Cancer surveillance of patients with longstanding ulcerative colitis: a clinical, endoscopical, and histological study

Escherichia coli K12 Upregulates Programmed Cell Death Ligand 1 (PD-L1) Expression in Gamma Interferon-Sensitized Intestinal Epithelial Cells via the NF-κB Pathway

Programmed cell death ligand-1 (PD-L1) is an immune checkpoint protein which is used by tumor cells for immune evasion. PD-L1 is upregulated in inflamed intestinal tissues. The intestinal tract is colonized by millions of bacteria, most of which are commensal bacterial species. We hypothesized that under inflammatory conditions, some commensal bacterial species contribute to increased PD-L1 expression in intestinal epithelium and examined this hypothesis. Human intestinal epithelial HT-29 cells with and without interferon (IFN)-γ sensitization were incubated with six strains of four enteric bacterial species. The mRNA and protein levels of PD-L1 in HT-29 cells were examined using quantitative real-time PCR and flow cytometry, respectively. The levels of interleukin (IL)-1β, IL-18, IL-6, IL-8, and tumor necrosis factor (TNF)-α secreted by HT-29 cells were measured using enzyme-linked immunosorbent assay. Apoptosis of HT-29 cells was measured using a caspase 3/7 assay. We found that Escherichia coli K12 significantly upregulated both PD-L1 mRNA and protein in IFN-γ-sensitized HT-29 cells. E. coli K12 induced the production of IL-8 in HT-29 cells, however, IL-8 did not affect HT-29 PD-L1 expression. Inhibition of the nuclear factor-kappa B pathway significantly reduced E. coli K12-induced PD-L1 expression in HT-29 cells. The other two E. coli strains and two enteric bacterial species did not significantly affect PD-L1 expression in HT-29 cells. Enterococcus faecalis significantly inhibited PD-L1 expression due to induction of cell death. Data from this study suggest that some gut bacterial species have the potential to affect immune function under inflammatory conditions via upregulating epithelial PD-L1 expression.

Multiscale Modeling of Inflammation-Induced Tumorigenesis Reveals Competing Oncogenic and Oncoprotective Roles for Inflammation

Chronic inflammation is a serious risk factor for cancer; however, the routes from inflammation to cancer are poorly understood. On the basis of the processes implicated by frequently mutated genes associated with inflammation and cancer in three organs (stomach, colon, and liver) extracted from the Gene Expression Omnibus, The Cancer Genome Atlas, and Gene Ontology databases, we present a multiscale model of the long-term evolutionary dynamics leading from inflammation to tumorigenesis. The model incorporates cross-talk among interactions on several scales, including responses to DNA damage, gene mutation, cell-cycle behavior, population dynamics, inflammation, and metabolism-immune balance. Model simulations revealed two stages of inflammation-induced tumorigenesis: a precancerous state and tumorigenesis. The precancerous state was mainly caused by mutations in the cell proliferation pathway; the transition from the precancerous to tumorigenic states was induced by mutations in pathways associated with apoptosis, differentiation, and metabolism-immune balance. We identified opposing effects of inflammation on tumorigenesis. Mild inflammation removed cells with DNA damage through DNA damage-induced cell death, whereas severe inflammation accelerated accumulation of mutations and hence promoted tumorigenesis. These results provide insight into the evolutionary dynamics of inflammation-induced tumorigenesis and highlight the combinatorial effects of inflammation and metabolism-immune balance. This approach establishes methods for quantifying cancer risk, for the discovery of driver pathways in inflammation-induced tumorigenesis, and has direct relevance for early detection and prevention and development of new treatment regimes. Cancer Res; 77(22); 6429-41. ©2017 AACR.

Strategies for detecting colon cancer in patients with inflammatory bowel disease

BACKGROUND

Patients with longstanding ulcerative colitis and colonic Crohn's disease have an increased risk of colorectal cancer (CRC) compared with the general population. This review assessed the evidence that endoscopic surveillance may prolong life by allowing earlier detection of CRC or its pre-cursor lesion, dysplasia, in patients with inflammatory bowel disease (IBD).

OBJECTIVES

To assess the effectiveness of cancer surveillance programs for diagnosis of IBD-associated colorectal cancer and in reducing the mortality rate from colorectal cancer in patients with IBD.

SEARCH METHODS

We searched MEDLINE, EMBASE, CENTRAL and clinical clinicaltrials.gov from inception to 19 September 2016. We also searched conference abstracts and reference lists to identify additional studies.

SELECTION CRITERIA

Potentially relevant articles were reviewed independently and unblinded by two authors to determine eligibility. Randomised controlled trials (RCTs) or observational studies (cohort or case control) assessing any form of endoscopic surveillance aimed at early detection of CRC were considered for inclusion. Studies had to have a no surveillance comparison group to be eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Eligible studies were reviewed in duplicate and the results of the primary research trials were independently extracted by two authors. The primary outcome was detection of CRC. Secondary outcomes included death from CRC, time to cancer detection, time to death and adverse events. Deaths from CRC were derived from life tables, survival curves or where possible, by calculating life tables from the data provided. The presence of significant heterogeneity among studies was tested by the chi-square test. Because this is a relatively insensitive test, a P value of less than 0.1 was considered statistically significant. Provided statistical heterogeneity was not present, the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled odds ratio (OR) and 95% confidence intervals as described by Cochrane and Mantel and Haenszel. The methodological quality of the included studies was assessed using the Newcastle-Ottawa scale for non-randomised studies The overall quality of the evidence supporting the primary and selected secondary outcomes was assessed using the GRADE criteria.

