Colorectal cancer complicating ulcerative colitis: a review

Considerations for Colorectal Neoplasia Detection in Inflammatory Bowel Disease Clinical Trials

BACKGROUND

High-quality colonoscopic surveillance can lead to earlier and increased detection of colorectal neoplasia in patients with inflammatory bowel disease (IBD). In IBD clinical trials, endoscopy is used to assess mucosal disease activity before and after treatment but also provides an opportunity to surveil for colorectal neoplasia during follow-up.

SUMMARY

Best practices for colorectal cancer identification in IBD clinical trials require engagement and collaboration between the clinical trial sponsor, site endoscopist and/or principal investigator, and central read team. Each team member has unique responsibilities for maximizing dysplasia detection in IBD trials.

KEY MESSAGES

Sponsors should work in accordance with scientific guidelines to standardize imaging procedures, design the protocol to ensure the trial population is safeguarded, and oversee trial conduct. The site endoscopist should remain updated on best practices to tailor sponsor protocol-required procedures to patient needs, examine the mucosa for disease activity and potential dysplasia during all procedures, and provide optimal procedure videos for central read analysis. Central readers may detect dysplasia or colorectal cancer and a framework to report these findings to trial sponsors is essential. Synergistic relationships between all team members in IBD clinical trials provide an important opportunity for extended endoscopic evaluation and colorectal neoplasia identification.

Identification of Immune-Related Gene Signature and Prediction of CeRNA Network in Active Ulcerative Colitis

Background

Ulcerative colitis (UC) is an inflammatory disease of the intestinal mucosa, and its incidence is steadily increasing worldwide. Intestinal immune dysfunction has been identified as a central event in UC pathogenesis. However, the underlying mechanisms that regulate dysfunctional immune cells and inflammatory phenotype remain to be fully elucidated.

Methods

Transcriptome profiling of intestinal mucosa biopsies were downloaded from the GEO database. Robust Rank Aggregation (RRA) analysis was performed to identify statistically changed genes and differentially expressed genes (DEGs). Gene Set Enrichment Analysis (GSEA), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to explore potential biological mechanisms. CIBERSORT was used to evaluate the proportion of 22 immune cells in biopsies. Weighted co-expression network analysis (WGCNA) was used to determine key module-related clinical traits. Protein-Protein Interaction (PPI) network and Cytoscape were performed to explore protein interaction network and screen hub genes. We used a validation cohort and colitis mouse model to validate hub genes. Several online websites were used to predict competing endogenous RNA (ceRNA) network.

Results

RRA integrated analysis revealed 1838 statistically changed genes from four training cohorts (adj. p-value < 0.05). GSEA showed that statistically changed genes were enriched in the innate immune system. CIBERSORT analysis uncovered an increase in activated dendritic cells (DCs) and M1 macrophages. The red module of WGCNA was considered the most critical module related to active UC. Based on the results of the PPI network and Cytoscape analyses, we identified six critical genes and transcription factor NF-κB. RT-PCR revealed that andrographolide (AGP) significantly inhibited the expression of hub genes. Finally, we identified XIST and three miRNAs (miR-9-5p, miR-129-5p, and miR-340-5p) as therapeutic targets.

Conclusions

Our integrated analysis identified four hub genes (CXCL1, IL1B, MMP1, and MMP10) regulated by NF-κB. We further revealed that AGP decreased the expression of hub genes by inhibiting NF-κB activation. Lastly, we predicted the involvement of ceRNA network in the regulation of NF-κB expression. Collectively, our results provide valuable information in understanding the molecular mechanisms of active UC. Furthermore, we predict the use of AGP and small RNA combination for the treatment of UC.

Evidence-based clinical practice guidelines for inflammatory bowel disease 2020

Inflammatory bowel disease (IBD) is a general term for chronic or remitting/relapsing inflammatory diseases of the intestinal tract and generally refers to ulcerative colitis (UC) and Crohn's disease (CD). Since 1950, the number of patients with IBD in Japan has been increasing. The etiology of IBD remains unclear; however, recent research data indicate that the pathophysiology of IBD involves abnormalities in disease susceptibility genes, environmental factors and intestinal bacteria. The elucidation of the mechanism of IBD has facilitated therapeutic development. UC and CD display heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management depends on the understanding and tailoring of evidence-based interventions by physicians. In 2020, seventeen IBD experts of the Japanese Society of Gastroenterology revised the previous guidelines for IBD management published in 2016. This English version was produced and modified based on the existing updated guidelines in Japanese. The Clinical Questions (CQs) of the previous guidelines were completely revised and categorized as follows: Background Questions (BQs), CQs, and Future Research Questions (FRQs). The guideline was composed of a total of 69 questions: 39 BQs, 15 CQs, and 15 FRQs. The overall quality of the evidence for each CQ was determined by assessing it with reference to the Grading of Recommendations Assessment, Development and Evaluation approach, and the strength of the recommendation was determined by the Delphi consensus process. Comprehensive up-to-date guidance for on-site physicians is provided regarding indications for proceeding with the diagnosis and treatment.

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.

Family History Associates With Increased Risk of Colorectal Cancer in Patients With Inflammatory Bowel Diseases

BACKGROUND & AIMS

Individuals with inflammatory bowel diseases (IBDs) have an increased risk of developing colorectal cancer (CRC). Although family history of CRC is a well-established risk factor in healthy individuals, its role in patients with IBD is less clear. We aimed to estimate the risk of CRC in a cohort of patients with IBD from Utah and the significance of family history of CRC in a first-degree relative (FDR).

METHODS

We identified Utah residents with IBD, using the Intermountain Healthcare and University of Utah Health Sciences databases, from January 1, 1996, through December 31, 2011. CRCs were identified using the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. CRC incidence was compared with that of the state population by standardized incidence ratios (SIRs).

RESULTS

A cohort of 9505 individuals with IBD was identified and 101 developed CRC during the study period. The SIR for CRC in patients with Crohn's disease was 3.4 (95% CI, 2.3-4.4), and in patients with ulcerative colitis was 5.2 (95% CI, 3.9-6.6). Patients with IBD and a concurrent diagnosis of primary sclerosing cholangitis had the greatest risk of CRC (SIR, 14.8; 95% CI, 8.3-21.2). A history of CRC in a FDR was associated with a nearly 8-fold increase in risk of CRC in patients with IBD (SIR, 7.9; 95% CI, 1.6-14.3), compared with the state population.

CONCLUSIONS

Patients with IBD have a 3- to 5-fold increase in risk of CRC, and those with CRC in a FDR have an almost 8-fold increase in risk. Family history may act as a simple measure to identify individuals with IBD at highest risk for CRC and indicates the need for enhanced surveillance in this population.

Medical and Surgical Management of Pediatric Ulcerative Colitis

Inflammatory bowel disease (IBD) describes a spectrum of idiopathic, lifelong, and progressive intestinal inflammatory conditions that includes Crohn's disease, ulcerative colitis, and indeterminate colitis. A worldwide increase in the incidence of IBD has been observed. In comparison to adults, IBD occurring during childhood and adolescence has several unique clinical characteristics and surgical management issues. In this article, we provide an overview contrasting these important differences.

