The changing face of colorectal cancer in inflammatory bowel disease: progress at last!

Timing for dose-down of 5-ASA depends on mucosal status with ulcerative colitis

OBJECTIVE

Although aminosalicylic acid (ASA) preparations have been used as first-line drugs for the treatment of ulcerative colitis (UC), no consistent view has been established regarding the ASA dose during the remission-maintenance phase of the disease. In this study, we examined whether the ASA dose should be reduced during the remission-maintenance phase.

MATERIALS AND METHODS

This study included 203 patients in the remission-maintenance phase of UC. The Mayo endoscopic subscore (MES) was used to evaluate mucosa. Comparison and analysis were performed between patients whose ASA dose had been unchanged and whose dose had been reduced, between patients with endoscopic healing (EH) group and those without endoscopic healing (WEH) group, and between patients with an MES of 0 and 1.

RESULTS

Comparison between the unchanged-ASA and reduced-ASA groups revealed that the remission-maintenance rate was higher in the unchanged-ASA group (p < 0.001). Next, the remission-maintenance rate was higher in the EH/unchanged-ASA group than in the EH/reduced-ASA group (p = 0.042). Comparison between the MES 0 and 1 groups revealed that the remission-maintenance rate was higher in the MES 0 group (p = 0.007). In addition, no significant difference in remission-maintenance rates was observed between the MES 0/unchanged-ASA group and the MES 0/reduced-ASA group (p = 0.108).

CONCLUSION

When the same ASA dose is maintained regardless of the presence or absence of EH, remission is more likely to be maintained. If the ASA dose must be reduced, dose reduction is more advantageous after an MES of 0 is achieved.

MicroRNA in inflammatory bowel disease: Translational research and clinical implication

Idiopathic inflammatory bowel disease (IBD) predominantly includes ulcerative colitis and Crohn’s disease. The pathogenesis of IBD is complex and not completely understood. MicroRNAs belong to a class of noncoding small RNAs that post-transcriptionally regulate gene expression. Unique microRNA expression profiles have been explored in IBD. In this review, we focus on the unique microRNA expression pattern in both tissue and peripheral blood from IBD patients and emphasize the potential diagnostic and therapeutic applications. The discovery of microRNAs has contributed to our understanding of IBD pathogenesis and might lead to clinical advance in new therapeutics.

Chromoendoscopy versus narrow band imaging for colonic surveillance in inflammatory bowel disease

BACKGROUND

Mucosal dye spraying (chromoendoscopy [CE]) has been shown in controlled studies to enhance lesion detection in colitis surveillance. Narrow band imaging (NBI) potentially offers a more convenient mode of highlighting mucosal lesions. The primary objectives of this study were to compare CE and NBI in colitis surveillance with respect to lesion detection. A secondary objective was to assess the accuracy of the mucosal pit pattern (Kudo classification) with NBI in predicting mucosal histology.

METHODS

Patients with colitis of 8 years or greater disease duration underwent screening colonoscopy with NBI, followed immediately by CE by 2 endoscopists blinded to each other's results. All lesions were biopsied to confirm histology. Diagnostic yield of each modality for dysplastic lesions. Accuracy of Kudo classification by NBI for neoplasia.

RESULTS

Forty-four participants were enrolled. One hundred forty-four colonic lesions were identified in total. Overall, CE identified more lesions than NBI (131 versus 102, P < 0.001); however, most were nondysplastic. CE detected 23 neoplastic (dysplastic or indefinite for dysplasia) lesions in 11 patients and NBI 20 lesions in 10 patients, P = 0.180. Kudo assessment by NBI had low sensitivity for dysplasia (42%) and modest accuracy (74%) for dysplasia.

CONCLUSIONS

NBI detected fewer lesions than CE in chronic colitis; however, most were not dysplastic. There was a nonsignificant trend in favor of CE for detection of dysplasia. At present, NBI cannot be recommended as an alternative to CE for dysplasia surveillance in colitis.