MAIN RESULTS

No RCTs were identified. Five observational studies (N = 7199) met the inclusion criteria. The studies scored well on the Newcastle-Ottawa scale, but due to the nature of observational studies, a high risk of bias was assigned to all the studies. Three studies were pooled to assess the rate of cancer detected in the surveillance group compared to the non-surveillance group. The studies found a significantly higher rate of cancer detection in the non surveillance group compared to the surveillance group. CRC was detected in 1.83% (53/2895) of patients in the surveillance group compared to 3.17% (135/4256) of patients in the non-surveillance group (OR 0.58, 95% CI 0.42 to 0.80; P = 0.0009). Four studies were pooled to assess the death rate associated with CRC in patients who underwent surveillance compared to patients who did not undergo surveillance. There was a significantly lower death rate associated with CRC in the surveillance group compared to the non-surveillance group. Eight per cent (15/176) of patients in the surveillance group died from CRC compared to 22% (79/354) of patients in the non-surveillance group (OR 0.36, 95% CI 0.19 to 0.69, P=0.002). Data were pooled from two studies to examine the rate of early stage versus late stage colorectal cancer (Duke stages A & B compared to Duke stages C & D) in patients who underwent surveillance compared to patients who do not undergo surveillance. A significantly higher rate of early stage CRC (Duke A & B) was detected in the surveillance group compared to the non-surveillance group. Sixteen per cent (17/110) of patients in the surveillance group had early stage CRC compared to 8% (9/117) of patients in the non-surveillance group (OR 5.40, 95% CI 1.51 to 19.30; P = 0.009). A higher rate of late stage CRC (Duke C & D) was observed in the non-surveillance group compared to the surveillance group. Nine per cent (10/110) of patients in the surveillance group had late stage CRC compared to 16% (19/117) of patients in the non-surveillance group (OR 0.46, 95% CI 0.08 to 2.51; P = 0.37). A GRADE analysis indicated that the quality of the data was very low for all of these outcomes. The included studies did not report on the other pre-specified outcomes including time to cancer detection, time to death and adverse events.

AUTHORS' CONCLUSIONS

The current data suggest that colonoscopic surveillance in IBD may reduce the development of both CRC and the rate of CRC-associated death through early detection, although the quality of the evidence is very low. The detection of earlier stage CRC in the surveillance group may explain some of the survival benefit observed. RCTs assessing the efficacy of endoscopic surveillance in people with IBD are unlikely to be undertaken due to ethical considerations.

Detection of colonic dysplasia in patients with ulcerative colitis using a targeted fluorescent peptide and confocal laser endomicroscopy: A pilot study

Aim

Targeted molecular probes have been used to detect sporadic colonic dysplasia during confocal laser endomicroscopy (CLE) with promising results. This is a feasibility pilot study aiming to assess the potential role of CLE combined with a fluorescent-labeled peptide to stain and detect dysplasia associated with Ulcerative Colitis.

Method

A phage-derived heptapeptide with predicted high binding affinity for dysplastic tissue, was synthesized and labeled with fluorescein. Eleven lesions with suspected dysplasia at endoscopy were excised from nine patients with long-standing ulcerative colitis. Specimens were sprayed with the peptide and examined by CLE. The CLE images were then compared to the corresponding histological sections.

Results

At definitive histology, 4 lesions were diagnosed as inflammatory polyps, 6 as dysplastic lesions and one as invasive cancer. In inflammatory polyps, the fluorescence signal came from peri-cryptal spaces and crypt lumen due to passive accumulation of the peptide in these areas. Dysplasia was associated with active binding of the peptide to dysplastic colonocytes.

Conclusion

Ex vivo staining of ulcerative colitis-associated dysplasia using a fluorescent labeled molecular probe and CLE is feasible. In vivo studies on larger populations are required to evaluate the safety and the effective contribution of molecular probes in cancer surveillance of ulcerative colitis.

Diagnostic yield of endomicroscopy for dysplasia in primary sclerosing cholangitis associated inflammatory bowel disease: a feasibility study

BACKGROUND AND STUDY AIMS

Primary sclerosing cholangitis associated inflammatory bowel disease (PSC-IBD) is characterized by a high risk of colorectal dysplasia. Surveillance colonoscopies with random biopsies have doubtful power for dysplasia detection. Our aim was to prospectively investigate the feasibility and efficacy of pCLE in surveillance colonoscopies in patients with PSC-IBD.

PATIENTS AND METHODS

Sixty-nine patients with PSC-IBD underwent colonoscopy in 2 steps. On the way from rectum to cecum, the mucosa was inspected with high definition endoscopy (HDE) and random biopsies were taken according to the standard routine. On the way from cecum to rectum, fluorescein-enhanced pCLE and chromoendoscopy were performed. Regions where random biopsies had been taken, as well as visible lesions, were examined with pCLE and targeted biopsies were taken of lesions suspicious for dysplasia. Two investigators, blinded to histology and endoscopy results, analyzed all pCLE videos off-line.

RESULTS

Nineteen biopsies obtained in 13 patients (17 targeted biopsies, 2 random biopsies) revealed the presence of low-grade dysplasia. Thirteen lesions with dysplasia were endoscopically visible but by using pCLE-targeted biopsies, additional endoscopically invisible dysplasias in 4 biopsies obtained from 3 patients were detected. The sensitivity, specificity, and accuracy of pCLE in predicting dysplasia were respectively 89 % (95 % CI: 65 - 98), 96 % (95 % CI: 94 - 97), and 96 % (95 % CI: 94 - 97). pCLE showed a good performance for differentiating neoplastic from non-neoplastic mucosa with negative predictive value of 99 %.

CONCLUSIONS

pCLE in PSC-IBD surveillance is feasible and may be a good complement to HDE. Future research should aim at elucidating whether real-time pCLE is applicable in PSC-IBD surveillance.

Use of probe-based confocal laser endomicroscopy (pCLE) in gastrointestinal applications. A consensus report based on clinical evidence

BACKGROUND

Probe-based confocal laser endomicroscopy (pCLE) provides microscopic imaging during an endoscopic procedure. Its introduction as a standard modality in gastroenterology has brought significant progress in management strategies, affecting many aspects of clinical care and requiring standardisation of practice and training.

