUND

Villous elements and dysplasia grade in small adenomas are used in many countries to guide post-polypectomy colonoscopy intervals.

AIMS

Measure agreement in interpretation of villous elements and dysplasia in small adenomas.

METHODS

Consecutive endoscopically resected adenomas <10mm in size (203 adenomas less than 6mm and 149 adenomas 6-9 mm in size) were reviewed by 3 expert gastrointestinal pathologists. Interpretations were compared to routine clinical pathology readings at our institution and to each other.

RESULTS

All pathologists used the same definitions for villous and tubular histology. The overall kappas for villous elements in <6mm and 6-9 mm adenomas were 0.29 and 0.26, respectively. Interpretation of dysplasia grade had kappas of 0.02 and 0.09 for adenomas <6mm and 6-9 mm, respectively. Two expert pathologists who used cytologic criteria had much higher fractions of high grade dysplasia compared to the third expert and the pathologists at our centre, who relied on architectural criteria.

CONCLUSIONS

Villous elements and dysplasia grade in small adenomas are problematic as determinants of post-polypectomy surveillance intervals. Uniform pathologic criteria for dysplasia grade are needed.

Much of the genetic risk of colorectal cancer is likely to be mediated through susceptibility to adenomas

Several single-nucleotide polymorphisms (SNPs) have been associated with colorectal cancer (CRC) susceptibility. Most CRCs arise from adenomas, and SNPs therefore might affect predisposition to CRC by increasing adenoma risk. We found that 8 of 18 known CRC-associated SNPs (rs10936599, rs6983267, rs10795668, rs3802842, rs4444235, rs1957636, rs4939827, and rs961253) were over-represented in CRC-free patients with adenomas, compared with controls. Ten other CRC-associated SNPs (rs6691170, rs6687758, rs16892766, rs7136702, rs11169552, rs4779584, rs9929218, rs10411210, rs4813802, and rs4925386) were not associated significantly with adenoma risk. Genetic susceptibility to CRC in the general population is likely to be mediated in part by predisposition to adenomas.

Refinement and reproducibility of histologic criteria for the assessment of microscopic lesions in patients with gastroesophageal reflux disease: the Esohisto Project

BACKGROUND

Standardized criteria for assessing microscopic esophageal lesions are required to test their utility as markers of gastroesophageal reflux disease (GERD).

AIMS

To finalize draft criteria for assessing microscopic esophageal lesions associated with gastroesophageal reflux and to test them for interobserver agreement.

METHODS

An international group of gastrointestinal pathologists was convened to finalize, using a consensus-based approach, draft criteria for recognizing microscopic esophageal lesions. Finalized criteria were retested for interobserver variability by four of the pathologists using 120 digitized esophageal biopsy slides from patients with GERD.

RESULTS

The finalized criteria included further clarification on lesion definitions and new guidance on how to select the area for assessing each lesion. This latter refinement was guided by the high interobserver agreement observed when draft criteria were previously applied to biopsies where the assessment area was preselected. When finalized criteria were applied in the current study to digitized biopsies without a preselected assessment area, the pairwise agreement was 73-97% for basal cell hyperplasia, papillary elongation, intraepithelial eosinophil, neutrophil and mononuclear cell numbers, and active/healed erosions, with slightly lower agreement (64%) for dilated intercellular spaces (DIS). When a combined severity score was applied, the level of agreement was 77%. The mean kappa ranged from fair to high (0.26-0.77) for individual lesions and was high for the combined score (0.64).

CONCLUSIONS

These levels of agreement are comparable with or higher than those for other accepted histologic definitions. Further steps include clinical validation of these criteria by correlating microscopic lesions with clinical variables such as esophageal acid exposure.