Clinicopathological features of ulcerative colitis-associated colorectal cancer pointing to efficiency of surveillance colonoscopy in a large retrospective Japanese cohort

PURPOSE

Cancer surveillance has been conducted in patients with ulcerative colitis (UC), and the number of operative cases of ulcerative colitis-associated colorectal cancer (UC-CRC) has been increasing. The aim of this study was to clarify the clinicopathological features and prognoses of UC-CRC patients and the relationship between surveillance colonoscopy and UC-CRC.

METHODS

The clinical records of 1,274 UC patients who required surgery between 1984 and 2010 at a single institution were reviewed retrospectively. Of these, 83 patients had CRC (107 sections). All cases were extracted from the database, along with their clinicopathological data.

RESULTS

The 5-year survival rate of the UC-CRC group was 89 %. The 5-year survival rate was 100 % in stages 0 and II, 96 % in stage I, 56 % in stage III, and 0 % in stage IV. Surveillance colonoscopy was performed for 40 of the 83 patients. Of 40 patients, 30 with UC who underwent surveillance colonoscopies and 22 of 43 patients without surveillance colonoscopies were in stages 0 to I (P = 0.04).

CONCLUSION

The number of UC-CRC patients who are diagnosed by surveillance colonoscopy is increasing, and many of them are detected in the very early stages (stages 0 or I). Thus, the survival rate of UC-CRC is better than before. Surveillance colonoscopy proofs efficient as CRC are detected in earlier stages.

Gene signature distinguishes patients with chronic ulcerative colitis harboring remote neoplastic lesions

BACKGROUND

Individuals with ulcerative colitis (UC) are at increased risk for colorectal cancer. The standard method of surveillance for neoplasia in UC by colonoscopy is invasive and can miss flat lesions. We sought to identify a gene expression signature in nondysplastic mucosa without active inflammation that could serve as a marker for remote neoplastic lesions.

METHODS

Gene expression was analyzed by complementary DNA microarray in 5 normal controls, 4 UC patients without dysplasia, and 11 UC patients harboring remote neoplasia. Common gene ontology pathways of significantly differentially expressed genes were identified. Expression of genes which were progressively and significantly upregulated from controls to UC without neoplasia, to UC with remote neoplasia were evaluated by real-time polymerase chain reaction. Several gene products were also examined by immunohistochemistry.

RESULTS

Four hundred and sixty-eight genes were significantly upregulated, and 541 genes were significantly downregulated in UC patients with neoplasia compared with UC patients without neoplasia. Nine genes (ACSL1, BIRC3, CLC, CREM, ELTD1, FGG, S100A9, THBD, and TPD52L1) were progressively and significantly upregulated from controls to nondysplastic UC to UC with neoplasia. Immunostaining of proteins revealed increased expression of S100A9 and REG1α in UC-associated cancer and in nondysplastic tissue from UC patients harboring remote neoplasia compared with UC patients without neoplasia and controls.

CONCLUSIONS

Gene expression changes occurring as a field effect in the distal colon of patients with chronic UC identify patients harboring remote neoplastic lesions. These markers may lead to a more accurate and less invasive method of detection of neoplasia in patients with inflammatory bowel disease.

miR-143 and miR-145 are downregulated in ulcerative colitis: putative regulators of inflammation and protooncogenes

BACKGROUND

miR-143 and miR-145 are believed to function as colon cancer tumor suppressors, as they inhibit colon cancer cell growth and are downregulated in sporadic colonic tumors. We speculated that miR-143 and miR-145 might also be downregulated and contribute to malignant transformation of colonic epithelium in longstanding ulcerative colitis (UC).

METHODS

Biopsies were obtained 20 cm proximal to the anus from individuals with quiescent UC and from normal controls. RNA and proteins were extracted and measured. miR-143 and miR-145 were quantified by real-time polymerase chain reaction (PCR) and miR-145 was also assessed by in situ hybridization. Putative targets of these miRNAs, K-RAS, API5, MEK-2 (miR-143), and IRS-1 (miR-145) were determined by western blotting. To assess the effects of miR-143 and miR-145 on these predicted targets, HCT116 and HCA-7 colorectal cancer cells were transfected with miR-143 and miR-145 and expression levels of these proteins were measured.

