Colorectal cancer prevention in ulcerative colitis: a case-control study

Radical induction theory of ulcerative colitis

To propose a new pathogenesis called Radical Induction to explain the genesis and progression of ulcerative colitis (UC). UC is an inflammatory bowel disease. Colonic inflammation in UC is mediated by a buildup of white blood cells (WBCs) within the colonic mucosal lining; however, to date there is no answer for why WBCs initially enter the colonic mucosa to begin with. A new pathogenesis termed “Radical Induction Theory” is proposed to explain this and states that excess un-neutralized hydrogen peroxide, produced within colonic epithelial cells as a result of aberrant cellular metabolism, diffuses through cell membranes to the extracellular space where it is converted to the highly damaging hydroxyl radical resulting in oxidative damage to structures comprising the colonic epithelial barrier. Once damaged, the barrier is unable to exclude highly immunogenic fecal bacterial antigens from invading the normally sterile submucosa. This antigenic exposure provokes an initial immune response of WBC infiltration into the colonic mucosa. Once present in the mucosa, WBCs are stimulated to secrete toxins by direct exposure to fecal bacteria leading to mucosal ulceration and bloody diarrhea characteristic of this disease.

Preventing neoplastic progression in ulcerative colitis

Patients with ulcerative colitis (UC) and Crohn's colitis carry an increased risk for developing colorectal cancer (CRC). Patients with more extensive colitis, greater duration of disease, concomitant primary sclerosing cholangitis, and a family history of CRC are at greatest risk among UC patients. Young age at disease onset and greater inflammatory burden have also been proposed as risk factors. Maneuvers that limit the impact of cancer in colitis include prophylactic colectomy, which is unacceptable to most UC and Crohn's colitis patients, and dysplasia surveillance. Although recommended in a number of practice guidelines, surveillance has not yet been demonstrated to reduce CRC mortality or morbidity. A number of factors, including low levels of agreement among pathologists interpreting surveillance specimens, patients lost to follow-up, failure to recommend colectomy once dysplasia has been discovered, and others, hinder the success of surveillance. In an effort to compensate for the limitations of surveillance, chemoprevention and newer endoscopic and molecular techniques are being assessed for their effectiveness in augmenting or replacing conventional surveillance.

Animal models of inflammatory bowel disease

In inflammatory bowel disease (IBD), experimental models have proven to be important tools for detecting potential therapeutic agents and for investigating the mechanisms of pathogenesis. This review is intended to cover recent advances in basic IBD model applications. The use of more than 20 animal models has allowed the detection of numerous protective pharmacological agents, including a number of immunomodulatory agents that have entered the therapeutic armamentarium. The models have been classified into five main categories based on the methods of induction: gene knockout (KO), transgenic, chemical, adoptive transfer, and spontaneous (each with subcategories).

Consensus conference: Colorectal cancer screening and surveillance in inflammatory bowel disease

The idiopathic inflammatory bowel diseases, ulcerative colitis and Crohn's colitis, are associated with an increased risk for developing colorectal cancer. To reduce colorectal cancer mortality in inflammatory bowel disease, most patients and their physicians choose to follow a program of surveillance colonoscopy in an attempt to detect early neoplastic lesions at a curable stage. Colectomy is typically reserved for patients whose biopsy findings are indicative of heightened cancer risk based on interpretation by pathologists. Despite the absence of prospective controlled clinical trials to formally evaluate the benefits, risks, and costs of this approach, enough circumstantial evidence has accrued to warrant its widespread adoption in practice. Nevertheless, no standardized guidelines have yet been set forth to guide the gastroenterologist in performing surveillance. A panel of international experts was assembled to develop consensus recommendations for the performance of surveillance. The findings are presented herein.

Proposal of a new clinical index predictive of endoscopic severity in ulcerative colitis