Colorectal Malignancy in a Prospective Irish Inflammatory Bowel Disease Population 15 Years Since Diagnosis: Comparison with the EC-IBD Cohort

BACKGROUND AND AIM

As part of the EC-IBD prospective inception cohort study, we had unique opportunity to follow up our patients since diagnosis in the early 1990s.

PATIENTS AND METHODS

All patients from the greater Dublin area (n = 192) were followed up from inception between 1991 and 1993 until the 30 September 2009. Patients who developed malignancies were logged electronically with verification of the site and histology.

RESULTS

Of the initial 192 patients, 133 were included in the 15-year follow-up. Of those, 80 (60.2%) had UC and 53 (39.8%) had CD. There were 82 (61.7%) males and 51 (38.3%) females. Six patients had extraintestinal malignancy; however, there was no CRC related to IBD noted in our cohort. Four of the 6 identified cases had UC (64%) with a mean age of 54.25 years at the time of cancer diagnosis, whereas the two CD patients had a mean age of 51.5 years at the time of cancer diagnosis.

CONCLUSION

CRC was not observed in our cohort. The six extraintestinal malignancies did not show significant relation to IBD. The high total colectomy rate (in the prebiological therapy era) may have contributed to low malignancy rate.

Colorectal Cancer in Inflammatory Bowel Diseases: A Population-Based Study in Utah

BACKGROUND AND AIMS

The molecular, endoscopic, and histological features of IBD-associated CRC differ from sporadic CRC. The objective of this study was to describe the prevalence, clinical features, and prognosis of IBD-associated CRC compared to patients with sporadic CRC in a US statewide population-based cohort.

METHODS

All newly diagnosed cases of CRC between 1996 and 2011 were obtained from Utah Cancer Registry. IBD was identified using a previously validated algorithm, from statewide databases of Intermountain Healthcare, University of Utah Health Sciences, and the Utah Population Database. Logistic regression was performed to identify risk factors associated with IBD-associated cancer and Cox regression for differences in survival.

RESULTS

Among 12,578 patients diagnosed with CRC, 101 (0.8%) had a prior history of IBD (61 ulcerative colitis and 40 Crohn's disease). The mean age at CRC diagnosis was greater for patients without IBD than those with IBD (67.1 vs 52.8 years, P < 0.001). Individuals with IBD-associated CRC were more likely to be men (odds ratio [OR] 1.90, 95% CI 1.23-2.92), aged less than 65 years (OR 6.77, 95% CI 4.06-11.27), and have CRC located in the proximal colon (OR 2.79, 95% CI 1.85-4.20) than those with sporadic CRC. Nearly 20% of the IBD-associated CRCs had evidence of primary sclerosing cholangitis. After adjustment for age, gender, and stage at diagnosis, the excess hazard of death after CRC diagnosis was 1.7 times higher in IBD than in non-IBD patients (95% CI 1.27-2.33).

CONCLUSIONS

The features of patients with CRC and IBD differ significantly from those without IBD and may be associated with increased mortality.

Caerulein-induced pancreatitis augments the expression and phosphorylation of collapsin response mediator protein 4

BACKGROUND

Chronic pancreatitis is a significant risk factor for pancreatic cancer. Previously, we demonstrated that the pancreatic cancer cells show enhanced expression of collapsin response mediator protein 4 (CRMP4) that strongly correlates with severe venous invasion, liver metastasis, and poor prognosis. However, involvement of CRMP4 in acute or chronic pancreatitis remains unknown.

METHODS

Acute and chronic pancreatitis mice models were developed by periodic injection of caerulein. The expression levels of CRMP4 and its phosphorylation were examined.

RESULTS

Elevated CRMP4 levels were observed in the infiltrated lymphocytes as well as in the pancreas parenchyma of both acute and chronic pancreatitis. The expression pattern of phosphorylated CRMP4 was similar to that of CRMP4. Cdk5 partially co-localized with the phosphorylated CRMP4.

CONCLUSIONS

Pancreatitis induces CRMP4 expression in the pancreas parenchyma and in the infiltrated lymphocytes. Overlapping expression of CRMP4 and Cdk5 may suggest that the Cdk5 is at least, in part, responsible for the phosphorylation of CRMP4. The results suggest that CRMP4 is involved in the inflammatory response in pancreatitis. Understanding the mechanisms of CRMP4 would help us to develop novel therapeutic strategies against acute or chronic pancreatitis, and pancreatic cancer.

Chronic subordinate colony housing paradigm: a mouse model to characterize the consequences of insufficient glucocorticoid signaling

Chronic, in particular chronic psychosocial, stress is a burden of modern societies and known to be a risk factor for numerous somatic and affective disorders (in detail referenced below). However, based on the limited existence of appropriate, and clinically relevant, animal models for studying the effects of chronic stress, the detailed behavioral, physiological, neuronal, and immunological mechanisms linking stress and such disorders are insufficiently understood. To date, most chronic stress studies in animals employ intermittent exposure to the same (homotypic) or to different (heterotypic) stressors of varying duration and intensity. Such models are only of limited value, since they do not adequately reflect the chronic and continuous situation that humans typically experience. Furthermore, application of different physical or psychological stimuli renders comparisons to the mainly psychosocial stressors faced by humans, as well as between the different stress studies almost impossible. In contrast, rodent models of chronic psychosocial stress represent situations more akin to those faced by humans and consequently seem to hold more clinical relevance. Our laboratory has developed a model in which mice are exposed to social stress for 19 continuous days, namely the chronic subordinate colony housing (CSC) paradigm, to help bridge this gap. The main aim of the current review article is to provide a detailed summary of the behavioral, physiological, neuronal, and immunological consequences of the CSC paradigm, and wherever possible relate the findings to other stress models and to the human situation.

Chromoendoscopy for colorectal cancer surveillance in patients with inflammatory bowel disease

Chromoendoscopy utilizes colorimetric techniques to increase detection of lesions that are difficult to see or cannot be seen with conventional white light endoscopy. Multiple studies have demonstrated that chromoendoscopy with dye spraying significantly increases the detection of dysplastic lesions in patients with chronic inflammatory bowel disease (IBD) of the colon undergoing colonoscopy. Furthermore, chromoendoscopy may obviate the need for random biopsies and pending additional studies and may allow increased intervals between surveillance exams, reducing costs while increasing the sensitivity for detection of dysplasia per exam. Despite convincing data supporting the use of chromoendoscopy for IBD colonic surveillance, it is seldom utilized outside of academic centers. Here, we review the current approach to colorectal cancer surveillance in IBD focusing on the data supporting the use of chromoendoscopy including its use in a community setting and offer practical recommendations for incorporating chromoendoscopy as a routine part of surveillance in IBD regardless of practice setting.

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.

Colon capsule endoscopy is a safe and useful tool to assess disease parameters in patients with ulcerative colitis

OBJECTIVE

Colon capsule endoscopy (CCE) is a new endoscopic technique that is minimally invasive and allows evaluation of the colon mucosa without pain, sedation, and gas insufflation. To date, few studies have investigated the use of CCE in patients with ulcerative colitis (UC). This study compares the ability of CCE and a conventional colonoscopy to assess mucosal disease activity and the extent of inflammatory mucosa in patients with UC.