OBJECTIVE

This study aimed to provide guidance on the standardisation of its practice and training in Barrett's oesophagus, biliary strictures, colorectal lesions and inflammatory bowel diseases.

METHODS

Initial statements were developed by five group leaders, based on the available clinical evidence. These statements were then voted and edited by the 26 participants, using a modified Delphi approach. After two rounds of votes, statements were validated if the threshold of agreement was higher than 75%.

RESULTS

Twenty-six experts participated and, among a total of 77 statements, 61 were adopted (79%) and 16 were rejected (21%). The adoption of each statement was justified by the grade of evidence.

CONCLUSION

pCLE should be used to enhance the diagnostic arsenal in the evaluation of these indications, by providing microscopic information which improves the diagnostic performance of the physician. In order actually to implement this technology in the clinical routine, and to ensure good practice, standardised initial and continuing institutional training programmes should be established.

Outcome of "indefinite for dysplasia" in inflammatory bowel disease: correlation with DNA flow cytometry and other risk factors of colorectal cancer

Dysplasia that develops in the setting of inflammatory bowel disease precedes colorectal cancer (CRC). The category of "indefinite for dysplasia (IND)" is used often in equivocal cases, but its clinical significance remains unclear. Flow cytometric analysis of DNA content (aneuploidy) has shown some promise in stratifying patients into low or high risk of CRC, but there are few reports that have specifically evaluated the outcome of IND. As such, we analyzed a series of 84 IND inflammatory bowel disease patients seen at the University of Washington and Harborview Medical Centers from 2003 to 2013 to determine the outcome of IND. Hospital electronic medical records were further reviewed to correlate outcome with the type of lesion (flat versus polypoid), primary sclerosing cholangitis, active inflammation in the area of IND, and DNA flow cytometric data. The data show that 13% of IND cases were found to have low-grade dysplasia, whereas only 2% of IND cases showed advanced neoplasia (high-grade dysplasia or CRC) after a mean follow-up of 28 months. The risk of neoplasia was not significantly associated with the type of lesion (P = .94 from log-rank test), primary sclerosing cholangitis (P = .94), or active inflammation (P = .41) in this cohort. However, the finding of DNA aneuploidy at baseline IND was predictive of subsequent detection of neoplasia (P = .037). IND patients with abnormal DNA flow cytometric results may warrant more careful follow-up, but conversely, IND in the setting of normal DNA content may require less frequent surveillance colonoscopy.

Defining quality indicators for best-practice management of inflammatory bowel disease in Canada

BACKGROUND

There is a paucity of published data regarding the quality of care of inflammatory bowel disease (IBD) in Canada. Clinical quality indicators are quantitative end points used to guide, monitor and improve the quality of patient care. In Canada, where universal health care can vary significantly among provinces, quality indicators can be used to identify potential gaps in the delivery of IBD care and standardize the approach to interprovincial management.

METHODS

The Emerging Practice in IBD Collaborative (EPIC) group generated a shortlist of IBD quality indicators based on a comprehensive literature review. An iterative voting process was used to select quality indicators to take forward. In a face-to-face meeting with the EPIC group, available evidence to support each quality indicator was presented by the EPIC member aligned to it, followed by group discussion to agree on the wording of the statements. The selected quality indicators were then ratified in a final vote by all EPIC members.

RESULTS

Eleven quality indicators for the management of IBD within the single-payer health care system of Canada were developed. These focus on accurate diagnosis, appropriate and timely management, disease monitoring, and prevention or treatment of complications of IBD or its therapy.

CONCLUSIONS

These quality indicators are measurable, reflective of the evidence base and expert opinion, and define a standard of care that is at least a minimum that should be expected for IBD management in Canada. The next steps for the EPIC group involve conducting research to assess current practice across Canada as it pertains to these quality indicators and to measure the impact of each of these indicators on patient outcomes.

Chromoendoscopy and Advanced Imaging Technologies for Surveillance of Patients with IBD

Inflammatory bowel disease patients with long-standing colitis have an increased risk of colorectal cancer. The high rate of interval colitis-associated cancers among patients who adhere to a nontargeted, random biopsy surveillance strategy underlies the need for improved methods of early dysplasia detection. Compelling evidence supports the efficacy of chromoendoscopy for increasing the detection rate of dysplasia; however, this technology is currently underutilized in the clinical setting. Other contrast-based technologies-including confocal laser endomicroscopy (Pentax), endocytoscopy, multiband imaging, i-scan (Pentax), and molecular-targeted techniques-show promise in the detection of dysplasia in patients with inflammatory bowel disease. The strategies currently available for identifying patients with dysplasia or colitis-associated cancers remain inadequate and need to demonstrate both cost and time efficiency before they can be adopted in community-based practices.

Diagnostic accuracy of confocal laser endomicroscopy in diagnosing dysplasia in patients affected by long-standing ulcerative colitis

AIM: To evaluate the diagnostic accuracy of confocal laser endomicroscopy (CLE) for the detection of dysplasia in long-standing ulcerative colitis (UC).

METHODS: We prospectively performed a surveillance colonoscopy in 51 patients affected by long-standing UC. Also, in the presence of macroscopic areas with suspected dysplasia, both targeted contrasted indigo carmine endoscopic assessment and probe-based CLE were performed. Colic mucosal biopsies and histology, utilised as the gold standard, were assessed randomly and on visible lesions, in accordance with current guidelines.

RESULTS: Fourteen of the 51 patients (27%) showed macroscopic mucosal alterations with the suspected presence of dysplasia, needing chromoendoscopic and CLE evaluation. In 5 macroscopically suspected cases, the presence of dysplasia was confirmed by histology (3 flat dysplasia; 2 DALMs). No dysplasia/cancer was found on any of the outstanding random biopsies. The diagnostic accuracy of CLE for the detection of dysplasia compared to standard histology was sensitivity 100%, specificity 90%, positive predictive value 83% and negative predictive value 100%.