Canadian Association of Pathologists-Association canadienne des pathologistes National Standards Committee/Immunohistochemistry: best practice recommendations for standardization of immunohistochemistry tests

Immunohistochemical and immunocytochemical assays are highly complex diagnostic analyses used to aid in the accurate identification and biologic characterization of tissue types in neoplastic and nonneoplastic diseases. Immunohistochemical tests are applied mainly to the diagnosis of neoplasms. Some immunohistochemical tests provide information of important prognostic and predictive value in selected human neoplasms and, as such, are often critical for the appropriate and effective treatment of patients. This document provides recommendations and opinions of the Canadian Association of Pathologists-Association canadienne des pathologistes National Standards Committee/Immunohistochemistry relevant to clinical immunohistochemical terminology, classification of immunohistochemical tests based on risk assessment, and quality control and quality assurance and summarizes matters to be considered for appropriate immunohistochemical/immunocytochemical test development, performance, and interpretation in diagnostic pathology and laboratory medicine.

Cardiovascular events associated with rofecoxib: final analysis of the APPROVe trial

BACKGROUND

Selective inhibition of cyclo-oxygenase-2 has been associated with an increased risk of cardiovascular events in several clinical trials. The Adenomatous Polyp Prevention on Vioxx (APPROVe) study assessed the effect of 3-year treatment with a cyclo-oxygenase-2 inhibitor, rofecoxib (25 mg), on recurrence of neoplastic polyps of the large bowel. We report the cardiovascular outcomes of a long-term follow-up of participants in the trial.

METHODS

The APPROVe study is a multicentre, randomised, placebo-controlled, double-blind trial. 2587 patients with a history of colorectal adenomas were recruited at 108 centres worldwide during 2000 and 2001. Participants were followed for adverse events while on treatment and during the following 14 days. However, after early termination of treatment because of cardiovascular toxicity, we attempted to follow up all randomised patients for at least 1 year after stopping study treatment. External committees blindly assessed potential serious cardiovascular events. The focus of the analysis was the combined incidence of non-fatal myocardial infarction, non-fatal stroke, and death from cardiovascular, haemorrhagic, and unknown causes (Antiplatelet Trialists' Collaboration [APTC] combined endpoint). We used Cox proportional hazards regression to calculate endpoint hazard ratios. The study is registered with ClinicalTrials.gov, number NCT0282386.

FINDINGS

We obtained extended post-treatment cardiovascular follow-up data from 84% of participants, and extended mortality follow-up from 95%. In total, 59 individuals had an APTC endpoint in the rofecoxib group and 34 in the placebo group (hazard ratio 1.79, 95% CI 1.17-2.73; p=0.006). In the first year after cessation of treatment, there was a non-significant increase in the risks of APTC endpoints. The APTC hazard ratio did not substantially change over time.

INTERPRETATION

Use of rofecoxib is associated with increased rates of APTC events. Study data are compatible with an early increase in risk that persists for one year after stopping treatment.

Gastrointestinal stromal tumors: diagnostic challenges and practical approach to differential diagnosis

Over the last decade, gastrointestinal stromal tumors (GISTs) have evolved from histogenetically obscure gastrointestinal mesenchymal tumors to well-defined tumors with distinctive clinical, morphologic, ultrastructural, histogenetic, and molecular characteristics, for which targeted therapy is available. This is largely attributable to the discovery of CD117 overexpression and activating mutations in c-kit or platelet-derived growth factor alpha genes in most of GISTs. The availability of specific diagnostic tests and targeted therapy for GISTs has led to an increased awareness of these tumors. At the same time, the list of potential GIST mimics has lengthened considerably and it has become increasingly important that GISTs be distinguished from their mimics because correct diagnosis has implications for both treatment and prognosis. The purpose of this review is to provide an update of the expanding differential diagnosis of GISTS, to draw attention to unusual GIST variants, to provide a practical approach the differential diagnosis of GISTs and to highlight some of the challenges faced by pathologists in resolving this differential diagnosis.

A randomized trial of rofecoxib for the chemoprevention of colorectal adenomas

BACKGROUND & AIMS

In human and animal studies, nonsteroidal anti-inflammatory drugs have been associated with a reduced risk of colorectal neoplasia. Although the underlying mechanisms are unknown, inhibition of cyclooxygenase (COX), particularly COX-2, is thought to play a role. We conducted a randomized, placebo-controlled, double-blind trial to assess whether use of the selective COX-2 inhibitor rofecoxib would reduce the risk of colorectal adenomas.