METHODS

Forty-two patients (27 men, mean age 48.5 years) with known UC and indication for colonoscopy were enrolled in this single-blind, prospective study. All patients underwent CCE, followed by a colonoscopy. The activity and extent of the disease was assessed using Mayo scores and Montreal scores, respectively.

RESULTS

There was a good correlation between CCE and colonoscopy in disease severity (κ=0.79; 95% confidence interval: 0.62-0.96) and extent of inflammation (κ=0.71; 95% confidence interval: 0.52-0.90) observed. The ability of CCE to assess a broad segment of distal ileum led to a change in the diagnosis of UC to ileocolonic Crohn's disease in three patients. Bowel preparation was considered adequate in 80% of the patients and no serious adverse events related to the CCE procedure or bowel preparation were reported.

CONCLUSION

CCE is a safe and useful method for the evaluation of patients with UC. The ability of CCE to assess distal ileum provides an advantage to colonoscopy as CCE can identify patients who have been incorrectly diagnosed with UC, resulting in a change in their diagnosis to Crohn's disease.

Disparity expression of Notch1 in benign and malignant colorectal diseases

BACKGROUND AND OBJECTIVES

Although there was growing evidence supporting the hypothesis that Notch1 was one of the few candidate genes linked with colorectal cancer (CRC) susceptibility, the precise level of Notch1 protein expression in benign and malignant colorectal diseases was still unknown. Our study has investigated the Notch1 expression in benign and malignant colorectal diseases as well as to investigate the role and clinicopathological significance of aberrant expression of Notch1 in CRC.

METHODS

The protein expression of Notch1 was examined by immunohistochemistry in 901 clinical specimens with colorectal diseases, including 220 patients with ulcerative colitis, 232 patients with colorectal adenoma and 449 patients with colorectal cancer. Associations between the expression of Notch1 and various clinicopathological features, as well as survival status, were studied.

RESULTS

Cytoplasmic Notch1 was expressed in 7.7% of patients with ulcerative colitis, 14.7% of patients with colorectal adenoma and 58.0% of patients with colorectal cancer, respectively. Colorectal cancer patients with high expression levels of Notch1 showed lower overall survival (OS) and disease-free survival (DFS) rates than those patients with low Notch1 expression.

CONCLUSIONS

Expression level of Notch1 was gradually increased from precancerous lesions to cancer. It might play as an oncogene in the CRC development, and might be potentially used as a biomarker for prognosis of CRCs.

Mutant N-RAS protects colorectal cancer cells from stress-induced apoptosis and contributes to cancer development and progression

N-RAS is one member of a family of oncoproteins that are commonly mutated in cancer. Activating mutations in NRAS occur in a subset of colorectal cancers, but little is known about how the mutant protein contributes to the onset and progression of the disease. Using genetically engineered mice, we find that mutant N-RAS strongly promotes tumorigenesis in the context of inflammation. The protumorigenic nature of mutant N-RAS is related to its antiapoptotic function, which is mediated by activation of a noncanonical mitogen-activated protein kinase pathway that signals through STAT3. As a result, inhibition of MAP-ERK kinase selectively induces apoptosis in autochthonous colonic tumors expressing mutant N-RAS. The translational significance of this finding is highlighted by our observation that NRAS mutation correlates with a less favorable clinical outcome for patients with colorectal cancer. These data show for the first time the important role that N-RAS plays in colorectal cancer.

Chronic psychosocial stress increases the risk for inflammation-related colon carcinogenesis in male mice

Patients with inflammatory bowel diseases (IBDs) have a higher risk of developing colorectal cancer (CRC) than the general population. Furthermore, chronic psychosocial stress increases the likelihood of developing IBD and multiple types of malignant neoplasms, including CRC. Here, for the first time, we investigate the effects of chronic psychosocial stress in male mice on an artificially induced CRC, by employing the chronic subordinate colony (CSC) housing paradigm in combination with the reliable azoxymethane (AOM)/dextran sodium sulfate (DSS) CRC model. Colonoscopy revealed that CSC mice showed accelerated macroscopic suspect lesions. In addition, more CSC mice developed low-grade dysplasia (LGD) and/or high-grade dysplasia (HGD) in the colonic tissue compared to the single-housed control mice (SHC). CSC mice showed an increased number of Ki67+ and a decreased number of terminal deoxynucleotidyl transferase dUTP nick end labeling epithelial cells in colonic tissue. Colonic liver receptor homolog-1 (LRH-1), cyclooxygenase II (COXII), tumor necrosis factor, forkhead box P3 (FoxP3) mRNA as well as colonic ß-catenin, COXII, and LRH-1 protein expression were also increased in CSC compared with SHC mice. Although the number of CD4+ Th cells was increased, a tendency toward a decreased colonic interferon-γ (IFN-γ) mRNA expression was observed. Furthermore, despite an increased percentage of CD3+ cells and CD3+/FoxP3+ double-positive cells within mesenteric lymph node cells of CSC mice, IFN-γ secretion from these cells was unaffected. Altogether, our results suggest that chronic psychosocial stress increases the risk for AOM/DSS-induced and, thus, inflammation-related CRC. Finally, assessment of additional time points may test whether the shift from tumor-protective Th1 cell to regulatory T-cell immunity represents a consequence of increased carcinogenesis or a causal factor involved in its development.

Blueberry husks and probiotics attenuate colorectal inflammation and oncogenesis, and liver injuries in rats exposed to cycling DSS-treatment

Long-term colonic inflammation promotes carcinogenesis and histological abnormalities of the liver, and colorectal tumours frequently arise in a background of dysplasia, a precursor of adenomas. Altered colonic microbiota with an increased proportion of bacteria with pro-inflammatory characteristics, have been implicated in neoplastic progression. The composition of the microbiota can be modified by dietary components such as probiotics, polyphenols and dietary fibres. In the present study, the influence of probiotics in combination with blueberry husks on colorectal carcinogenesis and subsequent liver damage was evaluated.

Colorectal tumours were induced in rats by cyclic treatment with dextran sulphate sodium (DSS). Blueberry husks and a mixture of three probiotic strains (Bifidobacterium infantis DSM 15159, Lactobacillus gasseri, DSM 16737 and Lactobacillus plantarum DSM 15313) supplemented a basic diet fortified with oats. The condition of the rats was monitored using a disease activity index (DAI). A qualitative and quantitative histological judgement was performed on segments of distal colon and rectum and the caudate lobe of the liver. The formation of short-chain fatty acids, bacterial translocation, the inflammatory reaction and viable count of lactobacilli and Enterobaceriaceae were addressed.

Blueberry husks with or without probiotics significantly decreased DAI, and significantly reduced the number of colonic ulcers and dysplastic lesions. With a decreased proportion of blueberry husk in the diet, the probiotic supplement was needed to achieve a significant decrease in numbers of dysplastic lesions. Probiotics decreased faecal viable count of Enterobacteriaceae and increased that of lactobacilli. Blueberry husks with or without probiotics lowered the proportion of butyric acid in distal colon, and decreased the haptoglobin levels. Probiotics mitigated hepatic injuries by decreasing parenchymal infiltration and the incidence of stasis and translocation. The results demonstrate a dietary option for use of blueberry husks and probiotics to delay colonic carcinogenesis and hepatic injuries in the rat model.