RESULTS

In UC, miR-143 and miR-145 were significantly downregulated 8.3-fold (3.4-20.1) (P < 0.0001) and 4.3-fold (2.3-7.8) (P < 0.0001), respectively, compared to normal colon. In contrast, IRS-1, K-RAS, API5, and MEK-2 were upregulated in UC, consistent with their assignments as targets of these miRNAs. Furthermore, transfected miR-143 and miR-145 significantly downregulated these proteins in HCT116 or HCA-7 cells.

CONCLUSIONS

Compared to normal colonic mucosa, in chronic UC miR-143 and miR-145 were significantly downregulated and their predicted targets, IRS-1, K-RAS, API5, and MEK-2 were upregulated. We postulate that loss of these tumor suppressor miRNAs predispose to chronic inflammation and neoplastic progression in IBD.

Physician assessment of ulcerative colitis activity correlates poorly with endoscopic disease activity

BACKGROUND

Subjective physician assessment is the cornerstone of routine ulcerative colitis (UC) management. Endoscopic and histologic assessment of UC provides objective measures of inflammatory disease activity. The level of agreement between physician impression of UC activity and endoscopic disease activity has not been evaluated. The aim was to assess the level of agreement between physician's clinical impression of UC disease activity and endoscopic and histologic findings of inflammation.

METHODS

Using the Medical Archival Retrieval System at the University of Pittsburgh Medical Center, we reviewed clinical information on all UC patients between 1995 and 2008 who had clinic visits recorded prior to colonoscopy. Clinical UC disease activity was defined by the physician's clinical impression and the endoscopic and histologic activity by colonoscopy with biopsy. The level of agreement between colonoscopy assessment of UC with histologic and clinical assessment was determined by sensitivity, specificity, positive and negative predictive values, and the kappa coefficient.

RESULTS

There were 369 UC patients who had a clinic visit proximate to a colonoscopy. The mean age of patients was 46 ± 16 years (50% female). The performance of clinical impression in recognizing disease activity, as determined by endoscopy, was relatively poor: sensitivity = 56.0%, predictive value negative = 56.8%, kappa coefficient = 0.35. In contrast, the performance of histological evaluation in recognizing disease activity was markedly better: sensitivity = 93.5%, predictive value negative = 89.1%, kappa coefficient = 0.70.

CONCLUSIONS

The physician's clinical impression of UC activity shows poor agreement with endoscopy and histology, with over one-third of patients with chronic inflammation underrecognized by clinical impression. The consequences of underestimated UC activity by clinical assessment may include undertreatment of active disease and uncontrolled chronic inflammation.

Randomised clinical trial: delayed-release oral mesalazine 4.8 g/day vs. 2.4 g/day in endoscopic mucosal healing--ASCEND I and II combined analysis

BACKGROUND

Recent studies have focused on the importance of mucosal healing in ulcerative colitis (UC). However, it was still unclear whether higher doses of delayed-release mesalazine (mesalamine) could provide additional benefit.

AIM

To examine how two doses of delayed-release mesalazine (4.8 g/day and 2.4 g/day) from ASCEND I and II compare in their relative ability to heal colonic mucosa over time.

METHODS

Primary data from two prospective 6-week, double-blind, randomised studies in patients with mildly to moderately active UC were pooled and analysed retrospectively. The mucosal healing analysis focuses on moderately active UC patients (n=391), comprising a majority of patients (84%). Additional analyses examined the relationship between mucosal healing and dose, clinical response to therapy and patient quality of life (Inflammatory Bowel Disease Questionnaire, IBDQ).

RESULTS

At week 3, mucosal healing (endoscopy subscore of 0 or 1) was achieved in 65% of moderately active UC patients on 4.8 g/day and 58% of patients on 2.4 g/day (P=0.219). At week 6, this increased to 80% for 4.8 g/day and 68% for 2.4 g/day (P=0.012). Healing rates with the higher dose were also greater across all extents of disease and in patients with prior steroid use. At 6 weeks, clinical response to therapy and mucosal healing were found to be well correlated (kappa=0.694). Likewise, the change in IBDQ at week 6 showed a significant relationship with mucosal healing (P<0.0001).

