Observer study of the grading of dysplasia in ulcerative colitis: comparison with clinical outcome

Screening and Surveillance of Colorectal Cancer: A Review of the Literature

Colorectal cancer (CRC) has the highest mortality rate among men and is the second highest among women under fifty, with incidence and mortality rates rising in younger populations. Studies indicate that up to one-third of patients diagnosed before fifty have a family history or genetic factors, highlighting the need for earlier screening. Contrariwise, diagnosis in healthy subjects through screening strategies enables early-stage detection of the tumor and better clinical outcomes. In recent years, mortality rates of CRC in Western countries have been on a steady decline, which is largely attributed to widespread screening programs and advancements in treatment modalities. Indeed, early detection through screening significantly improves prognosis, with stark differences in survival rates between localized and metastatic disease. This article aims to provide a comprehensive review of the existing literature, delving into the performance and efficacy of various CRC screening strategies. It navigates through available screening tools, evaluating their efficacy and cost-effectiveness. The discussion extends to delineating target populations for screening, emphasizing the importance of tailored approaches for individuals at heightened risk.

Pathology and Clinical Significance of Inflammatory Bowel Disease-Associated Colorectal Dysplastic Lesions

Timely diagnosis and effective management of colorectal dysplasia play a vital role in preventing mortality from colorectal cancer in patients with chronic inflammatory bowel disease. This review provides a contemporary overview of the pathologic and endoscopic classification of dysplasia in inflammatory bowel disease, their roles in determining surveillance and management algorithms, and emerging diagnostic and therapeutic approaches that might further enhance patient management.

Clinical Proteomics for Solid Organ Tissues

The evaluation of biopsied solid organ tissue has long relied on visual examination using a microscope. Immunohistochemistry is critical in this process, labeling and detecting cell lineage markers and therapeutic targets. However, while the practice of immunohistochemistry has reshaped diagnostic pathology and facilitated improvements in cancer treatment, it has also been subject to pervasive challenges with respect to standardization and reproducibility. Efforts are ongoing to improve immunohistochemistry, but for some applications, the benefit of such initiatives could be impeded by its reliance on monospecific antibody-protein reagents and limited multiplexing capacity. This perspective surveys the relevant challenges facing traditional immunohistochemistry and describes how mass spectrometry, particularly liquid chromatography-tandem mass spectrometry, could help alleviate problems. In particular, targeted mass spectrometry assays could facilitate measurements of individual proteins or analyte panels, using internal standards for more robust quantification and improved interlaboratory reproducibility. Meanwhile, untargeted mass spectrometry, showcased to date clinically in the form of amyloid typing, is inherently multiplexed, facilitating the detection and crude quantification of 100s to 1000s of proteins in a single analysis. Further, data-independent acquisition has yet to be applied in clinical practice, but offers particular strengths that could appeal to clinical users. Finally, we discuss the guidance that is needed to facilitate broader utilization in clinical environments and achieve standardization.

Association Between Loss of SATB2 Expression in Inflammatory Bowel Disease Indefinite for Dysplasia and a Diagnosis of Definitive Dysplasia on Follow-up

Special AT-rich sequence-binding protein 2 (SATB2) is a sensitive and specific biomarker for sporadic colonic adenocarcinomas. Previous studies have found that SATB2 is lost in some adenocarcinomas and dysplasias associated with inflammatory bowel disease (IBD). In establishing these findings, the prior studies did not examine cases of IBD interpreted as indefinite for dysplasia. We examined SATB2 expression in this diagnostic category to determine if any potential loss is associated with a diagnosis of definitive dysplasia on follow-up. To investigate this possibility, we collected 87 biopsies of IBD indefinite for dysplasia from 62 patients and stained them with SATB2. Among patients' indefinite for dysplasia, we found SATB2 loss in 6/62 (9.7%). Among those with follow-up (n=51), we observed 5/6 (83%) with a future dysplasia in those with SATB2 loss compared with 10/45 (22%) in those with SATB2 retention, absolute difference 61.1% (95% confidence interval=28.9%-93.3%). We conclude that loss of SATB2 on biopsies otherwise interpreted as IBD indefinite for dysplasia may mark a population at high risk for showing definitive dysplasia on future biopsies.

Differentially Deregulated MicroRNAs as Novel Biomarkers for Neoplastic Progression in Ulcerative Colitis

INTRODUCTION

Colorectal cancer (CRC) is a potentially life-threatening complication of long-standing ulcerative colitis (UC). MicroRNAs (miRNA) are epigenetic regulators that have been involved in the development of UC-associated CRC. However, their role as potential mucosal biomarkers of neoplastic progression has not been adequately studied.

METHODS

In this study, we analyzed the expression of 96 preselected miRNAs in human formalin-fixed and paraffin-embedded tissue of 52 case biopsies (20 normal mucosa, 20 dysplasia, and 12 UC-associated CRCs) and 50 control biopsies (10 normal mucosa, 21 sporadic adenomas, and 19 sporadic CRCs) by using Custom TaqMan Array Cards. For validation of deregulated miRNAs, we performed individual quantitative real-time polymerase chain reaction in an independent cohort of 50 cases (13 normal mucosa, 25 dysplasia, and 12 UC-associated CRCs) and 46 controls (7 normal mucosa, 19 sporadic adenomas, and 20 sporadic CRCs).

RESULTS

Sixty-four miRNAs were found to be differentially deregulated in the UC-associated CRC sequence. Eight of these miRNAs were chosen for further validation. We confirmed miR-31, -106a, and -135b to be significantly deregulated between normal mucosa and dysplasia, as well as across the UC-associated CRC sequence (all P < 0.01). Notably, these miRNAs also confirmed to have a significant differential expression compared with sporadic CRC (all P < 0.05).

DISCUSSION

UC-associated and sporadic CRCs have distinct miRNA expression patterns, and some miRNAs indicate early neoplastic progression.

The Fate of Unifocal Versus Multifocal Low-Grade Dysplasia at the Time of Colonoscopy in Patients With IBD

BACKGROUND

Recommendations regarding management of colorectal dysplasia in the setting of IBD continue to evolve.

OBJECTIVE

This study aimed to determine the rate of progression from dysplasia to adenocarcinoma, specifically focusing on the differences in unifocal and multifocal low-grade dysplasia and dysplasia found on random biopsy versus targeted biopsies.

DESIGN

This is a retrospective review.

SETTING

This study was conducted at an IBD referral center.

PATIENTS

All adult patients (≥18 years of age) with a known diagnosis of either ulcerative colitis or Crohn's disease, who underwent a surveillance colonoscopy between January 1, 2010 and January 1, 2019, were selected.

MAIN OUTCOMES MEASURES

The primary outcomes measured were the progression of dysplasia and the risk factors for progression.

RESULTS

A total of 23,751 surveillance colonoscopies were performed among 12,289 patients between January 1, 2010 and January 1, 2019. The mean age at colonoscopy was 52.1 years (SD 16.9 years), 307 patients (2.5%) had a history of primary sclerosing cholangitis, and 3887 (3.15%) had a family history of colorectal cancer. There was a total of 668 patients (5.4%) with low-grade dysplasia, 76 patients (0.62%) with high-grade dysplasia, and 68 patients (0.55%) with adenocarcinoma in the series. The 1-, 2-, and 5-year cumulative incidence rate of progressing from low-grade dysplasia to high-grade dysplasia were 1.6%, 4.8%, and 7.8%. The 1- and 2-year cumulative incidence rates of progressing from low-grade dysplasia to adenocarcinoma were 0.7% and 1.6%. There were no significant differences in unifocal and multifocal progression. Primary sclerosing cholangitis, ulcerative colitis, male sex, and advanced age were all found to be significant risk factors for neoplasia on multivariable analysis.

LIMITATIONS

A retrospective database was a source of information.