Increased risk of colorectal cancer and dysplasia in patients with Crohn's colitis and primary sclerosing cholangitis

BACKGROUND

Almost 10% of all patients with primary sclerosing cholangitis receive a diagnosis of Crohn's disease. Clinical characteristics and the risk of colon cancer or dysplasia in Crohn's disease and primary sclerosing cholangitis are less well examined than in ulcerative colitis.

OBJECTIVE

This study aimed to describe the clinical characteristics and risk of colorectal dysplasia and cancer in Crohn's disease in patients with primary sclerosing cholangitis.

DESIGN

This is a cohort study of all patients diagnosed with primary sclerosing cholangitis and colorectal Crohn's disease at Karolinska University Hospital, Huddinge, 1978 to 2006. Each patient was matched for age and the onset of Crohn's disease to 2 controls with colorectal Crohn's disease without liver disease.

SETTING

This study was conducted at a tertiary referral center.

PATIENTS

Twenty-eight patients (61% male) with primary sclerosing cholangitis and Crohn's disease and 46 patients (50% male) with Crohn's disease alone were studied. Clinical and endoscopic data were retrieved from medical records. Colonic biopsies from patients with primary sclerosing cholangitis were re-reviewed.

MAIN OUTCOME MEASURES

The primary outcome measured was the proportion of patients developing colorectal cancer.

RESULTS

Colorectal cancer or dysplasia developed in 9 patients with primary sclerosing cholangitis and in 3 controls. Patients with primary sclerosing cholangitis were more likely to develop colorectal dysplasia or cancer than controls (OR 6.78; 95% CI (1.65-27.9); P = .016). In patients with primary sclerosing cholangitis compared with controls, perianal fistulas occurred in 3% vs 33% (P = .003), bowel strictures occurred in 7% vs 30% (P = .03), and bowel surgery was performed in 18% vs 46% (P = .01). Histological granulomas were seen in 29% of the patients with primary sclerosing cholangitis compared with 43% in controls (P = not significant).

LIMITATIONS

This study was limited by its retrospective nature and the limited cohort.

CONCLUSIONS

Primary sclerosing cholangitis is a risk factor for the development of colorectal cancer and dysplasia in Crohn's disease. Obstructing disease and perianal fistulas are rare in primary sclerosing cholangitis and less common than in colonic Crohn's disease without liver disease.

Tumor development in murine ulcerative colitis depends on MyD88 signaling of colonic F4/80+CD11b(high)Gr1(low) macrophages

Patients with prolonged ulcerative colitis (UC) frequently develop colorectal adenocarcinoma for reasons that are not fully clear. To analyze inflammation-associated colonic tumorigenesis, we developed a chronic form of oxazolone-induced colitis in mice that, similar to UC, was distinguished by the presence of IL-13-producing NKT cells. In this model, the induction of tumors using azoxymethane was accompanied by the coappearance of F4/80+CD11b(high)Gr1(low) M2 macrophages, cells that undergo polarization by IL-13 and are absent in tumors that lack high level IL-13 production. Importantly, this subset of macrophages was a source of tumor-promoting factors, including IL-6. Similar to dextran sodium sulfate-induced colitis, F4/80+CD11b(high)Gr1(intermediate) macrophages were present in the mouse model of chronic oxazolone-induced colitis and may influence tumor development through production of TGF-β1, a cytokine that inhibits tumor immunosurveillance. Finally, while robust chronic oxazolone-induced colitis developed in myeloid differentiation primary response gene 88-deficient (Myd88-/-) mice, these mice did not support tumor development. The inhibition of tumor development in Myd88-/- mice correlated with cessation of IL-6 and TGF-β1 production by M2 and F4/80+CD11b(high)Gr1(intermediate) macrophages, respectively, and was reversed by exogenous IL-6. These data show that an UC-like inflammation may facilitate tumor development by providing a milieu favoring development of MyD88-dependent tumor-supporting macrophages.

Dysplastic lesions in ulcerative colitis: changing paradigms

Crohn and Rosenberg first highlighted the increased risk of colorectal cancer in ulcerative colitis in 1925. Cancer rates as high as 34 percent after 30 yrs of disease have been reported in several population-based studies, although the reported risk varies substantially. Lower rates have been reported in: population-versus specialist centre-cohorts, local practices with a high colectomy rate and high 5-aminosalicylate usage, and more recent as opposed to older reports. Despite this variation in reported risk, and lack of controlled evidence for cancer reduction, colonoscopic surveillance programmes are a routine part of care in many centres. Cancer is believed to arise most commonly in dysplastic epithelium, and the detection of either dysplasia or early cancer forms the basis of such programmes. Further confusion stems from the variety of terms used to describe dysplastic change.

Inflammatory bowel disease in children: current trends

Once considered rare in the East, inflammatory bowel disease (IBD) is now recognized to be an emerging entity in that region. East or West, the clinical features of and treatment options for IBD are the same, but it is possible that the exact pathogeneses or the initiating events differ. In this review, existing knowledge of IBD and new discoveries in the epidemiology, genetics and treatment of IBD are discussed in detail. The diagnosis and management of IBD in children has changed dramatically over the last decade, mainly due to increased awareness, the availability of newer diagnostic modalities such as MRI and video capsule endoscopy, and newer, more powerful treatments such as biologics. It is hoped that the combination of innovative research and advances in drug discoveries will change the natural history of IBD and make a major difference in children who are suffering from this unfortunate lifelong chronic inflammatory disorder.

Analysis of mutations in TP53, APC, K-ras, and DCC genes in the non-dysplastic mucosa of patients with inflammatory bowel disease

BACKGROUND AND AIMS

Patients with ulcerative colitis (UC) and Crohn's disease (CD) have a high risk for colorectal cancer (CRC). To understand the molecular basis of colitis-associated CRC, we analyzed alterations in TP53, APC, K-ras, and DCC genes in the non-dysplastic UC and CD colon.

MATERIALS AND METHODS

Endoscopic biopsies were collected from six predefined colon sites of 35 UC and 12 CD patients for DNA extraction and genetic analysis.

RESULTS

A mutation was found in codon 1141 of the APC gene of two CD patients, being somatic in one and germinative in the other. The mutation seen in both patients was a base exchange of thymine for cytosine, resulting in an exchange of leucine for serine. We did not detect any mutations in the other samples analyzed.

CONCLUSIONS

Mutations in APC gene may occur in the non-dysplastic CD mucosa of patients with disease for more than 10 years. The follow-up of these patients will show the likelihood of mutant APC progressing to CRC in CD. Further analysis will be required for evaluating the impact of these findings in the context of cancer surveillance in inflammatory bowel disease.