Assessment of disease activity by clinical parameters in ulcerative colitis is still controversial. Different clinical indexes have been proposed. Colonoscopy provides detailed information on mucosal damage. The aim of this study was to identify, among 21 clinical and laboratory parameters, which were predictive of endoscopic activity. We included 137 consecutive patients with ulcerative colitis who underwent colonoscopy, clinical examination, and blood tests within 4 weeks. Endoscopic severity was recorded using a simple score (range, 0-30). The multiple stepwise regression coefficient of each significant variable predictive of mucosal damage was used to develop a new activity index predictive of endoscopic appearance (Endoscopic-Clinical Correlation Index; ECCI). We tested the ability of our score to discriminate patients with severe endoscopic disease, calculating the area under the receiver operator characteristic curve, and we compared it to activity indexes proposed by other authors. Endoscopic severity was significantly influenced by four parameters: bloody stool, nocturnal bowel movements, body temperature >37.5 degrees C, and serum albumin. The new scoring system was calculated as ECCI = {[serum albumin x (-26)] + (bloody stool x 17) + (nocturnal bowel movements x 16) + [fever (0 or 1) x 39]} + 107. The ECCI accurately identified patients with severe endoscopic disease in our sample (sensitivity = 81%, specificity = 95%). In conclusion, the ECCI should be useful in clinical practice because it is simple and strongly related to endoscopic activity.

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.

Long-term risk of cancer in ulcerative colitis: a population-based cohort study from Copenhagen County

BACKGROUND & AIMS

Ulcerative colitis (UC) is associated with an increased risk for colorectal cancer (CRC) and possibly also increased risk for cancers outside the intestinal tract. We followed-up a population-based cohort of 1160 patients with UC diagnosed in Copenhagen County between 1962 and 1987 for up to 36 years to analyze the overall and site-specific cancer risk.

METHODS

Observed vs. expected cancers were presented as standardized morbidity ratio (SMR) with 95% exact confidence intervals (CI) calculated by using individual person-years at risk and sex- and age-specific incidence rates for the Danish background population in 1995.

RESULTS

The cohort was followed-up for a median of 19 years, or 22,290 person-years. A total of 124 malignancies were observed compared with 139.85 expected (SMR, .89; 95% CI, .74-1.07). The observed number of CRCs was almost exactly equal to expected: 13 cases vs. 12.42 (SMR, 1.05; 95% CI, .56-1.79). The cumulative probability of CRC was .4% by 10 years, 1.1% by 20 years, and 2.1% by 30 years of disease. Among men, melanoma was increased (SMR, 3.45; 95% CI, 1.38-7.10); otherwise, no increased risk for cancer could be detected. No hepatobiliary cancers and no increased risk for lymphoma or leukemia were found.

CONCLUSIONS

Neither the overall cancer risk, nor the CRC risk, were increased in this population-based cohort after a median of 19 years of follow-up evaluation. An active surgical approach in medical treatment failures and long-term use of 5-aminosalicylic acid (5-ASA) as relapse prevention may explain this remarkable result.

Mesalazine (5-aminosalicylic acid) micropellets show similar efficacy and tolerability to mesalazine tablets in patients with ulcerative colitis--results from a randomized-controlled trial

BACKGROUND

Formulations containing 5-aminosalicylic acid, such as mesalazine, are the gold standard of treatment for mild-to-moderate ulcerative colitis. Current oral regimens require the use of large tablets and frequent dosing to reach the recommended treatment dose. Mesalazine micropellets were designed to allow less frequent dosing in an easier to swallow formulation.

AIM

To compare the efficacy of mesalazine micropellets with the tablet formulation in patients with mild-to-moderate ulcerative colitis.

METHODS

This phase 2, double-blind, active-controlled, parallel-group, multiple dose clinical trial randomized 362 patients to either mesalazine micropellets or tablets, at a dosage of 3 g/day. The primary efficacy end-point was the incidence of clinical remission within 8 weeks, defined as the sum of clinical activity index components 1-4 (CAI(C1-4)) < or = 2.

RESULTS

CAI(C1-4) decreased significantly in both treatment groups within 8 weeks. The micropellet formulation showed confirmatory non-inferiority with statistical significance compared with the tablet formulation, with regard to the incidence of clinical remission (odds ratio in according-to-protocol population 1.008; 95% CI: 0.623-1.632). There was no significant difference in the incidence of adverse events.

CONCLUSIONS

The mesalazine micropellet formulation is as effective as tablets in patients with mild-to-moderate ulcerative colitis, enabling a larger dose to be taken comfortably and conveniently, thereby potentially improving patient compliance, treatment response and quality of life.