CONCLUSION

Progression of low-grade dysplasia to adenocarcinoma, regardless of its being unifocal or multifocal, remains very low in the setting of adequate surveillance and medical management. The presence of multifocal low-grade dysplasia should not change the decision making to pursue ongoing endoscopic surveillance versus proctocolectomy. Patients who had primary sclerosing cholangitis with dysplasia found on random biopsies may be at highest risk for dysplasia progression. See Video Abstract at http://links.lww.com/DCR/A649.

EL DESENLACE DE LA DISPLASIA DE BAJO GRADO UNIFOCAL VERSUS MULTIFOCAL DURANTE LA COLONOSCOPIA EN PACIENTES CON ENFERMEDAD INFLAMATORIA INTESTINAL

ANTECEDENTES:Las recomendaciones para el tratamiento de la displasia colorrectal en el contexto de la enfermedad inflamatoria intestinal siguen evolucionando.OBJETIVO:Determinar la tasa de progresión de displasia a adenocarcinoma, centrándose específicamente en las diferencias en displasia de bajo grado unifocal y multifocal, y displasia encontradas en biopsias aleatorias versus biopsias dirigidas.DISEÑO:Revisión retrospectiva.ÁMBITO:Centro de referencia de EII.PACIENTES:Todos los pacientes adultos (> 18 años) con un diagnóstico comprobado de colitis ulcerosa o enfermedad de Crohn que se sometieron a una colonoscopia de vigilancia entre el 1 de enero de 2010 y el 1 de enero de 2019.PRINCIPALES VARIABLES ANALIZADAS:Progresión de la displasia y factores de riesgo de progresión.RESULTADOS:Se realizaron un total de 23.751 colonoscopias de vigilancia en 12.289 pacientes entre el 1/1/2010 y el 1/1/2019. La edad media en el momento de la colonoscopia fue de 52,1 años (DE 16,9 años), 307 pacientes (2,5%) tenían antecedentes de colangitis esclerosante primaria y 3887 (3,15%) tenían antecedentes familiares de cáncer colorrectal. Hubo un total de 668 pacientes (5,4%) con displasia de bajo grado, 76 pacientes (0,62%) con displasia de alto grado y 68 pacientes (0,55%) con adenocarcinoma en la serie. La tasa de incidencia acumulada de 1, 2, 5 años de progresión de displasia de bajo grado a displasia de alto grado fue del 1,6%, 4,8% y 7,8%. Las tasas de incidencia acumulada de 1 y 2 años de progresión de displasia de bajo grado a adenocarcinoma fueron 0,7% y 1,6%, respectivamente. No hubo diferencias significativas en la progresión unifocal y multifocal. Se encontró que la colangitis esclerosante primaria, la colitis ulcerosa, el sexo masculino y la edad avanzada eran factores de riesgo significativos de neoplasia en el análisis multivariable.LIMITACIONES:Base de datos retrospectiva.CONCLUSIÓN:La progresión de la displasia de bajo grado a adenocarcinoma, independientemente de que sea unifocal o multifocal, sigue siendo muy baja en el contexto de una vigilancia y un tratamiento médico adecuados. La presencia de displasia multifocal de bajo grado no debería cambiar la toma de decisión para continuar con vigilancia endoscópica continua o realizar la proctocolectomía. Los pacientes con colangitis esclerosante primaria y displasia encontrada en biopsias aleatorias pueden tener una mayor progresión de la displasia. Consulte Video Resumen en http://links.lww.com/DCR/A649.

Genomic Landscape of Early-stage Colorectal Neoplasia Developing From the Ulcerative Colitis Mucosa in the Japanese Population

BACKGROUNDS

Colorectal neoplasias (CRN)s developing from the ulcerative colitis (UC) mucosa include both colitic and sporadic neoplasias. Although several genomic analyses of advanced colitis-associated cancer are available, such studies do not distinguish between colitic and sporadic cases, and the early-stage genomic alterations involved in the onset of colitic cancer remain unclear. To address this, we performed a genomic analysis of early-stage CRN developing from the UC mucosa (CRNUC).

METHODS

We extracted DNA from 36 early-stage CRNUCs (T1 cancer, 10; dysplasia, 26) from 32 UC patients and performed targeted sequencing of 43 genes commonly associated with colitis-associated cancer and compared the results with sequencing data from the Japanese invasive colitis-associated cancer.

RESULTS

The most frequently mutated gene in the CRNUC cohort was APC (mutated in 47.2% of the cases), followed by TP53 (44.4%), KRAS (27.8%), and PRKDC (27.8%). None of the TP53 mutations occurred at any of the hotspot codons. Although the TP53 mutations in The Cancer Genome Atlas of Colorectal Cancer were dispersed throughout the gene, those detected here in CRNUC cases were concentrated in the amino terminal part of the DNA-binding domain. Interestingly, the mutations in KRAS and TP53 were mutually exclusive in CRNUC, and CRNUCs with KRAS mutations had histologically serrated lesions in the gland duct. Mayo endoscopic subscore was higher in TP53-mutated CRNUCs and lower in KRAS-mutated CRNUCs.

CONCLUSIONS

Our findings suggest that early-stage CRNUC can be classified into 2 groups: those developing through the carcinogenic pathway via TP53 mutations and those developing through the carcinogenic pathway via KRAS mutations.

Interobserver agreement and the impact of mentorship on the diagnosis of inflammatory bowel disease-associated dysplasia among subspecialist gastrointestinal pathologists

The diagnosis of inflammatory bowel disease (IBD)-associated dysplasia is challenging, and past studies have demonstrated considerable interobserver variability in such diagnoses. This study aimed to assess interobserver agreement in IBD dysplasia diagnoses among subspecialty GI pathologists and to explore the impact of mentorship on diagnostic variability. Twelve GI pathologist mentees and 7 GI pathologist mentors reviewed 163 digitized slides. Participants rendered a diagnosis of negative for dysplasia, indefinite for dysplasia, low-grade dysplasia, or high-grade dysplasia and provided a confidence level for each case. Interobserver agreement and reliability were assessed using Cohen's and Fleiss' kappa (κ) statistics and intraclass correlation coefficient (ICC) analysis. The overall κ coefficient was 0.42 (95% CI: 0.38-0.46). The overall ICC was 0.67 (95% CI: 0.62-0.72). Κ coefficients ranged from 0.31 to 0.49 for mentor/mentee pairs and from 0.34 to 0.55 for pairs of mentees of the same mentor. The combined κ coefficient was 0.44 (95% CI: 0.39-0.48) for all mentees and 0.39 (95% CI: 0.34-0.43) for all mentors. Common features in low agreement cases included mucosal atrophy, areas of stark contrast, serrations, decreased goblet cells, absent surface epithelium, and poor orientation. Participants were confident in most diagnoses, and increased confidence levels generally correlated with higher interobserver agreement. Interobserver agreement among subspecialist GI pathologists in this curated cohort of IBD dysplasia cases was fair to moderate. Mentorship during GI pathology fellowship does not appear to be a significant factor contributing to interobserver variability, but increased experience also does not seem to improve interobserver agreement.

Risk of Colon Cancer and Recommended Surveillance Strategies in Patients with Ulcerative Colitis

Longstanding and extensive ulcerative colitis (UC) are associated with the subsequent development of colorectal cancer (CRC). This article summarizes key strategies for colonoscopic surveillance, the most widely used and evidence-based method of CRC prevention. As currently constituted and practiced, surveillance examinations every 1 to 3 years with lesion detection and removal using high-definition endoscopic systems with or without pancolonic spray-dye chromoendoscopy is the best method for mitigating the development of CRC morbidity and mortality. For patients with primary sclerosing cholangitis with UC, surveillance should begin at the time of diagnosis and colonoscopy should be performed annually.