RAS mutations affect tumor necrosis factor-induced apoptosis in colon carcinoma cells via ERK-modulatory negative and positive feedback circuits along with non-ERK pathway effects

More than 40% of colon cancers have a mutation in K-RAS or N-RAS, GTPases that operate as central hubs for multiple key signaling pathways within the cell. Utilizing an isogenic panel of colon carcinoma cells with K-RAS or N-RAS variations, we observed differences in tumor necrosis factor-alpha (TNFalpha)-induced apoptosis. When the dynamics of phosphorylated ERK response to TNFalpha were examined, K-RAS mutant cells showed lower activation whereas N-RAS mutant cells exhibited prolonged duration. These divergent trends were partially explained by differential induction of two ERK-modulatory circuits: negative feedback mediated by dual-specificity phosphatase 5 and positive feedback by autocrine transforming growth factor-alpha. Moreover, in the various RAS mutant colon carcinoma lines, the transforming growth factor-alpha autocrine loop differentially elicited a further downstream chemokine (CXCL1/CXCL8) autocrine loop, with the two loops having opposite effects on apoptosis. Although the apoptotic responses of the RAS mutant panel to TNFalpha treatment showed significant dependence on the respective phosphorylated ERK dynamics, successful prediction across the various cell lines required contextual information concerning additional pathways including IKK and p38. A quantitative computational model based on weighted linear combinations of these pathway activities successfully predicted not only the spectrum of cell death responses but also the corresponding chemokine production responses. Our findings indicate that diverse RAS mutations yield differential cell behavioral responses to inflammatory cytokine exposure by means of (a) differential effects on ERK activity via multiple feedback circuit mechanisms, and (b) differential effects on other key signaling pathways contextually modulating ERK-related dependence.

[Chromoendoscopy in inflammatory bowel disease]

The risk of colorectal cancer in case of IBD-related pancolitis reaches 2% after 10 years follow-up, 8% after 20 years up to 18% at 30 years, and was probably over-estimated in the first series. Chromoendoscopy appears to be helpful in the surveillance of IBD, and moreover recommended, using carmine indigo or methylene blue with a well-standardized procedure. Its place regarding other techniques like virtual coloration has to be clarified with randomized studies. The chromoendoscopy allows the operator to perform targeted biopsies, which appear to be more efficient for the detection of dysplasia than systematic biopsies performed every 10 cm. Nevertheless, it is too soon to remove systematic biopsies from scientific recommendations.

Colorectal carcinoma in indeterminate colitis

BACKGROUND

For all the interest in the natural history of colorectal cancer (CRC) in ulcerative colitis (UC) and Crohn's disease (CD), surprisingly few data have been published regarding CRC in indeterminate colitis (IC). We present our experience with 15 cases of IC-associated CRC in order to assess their clinicopathological features and to determine their survival rates.

METHODS

We retrospectively reviewed the medical records of patients with IC admitted to the Mount Sinai Hospital between 1994 and 2007 and who developed CRC. All patients were operated on and follow-up was complete for all patients to the closing date of study or to the time of death.

RESULTS

A total of 19 adenocarcinomas were present in this series. There were 3 patients with multiple cancers; all cancers occurred in segments of colitis. The mean age at onset of IC was 28 years and the average time progression from the IC diagnosis to CRC was 19 years. Dysplasia was detected in 10 of the cases; 3 patients had mucinous tumors. Five patients had stage I tumors; 5 stage II; 4 stage III; 1 stage IV. There were 4 deaths due to CRC. The overall 5-year survival was 42%.

CONCLUSIONS

CRC in IC shares most of the clinical and pathologic features as well as survival outcomes with CRC that occurs in the most prevalent forms of inflammatory bowel disease (IBD), UC and CD. Surveillance regimens currently used in the other forms of IBD seem applicable to IC patients as well.

Inducible heat shock protein 70 prevents multifocal flat dysplastic lesions and invasive tumors in an inflammatory model of colon cancer

BACKGROUND

Heat shock protein 70 (Hsp70) regulates protein biosynthesis and refolding of denatured proteins. Since Hsp70 participates in recovery from stress injury, we examined the effect of Hsp70 genetic deletion in the azoxymethane (AOM)/dextran sulfate sodium (DSS) model of inflammation and colon cancer.

METHODS

Hsp70 mutant mice (Hsp70.1(-/-)/70.3(-/-)) and wild-type (WT) littermates received AOM and three cycles of DSS and were killed 24 weeks later. Tumors were graded for histology and immunostained for p53, adenomatous polyposis coli, beta-catenin, cyclooxygenase-2 (Cox-2) and inducible nitric oxide synthase (iNOS) and sequenced for p53 mutations.

RESULTS

Elevated adenomas developed in 4/10 WT mice with no dysplasia in adjacent mucosa. In contrast, 7/8 Hsp70 knock out (KO) mice developed chronic mucosal inflammation and multifocal areas of flat dysplasia and 4/8 progressed to invasive carcinomas arising in a background of flat dysplastic mucosa. These differences in the incidence of flat dysplasia and invasive cancers were significant (P < 0.05). Nuclear p53 was stronger in Hsp70 KO tumors compared with WT tumors, and sequencing confirmed p53 mutations in 2/5 tumors from Hsp70(-/-) versus 0/5 in WT mice. In Hsp70 WT tumors, beta-catenin was predominantly nuclear, compared with membranous beta-catenin in Hsp70(-/-) tumors, suggesting that Hsp70 regulates beta-catenin in colonic tumorigenesis. Cox-2 and iNOS levels were increased in tumors from Hsp70(-/-) mice compared with Hsp70 WT tumors.

CONCLUSIONS

Hsp70-deleted mice treated with AOM/DSS develop flat invasive colonic tumors that mimic many histological and molecular features of ulcerative colitis colon cancer. This model will be useful to dissect the role of Hsp70 in inflammatory bowel disease colon cancer.

Endoscopic resection of adenoma-like mass in chronic ulcerative colitis using a combined endoscopic mucosal resection and cap assisted submucosal dissection technique

BACKGROUND

Resection of an adenoma-like mass (ALM) in chronic ulcerative colitis (CUC) complicated by mucosal fibrosis has historically not been technically feasible. Endoscopic submucosal dissection techniques may now provide a therapeutic tool enabling the division of submucosal fibrotic scarring, hence enabling endoluminal resection for the first time in this select patient group. The aim was prospective evaluation of endoscopic submucosal dissection-assisted (ESD) resection of flat, sessile, and lateral spreading tumors in CUC complicated by submucosal desmoplasis. Clinical endpoints were postresection recurrence rates, R0 resection status, and complications.

METHODS

ESD-assisted endoscopic mucosal resection (EMR) using the Olympus KD-630L insulation-tipped knife was performed on selected lesions.

RESULTS

Sixty-nine patients met inclusion criteria, of which 2 were excluded due to follow-up default. En bloc resection was performed in 52/67 (78%) cases with 15/67 (7%) requiring a piecemeal approach. R0 resection was achieved in 49/52 (94%) of lesions undergoing en bloc resection (perforation rate 2/67 [3%]). Bleeding complications occurred in 7/67 (10%) of cases. No metachronous circumscribed intraepithelial neoplastic lesions or cancer was detected at follow-up. At a median of 18 months follow-up, overall cure rates for the ESD-assisted EMR cohort was 66/67 (98%).

CONCLUSIONS

We have shown for the first time that endoscopic resection of ALM even in the presence of complicating mucosal fibrosis is technically achievable using a combined ESD-assisted EMR technique. In an appropriately selected cohort, this technique may provide a technically feasible and clinically acceptable therapy where otherwise colectomy would be required.