Review article: the chemoprevention of colorectal carcinoma

This review aims to provide an insight into some of the common pathways involved in the development of colorectal cancer--so-called chromosomal instability and microsatellite instability. There is both clinical and molecular evidence to show that colorectal cancer development occurs over an extended period of time. Together with a knowledge of the molecular pathogenesis of colorectal cancer, this time window allows physicians to counteract cancer development, a strategy known as chemoprevention. In familial and sporadic colorectal cancer, aspirin, other nonsteroidal anti-inflammatory drugs and cyclo-oxygenase-2 inhibitors have been tested for their ability to reduce polyp and cancer development in clinical studies. In inflammatory bowel disease-related colorectal cancer, evidence from retrospective case-control studies shows that mesalazine (mesalamine) can reduce the development of dysplastic lesions or cancer. Although the mechanisms behind this are incompletely understood, general anti-inflammatory, oxygen scavenger and some pro-apoptotic and cyclo-oxygenase inhibitory activities of mesalazine are thought to be involved. New molecular evidence points to a direct DNA stabilizing effect of mesalazine, resulting in a significant reduction of spontaneous microsatellite mutations.

Management of ulcerative colitis and Crohn's disease

The conventional medical treatment of IBD consists of aminosalicylates, corticosteroids, immunosuppressive drugs (azathioprine, 6-mercaptopurin, methotrexate, cyclosporin) and antibiotics. The only drugs able to modify the disease course are azathioprine, its metabolite 6-mercaptopurin and methotrexate. However, these drugs have a slow onset of action and are associated with important side-effects in some patients, necessitating the discontinuation of the drug. Moreover, up to 60% of patients do not respond to these drugs long-term. Fortunately, the management of IBD has entered a new era in the beginning of the 1990s with the development of new biological therapies, selectively blocking the inflammatory cascade. The novel molecules have arisen from the increasing knowledge about the disease pathogenesis and their production has been precipitated by the techniques of molecular biology. Infliximab, the first available biological for Crohn's disease has certainly revolutionised standard treatment. Because of its profound clinical, endoscopic and histological effects, the standard step up approach in the treatment of IBD has been challenged. A large array of new rationally designed biologicals, with a better safety profile and equally selectively acting is underway, and is likely to change our current practise even more dramatically in the next decade.

IKKbeta links inflammation and tumorigenesis in a mouse model of colitis-associated cancer

A link between inflammation and cancer has long been suspected, but its molecular nature remained ill defined. A key player in inflammation is transcription factor NF-kappaB whose activity is triggered in response to infectious agents and proinflammatory cytokines via the IkappaB kinase (IKK) complex. Using a colitis-associated cancer model, we show that although deletion of IKKbeta in intestinal epithelial cells does not decrease inflammation, it leads to a dramatic decrease in tumor incidence without affecting tumor size. This is linked to increased epithelial apoptosis during tumor promotion. Deleting IKKbeta in myeloid cells, however, results in a significant decrease in tumor size. This deletion diminishes expression of proinflammatory cytokines that may serve as tumor growth factors, without affecting apoptosis. Thus, specific inactivation of the IKK/NF-kappaB pathway in two different cell types can attenuate formation of inflammation-associated tumors. In addition to suppressing apoptosis in advanced tumors, IKKbeta may link inflammation to cancer.

Ulcerative colitis practice guidelines in adults (update): American College of Gastroenterology, Practice Parameters Committee

Guidelines for clinical practice are intended to indicate preferred approaches to medical problems as established by scientifically valid research. Double-blind placebo-controlled studies are preferable, but compassionate use reports and expert review articles are utilized in a thorough review of the literature conducted through Medline with the National Library of Medicine. When only data that will not withstand objective scrutiny are available, a recommendation is identified as a consensus of experts. Guidelines are applicable to all physicians who address the subject without regard to the specialty training or interests and are intended to indicate the preferable but not necessarily the only acceptable approach to a specific problem. Guidelines are intended to be flexible and must be distinguished from standards of care, which are inflexible and rarely violated. Given the wide range of specifics in any health-care problem, the physician must always choose the course best suited to the individual patient and the variables in existence at the moment of decision. Guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee and approved by the Board of Trustees. Each has been extensively reviewed and revised by the Committee, other experts in the field, physicians who will use them, and specialists in the science of decision of analysis. The recommendations of each guideline are therefore considered valid at the time of their production based on the data available. New developments in medical research and practice pertinent to each guideline will be reviewed at a time established and indicated at the publication in order to assure continued validity.