Pathologist Experience and Concordance in the Diagnosis of Dysplasia in Long-standing Inflammatory Bowel Disease

Surveillance colonoscopies focused to detect dysplasia are recommended to prevent colorectal cancer in patients with long-standing colonic inflammatory bowel disease (IBD). To date, histologic diagnosis and gradation of IBD-related dysplasia has been challenged by a high variability among pathologists. We aimed to analyze the observer characteristics that are correlated with concordance deviations in this diagnosis. Eight pathologists evaluated a set of 125 endoscopic biopsy samples with a representative distribution of nondysplastic and dysplastic lesions from long-standing IBD patients. Two rounds of diagnosis were carried out during a period of 18 months. The κ test was applied to analyze concordance. Pathologists were grouped on the basis of their experience. A subanalysis was performed by eliminating the highly prevalent nondysplastic samples, as well as an analysis after observers' grouping. Overall interobserver agreement was good (κ=0.73), with an even higher pairwise value (κ=0.86) as well as the intraobserver agreement values (best κ=0.85). After eliminating the highly prevalent nondysplastic samples, the interobserver agreement was still moderate to good (best overall κ=0.50; best paired κ=0.72). Notable differences were seen between the pathologists with a high-volume and low-volume practice (best overall κ=0.61 and 0.41, respectively). The agreement in the diagnosis of dysplasia in IBD endoscopic biopsies may have been undervalued over time. This is the first study evaluating pathologists' diagnostic robustness in this field. The results suggest that examining a large volume of samples is the key factor to increase the consistency in the diagnosis and gradation of IBD-related dysplasia.

Sporadic adenoma or ulcerative colitis associated neoplasia? The endoscopist's information has an impact on diagnosis and patient management

BACKGROUND

Diagnosing low grade intraepithelial neoplasia (LGIN) in patients with ulcerative colitis (UC) is difficult. Distinguishing between sporadic adenoma (SA) and UC associated LGIN is even more challenging but has clinical impact. We aimed to examine, if the morphological distinction between both entities is reliably possible, how it influences patient's outcome and the role of the endoscopist in this decision with respect to current endoscopy classification schemes.

METHODS

Seven pathologists retrospectively reevaluated 425 cases of LGIN in UC patients, diagnosed between 2009 and 2017 with preceding expert consensus and follow up in two separate readings, based on published morphological differentiation criteria. In the first evaluation, the observers were blinded to any clinical data. In the second evaluation, they knew patients' age as well as endoscopic features. They also rated their subjective diagnostic certainty.

RESULTS

Diagnostic correctness improved significantly in the second assessment as did the pathologists' confidence in their diagnoses (p < 0.001 - p = 0.019). Knowledge of clinical and endoscopical data led to a higher percentage of SA (71.8% vs. 85.6%). UC associated LGIN showed significant earlier LGIN relapse as well as more high grade intraepithelial neoplasia and carcinoma during follow up (p < 0.001, p < 0.001, p = 0.005).

CONCLUSIONS

Distinction between SA and UC associated LGIN is important as it has an impact on patients' follow up and treatment. Morphological distinction remains difficult with moderate interobserver variability. Adequate clinical information significantly improves pathologists' diagnoses as well as their confidence in their diagnoses.

Association Between Indefinite Dysplasia and Advanced Neoplasia in Patients With Inflammatory Bowel Diseases Undergoing Surveillance

BACKGROUND & AIMS

Little is known about the clinical significance of indefinite dysplasia (IND) in patients with inflammatory bowel diseases (IBD) undergoing colonoscopic surveillance for colorectal neoplasia.

METHODS

We conducted a retrospective cohort analysis of 492 patients with colonic IBD for 8 or more years or concomitant primary sclerosing cholangitis, with no history of advanced colorectal neoplasia (high-grade dysplasia or colorectal cancer) or colectomy, undergoing colorectal neoplasia surveillance at a tertiary IBD referral center from 2001 through 2017. Subjects received consistent histopathologic grading of dysplasia. We collected data on time to development of (advanced) colorectal neoplasia or colectomy using Kaplan Meier methods. We identified factors independently associated with (advanced) colorectal neoplasia with multivariable Cox regression analysis.

RESULTS

After 2149 person-years of follow-up, 53 patients (10.8%) received a diagnosis of IND without prior or synchronous low-grade dysplasia (LGD). Compared to patients without dysplasia, patients with IND had a significantly higher risk of advanced colorectal neoplasia (adjusted hazard ratio, 6.85; 95% CI, 1.78-26.4) and colorectal neoplasia (adjusted hazard ratio, 3.25; 95% CI, 1.50-7.05), but not colectomy (P = .78). Compared to IND, LGD was associated with a significantly higher risk of advanced colorectal neoplasia (P = .05). Following a diagnosis of no dysplasia, IND only, or LGD, the incidence rates of advanced colorectal neoplasia were 0.4% per patient-year, 3.1% per patient-year, and 8.4% per patient-year, respectively.

CONCLUSIONS

In a retrospective analysis of patients with IBD undergoing colorectal neoplasia surveillance with consistent histopathologic grading of dysplasia, IND was independently associated with a significant increase in risk of advanced colorectal neoplasia. These findings require validation and if confirmed, a reappraisal of the colorectal neoplasia surveillance guidelines.

Long-term Risk of Advanced Neoplasia After Colonic Low-grade Dysplasia in Patients With Inflammatory Bowel Disease: A Nationwide Cohort Study

BACKGROUND AND AIMS

The long-term risk of high-grade dysplasia [HGD] and colorectal cancer [CRC] following low-grade dysplasia [LGD] in inflammatory bowel disease [IBD] patients is relatively unknown. We aimed to determine the long-term cumulative incidence of advanced neoplasia [HGD and/or CRC], and to identify risk factors for advanced neoplasia in a nationwide IBD cohort with a history of LGD.

METHODS

This is a nationwide cohort study using data from the Dutch National Pathology Registry [PALGA] to identify all IBD patients with LGD between 1991 and 2010 in the Netherlands. Follow-up data were collected until January 2016. We determined the cumulative incidence of advanced neoplasia and identified risk factors via multivariable Cox regression analysis.

RESULTS

We identified 4284 patients with colonic LGD with a median follow-up of 6.4 years after initial LGD diagnosis. The cumulative incidence of subsequent advanced neoplasia was 3.6, 8.5, 14.4 and 21.7%, after 1, 5, 10 and 15 years, respectively. The median time to develop advanced neoplasia after LGD was 3.6 years. Older age [≥ 55 years] at moment of LGD (hazard ratio [HR] 1.73, 95% confidence interval [CI] 1.44-2.06), male sex [HR 1.33, 95% CI 1.10-1.60], and follow-up at an academic [vs non-academic] medical centre [HR 1.37, 95% CI 1.07-1.76] were independent risk factors for advanced neoplasia following LGD.

CONCLUSIONS

In a large nationwide cohort with long-term follow-up of IBD patients with LGD, the cumulative incidence of advanced neoplasia was 21.7% after 15 years. Older age at LGD [≥55 years], male sex and follow-up by a tertiary IBD referral centre were independent risk factors for advanced neoplasia development after initial LGD.

Intraobserver and Interobserver Variability in the Assessment of Dysplasia in Ampullary Mucosal Biopsies

Endoscopic mucosal biopsies of the ampulla of Vater (AmpBx) are obtained to histologically assess for dysplasia or carcinoma. However, biopsy material is often scant and a host of factors can induce histologic changes that pose diagnostic challenges. We sought to investigate observer variability in interpretation of AmpBx and the impact clinical data may have on diagnostic interpretation. Thirty-one cases from institutional archives were selected, including 12 cases of reactive atypia (RA), 8 indefinite for dysplasia (ID), and 11 showing low-grade dysplasia (LGD). Slides were independently reviewed at 3 time points with and without clinical information by 6 pathologists who categorized the biopsies RA, ID, or LGD. Following the reviews, intraobserver and interobserver agreement was assessed. Review of AmpBx without clinical data showed fair (κ, 0.27), poor (κ, 0.07), and good (κ, 0.42) interobserver agreement for diagnoses of RA, ID, and LGD, respectively. Interobserver agreement improved for LGD (κ, 0.66 and 0.73) when clinical information was provided; however, agreement remained fair for RA (κ, 0.4 and 0.42) and poor-to-fair for ID (κ, 0.17 and 0.25). When follow-up data were reviewed, all cases that reached unanimous agreement had that diagnosis substantiated by subsequent endoscopic or histologic findings. The same was true of 13 of 19 cases that reached majority consensus. Given the potential clinical consequences of these diagnoses combined with the significant intraobserver and interobserver variability found in this study, we conclude that better-defined diagnostic criteria and consensus reads on difficult cases would assist in the histologic assessment of these challenging cases.