Chromoscopic endomicroscopy: in vivo cellular resolution imaging of the colorectum

Advances in imaging technology and engineering have now permitted functional integration of a confocal endomicroscope into the distal tip of a conventional video colonoscope enabling imaging of the surface epithelium and the underlying lamina propria during ongoing video endoscopy. For the first time, the endoscopist is now able to resolve the surface and subsurface mucosa at cellular resolution in vivo and in real time. A new era in endoscopic imaging has therefore begun - histoendoscopy. In addition to providing a high-accuracy in vivo optical biopsy tool for the differentiation between benign hyperplasia, intra-epithelial neoplasia and carcinoma in sporadic cohorts, endomicroscopy with targeted biopsies has now been shown to increase the yield of intra-epithelial neoplasia complicating ulcerative colitis. Furthermore, recent data examining endomicroscopic molecular ex vivo imaging using anti-CD44v6 antibody has identified aberrant crypt foci based on their surface molecular expression. Receptor overexpression in vivo in humans may, in the near future, be exploited for the diagnosis of inflammation, neoplasia and in predicting targeted molecular therapy. Endomicroscopy will be key to this immuno-imaging interface. Within the present review, we discuss the current clinical evidence in support of confocal endomicroscopy and explore the new diagnostic possibilities for this technology.

In vivo confocal laser scanning chromo-endomicroscopy of colorectal neoplasia: changing the technological paradigm

Recently, miniaturization of a novel confocal laser endomicroscope (Optiscan Pty, Notting Hill, Victoria, Australia) has permitted functional integration into the distal tip of a conventional video colonoscope (Pentax EC3870K; Pentax, Tokyo, Japan) enabling imaging of the surface epithelium and the underlying lamina propria during ongoing video endoscopy. Using endomicroscopy and intravenous sodium fluorescein as a contrast agent, 'virtual histology' can be created, which allows visualization of both the surface epithelium, and some of the lamina propria (down to a quarter of a millimetre), including the microvasculature. Confocal endomicroscopy may have major implications in the future of colonoscopy as uniquely it allows in vivo diagnosis of colonic intraepithelial neoplasia and carcinoma enabling 'smart' biopsy targeting and hence potentially influencing 'on table' management decisions. Initial pilot data have now shown that confocal imaging in vivo using the newly developed EC3870K has high overall accuracy for the immediate diagnosis of intraepithelial neoplasia and carcinoma in sporadic screened cohorts, but also has a role in the detection of intraepithelial neoplasia detection in chronic ulcerative colitis cancer screening when used in conjunction with methylene blue chromoscopy. We discuss the current evidence in support of confocal endomicroscopy in the colorectum and explore the new diagnostic possibilities for this technology.

Surveillance of patients at increased risk of colon cancer: inflammatory bowel disease and other conditions

Colorectal cancer (CRC) is the second most common cause of cancer-related mortality in the United States. Colonoscopic screening with removal of adenomatous polyps in individuals at average risk is known to decrease the incidence and associated mortality from colon cancer. Certain conditions, notably inflammatory bowel disease involving the colon, a family history of polyps or cancer, a personal history of colon cancer or polyps, and other conditions such as acromegaly, ureterosigmoidostomy, and Streptococcus bovis bacteremia are associated with an increased risk of colonic neoplasia. This article reviews the CRC risks associated with these conditions and the currently recommended surveillance strategies.

A urokinase-type plasminogen activator deficiency diminishes the frequency of intestinal adenomas in ApcMin/+ mice

The interaction of urokinase-type plasminogen activator (uPA) and its receptor, uPAR, on cell surfaces facilitates the generation of cell-bound plasmin, thus allowing cells to establish a proteolytic front that enables their migration through protein barriers. This complex also activates cell signalling pathways that influence cell functions. Clinical studies have identified uPA as an indicator of poor overall survival in patients with colorectal cancer. In the current study, a mouse model of colon cancer, Apc(Min/+), with an additional deficiency of uPA (Apc(Min/+)/Plau-/-) was used to determine the effects of uPA on tumour initiation and growth. Utilizing this model, it was found that the number of tumours was diminished in these mice relative to Apc(Min/+) mice, which correlated with the decreased leukocyte infiltration in the tumours. However, tumour growth was not impeded in Apc(Min/+)/Plau-/- mice, and proliferation and tumour vascularization were, in fact, enhanced in Apc(Min/+)/Plau-/- mice. These latter effects are consistent with a mechanism involving up-regulation of COX-2 expression and Akt pathway activation in Apc(Min/+)/Plau-/- mice. The results from this study suggest that uPA plays dual and opposing roles in regulating lesion development: one early, during the transition from normal epithelia to dysplastic lesions, and another later during tumour growth.

Neoplastic precursor lesions related to the development of cancer in inflammatory bowel disease

Dysplasia is an intermediate stage in the progression from inflammation to cancer in patients with inflammatory bowel disease. Clinically, dysplasia is used to define appropriate endpoints for colectomy in high-risk patients undergoing endoscopic surveillance. Surveillance is currently the only credible alternative to prophylactic colectomy for high-risk patients. The success of surveillance can be maximized by adherence of gastroenterologists to recommended procedural guidelines, adherence of pathologists to standardized histological criteria and nomenclature, and a joint commitment to close clinical-pathological communication. Technical enhancements to conventional endoscopy hold promise of improved efficiency and accuracy. Molecular-based testing may have a future role for risk stratification and early detection of neoplasia in inflammatory bowel disease.

Techniques for targeting screening in ulcerative colitis

Patients with longstanding chronic ulcerative colitis are "at risk" of developing colorectal cancer. Approximately 1 in 6 patients will die as a result of colorectal malignancy, which can often be difficult to detect using conventional "white light" colonoscopy. New endoscopic techniques and technologies including the use of dye sprays, "chromoendoscopy", high magnification chromoscopic colonoscopy and recently chromoscopic assisted confocal laser scanning in vivo endomicroscopy have now been introduced to improve the diagnostic yield of intraepithelial neoplasia at screening colonoscopy. This review details the true "risk" of colorectal cancer complicating ulcerative colitis, discusses the objective evidence to support current endoscopic screening guidelines, and describes the imminent technological paradigm shift about to occur in the endoscopic management and detection of intraepithelial neoplasia.

Confocal endomicroscopy in ulcerative colitis: differentiating dysplasia-associated lesional mass and adenoma-like mass

BACKGROUND & AIMS

The management of dysplasia-associated lesional mass (DALM) and adenoma-like mass (ALM) in chronic ulcerative colitis (CUC) differs radically, involving total pan-proctocolectomy vs endoscopic resection and surveillance. Such lesions cannot be reliably differentiated using conventional colonoscopy. Confocal laser scanning imaging enables in vivo surface and subsurface cellular resolution imaging during ongoing video endoscopy. The aim of this study was to prospectively assess the clinical applicability and predictive power of the Pentax EC3870K endomicroscope for the in vivo differentiation of ALM and DALM in CUC during ongoing videocolonoscopy.

METHODS

Patients were recruited who had a diagnosis of ALM or DALM within the previous 16 weeks. Confocal laser endomicroscopic (CLE) imaging of the circumscribed lesion and 4 adjacent mucosal segments was performed. Targeted biopsy with and without tissue sampling with endoscopic mucosal resection was performed and compared with conventional histopathology as the gold standard.