Crohn's is not a 6-week disease: lifelong management of mild to moderate Crohn's disease

Crohn's disease is an idiopathic, chronic inflammatory disorder of the digestive tract with heterogeneous clinical presentations. Crohn's is currently not a curable disease, and patients are faced with a lifetime of recurrent disease flare-ups and remissions. Management strategies for Crohn's must therefore be targeted toward lifelong management, taking into consideration not only the short-term but also the long-term aspects of the disease. With this in mind, here we review the classifications and natural history of Crohn's disease and discuss possible predictive factors for the disease evolution in a patient. Here we also evaluate the current preferable treatment practices, based on scientifically valid research and collective clinical experience, for the management of mild to moderate Crohn's disease.

Epidemiology of IBD during the twentieth century: an integrated view

Current incidence figures on ulcerative colitis and Crohn's disease--presented in a recent multicenter study in Europe--are given, and differences in the frequency and clinical appearances of the two conditions are discussed. Trends in the frequency and clinical appearance of inflammatory bowel disease during the twentieth century are summarized, as well as the differences over time and from place to place. Correlations between age, sex, localization of disease and clinical symptoms are given. Risk of progression to more extensive disease in patients with proctitis is shown. Incidences of inflammatory bowel disease in childhood and among migrated ethnic groups are discussed. Survival and cancer risk among patients with ulcerative colitis and Crohn's disease are shown from long-term clinical epidemiological studies of well-defined patient groups. Trends in these important prognostic parameters over time are shown, as well as factors influencing prognosis of the diseases.

Bowel inflammation as measured by fecal calprotectin: a link between lifestyle factors and colorectal cancer risk

The mechanisms by which the lifestyle risk factors obesity, physical inactivity, and low fiber intake predispose to colorectal cancer (CRC) are unclear. Chronic bowel inflammation predisposes to malignancy in cases of inflammatory bowel disease. Many lifestyle risk factors for CRC are associated with evidence of systemic inflammation as indicated by circulating levels of C-reactive protein (CRP), but it is unknown how this relates to inflammation at tissue level. Little is known about the degree of bowel inflammation in general population and the factors that affect it. Therefore, we aimed to assess the relation of levels of bowel inflammation in the general population and lifestyle risk factors for CRC, and to additionally assess whether these associations, if present, were attenuated by controlling for evidence of systemic inflammation. Average CRC risk subjects (320) of either sex aged 50-70 were recruited in South London. A stool sample was provided for calprotectin measurement (a marker of bowel inflammation), serum for CRP, and a detailed dietary and lifestyle questionnaire completed. There was a significant positive relationship between fecal calprotectin and increasing age (P = 0.002), obesity (P = 0.04), physical inactivity (P = 0.01), and an inverse relationship with fiber intake (P = 0.02) and vegetable consumption (P = 0.04). The relationship with obesity was attenuated by controlling for serum CRP. Fecal calprotectin levels are associated with lifestyle risk factors for colorectal cancer. Low-level asymptomatic bowel inflammation may be the link between lifestyle and the pathogenesis of CRC, and circulating proinflammatory cytokines may be part of the mechanism for this link.

Diagnosis and management of dysplasia in patients with inflammatory bowel diseases

Patients with ulcerative colitis and Crohn's colitis face an increased lifetime risk of developing colorectal cancer. Factors associated with increased risk include long duration of colitis, extensive colonic involvement, primary sclerosing cholangitis, a family history of colorectal cancer, and, according to some studies, early disease onset and more severely active inflammation. Although prophylactic proctocolectomy can essentially eliminate the risk of cancer, most patients and their physicians opt instead for a lifelong program of surveillance. This entails regular medical follow-up, management with antiinflammatory and putative chemopreventive agents, and periodic colonoscopic examinations combined with extensive biopsy sampling throughout the colon. The main objective of regular colonoscopy is to detect neoplasia at a surgically curative and preferably preinvasive stage, i.e., dysplasia. An initial screening colonoscopy should be performed 7-8 years from disease onset or immediately in patients with primary sclerosing cholangitis. Surveillance should then continue annually or biennially so long as no dysplasia is found or suspected. Biopsy specimens are graded pathologically as negative, indefinite for dysplasia, low-grade dysplasia, high-grade dysplasia, or invasive cancer. The diagnosis and grading of dysplasia can be very challenging and should be confirmed by an expert pathologist whenever intervention or a change in management is contemplated. If 1 or more biopsy specimens are indefinite for dysplasia, colonoscopy intervals should be reduced. A patient with low- or high-grade dysplasia found in a discrete adenoma-like polyp, but nowhere else, can be safely managed with polypectomy and accelerated surveillance. However, dysplasia of any grade found in an endoscopically nonresectable polyp and high-grade dysplasia found in flat mucosa are both strong indications for proctocolectomy. Evidence further suggests that the same may be true even of low-grade dysplasia in flat mucosa. Chromoendoscopy holds promise for facilitating the endoscopic detection of neoplasia. The clinical application of newer molecular methods to detect neoplasia, particularly gene microarrays and stool DNA testing, also deserve further study.