METHODS

We randomized 2587 subjects with a recent history of histologically confirmed adenomas to receive daily placebo or 25 mg rofecoxib. Randomization was stratified by baseline use of cardioprotective aspirin. Colonoscopic follow-up evaluation was planned for 1 and 3 years after randomization. The primary end point was all adenomas diagnosed during 3 years' treatment. In a modified intent-to-treat analysis, we computed the relative risk of any adenoma after randomization, using Mantel-Haenszel statistics stratified by low-dose aspirin use at baseline.

RESULTS

Adenoma recurrence was less frequent for rofecoxib subjects than for those randomized to placebo (41% vs 55%; P < .0001; relative risk [RR], 0.76; 95% confidence interval [CI], 0.69-0.83). Rofecoxib also conferred a reduction in risk of advanced adenomas (P < .01). The chemopreventive effect was more pronounced in the first year (RR, 0.65; 95% CI, 0.57-0.73) than in the subsequent 2 years (RR, 0.81; 95% CI, 0.71-0.93). As reported previously, rofecoxib was associated with increased risks of significant upper gastrointestinal events and serious thrombotic cardiovascular events.

CONCLUSIONS

In this randomized trial, rofecoxib significantly reduced the risk of colorectal adenomas, but also had serious toxicity.

Histopathological alterations in irritable bowel syndrome

Irritable bowel syndrome is a common disorder defined by a symptom complex including abdominal pain and altered bowel habit. The etiopathogenesis appears to be multifactorial and to involve altered gastrointestinal motor function, enhanced perception of visceral stimuli and psychosocial factors. More recently a role for mucosal immune activation has been suggested. Routine histologic examination reveals no mucosal abnormality in the majority of cases but quantitative histological, immunohistochemical and ultrastructural analyses reveal subtle morphologic changes involving lymphocytes, mast cells, enterochromaffin cells and enteric nerves. The recent appreciation of these changes has led to new hypotheses linking central and enteric nervous systems to immune processes. This review highlights the spectrum of morphologic changes that occur in irritable bowel syndrome, examines their relationship to the pathophysiology of irritable bowel syndrome and considers their relevance to daily pathology practice.

A randomized trial of rofecoxib for the chemoprevention of colorectal adenomas

BACKGROUND & AIMS

In human and animal studies, nonsteroidal anti-inflammatory drugs have been associated with a reduced risk of colorectal neoplasia. Although the underlying mechanisms are unknown, inhibition of cyclooxygenase (COX), particularly COX-2, is thought to play a role. We conducted a randomized, placebo-controlled, double-blind trial to assess whether use of the selective COX-2 inhibitor rofecoxib would reduce the risk of colorectal adenomas.

METHODS

We randomized 2587 subjects with a recent history of histologically confirmed adenomas to receive daily placebo or 25 mg rofecoxib. Randomization was stratified by baseline use of cardioprotective aspirin. Colonoscopic follow-up evaluation was planned for 1 and 3 years after randomization. The primary end point was all adenomas diagnosed during 3 years' treatment. In a modified intent-to-treat analysis, we computed the relative risk of any adenoma after randomization, using Mantel-Haenszel statistics stratified by low-dose aspirin use at baseline.

RESULTS

Adenoma recurrence was less frequent for rofecoxib subjects than for those randomized to placebo (41% vs 55%; P < .0001; relative risk [RR], 0.76; 95% confidence interval [CI], 0.69-0.83). Rofecoxib also conferred a reduction in risk of advanced adenomas (P < .01). The chemopreventive effect was more pronounced in the first year (RR, 0.65; 95% CI, 0.57-0.73) than in the subsequent 2 years (RR, 0.81; 95% CI, 0.71-0.93). As reported previously, rofecoxib was associated with increased risks of significant upper gastrointestinal events and serious thrombotic cardiovascular events.

CONCLUSIONS

In this randomized trial, rofecoxib significantly reduced the risk of colorectal adenomas, but also had serious toxicity.