Histopathological diagnosis of ulcerative colitis-associated neoplasia

In patients with ulcerative colitis, tumor development occurs with an increase in the duration of the disease. Such lesions, known as ulcerative colitis-associated neoplasia (UCAN), histologically show a broad variety of findings such as low-grade dysplasia, high-grade dysplasia, and invasive carcinoma. For pathologists, however, the histopathological diagnosis of UCAN is occasionally difficult. Problems in pathological diagnosis can be summarized into the following three categories: (i) difficulty in discriminating UCAN from non-neoplastic inflammatory change; (ii) difficulty in discriminating UCAN from sporadic epithelial neoplasm; and (iii) difficulty in histological grading of UCAN. For most lesions, pathologists can make conclusive histological diagnoses without any problems. However, pathologists occasionally face diagnostic difficulties, especially in cases of lesions with borderline or indefinite histology and, therefore, at least two experienced gastrointestinal pathologists are needed to confirm the diagnosis. Hence, a confirmation is usually preferable for the estimation of tumor depth and lymphovascular invasion in digestive tract cancers as well as in UCAN. Immunohistochemistry for p53 and Ki-67 (MIB-1) is occasionally useful as an ancillary tool. Since UCAN has distinct characteristics compared to sporadic epithelial neoplasia, its treatment strategy should be carefully discussed by a multidisciplinary team, especially for cases of lesions with indefinite histology. At present, although surgical intervention such as total colectomy is the most promising procedure for UCAN, recent advances in endoscopic diagnosis and therapy are expected to improve future treatment strategy.

Interobserver Agreement in the Diagnosis of Inflammatory Bowel Disease-Associated Neoplasia in China in Comparison to Subspecialized American Gastrointestinal Pathologists

Background

The aim of this study was to evaluate the interobserver variability in diagnosing inflammatory bowel disease (IBD)-associated neoplasia among practicing pathologists from China using telepathology, a practice of remote diagnostic consultation increasingly used nationally and internationally, and its comparison with the interpretation of subspecialized gastrointestinal (GI) pathologists from the United States (US).

Methods

Eight GI pathologists from the US and 4 pathologists from China with an interest in GI pathology participated in this study. A total of 50 colonic biopsies from patients with a clinical history of IBD from 8 medical centers in China were included. All microscopic slides in each case were digitized using an Aperio system. One pathologist (XL) reviewed the digitized full-slide images, and selected areas of interest were captured at low, medium, and high magnifications at a resolution of 1712 × 1072 pixels and saved as tagged image file format (TIFF) files on read-only DVD. Each pathologist evaluated the images and selected the most appropriate diagnostic category for each case (negative, indefinite, low-grade dysplasia [LGD], high-grade dysplasia [HGD], and carcinoma). A Fleiss' kappa coefficient (K) analysis was performed to determine interobserver agreement and the agreement of each pathologist from China with the consensus diagnosis (defined as diagnostic agreement by at least 4 participating US GI pathologists).

Results

There was substantial interobserver agreement among 4 pathologists from China on the interpretation of IBD-associated neoplasia (kappa value 0.68, 95% confidence interval: 0.56-0.78). A consensus diagnosis included negative (n = 22), LGD (n = 22), HGD (n = 3), carcinoma (n = 2), and indefinite for dysplasia (n = 1). Using consensus diagnoses as references, the agreement between each pathologist from China and the consensus diagnosis was substantial with kappa values ranging from 0.75 to 0.80.

Conclusions

This study reveals substantial interobserver agreement for the interpretation of colonic neoplasia in IBD using digitized images among Chinese pathologists as well as between each Chinese pathologist and a consensus diagnosis generated by US GI pathologists.

SMAD2 and the Relationship of Colorectal Cancer to Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) affecting the colon [Crohn's disease (CD) and ulcerative colitis (UC)] are associated with an increased risk of colorectal cancer (CRC). Our previous work using oligonucleotide array data indicated that SMAD2 was significantly underexpressed in UC dysplastic tissue compared to benign UC. The aim of this current study was to determine whether single nucleotide polymorphisms (SNPs) within the SMAD2 gene are associated with IBD dysplasia/cancer. We performed an SNP haplotype-based case-control association study. Leukocyte DNA was obtained from 489 unrelated Caucasians (158 UC, 175 CD, 71 CRC, 85 controls). Eleven SNPs were genotyped. All 11 SNPs were in Hardy-Weinberg equilibrium in the control population. Strong linkage disequilibrium was observed among nearly all SMAD2 SNPs. There were no significant associations between SMAD2 allele or haplotype frequencies. Power calculations indicated good power for single-marker analysis (>0.8) and reasonably good power against effects of 0.1–0.15 for haplotype analysis. SMAD2 SNPs were not associated with the development of IBD dysplasia/cancer. This incongruity between our previous microarray data and the findings from this genotype study may be attributed to mechanisms such as alternative splicing of pre-mRNA SMAD2 and/or cross talk with other cellular pathways.

Screening of colorectal cancer: present and future

INTRODUCTION

Colorectal cancer (CRC) is the third most common cancer in males and second in females, and the fourth most common cause of cancer death worldwide. Currently, about 60-70% of diagnosed cases in symptomatic patients are detected at an advanced stage of disease. Earlier stage detection through the use of screening strategies would allow for better outcomes in terms of reducing the disease burden. Areas covered: The aim of this paper is to review the current published evidence from literature which assesses the performance and effectiveness of different screening tests for the early detection of CRC. Expert commentary: Adequate screening strategies can reduce CRC incidence and mortality. In the last few decades, several tests have been proposed for CRC screening. To date, there is still insufficient evidence to identify which approach is definitively superior, and no screening strategy for CRC can therefore be defined as universally ideal. The best strategy would be the one that can be economically viable and to which the patient can adhere best to over time. The latest guidelines suggest colonoscopy every 10 years or annual fecal immuno-chemical test (FIT) for people with normal risk, while for individuals with high risk or hereditary syndromes specific recommendations are provided.

Combining aneuploidy and dysplasia for colitis' cancer risk assessment outperforms current surveillance efficiency: a meta-analysis

PURPOSE

Cancer risk assessment for ulcerative colitis patients by evaluating histological changes through colonoscopy surveillance is still challenging. Thus, additional parameters of high prognostic impact for the development of colitis-associated carcinoma are necessary. This meta-analysis was conducted to clarify the value of aneuploidy as predictor for individual cancer risk compared with current surveillance parameters.

METHODS

A systematic web-based search identified studies published in English that addressed the relevance of the ploidy status for individual cancer risk during surveillance in comparison to neoplastic mucosal changes. The resulting data were included into a meta-analysis, and odds ratios (OR) were calculated for aneuploidy or dysplasia or aneuploidy plus dysplasia.

RESULTS

Twelve studies addressing the relevance of aneuploidy compared to dyplasia were comprehensively evaluated and further used for meta-analysis. The meta-analysis revealed that aneuploidy (OR 5.31 [95 % CI 2.03, 13.93]) is an equally effective parameter for cancer risk assessment in ulcerative colitis patients as dysplasia (OR 4.93 [1.61, 15.11]). Strikingly, the combined assessment of dysplasia and aneuploidy is superior compared to applying each parameter alone (OR 8.99 [3.08, 26.26]).