Adenomatous colonic polyps are rare in ulcerative colitis

BACKGROUND

Uncertainty exists as to whether dysplastic polyps in ulcerative colitis should always be managed as dysplasia-associated lesions/masses requiring colectomy, or whether some can be managed by polypectomy. The prevalence of non-inflammatory polyps in ulcerative colitis is unknown.

AIM

To compare dysplastic polyp occurrence in patients with ulcerative colitis and in patients without inflammatory bowel disease.

METHODS

The clinical, endoscopic and histological records of 150 ulcerative colitis patients (median disease duration, 10 years; 57% with pancolitis) undergoing colonoscopy were scrutinized for any polyp history. Two hundred and five patients undergoing colonoscopy for altered bowel habit, but without features suggestive of polyp presence, were used as a control group. Immunohistochemical staining of flat and polypoid mucosa for p16, beta-catenin, p53 and cyclo-oxygenase-2 was compared in the two groups.

RESULTS

Only six (4%) ulcerative colitis patients had ever had dysplastic polyps. Two had single adenomatous polyps proximal to the colitis segment. Of the four patients with dysplastic polyps within colitic mucosa, two were treated endoscopically, but in two the lesions were considered to be dysplasia-associated lesions/masses and colectomy was advised. In contrast, 24 controls had at least one adenomatous polyp (chi(2) = 6.7, P < 0.01). Ten (6.7%) ulcerative colitis patients and 24 (12%) control patients had metaplastic polyps (N.S.). Immunohistochemical staining was not discriminatory.

CONCLUSION

Despite the increased cancer risk in long-standing ulcerative colitis, adenomatous polyps arise less frequently in ulcerative colitis patients than in patients without ulcerative colitis.

Current therapy of ulcerative colitis in children

Ulcerative colitis presents in childhood in 10% of those affected, usually with pancolitis. Important features in management include growth, development and avoidance of treatment toxicity. This review addresses the current treatment options including both the paediatric evidence-based experience and areas where paediatric practice is informed by adult studies. Standard treatments include sulfasalazine or 5-aminosalicylates, corticosteroids, purine derivatives (azathioprine or 6-mercaptopurine) and surgery. Other immunosuppressant therapies and the emerging roles for biological therapies and probiotics are discussed.

Medical management of ulcerative colitis

Patients with ulcerative colitis have no increased mortality compared to population controls and the disease can be cured be colectomy. This review concentrates on the medical management of ulcerative colitis including the management of active colitis, acute severe colitis and first presentation of colitis, maintenance of remission and long-term complications.

Intestinal and extra-intestinal cancer in Crohn's disease: follow-up of a population-based cohort in Copenhagen County, Denmark

AIM

To determine the long-term risk of intestinal and extra-intestinal malignancies in Crohn's disease patients in Copenhagen County, Denmark.

METHODS

In Copenhagen County, a strictly population-based cohort of 374 patients with Crohn's disease diagnosed between 1962 and 1987 was followed until 1997 in order to determine the long-term risk of intestinal and extra-intestinal malignancies. Information on cancer occurrence was provided by the Danish National Cancer Registry and confirmed by the examination of hospital files. The observed number of cases was compared with the expected number, calculated from individually computed person-years at risk and 1995 cancer incidence rates for the background population.

RESULTS

The risk of small bowel adenocarcinoma was significantly increased, independent of age and gender (standardized morbidity ratio, 66.7; 95% confidence interval, 18.1-170.7). The risk of colorectal cancer was not increased, either in the total group of patients or in patients with colonic Crohn's disease exclusively (standardized morbidity ratio, 1.64; 95% confidence interval, 0.20-5.92). Extra-intestinal cancer did not occur more frequently than expected.