Gastrointestinal stromal tumours: consensus statement on diagnosis and treatment

In the multidisciplinary management of gastrointestinal stromal tumours (GISTs), there is a need to coordinate the efforts of pathology, radiology, surgery and oncology. Surgery is the mainstay for resectable nonmetastatic GISTs, but virtually all GISTs are associated with a risk of metastasis. Imatinib 400 mg/day with or without surgery is the recommended first-line treatment for recurrent or metastatic GIST; a higher dose may be considered in patients who progress, develop secondary resistance or present with specific genotypic characteristics. Adjuvant or neoadjuvant imatinib is not advised for resectable nonmetastatic GISTs. Neoadjuvant imatinib may be considered when surgery would result in significant morbidity or loss of organ function. Follow-up computed tomography imaging is recommended every three to six months for at least five years. Patients with metastatic disease should be continued on imatinib due to the high risk of recurrence on discontinuation of therapy. Treatment should be continued until there is progression or intolerable adverse effects. If dose escalation with imatinib fails, a clinical trial with novel agents alone or in combination may be considered. The present recommendations were developed at a surgical subcommittee meeting and a subsequent full Advisory Committee meeting held in Toronto, Ontario, in April 2005, under the sponsorship of Novartis Pharmaceuticals Canada Inc.

CDH1/E-cadherin germline mutations in early-onset gastric cancer

BACKGROUND

Gastric cancer remains a leading cause of cancer deaths worldwide. Genetic factors, including germline mutations in E-cadherin (CDH1, MIM#192090) in hereditary diffuse gastric cancer (HDGC, MIM#137215), are implicated in this disease. Family studies have reported CDH1 germline mutations in HDGC but the role of CDH1 germline mutations in the general population remains unclear.

AIMS

To examine the frequency of CDH1 germline mutations in a population-based series of early-onset gastric cancer (EOGC <50 years old).

METHODS

211 cases of EOGC were identified in Central-East Ontario region from 1989 to 1993, with archival material and histological confirmation of non-intestinal type gastric cancer available for 81 subjects. Eligible cases were analysed for CDH1 germline mutations by single-strand conformation polymorphism, variants were sequenced, and tumours from cases with functional mutations were stained for E-cadherin (HECD-1) using immunohistochemistry.

RESULTS

1155 (89%) of 1296 polymerase chain reactions amplified successfully. One new germline deletion (nt41delT) was identified in a 30-year-old patient with isolated cell gastric cancer. The overall frequency of germline CDH1 mutations was 1.3% (1/81) for EOGC and 2.8% (1/36) for early-onset isolated cell gastric cancer.

CONCLUSION

This is the first population-based study, in a low-incidence region, of genetic predisposition to gastric cancer. Combined with our previous report of germline hMLH1 mutations in two other subjects from this series, it is suggested that 2-3% of EOCG cases in North Americans may be owing to high-risk genetic mutations. These data should inform cancer geneticists on the utility of searching for specific genetic mutations in EOGC.

Tumor microsatellite instability in early onset gastric cancer

Gastric cancer (GC) remains a leading cause of cancer mortality worldwide. Genetic factors are implicated, including DNA mismatch repair (MMR) deficiency manifested as tumor microsatellite instability (MSI). However, a standardized panel of markers and a definition of low-versus-high level MSI in GC are lacking. We examined a population-based cohort of early onset (or=3 markers MSI+/MSI-high) demonstrated MMR protein deficiency. Three novel hMLH1 mutations (two germline frameshift and one somatic nonsense) were also found. The only significant clinicopathological associations were increased tumor size in MSI+ cases (P=0.04) and Lauren histotype (P=0.006) and tumor grade (P=0.007) in MSI-high cases. Tumor size, location, depth, nodal status, and Ming subtype were significant prognostic variables. Therefore, we propose a new definition of high-level MSI based on unifying characteristics of instability of more than or equal to three of six mononucleotide markers and loss of MMR protein expression.