CONCLUSIONS

This meta-analysis reveals that aneuploidy is an equally effective parameter for individual cancer risk assessment in ulcerative colitis as the detection of dysplasia. More important, the combined assessment of dysplasia and aneuploidy outperforms the use of each parameter alone. We suggest image cytometry for ploidy assessment to become an additional feature of consensus criteria to individually assess cancer risk in UC.

Risk of Neoplasia After Colectomy in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Colorectal neoplasia can still develop after colectomy for inflammatory bowel disease. However, data on this risk are scare, and there have been few conclusive findings, so no evidence-based recommendations have been made for postoperative surveillance. We conducted a systematic review and meta-analysis to determine the prevalence and incidence of and risk factors for neoplasia in patients with inflammatory bowel disease who have undergone colectomy, including the permanent-end ileostomy and rectal stump, ileorectal anastomosis (IRA), and ileal pouch-anal anastomosis (IPAA) procedures.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library through May 2014 to identify studies that reported prevalence or incidence of colorectal neoplasia after colectomy or specifically assessed risk factors for neoplasia development. Studies were selected, quality was assessed, and data were extracted by 2 independent researchers.

RESULTS

We calculated colorectal cancer (CRC) prevalence values from 13 studies of patients who underwent rectal stump surgery, 35 studies of IRA, and 33 studies of IPAA. Significantly higher proportions of patients in the rectal stump group (2.1%; 95% confidence interval [CI], 1.3%-3.0%) and in the IRA group (2.4%; 95% CI, 1.7%-3.0%) developed CRC than in the IPAA group (0.5%; 95% CI, 0.3%-0.6%); the odds ratio (OR) for CRC in the rectal stump or IRA groups compared with the IPAA group was 6.4 (95% CI, 4.3-9.5). A history of CRC was the most important risk factor for development of CRC after colectomy (OR for patients receiving IRA, 12.8; 95% CI, 3.31-49.2 and OR for patients receiving IPAA, 15.0; 95% CI, 6.6-34.5).

CONCLUSIONS

In a meta-analysis of published studies, we found the prevalence and incidence of CRC after colectomy to be less than 3%; in patients receiving IPAA it was less than 1%. Factors that increased risk of cancer development after colectomy included the presence of a residual rectum and a history of CRC. These findings could aid in development of individualized strategies for post-surgery surveillance.

Altered expression of caspases-4 and -5 during inflammatory bowel disease and colorectal cancer: Diagnostic and therapeutic potential

Caspases are a group of proteolytic enzymes involved in the co-ordination of cellular processes, including cellular homeostasis, inflammation and apoptosis. Altered activity of caspases, particularly caspase-1, has been implicated in the development of intestinal diseases, such as inflammatory bowel disease (IBD) and colorectal cancer (CRC). However, the involvement of two related inflammatory caspase members, caspases-4 and -5, during intestinal homeostasis and disease has not yet been established. This study demonstrates that caspases-4 and -5 are involved in IBD-associated intestinal inflammation. Furthermore, we found a clear correlation between stromal caspase-4 and -5 expression levels, inflammation and disease activity in ulcerative colitis patients. Deregulated intestinal inflammation in IBD patients is associated with an increased risk of developing CRC. We found robust expression of caspases-4 and -5 within intestinal epithelial cells, exclusively within neoplastic tissue, of colorectal tumours. An examination of adjacent normal, inflamed and tumour tissue from patients with colitis-associated CRC confirmed that stromal expression of caspases-4 and -5 is increased in inflamed and dysplastic tissue, while epithelial expression is restricted to neoplastic tissue. In addition to identifying caspases-4 and -5 as potential targets for limiting intestinal inflammation, this study has identified epithelial-expressed caspases-4 and -5 as biomarkers with diagnostic and therapeutic potential in CRC.

Colorectal neoplasia in IBD--a single-center analysis of patients undergoing proctocolectomy

PURPOSE

The risk, prevention, and treatment of colorectal neoplasia in inflammatory bowel disease (IBD) are still a matter of debate. The aim of this study was to analyze the occurrence of colorectal neoplasia in IBD patients who underwent proctocolectomy.

METHODS

The study population comprised of 123 IBD patients who underwent proctocolectomy because of neoplasia, therapy refractivity, or complications between January 2000 and July 2011.

RESULTS

One hundred fourteen (92.7%) patients were pre-operatively diagnosed with ulcerative colitis, 5 (4.1%) with colitis indeterminata, and 4 (3.3%) with colonic Crohn's disease. Colectomy was indicated in 39 (31.7%) patients because of a neoplasia, in 68 (55.3%) because of a refractory course of the disease, and in 16 (13.0%) because of complications. Neoplasia was found in 36 patients on a histopathologic evaluation of the colectomy specimens. Ten (8.1%) patients post-operatively showed a pre-operatively not described advanced neoplasia. In three (2.4%) of these patients, the detection of advanced neoplasia (two high-grade intraepithelial neoplasias (IENs), one carcinoma) was a complete de novo finding. Carcinoma had not been diagnosed pre-operatively in six (4.9%) patients. A multifocal distribution of neoplasia was seen in 66.7% of patients with neoplasia. The median duration of disease was 15.5 years in case of neoplasia opposed to 6.0 years in those without neoplasia detection.

CONCLUSION

Our data demonstrate a high rate of pre-operatively undetected high-grade IENs and carcinoma and a frequent multifocal occurrence in IBD patients with long-standing inflammation of the colon. This should be kept in mind for treatment decisions particularly in patients with a chronic refractory course of the disease.

Inter-observer and intra-observer variability in the diagnosis of dysplasia in patients with inflammatory bowel disease: correlation of pathological and endoscopic findings

AIM

Colonic epithelial dysplasia is deemed the precursor lesion of cancer arising in inflammatory bowel disease (IBD). It has been suggested that many dysplastic lesions could be endoscopically detected to obtain target biopsies, leading to better yield. However, the clinical impact of a diagnosis of dysplasia may be hampered by a significant degree of histological and endoscopic intra-observer and inter-observer variability. This study aimed to evaluate intra-observer and inter-observer variability in the microscopic diagnosis of dysplasia in IBD and correlate endoscopic and histological findings.

METHOD

In total, 158 cases of ulcerative colitis and 14 of Crohn's disease with dysplasia were selected from a pathology database. Slides were blindly reviewed twice by two expert gastrointestinal pathologists. Results of endoscopic examinations were extracted from the reports. The degree of intra-observer and inter-observer variability was determined by kappa statistics.

RESULTS

Overall, there was an excellent degree of histopathological inter-observer agreement (κ = 0.786). The lowest level of agreement in the dysplasia group was for indefinite dysplasia (κ = 0.251). Negative and high grade dysplasia diagnosis reached the highest level of agreement with κ values of 0.822 [95% confidence interval (CI) 0.673-0.971] and 1.00 (95% CI 0.850-1.149), respectively. Intra-observer agreement was good and increased during the latter period of the study (κ = 0.734, 95% CI 0.642-0.826). Endoscopic-histological correlation was poor among the negative endoscopies, as up to 43% of cases were diagnosed with at least focal high grade dysplasia. The endoscopic-histological correlation improved when evaluating suspicious endoscopic lesions.

CONCLUSION

Dysplasia is reliably diagnosed by expert gastrointestinal pathologists but has poor correlation with an endoscopic diagnosis of dysplasia.

The oncogenic role of androgen receptors in promoting the growth of oral squamous cell carcinoma cells

OBJECTIVES

The aims of this study were to examine the expression of androgen receptors (AR) in oral squamous cell carcinoma (OSCC) cells and tumors and to determine the role of AR in regulating OSCC cell growth.

MATERIALS AND METHODS

Four OSCC cell lines were used for analyzing AR expression and transcriptional activity. The effects of AR knockdown on the growth and tumorigenicity of OSCC cells were examined. A series of 11 benign, 22 premalignant, and 21 malignant lesions of the oral cavity were used for analyzing AR expression.