CONCLUSIONS

This population-based study of patients with Crohn's disease revealed no increase in colorectal cancer risk, possibly due to maintenance treatment with 5-aminosalicylic acid preparations and surgery in treatment failure. In contrast, the risk of small bowel cancer was increased more than 60-fold, but the numbers were small. The risk of extra-intestinal cancer was not increased and no lymphomas were observed.

Severity of inflammation is a risk factor for colorectal neoplasia in ulcerative colitis

BACKGROUND & AIMS

Patients with ulcerative colitis are at increased risk of colorectal cancer. It is widely believed that this is secondary to colonic inflammation. However, the severity of colonic inflammation has never been shown to be a risk factor.

METHODS

We devised a case-control study of patients with long-standing extensive ulcerative colitis to examine various potential risk factors for neoplasia. All cases of colorectal neoplasia detected from our surveillance program between January 1, 1988, and January 1, 2002, were studied (n = 68). Each patient was matched with 2 control patients from the same surveillance population (n = 136). Matching was for sex, colitis extent, age at onset, duration of colitis, and year of index surveillance colonoscopy. Segmental colonoscopic and histological inflammation was recorded by using a simple score (0, normal; 1, quiescent/chronic inflammation; and 2, 3, and 4, mild, moderate, and severe active inflammation, respectively). Other data collected included history of primary sclerosing cholangitis, family history of colorectal cancer, and smoking and drug history (mesalamine 5-aminosalicylic acid, azathioprine, and folate).

RESULTS

Univariate analysis showed a highly significant correlation between the colonoscopic (odds ratio, 2.5; P = 0.001) and histological (odds ratio, 5.1; P < 0.001) inflammation scores and the risk of colorectal neoplasia. No other factors reached statistical significance. On multivariate analysis, only the histological inflammation score remained significant (odds ratio, 4.7; P < 0.001).

CONCLUSIONS

In long-standing extensive ulcerative colitis, the severity of colonic inflammation is an important determinant of the risk of colorectal neoplasia. Endoscopic and histological grading of inflammation could allow better risk stratification for surveillance programs.

Small intestinal adenocarcinoma in Crohn's disease: a case-control study

BACKGROUND

Small bowel adenocarcinoma is an uncommon complication of Crohn's disease. We sought to describe the clinical features, outcomes, and risk factors of small bowel adenocarcinoma in Crohn's disease.

METHODS

A centralized diagnostic index identified all patients with Crohn's disease with small bowel adenocarcinoma evaluated at our institution between 1976 and 2000, and the medical records were abstracted. Two controls with Crohn's disease were selected for each case, matched by gender and age.

RESULTS

Nine cases (four males) were identified. The patients presented with abdominal pain (89%), obstruction (89%), and weight loss (78%). Cancer was located in the ileum in 8 patients (89%) and the jejunum in 1 patient (11%). All cases but 1 had either lymph node involvement or metastasis. All cases had surgery, with 1 receiving adjuvant chemotherapy. No significant risk factors were found. The mortality rates at 1 and 2 years were 42% and 61%.

CONCLUSIONS

Small bowel adenocarcinoma is a rare complication of Crohn's disease that typically involves the ileum. Affected patients have symptomatic, advanced malignancies upon diagnosis. No significant risk factors were identified.

Strategies for detecting colon cancer and/or dysplasia in patients with inflammatory bowel disease

BACKGROUND

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

OBJECTIVES

To assess the effectiveness of cancer surveillance programs in reducing the death rate from colorectal cancer in patients with ulcerative colitis and colonic Crohn's disease.

SEARCH STRATEGY

The following strategies were used to identify relevant studies: 1. MEDLINE and the Cochrane Central Register of Controlled Trials were searched from 1966 to December 2002. The medical subject headings "Ulcerative Colitis", "Crohn Disease" or "Inflammatory Bowel Disease" and "Surveillance" or "Cancer" were used to perform key-word searches of the databases. 2. Hand searching of reference lists from papers.

SELECTION CRITERIA

Potentially relevant articles were reviewed independently and unblinded by three authors to determine if they fulfilled the selection criteria. Each article was rated as being eligible, ineligible, or without sufficient information to determine eligibility. Any disagreement between reviewers was resolved by consensus. Any trials published in abstract form were only considered if it was possible to obtain full details of the protocol and results from the authors.