Cardiovascular events associated with rofecoxib in a colorectal adenoma chemoprevention trial

BACKGROUND

Selective inhibition of cyclooxygenase-2 (COX-2) may be associated with an increased risk of thrombotic events, but only limited long-term data have been available for analysis. We report on the cardiovascular outcomes associated with the use of the selective COX-2 inhibitor rofecoxib in a long-term, multicenter, randomized, placebo-controlled, double-blind trial designed to determine the effect of three years of treatment with rofecoxib on the risk of recurrent neoplastic polyps of the large bowel in patients with a history of colorectal adenomas.

METHODS

A total of 2586 patients with a history of colorectal adenomas underwent randomization: 1287 were assigned to receive 25 mg of rofecoxib daily, and 1299 to receive placebo. All investigator-reported serious adverse events that represented potential thrombotic cardiovascular events were adjudicated in a blinded fashion by an external committee.

RESULTS

A total of 46 patients in the rofecoxib group had a confirmed thrombotic event during 3059 patient-years of follow-up (1.50 events per 100 patient-years), as compared with 26 patients in the placebo group during 3327 patient-years of follow-up (0.78 event per 100 patient-years); the corresponding relative risk was 1.92 (95 percent confidence interval, 1.19 to 3.11; P=0.008). The increased relative risk became apparent after 18 months of treatment; during the first 18 months, the event rates were similar in the two groups. The results primarily reflect a greater number of myocardial infarctions and ischemic cerebrovascular events in the rofecoxib group. There was earlier separation (at approximately five months) between groups in the incidence of nonadjudicated investigator-reported congestive heart failure, pulmonary edema, or cardiac failure (hazard ratio for the comparison of the rofecoxib group with the placebo group, 4.61; 95 percent confidence interval, 1.50 to 18.83). Overall and cardiovascular mortality was similar in the two groups.

CONCLUSIONS

Among patients with a history of colorectal adenomas, the use of rofecoxib was associated with an increased cardiovascular risk.

Chronic stress induces mast cell-dependent bacterial adherence and initiates mucosal inflammation in rat intestine

BACKGROUND & AIMS

Chronic psychological stress is an important factor in relapses of intestinal disorders, but it remains unclear if stress can induce primary gut inflammation in a previously healthy host.

METHODS

Mast cell-deficient (Ws/Ws) rats and wild-type control (+/+) rats were submitted to water avoidance stress or sham stress (1 h/day) for 10 consecutive days, as a model of ongoing life stress.

RESULTS

Both rat groups had similar systemic responses to stress, as assessed by changes in weight, corticosterone levels, and defecation. In +/+ rats, chronic stress induced barrier dysfunction in the ileum and colon (increased macromolecular permeability and depletion of mucus) and ultrastructural changes in epithelial cells (enlarged mitochondria and presence of autophagosomes) associated with bacterial adhesion and penetration into enterocytes. Moreover, hyperplasia and activation of mast cells, infiltration of neutrophils and mononuclear cells, and increased myeloperoxidase (MPO) activity were documented in the mucosa. In intestine of Ws/Ws rats, epithelial function and morphology were unchanged by chronic stress, bacterial-epithelial cell interaction was not demonstrated, and there was no evidence of inflammatory cell infiltration.

CONCLUSIONS

These findings suggest that chronic psychological stress can be an initiating factor in intestinal inflammation by impairing mucosal defenses against luminal bacteria and highlight the importance of mast cells in this process.

Defining the roles of perforin, Fas/FasL, and tumour necrosis factor alpha in T cell induced mucosal damage in the mouse intestine

BACKGROUND AND AIMS

Mucosal flattening and epithelial cell apoptosis are typical features of T cell induced inflammatory diseases of the bowel, such as coeliac disease and graft versus host disease. Mice injected with a T cell activating anti-CD3 antibody develop a severe diarrhoeal illness. We describe the histological features of this enteropathy and define the effector mechanisms involved in T cell induced mucosal injury in this in vivo model.