RESULTS

Thirty-six patients with 36 lesions fulfilled the study entry criteria. Using modified Mainz criteria for the in vivo diagnosis of ALM and DALM, the kappa coefficient of agreement between CLE and histopathologic evaluation was 0.91, and accuracy was 97% (95% confidence interval = 86%-99%).

CONCLUSIONS

This is the first study addressing the novel application of the Pentax EC3870K endomicroscopy system for the in vivo differentiation of ALM and DALM during ongoing video colonoscopy in CUC. We have shown that ALM and DALM can be differentiated with a high overall accuracy, enabling the safe selection of patients suitable for endoluminal resection versus immediate referral for pan-proctocolectomy.

Novel clinical in vivo roles for indigo carmine: high-magnification chromoscopic colonoscopy

Since the adenoma-carcinoma sequence was first proposed by Morson in the 1970s, it has become widely accepted that detection and subsequent removal of polypoid adenomas from the colon reduces the incidence of colorectal cancer. These adenomas are relatively easy to detect by conventional colonoscopy; however, large population studies have shown that despite resection of polypoid adenomas, interval colorectal cancers still occurred. Recent advances in technology have given today's endoscopists access to high-resolution and high-magnification scopes, which has facilitated detection of flat and depressed colorectal lesions. Current data suggest that such morphologically distinct lesions may account for up to 30% of all colorectal adenomas. Furthermore, flat and depressed lesions of the large bowel may confer greater malignant potential compared to polypoid adenomas. The majority of flat lesions show only subtle changes by conventional colonoscopy, but the use of stains, such as indigocarmine, in addition to magnification colonoscopy can enhance their detection significantly. In this paper, we discuss the rationale for detecting flat colorectal lesions. We explore the use of high-magnification colonoscopy and chromoendoscopy, with particular reference to the application of indigocarmine, in this patient group. We also discuss the novel therapeutic techniques now available for these lesions.

Role of chromoendoscopy in colon cancer surveillance in inflammatory bowel disease

Inflammation in the intestine is a well-known risk factor for neoplastic changes in the mucosa. In fact, it has been shown that long-standing ulcerative colitis and colonic Crohn's disease have a significantly increased risk for developing colorectal cancer, although the estimates vary widely between studies. Conventional colonoscopy is effective in detecting polypoid changes in the mucosa. However, it is now generally accepted that neoplastic changes in colitis are frequently flat and depressed, which are easily missed by use of routine colonoscopy. The introduction of chromoendoscopy, especially in combination with magnifying endoscopy, has greatly advanced our means to detect and differentiate neoplastic lesions in the colorectum. Accumulating evidence-based data indicate that implementation of chromoendoscopy into colon cancer surveillance protocols for patients with inflammatory bowel disease is effective. However, the introduction of chromoendoscopy into surveillance programs requires meticulous training and further studies to compare the value of chromoendoscopy to newer endoscopic devices and techniques, such as narrow band imaging.

Folate and colorectal cancer: an evidence-based critical review

Currently available evidence from epidemiologic, animal, and intervention studies does not unequivocally support the role of folate, a water-soluble B vitamin and important cofactor in one-carbon transfer, in the development and progression of colorectal cancer (CRC). However, when the portfolio of evidence from these studies is analyzed critically, the overall conclusion supports the inverse association between folate status and CRC risk. It is becoming increasingly evident that folate possesses dual modulatory effects on colorectal carcinogenesis depending on the timing and dose of folate intervention. Folate deficiency has an inhibitory effect whereas folate supplementation has a promoting effect on the progression of established colorectal neoplasms. In contrast, folate deficiency in normal colorectal mucosa appears to predispose it to neoplastic transformation, and modest levels of folic acid supplementation suppress, whereas supraphysiologic supplemental doses enhance, the development of cancer in normal colorectal mucosa. Several potential mechanisms relating to the disruption of one-carbon transfer reactions exist to support the dual modulatory role of folate in colorectal carcinogenesis. Based on the lack of compelling supportive evidence and on the potential tumor-promoting effect, routine folic acid supplementation should not be recommended as a chemopreventive measure against CRC at present.

Recent advances in chromoscopic colonoscopy and endomicroscopy

The basic rationale for secondary prevention of colorectal carcinoma is by endoscopic polypectomy. New technologies in the form of high-magnification or "zoom" colonoscopy complemented by chromoscopic agents permit early detection of neoplastic colorectal lesions, particularly flat and depressed types. Detailed morphologic characteristics of the surface crypt or "pit pattern" can be obtained with these techniques, enabling an in vivo "optical biopsy" and staging tool. Establishing suitability for endoscopic resection or surgical excision can be enhanced using these techniques. Furthermore, chromoscopic colonoscopy may have a role in routine endoscopic colorectal cancer surveillance programs in patients at high risk for colorectal neoplasia, such as those with long-standing ulcerative colitis and familial colorectal cancer syndromes. This review summarizes recent data regarding the prevalence and histopathologic characteristics of flat and depressed colorectal lesions in Western cohorts and describes how their detection and management can be improved by chromoscopy and magnification technology. We outline these techniques from a clinical perspective and describe the basic principles of endoscopic mucosal resection.

Review article: colorectal cancer surveillance in ulcerative colitis - what should we be doing?

Different societies have published guidelines for colorectal cancer (CRC) surveillance in ulcerative colitis (UC). While it would seem that most gastroenterologists and endoscopists agree with these guidelines, different studies have shown that in clinical practice, the concept of dysplasia is not fully understood, and therefore, the guidelines are not always followed. According to some studies, the reason why gastroenterologists do not follow the recommendations is inadequate education. The main advance in recent years in this subject is in endoscopic diagnosis of dysplasia. The magnification and chromoendoscopy allow targeted biopsies to be taken. Some studies indicate that nontargeted biopsies are not useful in ruling out dysplasia. It is also important to realize that most dysplasia is visible in conventional colonoscopy. In colonoscopy, it is not only significant to detect dysplasia-associated lesions or masses; the endoscopist should also be trained to detect, in the course of conventional exploration, subtle changes in colour or in mucosal surfaces that imply dysplasia. Adherence to guidelines had been extensively assessed in other disease conditions (asthma, hypertension, etc.). According to our knowledge there are no such data regarding CRC surveillance in UC. Some barriers that may affect physicians include: (i) knowledge (lack of awareness or lack of familiarity); (ii) attitudes (lack of agreement, lack of self-efficacy, lack of outcome expectancy, or the inertia of previous practice) and (iii) behaviour (external barriers). In conclusion, we need new guidelines for CRC surveillance in UC, which must take into account the advances in risk factors of dysplasia and new technologies to study colon dysplasia.