CONCLUSION: CLE is an accurate tool for the detection of dysplasia in long-standing UC and shows optimal values of sensitivity and negative predictivity. The scheduled combined application of chromoendoscopy and CLE could maximize the endoscopic diagnostic accuracy for diagnosis of dysplasia in UC patients, thus limiting the need for biopsies.

Ulcerative colitis and cancer

Patients with ulcerative colitis (UC) are at an increased risk for the development of colorectal cancer (CRC). Unlike sporadic CRC, the cancer in UC patients arises from a focal or multifocal dysplastic mucosa in areas of inflammation. The clinical features of UC-associated cancer are similar to those found in patients with hereditary non-polyposis colorectal cancer. As with other varieties of CRC, UC-associated cancer exhibits a variety of genetic and molecular changes/abnormalities. These abnormalities are however clustered in areas of mucosae with histological abnormalities. The magnitude and timing of these changes are however significantly different. Surveillance and identification of patients at risk for cancer are a challenging problem.

Altered expression of CK7 and CK20 in preneoplastic and neoplastic lesions in ulcerative colitis

This study is based on all patients with ulcerative colitis from a defined catchment area in Northern Sweden in a still ongoing colonoscopy surveillance programme, which started in 1977. From this material we selected tissue from eight groups of patients consisting of normal control biopsies (5), inactive colitis (10), active colitis (10), findings of low-grade dysplasia (10), high-grade dysplasia (6), aneuploidy (without dysplasia and with subsequent dysplasia) (10), and ulcerative colitis-associated cancers (5). The samples were evaluated according to immunohistochemical expression of CK7 and CK20. Colonic mucosa from normal controls and inactive colitis was found to be completely negative for CK7. In 9 out of 10 patients with active colitis, CK7 was sparsely expressed in a patchy manner and connected with active epithelial inflammatory areas. 7 out of 10 patients with low-grade dysplasia and 3 out of 6 with high-grade dysplasia were positive for CK7. Samples with aneuploidy without dysplasia were completely negative, while 2 out of 6 showing subsequent dysplasia were positive. Of the five cancers, two were positive for CK7. CK20 was expressed in nearly all samples but relatively more in the lower part of the crypts in neoplasia-associated lesions. Our results indicate a possible relationship between expression of CK7 and CK20 and neoplastic development of colorectal mucosa in patients with ulcerative colitis. Further studies are needed to elucidate whether these findings have clinical significance.

Review article: The relevance of surveillance endoscopy in long-lasting inflammatory bowel disease

BACKGROUND

Development of colitis-associated colorectal cancer is an important clinical problem in patients with colonic inflammatory bowel disease (IBD). British and American guidelines recommend to start surveillance after a disease duration of 8-10 or 15-20 years for patients with extensive or left-sided colitis, respectively.

AIM

To assess the evidence level of current surveillance strategies.

METHODS

A PubMed-based literature search using the search terms inflammatory bowel disease, ulcerative colitis, Crohn's disease, dysplasia, colorectal cancer and surveillance was performed.

RESULTS

Low-grade and high-grade dysplastic lesions progress to cancer in a high percentage of patients. Furthermore, concurrent cancer is found in approximately one-third of the patients with colonic dysplasia. Low-level evidence showing reduced colorectal cancer-related mortality in patients who were undergoing surveillance is available. Patients with concomitant primary sclerosing cholangitis form a subgroup of IBD patients with an even higher risk of colorectal neoplasia.

CONCLUSIONS

Colonic surveillance prolongs life expectancy of patients with long-lasting IBD.

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.

Detection and treatment of early flat and depressed colorectal cancer using high-magnification chromoscopic colonoscopy: a change in paradigm for Western endoscopists?

Japanese researchers reported flat and depressed colorectal lesions in the 1980s. Such lesions were thought irrelevant to Western populations and described as "Phantom" or "Akitas" carcinoma. Many depressed neoplasms arise through the de novo pathogenic sequence and demonstrate early invasive characteristics. All investigators report difficulties in identifying flat and depressed lesions using conventional colonoscopy. Failure to detect and treat such lesions may be responsible for the current shortfalls in secondary colorectal cancer prevention. Given the introduction of colorectal cancer screening programs in the United Kingdom, Europe, and the United States, it is essential to re-evaluate the significance of flat lesions as applicable to Western cohorts and explore the safety and efficacy of new endoscopic technology and interventional therapeutics.

Meta-analysis: cancer risk of low-grade dysplasia in chronic ulcerative colitis

BACKGROUND

The cancer risk of low-grade dysplasia (LGD) in chronic ulcerative colitis is variable and its management remain contentious.

AIM

To determine the risk of cancer or any advanced lesion once LGD is diagnosed.

METHODS

A MEDLINE, EMBASE and Pub Med search was conducted using the key words 'surveillance', 'colorectal cancer', 'low-grade dysplasia' and 'ulcerative colitis'. A random effects model of meta-analysis was used.

RESULTS

Twenty surveillance studies had 508 flat LGD or LGD with dysplasia-associated lesion or mass. An average of 4.3 colonoscopies was performed/patient post-LGD diagnosis (range: 3-7.6). An average of 18 biopsies taken per colonoscopy (range: 9-24) detected 73 advanced lesions (cancer or high-grade dysplasia) pre-operatively. The cancer incidence was 14 of 1000 (95% CI: 5.0-34) person years duration (pyd) and the incidence of any advanced lesion was 30 of 1000 pyd (95% CI: 12-76). When LGD is detected on surveillance there is a ninefold risk of developing cancer (OR: 9.0, 95% CI: 4.0-20.5) and 12-fold risk of developing any advanced lesion (OR: 11.9, 95% CI: 5.2-27).

CONCLUSIONS

The risk of developing cancer in patients with LGD is high. These estimates are valuable for decision-making when LGD is encountered on surveillance.