CONCLUSION

Mucosal healing rates in UC achieved at 6 weeks were statistically significantly higher with delayed-release mesalazine at 4.8 g/day vs. 2.4 g/day.

Ulcerative colitis-associated colorectal cancer shows a poorer survival than sporadic colorectal cancer: a nationwide Japanese study

BACKGROUND

The clinicopathological features of ulcerative colitis-associated colorectal cancer (UC-CRC) have not yet been fully clarified, especially in Asian populations. This study aimed to clarify the prognosis and clinicopathological features of UC-CRC in comparison with sporadic CRC in the Japanese population.

METHODS

Histologically diagnosed UC-CRC patients between 1978 to 1998 were extracted from the Multi-Institutional Registry of Large-Bowel Cancer in Japan, a large nationwide CRC database, and the clinicopathological features and postoperative survival rates of UC-CRC patients and sporadic CRC patients were compared.

RESULTS

Among the 108,536 CRC patients registered between 1978 and 1998, a total of 169 UC-CRC patients were identified, including 121 patients who had been treated surgically. The proportion of UC-CRC patients increased in the period between 1995 and 1998 compared to that between 1978 and 1994. Comparisons with the sporadic CRC patients showed that the UC-CRC patients were younger, had a higher proportion of multiple cancer lesions, had higher proportions of superficial type lesions and invasive type lesions morphologically, and had higher proportions of mucinous or signet ring cell carcinomas. In stage III, UC-CRC patients had a poorer survival rate than the sporadic CRC patients (43.3% versus 57.4%, P = 0.0320).

CONCLUSIONS

UC-CRC increased over the investigated time periods and showed a poorer survival than sporadic CRC in the advanced stage, while no difference was observed in the early stage. By detecting UC-CRC at an early stage we can expect a similar postoperative outcomes to that of sporadic CRC. These results stress the importance of surveillance for the early detection of UC-CRC.

Overexpression of translocator protein in inflammatory bowel disease: potential diagnostic and treatment value

BACKGROUND

Inflammatory bowel diseases (IBDs), such as ulcerative colitis and Crohn's disease, are chronic inflammatory disorders that increase the risk for colorectal cancer. The mitochondrial translocator protein (TSPO) is a high-affinity drug- and cholesterol-binding protein expressed in the colon and its expression is increased in colon cancers. The aim of this study was to investigate TSPO expression in IBD biopsies and to establish an animal model of IBD to examine the role of TSPO. In addition, we evaluated the potential use of TSPO drug ligands in diagnosing and treating IBD.

METHODS

TSPO expression in IBD biopsies was evaluated using immunohistochemistry. IBD was induced in a rat experimental model via treatment with dextran sodium sulfate (DSS). Colon morphology, TSPO expression, and proinflammatory cytokine production were evaluated in addition to the effect of TSPO drug ligands on disease pathology.

RESULTS

TSPO protein levels were elevated in the enterocytes of IBD biopsies. TSPO expression was localized to the enterocyte mitochondria. DSS treatment induced a time-dependent phenotype mimicking IBD with tissue injury and subsequent tissue regeneration. Coadministration of DSS and the TSPO drug ligands PK 11195 or Ro5-4864 increased both the rate of colon ulceration and regeneration, whereas administration of the TSPO drug ligand flunitrazepam partially prevented this pathology. These data correlated with changes in proinflammatory cytokine plasma levels, as well as increased cytokine production and secretion from the colon.

CONCLUSIONS

TSPO may serve as a marker of the IBD repair process, and TSPO drug ligands should be further evaluated for IBD treatment.

An updated approach to dysplasia in IBD

INTRODUCTION

Long-standing inflammation of the colorectum in ulcerative colitis (UC) and Crohn's disease (CD) has been associated with an increased risk of subsequent dysplasia and colorectal cancer. Historically, it was described that the neoplastic transformation in these inflammatory bowel diseases (IBDs) occurred via a different biologic pathway and not by the non-IBD polyp-cancer pathway and predictable lag time of progression. Therefore, prevention strategies have focused on the detection of dysplasia in flat mucosa, and existing guidelines have recommended performance of interval surveillance colonoscopies with random biopsies to identify such lesions with proctocolectomy when they are confirmed.