METHODS

Wild-type and genetically modified mice were injected with the anti-CD3 antibody 3C11 (50 microg). Changes in the murine intestine were characterised by light microscopy analysis and terminal uridine nick-end labelling (TUNEL) assay. The role of perforin, Fas/Fas ligand (FasL), tumour necrosis factor alpha (TNF-alpha), and interferon gamma (IFN-gamma) in T cell induced mucosal damage was assessed using selected immunodeficient mouse strains.

RESULTS

T cell activation caused severe damage, including small intestinal mucosal flattening and apoptosis of crypt epithelial cells. Mucosal damage was unaltered in anti-CD3 treated mice lacking IFN-gamma, Fas, or TNF-alpha receptors. In mice lacking TNF-alpha receptors and Fas (TNF-R1xR2 lpr/lpr strain), enterocyte apoptosis was diminished but there was no significant reduction in tissue damage. Apoptosis and mucosal injury were significantly reduced in perforin knockout mice. Abrogation of both FasL and perforin (perforin KOxgld mice) further significantly reduced tissue damage and apoptotic bodies.

CONCLUSIONS

T cell induced mucosal injury is mediated by the combined effect of multiple pathways but predominantly by perforin. The redundancy of the mechanisms of tissue damage will have significant impact on therapeutic strategies aimed at specific and targeted inhibition of inflammatory processes.

Telepathology for routine light microscopic and frozen section diagnosis

Telepathology (TP) uses telecommunication linkages to electronically capture, store, retrieve, and transmit images to distant sites. We assessed the feasibility of a dynamic real-time TP system for light microscopic (LM) diagnosis of anatomic pathology specimens, including frozen sections. Six pathologists, in 2 separate periods, read a set of 160 retrospectively retrieved slides (80 of which were frozen sections) by TP and LM. Reading times were recorded. Diagnoses were compared with the reference diagnosis (established by a group of 5 independent pathologists) and graded on a scale of 0 to 2 (2, correct; 1, incorrect but no clinical impact; 0, incorrect with clinical impact). Overall, LM was more accurate than TP compared with the reference diagnosis (score, 1.68 vs 1.54). There was no difference in accuracy between frozen section and paraffin-embedded tissue. Intraobserver agreement ranged from 82.5% to 88.2%. The average reading time was 6.0 minutes for TP and 1.4 minutes for LM. During the study, reading time decreased for TP but not for LM. These results show that despite marginally lower accuracy and longer reading times, TP isfeasible for routine light microscopic diagnosis, including frozen sections.

A reproducible grading scale for histological assessment of inflammation in ulcerative colitis

BACKGROUND

Evaluation of histological activity in ulcerative colitis needs to be reproducible but has rarely been tested. This could be useful both clinically and in clinical trials.

AIM

To develop reproducible criteria which are valid in the assessment of acute inflammation (activity) and chronicity, and to evaluate these features in an interobserver variability study.

METHODS

A six grade classification system for inflammation was developed which could also be fine tuned within each grade. The grades were: 0, structural change only; 1, chronic inflammation; 2, lamina propria neutrophils; 3, neutrophils in epithelium; 4, crypt destruction; and 5, erosions or ulcers. Ninety nine haematoxylin-eosin sections from endoscopically inflamed and non-inflamed mucosa from patients with distal ulcerative colitis were assessed in two separate readings by three pathologists independently and without knowledge of the clinical status. Interobserver agreement was compared pairwise using kappa statistics.

RESULTS

Initially, kappa values between the observers were 0.20, 0.42, and 0.26, which are too low to be of value. Following development of a semiquantitative pictorial scale for each criterion, kappa values improved to 0.62, 0.70, and 0.59. For activity defined by neutrophils between epithelial cells, kappa values were 0.903, 1.000, and 0.907. Complete agreement was reached in 64% of samples of endoscopically normal and in 66% of endoscopically inflamed tissue. Neutrophils in epithelium correlated with the presence of crypt destruction and ulceration.

CONCLUSION

A histological activity system was developed for ulcerative colitis that showed good reproducibility and modest agreement with the endoscopic grading system which it complemented. It has potential value both clinically and in clinical trials.