RESULTS

OSCC cells expressed AR proteins with differential activities. Stimulation of AR by dihydrotestosterone in OSCC cells caused an increase in cyclin D1 expression and promoted cell growth, whereas treatment with bicalutamide led to decreased cyclin D1 expression and inhibited cell growth. Knockdown of AR expression in OSCC cells resulted in decreased proliferation, increased apoptosis, and inhibited tumorigenicity. Results from immunohistochemical studies showed that AR immunoreactivity was found in 27% (3/11) of benign lesions, while 68% (15/22) of premalignant and 67% (14/21) of malignant lesions showed positive AR staining.

CONCLUSION

Our data suggest that OSCC cells express functional AR proteins which are critical for promoting cell growth and causing malignant disease.

Inflammatory cues acting on the adult intestinal stem cells and the early onset of cancer (review)

The observation that cancer often arises at sites of chronic inflammation has prompted the idea that carcinogenesis and inflammation are deeply interwoven. In fact, the current literature highlights a role for chronic inflammation in virtually all the steps of carcinogenesis, including tumor initiation, promotion and progression. The aim of the present article is to review the current literature on the involvement of chronic inflammation in the initiation step and in the very early phases of tumorigenesis, in a type of cancer where adult stem cells are assumed to be the cells of origin of neoplasia. Since the gastrointestinal tract is regarded as the best-established model system to address the liaison between chronic inflammation and neoplasia, the focus of this article will be on intestinal cancer. In fact, the anatomy of the intestinal epithelial lining is uniquely suited to study adult stem cells in their niche, and the bowel crypt is an ideal developmental biology system, as proliferation, differentiation and cell migration are all distributed linearly along the long axis of the crypt. Moreover, crypt stem cells are regarded today as the most likely targets of neoplastic transformation in bowel cancer. More specifically, the present review addresses the molecular mechanisms whereby a state of chronic inflammation could trigger the neoplastic process in the intestine, focusing on the generation of inflammatory cues evoking enhanced proliferation in cells not initiated but at risk of neoplastic transformation because of their stemness. Novel experimental approaches, based on triggering an inflammatory stimulus in the neighbourhood of adult intestinal stem cells, are warranted to address some as yet unanswered questions. A possible approach, the targeted transgenesis of Paneth cells, may be aimed at 'hijacking' the crypt stem cell niche from a status characterized by the maintenance of homeostasis to local chronic inflammation, with the prospect of initiating neoplastic transformation in that site.

Microscopic features of colorectal neoplasia in inflammatory bowel diseases

The risk of developing dysplasia leading to colorectal cancer (CRC) is increased in both ulcerative colitis and Crohn’s disease. The prognosis of CRC may be poorer in patients with inflammatory bowel disease (IBD) than in those without IBD. Most CRCs, in general, develop from a dysplastic precursor lesion. The interpretation by the pathologist of the biopsy will guide decision making in clinical practice: colonoscopic surveillance or surgical management. This review summarizes features of dysplasia (or intraepithelial neoplasia) with macroscopic and microscopic characteristics. From an endoscopic (gross) point of view, dysplasia may be classified as flat or elevated (raised); from a histological point of view, dysplasia is separated into 3 distinct categories: negative for dysplasia, indefinite for dysplasia, and positive for dysplasia with low- or high-grade dysplasia. The morphologic criteria for dysplasia are based on a combination of cytologic (nuclear and cytoplasmic) and architectural aberrations of the crypt epithelium. Immunohistochemical and molecular markers for dysplasia are reviewed and may help with dysplasia diagnosis, although diagnosis is essentially based on morphological criteria. The clinical, epidemiologic, and pathologic characteristics of IBD-related cancers are, in many aspects, different from those that occur sporadically in the general population. Herein, we summarize macroscopic and microscopic features of IBD-related colorectal carcinoma.

FOXE1 and SYNE1 genes hypermethylation panel as promising biomarker in colitis-associated colorectal neoplasia

BACKGROUND

Colitis-associated colorectal cancer affects individuals with inflammatory bowel disease (IBD) more often and earlier than cancer in the general population. Colonoscopy provides the surveillance gold standard. Changes to the surveillance intervals depending on endoscopic activity have been made, given data demonstrating that this is an important predictor of future dysplasia or cancer, but adjuvant, noninvasive clinical tools are still warranted to improve surveillance outcomes and to assist in management and interpretation of dysplasia. Methylation markers may be able to do this.

METHODS

SYNE1, FOXE1, NDRG4, and PHACTR3 genes were screened using methylation-specific PCR that permit the methylation status of the genes to be determined directly on biopsies. Ninety-three patients with long-standing IBD undergoing a cancer surveillance program, and 30 healthy controls were studied. These included colorectal adenocarcinomas on a background of IBD of various stages (n = 25), IBD-associated dysplastic lesions (n = 29), adenomas arising on a background of ulcerative colitis (n = 8), samples from patients with no evidence of dysplasia or cancer but long-standing IBD (n = 31), and symptomatic patients found to have normal colonoscopy (controls) (n = 30).

RESULTS

Gene promotor hypermethylation of SYNE1 and FOXE1 genes varied significantly between the groups and was increasingly likely with increased disease severity. Neither occurred in controls, whereas promotor hypermethylation was detected in biopsies of 60% of patients with colitis-associated colorectal cancer for FOXE1 and 80% for SYNE1. Promotor hypermethylation of either gene was highly significantly different between the groups overall.

CONCLUSIONS

FOXE1 and SYNE1 hypermethylation markers demonstrated significantly increased expression in neoplastic tissue. Promoter methylation analysis of these genes might be a useful marker of neoplasia in long-standing IBD.

Advanced endoscopic imaging for surveillance for dysplasia and colorectal cancer in inflammatory bowel disease: could the pathologist be further helped?

Patients with inflammatory bowel disease (IBD) have an increased risk of developing intestinal cancer. The magnitude of that increased risk as well as how best to mitigate it remain a topic of ongoing investigation in the field. It is important to quantify the risk of colorectal cancer in association with IBD. The reported risk varies widely between studies. This is partly due to the different methodologies used in the studies. Because of the limitations of surveillance strategies based on the detection of dysplasia, advanced endoscopic imaging and techniques involving the detection of alterations in mucosal antigens and genetic abnormalities are being investigated. Development of new biomarkers, predicting future occurrence of colonic neoplasia may lead to more biomarker-based surveillance. There are promising results that may lead to more efficient surveillance in IBD patients and more general acceptance of its use. A multidisciplinary approach, involving in particular endoscopists and pathologists, together with a centralized patient management, could help to optimize treatments and follow-up measures, both of which could help to reduce the IBD-associated cancer risk.

The fate of indefinite and low-grade dysplasia in ulcerative colitis and primary sclerosing cholangitis colitis before and after liver transplantation

BACKGROUND

Patients with primary sclerosing cholangitis (PSC) and ulcerative colitis (UC) are at an increased risk of colorectal neoplasia, but it is unknown if liver transplantation (LT) alters neoplasia progression.

AIM

To examine the natural history of indefinite dysplasia (IND) and low-grade dysplasia (LGD) that develop in patients with PSC-UC with and without LT.

METHODS

We performed a retrospective review of patients with PSC and UC evaluated at our institution between 1993 and 2011 who were diagnosed with IND or LGD before or after LT for PSC. The primary end point was neoplasia progression or persistent LGD.

RESULTS

Ninety-six patients (non-LT n = 63, LT n = 33) were examined. For the IND group, multifocal lesions were significantly associated with time to neoplasia progression [hazard ratio (HR), 3.5; 95% confidence interval (CI), 1.3-9.7], while 5-aminosalicylate (5-ASA) use was protective (HR, 0.2; 95% CI, 0.1-0.6). For patients with LGD, multifocal lesions were significantly associated with the primary end point (HR, 7.1; 95% CI, 1.7-28.3), while LT was protective (HR, 0.3; 95% CI, 0.1-0.9).