DISCUSSION

The use of a new technology higher-resolution colonoscopies has led to the appreciation more recently that dysplasia in IBD may be visible with standard optical colonoscopy and can be identified in an even more sensitive manner using chromoendoscopy. Furthermore, emerging evidence favors the intuitive understanding that neoplastic transformation in IBD is linked to the degree of inflammation and that disease control may therefore modify this risk and its subsequent prevention approaches.

CONCLUSION

Future IBD cancer prevention strategies and timing of surgery in at-risk patients will require a better understanding of this evolving field.

Colon cancer surveillance in inflammatory bowel disease patients: current and emerging practices

Colorectal cancer (CRC) is a feared complication of inflammatory bowel disease (IBD). The cumulative probability of developing this malignancy is significantly higher than in the general population, making IBD the third highest risk condition for CRC. Since CRC is such a concerning complication, it should be no surprise that patients and physicians want to know what the most important risk factors are for its development, as well as potential strategies for reducing these risks. This article reviews the current practice and emerging technologies for detecting and preventing colon cancer in patients with IBD.

Risk for colorectal cancer in ulcerative colitis: changes, causes and management strategies

The risk of colorectal cancer for any patient with ulcerative colitis is known to be elevated, and is estimated to be 2% after 10 years, 8% after 20 years and 18% after 30 years of disease. Risk factors for cancer include extent and duration of ulcerative colitis, primary sclerosing cholangitis, a family history of sporadic colorectal cancer, severity of histologic bowel inflammation, and in some studies, young age at onset of colitis. In this review, the authors discuss recent epidemiological trends and causes for the observed changes. Population-based studies published within the past 5 years suggest that this risk has decreased over time, despite the low frequency of colectomies. The crude annual incidence rate of colorectal cancer in ulcerative colitis ranges from approximately 0.06% to 0.16% with a relative risk of 1.0-2.75. The exact mechanism for this change is unknown; it may partly be explained by the more widespread use of maintenance therapy and surveillance colonoscopy.

Colorectal cancer and dysplasia in inflammatory bowel disease

Both ulcerative colitis and Crohn’s disease carry an increased risk of developing colorectal cancer. Established risk factors for cancer among patients with inflammatory bowel disease (IBD) include the younger age at diagnosis, greater extent and duration of disease, increased severity of inflammation, family history of colorectal cancer and coexisting primary sclerosing cholangitis. Recent evidence suggests that current medical therapies and surgical techniques for inflammatory bowel disease may be reducing the incidence of this complication. Nonetheless heightened vigilance and a careful, comprehensive approach to prevent or minimize the complications of invasive cancer are warranted in this unique cohort of patients. Current guidelines for the prevention and early detection of cancer in this high risk population are grounded in the concept of an inflammation-dysplasia-carcinoma sequence. A thorough understanding of the definition and natural history of dysplasia in IBD, as well as the challenges associated with detection and interpretation of dysplasia are fundamental to developing an effective strategy for surveillance and prevention, and understanding the limitations of the current approach to prevention. This article reviews the current consensus guidelines for screening and surveillance of cancer in IBD, as well as presenting the evidence and rationale for chemoprevention of cancer and a discussion of emerging technologies for the detection of dysplasia.

Surveillance of dysplasia in inflammatory bowel disease: The gastroenterologist-pathologist partnership

Cancer prevention in inflammatory bowel disease depends on the detection of precancerous dysplasia during scheduled screening and surveillance colonoscopy, but the detection and diagnosis of dysplasia remain challenging. In this article, we review the risks of cancer and dysplasia in ulcerative colitis and the current prevention recommendations, and through a sample case, we demonstrate an approach that involves an active partnership between the gastroenterologist or surgeon and pathologist. We address the challenge of management of polypoid lesions and incorporate new information about degree of inflammation as an additional risk of neoplasia in these patients.

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.

Ulcerative colitis: diagnosis and management

This article summarises the essential facts on the diagnosis and treatment of ulcerative colitis and is aimed at general practitioners who manage this condition