5-aminosalicylic acid is an attractive candidate agent for chemoprevention of colon cancer in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) is classically subdivided into ulcerative colitis (UC) and Crohn’s disease (CD). Patients with IBD have increased risk for colorectal cancer. Because the pathogenesis of colorectal carcinoma has not been entirely defined yet and there is no ideal treatment for colon cancer, cancer prevention has become increasingly important in patients with IBD. The two adopted methods to prevent the development of colon cancer in clinical practice include the prophylactic colectomy and colonoscopic surveillance. But patients and physicians seldom accept colectomy as a routine preventive method and most patients do not undergo appropriate colonoscopic surveillance. Chemoprevention refers to the use of natural or synthetic chemical agents to reverse, suppress, or to delay the process of carcinogenesis. Chemoprevention is a particularly useful method in the management of patients at high risk for the development of specific cancers based on inborn genetic susceptibility, the presence of cancer-associated disease, or other known risk factors. Prevention of colorectal cancer by administration of chemopreventive agents is one of the most promising options for IBD patients who are at increased risks of the disease. The chemopreventive efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) against intestinal tumors has been well established. But with reports that NSAIDs aggravated the symptoms of colitis, their sustained use for the purpose of cancer chemoprevention has been relatively contraindicated in IBD patients. Another hopeful candidate chemoprevention drug for IBD patients is 5-aminosalicylic acid (5-ASA), which is well tolerated by most patients and has limited systemic adverse effects, and no gastrointestinal toxicity. 5-ASA lacks the well-known side effects of long-term NSAIDs use. Retrospective correlative studies have suggested that the long-term use of 5-ASA in IBD patients may significantly reduce the risk of development of colorectal cancer. According to the literature, this agent might well satisfy clinical expectations with respect to a safe and effective chemopreventive agent.

Review article: colorectal carcinoma and inflammatory bowel disease

The risk of colorectal cancer for any patient with ulcerative colitis is estimated to be 2% after 10 years, 8% after 20 years and 18% after 30 years of disease. The relative risk of colorectal cancer in Crohn's colitis is approximately 5.6 and should raise the same concerns as in ulcerative colitis. Risk factors for colorectal cancer include disease duration, early onset, extensive disease, primary sclerosing cholangitis and a family history of sporadic colorectal cancer. All patients should have a review colonoscopy 8-10 years after diagnosis to establish the extent of the disease. Surveillance should begin 8-10 years after disease onset for pancolitis and 15-20 years after disease onset for left-sided disease. Regular surveillance is recommended, with a screening interval every 3 years in the second decade of disease and annually by the fourth decade. Random biopsies should be taken at regular intervals with attention paid to dysplasia-associated lesions or masses, irregular plaques, villiform elevations, ulcers and strictures. Dysplasia is recognized as a premalignant condition, but the likelihood of progression to cancer is difficult to predict. High-grade dysplasia, confirmed by two expert gastrointestinal pathologists, is a strong indication for colectomy, as is low-grade dysplasia, although the diagnosis of low-grade dysplasia is unreliable. Surveillance programmes indicate that the overall 5-year survival rate is higher in surveyed patients, although patients still present with Dukes C cancers or disseminated malignancy. Surveillance has huge socioeconomic implications. As surveillance is not 100% effective, alternative ways of reducing the cancer risk with chemopreventive agents, such as aminosalicylates, are being considered.

Ten year follow up of ulcerative colitis patients with and without low grade dysplasia

BACKGROUND AND AIMS

Low grade dysplasia (LGD) is believed to predispose to colorectal cancer (CRC), and proctocolectomy has been advocated when this is identified. Between 1978 and 1990, 160 patients with longstanding extensive ulcerative colitis (UC) were recruited for annual colonoscopic surveillance and 40 developed LGD at some stage. We report the outcome of this cohort 10 years after the original study ended.

METHODS

Retrospective cohort study and histopathological review of the original diagnoses of LGD. The outcome of 158/160 (98.8%) patients was established in 2000.

RESULTS

Of the 128 patients still alive and with an intact colon at the end of 1990, two were not traceable, 29 had LGD, and 97 had no dysplasia (controls). After 10 years, high grade dysplasia (HGD) or CRC developed in 3/29 LGD (10%) and in 4/97 controls (4.0%). Kaplan-Meier analysis from 1991 to death or colectomy did not show a statistically significant difference between the two groups (log rank test p=0.63). Histopathological review demonstrated the unreliability of LGD diagnosis. Agreement between pathologists was uniformly poor: kappa <0.4 for all comparisons.

CONCLUSION

LGD diagnosis is not sufficiently reliable to justify prophylactic colectomy. Conservative management of established LGD cases should not be ruled out.

Management of neoplastic polyps in inflammatory bowel disease

Dysplasia-associated lesions or masses (DALMs) are a heterogeneous population of lesions with different endoscopic and morphologic features. Non-adenoma-like DALMs should be removed via colectomy. Adenoma-like DALMs that occur outside areas of colitis can be treated like sporadic adenomas and removed by polypectomy. Recent data suggest that adenoma-like DALMs located within areas of colitis should be removed by polypectomy with complete excision and multiple biopsies of the site. As long as there is no flat dysplasia or adenocarcinoma elsewhere in the colon, a colectomy is not required. However, this group of patients requires increased colonoscopic surveillance.

Colonic dysplasia and cancer in inflammatory bowel disease

Extracolonic malignancies are a relatively rare complication of inflammatory bowel disease. In contrast, colorectal cancer remains a major concern for patients with long-standing UC. The best available evidence suggests that patients with long-standing Crohn's colitis are at similar risk for colorectal cancer as those patients with long-standing UC. In patients with UC, the magnitude of this increased risk appears to be greater in patients with more extensive colonic involvement. It appears that the magnitude of this risk increases with increasing duration of disease, at least in UC. Whether this reflects the increased risk of cancer that occurs with the aging process or a separate phenomena distinct to UC is unclear. To date, the methods available to reduce the risk of cancer are less than optimal. Although surgical procedures eliminate the risk, the mental and physical sequelae of these procedures can be substantial. Surveillance with colonoscopic biopsies is likely effective in reducing although not eliminating the risk of colorectal cancer. Efforts to develop chemopreventative agents and improved surveillance methods remain areas of active investigation.