CONCLUSIONS

In PSC-UC patients with IND, 5-ASA use was associated with a decreased the risk of neoplasia progression, regardless of transplant status. In contrast, multifocal IND and LGD were associated with neoplasia progression or persistent LGD. Patients who developed LGD following LT for PSC were less likely to have progressive neoplasia or persistent LGD, compared with those who had not been transplanted.

Fluorescence endoscopic detection of murine colitis-associated colon cancer by topically applied enzymatically rapid-activatable probe

OBJECTIVES

Screening colonoscopy to monitor for early colitis-associated colon cancer (CAC) is difficult due to the aberrant mucosal patterns associated with long-standing colitis. The aim of this study was to develop a rapid fluorescent detection method for use during colonoscopy for improving the detection of CAC utilising a topically applied enzymatically activatable probe (gGlu-HMRG) which fluoresces in the presence of γ-glutamyltranspeptidase (GGT), an enzyme associated with cancer.

METHODS

Expression of GGT in colon cell lines was examined with fluorescence microscopy and flow cytometry. A mouse model (azoxymethane/dextran sulphate sodium) of CAC was used and mice were examined with white light and fluorescence colonoscopy before and after topical gGlu-HMRG administration.

RESULTS

Expression of GGT, although variable, was higher in human colon cancer cells than normal human colon cells. Using fluorescence colonoscopy in mice, gGlu-HMRG fluorescent lesions were detected 5 min after topical administration and fluorescence persisted for at least 30 min. Fluorescence guided biopsy revealed all fluorescent lesions that contained cancer or dysplasia (n=16), whereas three out of 12 non-fluorescent lesions contained low grade dysplasia and others did not contain neoplastic histology. Microscopic inflammatory infiltration also had variable fluorescence but in general was much lower (∼10-fold) in signal than cancer. Repeat fluorescence endoscopy allowed individual tumours to be monitored.

CONCLUSION

These results suggest that gGlu-HMRG can improve endoscopic detection of CAC with a higher target to background ratio than conventional white light colonoscopy. This could be of benefit to patients with long-standing colitis who must undergo repeated screening colonoscopies.

Dysplastic lesions in inflammatory bowel disease: molecular pathogenesis to morphology

Context.-Inflammatory bowel disease (IBD) is a long-standing chronic active inflammatory process in the bowel with increased risk for the development of colorectal carcinoma. Several molecular events involved in chronic active inflammatory processes contribute to multistage progression of human cancer development, including reactive oxygen and nitrogen species, aberrant arachidonic acid metabolites and cytokines/growth factors, and immune dysfunction. These molecular events in IBD lead to genetic abnormality and promote aberrant cell proliferation, which further lead to epithelial changes encompassing a broad spectrum from inflammation-induced hyperplasia to dysplasia. Objective.-To review the (1) epidemiologic and molecular pathogenesis of the risk for colorectal cancer in IBD, (2) morphologic characterization, biomarker(s), and classification of dysplastic lesions, and (3) clinical management of dysplastic lesions arising in IBD. Data Sources.-The different IBD-related dysplastic lesions are illustrated by using morphology in conjunction with molecular pathways, and the "field cancerization" theory and its potential significance are discussed with a review of the literature. Conclusions.-Patients with IBD are at increased risk of developing colorectal cancer. The risk of developing carcinoma is related to the extent/duration/activity of the patient's disease. There is no consensus regarding the extent of carcinoma risk associated with IBD; however, all would agree that patients with IBD represent a group at significant risk for developing carcinoma and as such, warrant adequate surveillance and prevention. With better screening modalities and detection/characterization of dysplastic lesions, IBD-associated serrated lesions, and "field cancerization," we will improve our understanding of and approach to risk stratification.

Dysplasia in inflammatory bowel diseases

In both Crohn's disease and ulcerative colitis, the secondary prevention of colorectal cancer basically relies on the histological detection of dysplasia. In inflammatory bowel diseases, dysplasia identifies the subgroup of patients eligible for stricter surveillance (or prophylactic colectomy). In clinical practice, a number of issues may influence the benefits of clinico-pathological surveillance for inflammatory bowel disease patients with dysplasia, including: sampling errors, inconsistent biopsy assessments, patients' compliance with follow-up requirements, and how heath care is organized. Even in such a multifaceted context, it has been demonstrated that dysplasia surveillance is effective in reducing colorectal cancer-related mortality and morbidity. This paper focuses on current issues concerning the histological assessment of inflammatory bowel disease-associated dysplastic lesions.

Dysplasia is more common in the distal than proximal colon in ulcerative colitis surveillance

BACKGROUND

In patients with long-standing ulcerative colitis (UC), current dysplasia surveillance guidelines recommend four-quadrant biopsies every 10 cm throughout the colon. However, this may be inefficient if neoplastic lesions are localized in particular segments of the colorectum. The aim was to determine whether a difference exists in the anatomic distribution of dysplasia discovered in UC patients undergoing colonoscopic surveillance.

METHODS

From an institutional database of over 700 patients with UC who underwent two or more surveillance colonoscopies between 1994-2006, we identified all patients with flat (endoscopically invisible) low-grade dysplasia (fLGD) or advanced neoplasia (colorectal cancer [CRC] or high-grade dysplasia [HGD]). Pathology reports were reviewed regarding the anatomic location of all dysplastic lesions. Fisher's exact test was used to compare the frequencies of neoplasia among the different colonic segments.

RESULTS

We identified 103 patients who progressed to any neoplasia (fLGD, HGD, or CRC). These patients underwent a total of 396 colonoscopies. The mean age at first surveillance colonoscopy was 48.6 years, with a mean UC disease duration of 18.2 years; 100% had extensive disease. Fifty-five patients developed advanced neoplasia. The rectosigmoid was found to have a significantly greater number of biopsies positive for advanced neoplasia and for any neoplasia compared to all other colonic segments (P < 0.0007); 71.2% of all advanced neoplasia was in the rectosigmoid.

CONCLUSIONS

The majority of dysplastic lesions identified in a surveillance program was detected in the rectosigmoid. Endoscopists should consider taking a greater percentage of biopsies in these segments as opposed to more proximal areas.

Field cancerization in the GI tract

The widely accepted paradigm for tumorigenesis begins with rate-limiting mutations in a key growth control gene resulting in immediate lesion growth. Tumor progression occurs as cells within the tumor acquire additional carcinogenic mutations. However, there is clear evidence that the road to cancer can begin long before the growth of a clinically detectable lesion - indeed, long before any of the usual morphological correlates of preneoplasia are recognizable. Field cancerization, the replacement of the normal cell population by a histologically nondysplastic but protumorigenic mutant cell clone, underlies the development of many cancer types, and in this article we review field cancerization in the GI tract. We present the evidence that field cancerization can underpin tumorigenesis in all gastrointestinal compartments, discuss the homeostatic mechanisms that could permit clone spread and highlight how an understanding of the mechanisms driving field cancerization is a means to study human stem cell biology. Finally, we discuss how appropriate recognition of the role of field cancerization in tumorigenesis could impact patient care.

Pathogenesis and biomarkers of carcinogenesis in ulcerative colitis

One of the most serious complications of ulcerative colitis is the development of colorectal cancer. Screening patients with ulcerative colitis by standard histological examination of random intestinal biopsy samples might be inefficient as a method of cancer surveillance. This Review focuses on the current understanding of the pathogenesis of ulcerative colitis-associated colorectal cancer and how this knowledge can be transferred into patient management to assist clinicians and pathologists in identifying patients with ulcerative colitis who have an increased risk of colorectal cancer. Inflammation-driven mechanisms of DNA damage, including the generation and effects of reactive oxygen species, microsatellite instability, telomere shortening and chromosomal instability, are reviewed, as are the molecular responses to genomic stress. We also discuss how these mechanisms can be translated into usable biomarkers. Although progress has been made in the understanding of inflammation-driven carcinogenesis, markers based on these findings possess insufficient sensitivity or specificity to be usable as reliable biomarkers for risk of colorectal cancer development in patients with ulcerative colitis. However, screening for mutations in p53 could be relevant in the surveillance of patients with ulcerative colitis. Several other new biomarkers, including senescence markers and α-methylacyl-CoA-racemase, might be future candidates for preneoplastic markers in ulcerative colitis.