Review article: maintenance therapy in patients with ulcerative colitis

British Society of Gastroenterology guidelines recommend that all patients with ulcerative colitis should receive long-term therapy with a 5-aminosalicylic acid compound to maintain remission. Recent studies have shown that time spent in remission is longer when the maintenance dose is increased from 1.2 to 2.4 g/day, with patients with extensive disease benefiting most from an increase with dosage. A retrospective analysis also found that the frequency of relapse was lower in patients taking more than the median dose of 5-aminosalicylic acid (1.6 g/day) compared with those taking less than the median dose. Similarly, when 5-aminosalicylic acids are used to induce remission, continuing the induction dosage for an extra 4 weeks prolongs remission and reduces the frequency of relapse. However, patients rarely comply fully with the prescribed dose regimen, which can lead to effective under-dosing. The recent discovery that 5-aminosalicylic acids may act in ulcerative colitis by activating peroxisome proliferator-activated receptor-gamma, a nuclear receptor that plays a role in the control of cell proliferation and apoptosis, has given new impetus to the idea that long-term therapy with 5-aminosalicylic acid may reduce the risk of colorectal cancer. Epidemiological studies are beginning to provide evidence to support this view. Accumulating evidence suggests that the next revision of the clinical guidelines should suggest life-long doses of 5-aminosalicylic acid of > or =2 g/day for maintenance of remission in patients with ulcerative colitis.

Epidemiology and risk factors for colorectal dysplasia and cancer in ulcerative colitis

Patients with UC are at increased risk of CRC, but a series of population-based studies published within the past 5 years suggest that this risk has decreased over time. The crude annual incidence rate of CRC in UC ranges from approximately 1 in 500 to 1 in 1600. In some cohorts, an elevated risk of CRC relative to the general population can no longer be demonstrated. The exact mechanism for this decrease in risk remains unclear but may be attributable to a combination of more widespread use of maintenance therapy and surveillance colonoscopy as well as more judicious reliance on colectomy. In addition to the classic risk factors of increased extent and duration of UC, it seems that PSC, a family history of sporadic CRC, severity of histologic bowel inflammation, and young age at colitis onset are independent risk factors for cancer.

Survival after colorectal cancer in patients with ulcerative colitis: a nationwide population-based Danish study

OBJECTIVES

Patients with ulcerative colitis (UC) are at increased risk of colorectal cancer (CRC). Little is known about how UC impacts CRC prognosis. In a nationwide population-based study we examined the CRC prognosis in UC patients compared to CRC patients without UC.

METHODS

From the Danish Cancer Registry and the Danish Hospital Discharge Registry, we identified all CRC patients and all patients with UC in Denmark from 1977 to 1999. We compared survival in 279 UC patients with CRC to all other 71,259 CRC patients and computed mortality rate ratios (MRR). We also compared stage distribution at time of cancer diagnosis.

RESULTS

The mean age at time of CRC diagnosis was 62.6 yr in UC patients and 71.2 yr in patients without UC. Cancer stage distribution for localized cancer, regional spread, and distant metastasis were 46.6%, 30.1%, and 16.5% in UC patients compared to 44.0%, 28.3%, and 19.4% in CRC patients without UC. The overall MRR for UC patients with CRC compared with all other CRC patients were 1.24 (95% CI 1.02-1.51) in the first year and 1.17 (95% CI 1.01-1.36) after 5 yr of follow-up.

CONCLUSION

UC patients with CRC have a stage distribution similar to patients with CRC without UC. The prognosis of CRC is poorer for UC patients than for patients without UC.

Colorectal cancer prognosis among patients with inflammatory bowel disease

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) is associated with an increased risk for colorectal cancer (CRC). However, the genetic, endoscopic, and histologic features of IBD-associated CRC differ from cancers that arise sporadically. The objectives of this study were to describe the clinicopathologic features of IBD-associated CRC and to compare survival rates between patients with IBD-associated CRC and patients with sporadic CRC.

METHODS

There were 290 patients with IBD-associated CRC (241 with chronic ulcerative colitis [CUC] and 49 with Crohn's disease) and an equal number of age- and sex-matched sporadic CRC patients who were evaluated at the Mayo Clinic between 1976 and 1996. Medical records were reviewed retrospectively for demographic features, endoscopic and histologic characteristics, and vital status at the time of the last follow-up evaluation. The actuarial survival of each group was calculated by the Kaplan-Meier method. The influence of clinical features on survival was assessed using Cox proportional hazards regression modeling.

RESULTS

The median age at diagnosis of IBD-related CRC was 48 years. Fifty-five percent of IBD-related tumors were distal to the splenic flexure compared with 78% of sporadic tumors. During a median follow-up period of 5 years, 163 IBD-associated CRC patients died (56%), compared with 164 sporadic CRC patients (57%). The 5-year survival rates were 54% in the IBD-CRC subgroup vs 53% in the sporadic CRC subgroup (P = .94, log-rank).

CONCLUSIONS

CUC-related CRC is diagnosed at a relatively young age, and IBD-related tumors tend to be distributed more evenly across the colorectum than sporadic tumors. The survival rates for IBD-associated and sporadic CRC were similar.

Folate and prevention of colorectal cancer in ulcerative colitis

Patients with ulcerative colitis are at greater risk of developing colorectal cancer than the general population. Prophylactic colectomy is the only certain method of avoiding this risk. To avoid indiscriminate surgery, efforts have focused on colonoscopic surveillance in order to select for prophylactic surgery only patients at ultra-high risk. However this policy has not always been proven to reduce mortality for colorectal cancer in these patients. Recently, there has been growing interest in chemoprevention using folate. Folate maintains the normal DNA methylation process and steady-state levels of DNA precursors. These properties indicate that folate has potential as chemopreventive agent.

Practical uses of chromoendoscopy and magnification at colonoscopy

New technologies in the form of high-magnification or zoom colonoscopy complemented by chromoscopic agents permits early detection of neoplastic colorectal lesions, particularly flat and depressed types. Establishing suitability for endoscopic resection or surgical excision can be enhanced using these techniques. Chromoscopic colonoscopy may play an important role in the routine endoscopic colorectal cancer surveillance programs in patients assuming a high risk of colorectal neoplasia. This article summarizes recent data regarding the prevalence and histopathologic characteristics of flat and depressed colorectal lesion in Western cohorts and describes how their detection and management can be improved by chromoscopy and magnification technology. The techniques required for chromoscopic colonoscopy and magnification imaging are outlined along with a review of the literature on these subjects.

5-ASA and colorectal cancer chemoprevention in inflammatory bowel disease: can we afford to wait for 'best evidence'?

Patients with inflammatory bowel disease have a higher risk of developing colorectal cancer. The main risk factors for colorectal cancer are not suitable targets for therapeutic intervention, and primary chemoprevention is an intriguing therapeutic option. The analogies between acetyl-salicylic acid and 5-amino-salicylic acid, and the results obtained by using acetyl-salicylic acid as a chemopreventive agent in patients with sporadic colorectal cancer have prompted the study of potential chemopreventive effects of 5-amino-salicylic acid in inflammatory bowel disease. The results of both epidemiological and experimental studies have shown that long-term 5-amino-salicylic acid treatments appear to have a chemopreventive effect. The evidence for this effect is provided by retrospective and case-control studies whose results, however, do not reach the highest grades for evidence-based recommendations. Nevertheless, these results are supported by a series of experimental studies demonstrating the multiplicity of actions of 5-amino-salicylic acid. Although data regarding the chemopreventive effect of 5-amino-salicylic acid may not be rigorous enough to meet the criteria for the highest evidence-based medicine recommendations, we feel that the argument to wait until we have Grade A evidence is not necessarily rational in this case, because discontinuation of 5-amino-salicylic acid treatment to perform a randomised controlled trial would be unethical secondary to their proven efficacy for maintenance treatment.