Cancer surveillance in ulcerative colitis: critical analysis of long-term prospective programme

BACKGROUND

Patients with longstanding ulcerative colitis are at increased risk of colorectal cancer. In the literature, no agreement has yet been reached regarding prevention strategies. Our report sums up a prospective study started in 1980.

METHODS

A total of 65 patients affected by ulcerative colitis for more than seven years were admitted to a regular colonoscopic and biopsy follow-up programme.

RESULTS

Some 20 years after the beginning of the study, 23 (35.3%) patients have been operated upon, 2 patients have died but not from cancer 29 (44.66%) patients have abandoned the programme. Only 11 (16.9%) patients have remained under colonoscopic surveillance.

CONCLUSION

These results cast some doubts on the significance of such a programme and on its long-term feasibility.

Cancer in inflammatory bowel disease. An evidence-based analysis and guide for physicians and patients

The risk of cancer in IBD is real and is a cause of anxiety and concern among patients and practitioners. Current modalities for detecting dysplasia in IBD are crude and insensitive and subject to observer and sampling bias. This evidence-based review confirms a significant increased risk for colorectal cancer among patients with pancolonic UC and, to a lesser extent, in patients with left-sided disease. Risk increases with longer duration of disease; early age at diagnosis; coexisting PSC; and, perhaps, a family history of colorectal cancer. Physicians must pay greater attention to the manner in which they implement surveillance colonoscopies, including paying heed to the location and number of biopsy specimens required to maximize the benefit. With respect to CD, the evidence suggests that patients with extensive colonic involvement of long duration carry a similar risk of colorectal cancer to patients with UC and should be considered candidates for surveillance colonoscopy.

The risk of colorectal cancer in ulcerative colitis: a meta-analysis

BACKGROUND AND AIMS

Controversy surrounds the risk of colorectal cancer (CRC) in ulcerative colitis (UC). Many studies have investigated this risk and reported widely varying rates.

METHODS

A literature search using Medline with the explosion of references identified 194 studies. Of these, 116 met our inclusion criteria from which the number of patients and cancers detected could be extracted. Overall pooled estimates, with 95% confidence intervals (CI), of cancer prevalence and incidence were obtained using a random effects model on either the log odds or log incidence scale, as appropriate.

RESULTS

The overall prevalence of CRC in any UC patient, based on 116 studies, was estimated to be 3.7% (95% CI 3.2-4.2%). Of the 116 studies, 41 reported colitis duration. From these the overall incidence rate was 3/1000 person years duration (pyd), (95% CI 2/1000 to 4/1000). The overall incidence rate for any child was 6/1000 pyd (95% CI 3/1000 to 13/1000). Of the 41 studies, 19 reported results stratified into 10 year intervals of disease duration. For the first 10 years the incidence rate was 2/1000 pyd (95% CI 1/1000 to 2/1000), for the second decade the incidence rate was estimated to be 7/1000 pyd (95% CI 4/1000 to 12/1000), and in the third decade the incidence rate was 12/1000 pyd (95% CI 7/1000 to 19/1000). These incidence rates corresponded to cumulative probabilities of 2% by 10 years, 8% by 20 years, and 18% by 30 years. The worldwide cancer incidence rates varied geographically, being 5/1000 pyd in the USA, 4/1000 pyd in the UK, and 2/1000 pyd in Scandinavia and other countries. Over time the cancer risk has increased since 1955 but this finding was not significant (p=0.8).

CONCLUSIONS

Using new meta-analysis techniques we determined the risk of CRC in UC by decade of disease and defined the risk in pancolitics and children. We found a non-significant increase in risk over time and estimated how risk varies with geography.

The risk of colorectal cancer in ulcerative colitis: a meta-analysis

BACKGROUND AND AIMS

Controversy surrounds the risk of colorectal cancer (CRC) in ulcerative colitis (UC). Many studies have investigated this risk and reported widely varying rates.

METHODS

A literature search using Medline with the explosion of references identified 194 studies. Of these, 116 met our inclusion criteria from which the number of patients and cancers detected could be extracted. Overall pooled estimates, with 95% confidence intervals (CI), of cancer prevalence and incidence were obtained using a random effects model on either the log odds or log incidence scale, as appropriate.

RESULTS

The overall prevalence of CRC in any UC patient, based on 116 studies, was estimated to be 3.7% (95% CI 3.2-4.2%). Of the 116 studies, 41 reported colitis duration. From these the overall incidence rate was 3/1000 person years duration (pyd), (95% CI 2/1000 to 4/1000). The overall incidence rate for any child was 6/1000 pyd (95% CI 3/1000 to 13/1000). Of the 41 studies, 19 reported results stratified into 10 year intervals of disease duration. For the first 10 years the incidence rate was 2/1000 pyd (95% CI 1/1000 to 2/1000), for the second decade the incidence rate was estimated to be 7/1000 pyd (95% CI 4/1000 to 12/1000), and in the third decade the incidence rate was 12/1000 pyd (95% CI 7/1000 to 19/1000). These incidence rates corresponded to cumulative probabilities of 2% by 10 years, 8% by 20 years, and 18% by 30 years. The worldwide cancer incidence rates varied geographically, being 5/1000 pyd in the USA, 4/1000 pyd in the UK, and 2/1000 pyd in Scandinavia and other countries. Over time the cancer risk has increased since 1955 but this finding was not significant (p=0.8).

CONCLUSIONS

Using new meta-analysis techniques we determined the risk of CRC in UC by decade of disease and defined the risk in pancolitics and children. We found a non-significant increase in risk over time and estimated how risk varies with geography.