Colitis-associated DNA aneuploidy and dysplasia in Crohn's disease and risk of colorectal cancer

BACKGROUND

There is uncertainty about how patients with Crohn's colitis should be monitored for colorectal cancer (CRC). By analogy to ulcerative colitis, regular colonoscopy with biopsies for dysplasia has been used. We describe the occurrence of dysplasia and DNA aneuploidy in a cohort of patients with Crohn's colitis.

METHODS

In all, 245 patients with extensive colitis (225 with a firm diagnosis of Crohn's disease, and 20 diagnosed as indeterminate colitis) at Stockholm Söder Hospital and Karolinska University Hospital, Huddinge were included. They were followed with regular colonoscopies with biopsies both for dysplasia and DNA aneuploidy. The cumulative occurrence of DNA aneuploidy and dysplasia was estimated using Kaplan-Meier curves. Time sequences and interactions between DNA aneuploidy, dysplasia, and CRC were studied using Cox regression analysis, adjusted for age, sex, and age at diagnosis.

RESULTS

During a median follow-up time of 9.2 person-years, DNA aneuploidy was found in 53 patients (22%), with 10 patients having multifocal aneuploidy and high S-phase values. Dysplasia was found in 42 patients (17%), 10 having multifocal dysplasia. Relative risk (RR) of dysplasia given DNA aneuploidy was 5.3 (95% confidence interval [CI] 2.3-12). RR of CRC given dysplasia was 10 (95% CI 2-50), and RR of CRC given aneuploidy was 1.5 (95% CI 0.3-9.3).

CONCLUSIONS

Dysplasia and DNA aneuploidy including S-phase analysis may complement stratification of patients with Crohn’s

Surveillance for colitis-associated colon neoplasia

The risk of developing colon cancer is increased in colitis patients, particularly if the disease is extensive and its duration long-standing. Endoscopic guidelines have been developed with the goal of detecting early neoplastic changes prior to development of advanced malignancy. Unfortunately, the natural history of this superimposed neoplastic process in colitis appears to be very heterogeneous and poorly understood. Moreover, there are numerous confounding variables in colitis patients that limit accurate assessment of the surveillance effectiveness of colonoscopy and multi-site biopsy protocols. Although the clinical challenge posed to even the most experienced clinicians remains significant, evolving methods of endoscopic imaging may facilitate better evaluation of this highly select group of patients.

Colorectal dysplasia in chronic inflammatory bowel disease: pathology, clinical implications, and pathogenesis

CONTEXT

Colorectal cancer, the most lethal long-term complication of chronic inflammatory bowel disease (IBD), is the culmination of a complex sequence of molecular and histologic derangements of the intestinal epithelium that are initiated and at least partially sustained by chronic inflammation. Dysplasia, the earliest histologic manifestation of this process, plays an important role in cancer prevention by providing the first clinical alert that this sequence is underway and serving as an endpoint in colonoscopic surveillance of patients at high risk for colorectal cancer.

OBJECTIVE

To review the histology, nomenclature, clinical implications, and molecular pathogenesis of dysplasia in IBD.

DATA SOURCE

Literature review and illustrations from case material.

CONCLUSIONS

The diagnosis and grading of dysplasia in endoscopic surveillance biopsies play a decisive role in the management of patients with IBD. Although interpathologist variation, endoscopic sampling problems, and incomplete information regarding the natural history of dysplastic lesions are important limiting factors, indirect evidence that surveillance may be an effective means of reducing cancer-related mortality in the population with IBD has helped validate the histologic criteria, nomenclature, and clinical recommendations that are the basis of current practice among pathologists and clinicians. Emerging technologic advances in endoscopy may permit more effective surveillance, but ultimately the greatest promise for cancer prevention in IBD lies in expanding our thus far limited understanding of the molecular pathogenetic relationships between neoplasia and chronic inflammation.

Ulcerative colitis practice guidelines in adults: American College Of Gastroenterology, Practice Parameters Committee

Guidelines for clinical practice are aimed to indicate preferred approaches to medical problems as established by scientifically valid research. Double-blind placebo controlled studies are preferable, but compassionate-use reports and expert review articles are used in a thorough review of the literature conducted through Medline with the National Library of Medicine. When only data that will not withstand objective scrutiny are available, a recommendation is identified as a consensus of experts. Guidelines are applicable to all physicians who address the subject regardless of specialty training or interests and are aimed to indicate the preferable but not necessarily the only acceptable approach to a specific problem. Guidelines are intended to be flexible and must be distinguished from standards of care, which are inflexible and rarely violated. Given the wide range of specifics in any health-care problem, the physician must always choose the course best suited to the individual patient and the variables in existence at the moment of decision. Guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee and approved by the board of trustees. Each has been intensely reviewed and revised by the Committee, other experts in the field, physicians who will use them, and specialists in the science of decision analysis. The recommendations of each guideline are therefore considered valid at the time of composition based on the data available. New developments in medical research and practice pertinent to each guideline will be reviewed at a time established and indicated at publication to assure continued validity. The recommendations made are based on the level of evidence found. Grade A recommendations imply that there is consistent level 1 evidence (randomized controlled trials), grade B indicates that the evidence would be level 2 or 3, which are cohort studies or case-control studies. Grade C recommendations are based on level 4 studies, meaning case series or poor-quality cohort studies, and grade D recommendations are based on level 5 evidence, meaning expert opinion.

Endoscopic and pathological aspects of colitis-associated dysplasia

The risk of developing colorectal cancer in patients with colitis-associated dysplasia is considerable. Surveillance programs in patients with ulcerative colitis and Crohn's disease aim to detect dysplastic lesions early and rely heavily on taking random biopsy samples along the length of the colon. Diagnosing dysplasia can be difficult because of the heterogeneous endoscopic appearance of dysplasia and the poor interobserver agreement among pathologists when grading dysplasia. Colitis-associated dysplasia may present as a dysplasia-associated lesion or mass (DALM), which may be indistinguishable from a sporadic adenoma in non-colitic tissue, or may arise in flat mucosa of endoscopically normal appearance. Information about the endoscopic appearance, the colonic distribution and the histopathological grade of colitis-associated dysplasia is required to define the optimal treatment. This Review summarizes the endoscopic and histopathological features of colitis-associated dysplasia and the requirements for optimal interaction between endoscopists and pathologists, with the aim of reducing the uncertainties in the diagnosis of dysplastic lesions and improving the management of colitis-associated dysplasia.

Adherence to surveillance guidelines for dysplasia and colorectal carcinoma in ulcerative and Crohn's colitis patients in the Netherlands

AIM

To study adherence to the widely accepted surveillance guidelines for patients with long-standing colitis in The Netherlands.

METHODS

A questionnaire was sent to all 244 gastroenterologists in The Netherlands.

RESULTS

The response rate was 63%. Of all gastroenterologists, 95% performed endoscopic surveillance in ulcerative colitis (UC) patients and 65% in patients with Crohn's colitis. The American Gastroenterological Association (AGA) guidelines were followed by 27%, while 27% and 46% followed their local hospital protocol or no specific protocol, respectively. The surveillance was correctly initiated in cases of pancolitis by 53%, and in cases of left-sided colitis by 44% of the gastroenterologists. Although guidelines recommend 4 biopsies every 10 cm, less than 30 biopsies per colonoscopy were taken by 73% of the responders. Only 31%, 68% and 58% of the gastroenterologists referred patients for colectomy when low-grade dysplasia, high-grade dysplasia (HGD) or Dysplasia Associated Lesion or Mass (DALM) was present, respectively.

CONCLUSION

Most Dutch gastroenterologists perform endoscopic surveillance without following international recommended guidelines. This practice potentially leads to a decreased sensitivity for dysplasia, rendering screening for colorectal cancer in this population highly ineffective.