Diagnostic value of DNA image cytometry in ulcerative colitis

The increased risk of colorectal cancer in patients with extensive, long-standing ulcerative colitis is well established. The interpretation of dysplasia as the common precursor lesion of colorectal cancer in ulcerative colitis is, however, subject to inter- and intraobserver variation. The histologic diagnosis is particularly difficult in the presence of acute inflammation. Therefore, the analysis of ploidy patterns might be a more objective diagnostic tool. In the present study, the correlation of ploidy and dysplasia of the colonic mucosa was evaluated in the absence and presence of inflammation. Image cytometry was performed on 561 fixed, paraffin-embedded tissue specimens from 67 patients with ulcerative colitis. Twenty patients had long-standing and extensive disease, including eight patients in whom the colitis was associated with colorectal cancer. Dysplasia was only found in patients with long-standing colitis or with colorectal cancer and was significantly more often diagnosed in the case of concomitant inflammation. On the other hand, aneuploid patterns were shown to occur independent of inflammatory activity. Aneuploidy was present in all colorectal carcinomas associated with ulcerative colitis and in 46.2% of specimens with dysplasia. Moreover, aneuploidy was detectable in four of 12 samples with low-grade dysplasia as well as in one case devoid of any dysplastic alteration. Ulcerative colitis patients with low-grade dysplasia plus aneuploidy probably represent a subgroup that might be at higher risk of developing colorectal cancer than patients with low-grade dysplasia alone. All in all, image cytometry analysis might be instrumental in identifying neoplastic lesions even in cases of increased inflammatory activity or regenerative change.

How gastroenterologists screen for colonic cancer in ulcerative colitis: an analysis of performance

BACKGROUND

The aim of this study was to assess the colorectal cancer surveillance practices of British gastroenterologists for patients with ulcerative colitis.

METHODS

A questionnaire that investigated aspects of surveillance in patients with ulcerative colitis was mailed to all consultant gastroenterologists in the U.K. (n = 413).

RESULTS

Three hundred forty-one questionnaires were returned (response rate 83%). Ninety-four percent of consultants practice cancer surveillance in ulcerative colitis, with 35% maintaining a registry of patients in surveillance programs. All gastroenterologists perform surveillance in patients with pancolitis, 24% in those with left-sided colitis and 2% in patients with proctitis. The mean duration of disease before surveillance is commenced is 9.2 years for pancolitis and 12.4 years for left-sided colitis (p < 0.0001). Only 4% of gastroenterologists routinely offer patients with disease of more than 10 years' duration a prophylactic colectomy. Colonoscopies are conducted by an accredited gastroenterologist in 65% of cases and biopsies are reviewed by specialists in gastrointestinal pathology in 45%. When histology reveals low-grade dysplasia only 4% advise colectomy and when high-grade dysplasia is found 53% recommend colectomy. Sixteen percent of gastroenterologists were unaware of the significance of a dysplasia associated lesion or mass.

CONCLUSION

The majority of gastroenterologists practice surveillance on a disorganized basis. There is inconsistency in the management of patients with dysplasia and education of gastroenterologists is needed.

Cancer risk in patients with inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) are at increased risk for developing cancer of the gastrointestinal tract, particularly colorectal cancer. Because of the relative rarity of IBD in the general population, it has been difficult to quantify this risk. Efforts to reduce the risk have included both prophylactic surgery and endoscopic screening programs. Because of the potential impact on quality of life and life expectancy, the optimal strategy for reducing this risk has not been defined. This article reviews the current literature relating to the risk of cancer for patients with IBD and methods to reduce this risk.

Sialyl-Tn antigen as a marker of colon cancer risk in ulcerative colitis: relation to dysplasia and DNA aneuploidy

BACKGROUND & AIMS

Expression of the mucin-associated carbohydrate antigen sialyl-Tn (STn) and DNA aneuploidy has each been shown to correlate with malignant transformation in patients with sporadic colon cancer and in those with ulcerative colitis (UC). This study aimed to determine how STn expression topographically and temporally relates to aneuploidy and neoplasia in patients with long-standing UC.

METHODS

Twenty-six patients enrolled in a cancer surveillance program were studied, and 1691 mucosal specimens from repeated colonoscopies and colectomies were assessed in a standardized, prospective fashion for the presence of dysplasia, aneuploidy, and STn antigen.

RESULTS

STn was expressed in 47% of specimens from 6 patients who underwent colectomy for dysplasia and 7% of specimens from 6 well-matched patients who underwent surgery for medical intractability. Seven other patients who never developed dysplasia or aneuploidy expressed STn in 6% of biopsy specimens. STn expression was independent of aneuploidy in colons both with and without dysplasia. Of 5 patients with aneuploidy but without dysplasia, 4 expressed STn earlier than aneuploidy.

CONCLUSIONS

In UC, STn antigen and DNA aneuploidy are independent markers of neoplastic transformation. Determination of STn expression may complement dysplasia and aneuploidy for identification of risk for colonic neoplasia in UC.

p53 mutation in patients with ulcerative colitis in rectal biopsy

OBJECTIVES

Long standing ulcerative colitis (UC) has been known to be one of the precancerous diseases of colorectal cancer. Although the frequent loss of p53 allele (LOH) and aneuploidy were reported as the molecular events in carcinoma and dysplasia known as the precursor of UC, p53 genetic alteration was not reported in indefinite dysplasia and UC involved mucosa in long standing UC. Therefore, we investigated the mutational inactivation of the p53 gene in UC patients who showed dysplastic mucosa, as well as non-dysplastic mucosa on H & E stain and, secondly, if there is p53 mutation, we examined the relationship between p53 alteration and clinical data.

METHOD

Sixteen patients with UC who had different duration of colitis were studied by endoscopic examination with rectal mucosal biopsies, p53 gene alterations were detected by PCR-SSCP for exon 4-8 and immunohistochemical staining with p53 monoclonal antibody.

RESULTS

Among 16 patients, 2 patients (12%) showed dysplasia on H-E stain. The p53 point mutations were detected in 4 (two dysplasia and 2 normal looking mucosa) on PCR-SSCP. 4 patients who had p53 gene mutation were positive in immunohistochemical staining. With regard to clinical characteristics, these patients with p53 point mutation showed poor response to medical treatment.

CONCLUSION

These results suggest that the p53 mutation may be an early molecular event of cancerous change in UC.

Colonic cancer surveillance in ulcerative colitis is not essential for every patient

It is generally recognised that there is an increased risk of colonic cancer in patients with long-standing extensive colitis, and regular annual or biennial colonoscopic surveillance protocols have been recommended in order to detect early cancer. There is, however, little evidence to suggest that these protocols are of value. There have been no properly conducted controlled trials in this area, and the studies that have been reported are flawed by selection bias, the inclusion of patients with "pseudo disease" and protocol violators. Many studies have not distinguished between "screening colonoscopy" and "colonoscopic surveillance". Some have not drawn attention to the failures in the surveillance, i.e. patients with Dukes' grade C or worse, and overall the conclusions drawn have been unrealistically optimistic. The diagnosis of low grade dysplasia which has been accorded importance is insensitive, non-specific and is subject to gross interobserver error. It is of little clinical value. Colonoscopic surveillance using currently available techniques is of only marginal benefit to patients included within the protocol. It is not cost-effective and cannot be made to be so.

Colorectal cancer in patients with ulcerative colitis. A prospective cohort study in Italy

BACKGROUND

The aim of this study was to assess the development of dysplasia or cancer in patients with ulcerative colitis and to determine the effectiveness of colonoscopy and biopsy follow-up in colon cancer surveillance.

METHODS

From 1980 to 1986, 65 patients who had ulcerative colitis for 7 years or more participated in a surveillance program of colonoscopy and biopsy. This cohort was followed until December 1992. Forty-nine patients (75.4%) had extensive colitis and 16 (24.6%) left-sided colitis. The mean disease duration was 17.2 years. Three hundred four colonoscopies were performed. During each endoscopy, random biopsies were performed.

RESULTS

Seven patients had definite dysplasia of the colorectal mucosa. Four of them had high grade lesions and underwent surgery. In all of these patients, colon cancer (3 Dukes' Stage A, 1 Dukes' Stage B) was found. No cancer was found in the other patients. Pedunculated adenomas were excised from 6 other patients during colonoscopy. When dysplasia was diagnosed, these patients were older than those who were dysplasia free, whereas the age at onset of colitis was significantly higher in the former (P < 0.01). Fifteen patients discontinued follow-up. Two of them developed colon cancer diagnosed at an advanced stage.

CONCLUSIONS

Dysplasia, especially of high grade, is a marker of colon cancer risk in patients with longstanding ulcerative colitis. Intensive colonoscopy and biopsy surveillance can lead to the diagnosis of colon cancer at a potentially curable stage. In this series, older age appeared to be an additional risk factor. A careful selection of patients with ulcerative colitis seems mandatory to minimize the cost and optimize the benefit of colon cancer surveillance programs.

DNA aneuploidy in a case of rectosigmoid adenocarcinoma complicated by ulcerative colitis

A case of Borrmann type IV colorectal adenocarcinoma detected as a complication of long-standing ulcerative colitis is reported. Barium enema and colonoscopy disclosed a stenotic area associated with a tumoral mass and a flat elevated lesion in the rectosigmoid region and a submucosal tumor-like lesion in the rectum. Total colectomy was performed and histological studies demonstrated a moderately differentiated adenocarcinoma accompanied by high- and low-grade dysplasia. DNA ploidy pattern analysis showed aneuploidy in the adenocarcinoma and high-grade dysplasia, but diploidy in the normal and atrophic mucosa and in low-grade dysplasia. DNA aneuploid content was associated with the presence of colorectal carcinoma complicating ulcerative colitis, indicating that DNA content studies should be included in screening programs to detect early colorectal carcinoma following this disease, as a complementary study to histological assessment.

Preoperative diagnosis of a small, depressed rectal cancer complicating ulcerative colitis. Report of a case

PURPOSE

This study was designed to clarify the importance of detecting small, depressed colorectal cancer complicating ulcerative colitis.

METHODS

A 39-year-old Japanese male, who had an 18-year history of left-sided ulcerative colitis, was admitted to Fukuoka University Hospital for further evaluation of his colitis. Colonoscopy with a dye spraying method clearly revealed a small, depressed lesion and flat plaque-like lesions in the rectum. Biopsies taken from a depressed lesion and plaque-like lesions revealed a signet-ring cell carcinoma and dysplasia, respectively. Total colectomy was performed.

RESULTS

Sections from the depressed rectal lesion, measuring 7 x 8 mm in size, revealed a signet-ring cell carcinoma that diffusely invaded the muscularis propria. Lymph node metastasis was evident. Flat plaques and mucosa around the depressed lesion were positive for dysplasia.

CONCLUSION

This is the first report of a case of small, depressed rectal cancer complicating ulcerative colitis diagnosed by preoperative colonoscopy. To improve outcome of colonoscopic surveillance in ulcerative colitis, detecting such small, depressed lesions are important, and colonoscopy with a dye spraying method would be useful in detecting them.

The true extent of ulcerative colitis? A radiological, endoscopic and histological study

Twenty-six radiological, endoscopic and histological examinations of the large bowel were performed in 25 patients with ulcerative colitis. Extensive colitis was observed in 42% of the radiological, in 38% of the endoscopic, and in 27% of the histological examinations. Agreement as to the extent of the colitis between all three examination methods was reached in 53% of the cases. The endoscopic extent of colitis varied between left-sided and extensive in 41% of the patients during a 7-year median follow-up. The frequent change in the extent of ulcerative colitis and the considerable disagreement between radiography, colonoscopy and histology in evaluating the extent of colitis justify the question, "Does a true, unambiguous extent of colitis really exist?" It is more likely that the extent of colitis is just a function of time and the examination method used.