DATA COLLECTION AND ANALYSIS

Eligible articles were reviewed in duplicate and the results of the primary research trials were abstracted onto specially designed data extraction forms. The proportion of patients dying from bowel cancer or other causes in the control and surveillance groups of each study was derived from life tables, survival curves or where possible, by calculating life tables from the data provided. Data from the original research articles were converted into 2x2 tables (survival versus death x surveillance versus control) for each of the individual studies for comparable follow-up intervals. 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 (p>0.10), the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled relative risk (RR) and 95% confidence intervals as described by Cochrane and Mantel and Haenszel.

MAIN RESULTS

Karlen 1998a found that 2/40 of the patients dying of colorectal cancer had undergone surveillance colonoscopy on at least one occasion compared with 18/102 of the controls (RR 0.28, 95% confidence interval 0.07 to 1.17). One of 40 patients who died from colorectal cancer had undergone surveillance colonoscopies on two or more occasions compared with 12/102 controls (RR 0.22, 95% confidence interval 0.03 to 1.74) in contrast to a more modest effect observed for patients who had only one colonoscopy (RR 0.43, 95% confidence intervals 0.05 to 3.76). Choi 1993 found that carcinoma was detected at a significantly earlier stage in the surveillance group; 15/19 had Duke's A or B carcinoma in the surveilled group compared to 9/22 in the non-surveilled group (P= 0.039). The 5-year survival rate was 77.2% for cancers occurring in the surveillance group and 36.3% for the no-surveillance group (P= 0.026). Four of 19 patients in the surveillance group died from colorectal cancer compared to 11 of 22 patients in the non-surveillance group (RR 0.42, 95% CI 0.16 to 1.11). Lashner 1990 found that four of 91 patients in the surveillance group died from colorectal cancer compared to 2 of 95 patients in the non-surveilled group (RR 2.09, 95% CI 0.39 to 11.12). Colectomy was less common in the surveillance group, 33 compared to 51 (p < 0.05) and was performed four years later (after 10 years of disease) in the surveillance group. For the pooled data analysis 8/110 patients in the surveillance group died from colorectal cancer compared to 13/117 patients in the non-surveillance group (RR 0.81, 95% CI 0.17 to 3.83).

REVIEWERS' CONCLUSIONS

There is no clear evidence that surveillance colonoscopy prolongs survival in patients with extensive colitis. There is evidence that cancers tend to be detected at an earlier stage in patients who are undergoing surveillance and these patients have a correspondingly better prognosis but lead-time bias could contribute substantially to this apparent benefit. There is indirect evidence that surveillance is likely to be effective at reducing the risk of death from IBD-associated colorectal cancer and indirect evidence that it is acceptably cost-effective.

Colorectal cancer in inflammatory bowel disease

PURPOSE OF REVIEW

Patients with inflammatory bowel disease, either Crohn disease or ulcerative colitis, are at an increased risk for developing colorectal carcinoma.

RECENT FINDINGS

Surveillance colonoscopy, although never formally evaluated in a prospective controlled trial, is performed in an effort to reduce this risk. Novel methods of detecting dysplasia are constantly being evaluated, including chromoendoscopy and biomarkers of carcinoma, in an attempt to stratify patients who are at a higher risk of developing high-grade dysplasia or carcinoma.

SUMMARY

Because of the potential impact on quality of life and life expectancy, an optimal strategy for reducing the risk of developing colorectal cancer in patients with inflammatory bowel disease needs to be defined.

Prevalence and management of inflammatory bowel disease: a cross-sectional study from central England

OBJECTIVES

To estimate the prevalence of inflammatory bowel disease (IBD) from the information in general practitioners' records and to describe patient management, including the prescribing of 5-aminosalicylates and adherance to treatment in ulcerative colitis, and frequency of advice given concerning cessation of smoking.

METHODS

Fifteen general practices were recruited through the Trent Focus Collaborative Research Network, UK, to take part in a cross-sectional study. They identified confirmed cases of IBD and used a pro-forma to collect data for collation and analysis.

RESULTS

Searches identified 344 IBD cases from a combined list of 86 801 patients, suggesting a prevalence of 396 per 100 000 (95% confidence interval, 356-440). Practices considered 32% of patients to be under the sole care of general practitioners; only 59% had been seen in secondary care during the previous year and the numbers of outpatient and general practitioner consultations were similar. Smoking cessation advice was documented for similar numbers of smokers with Crohn's disease and ulcerative colitis. Excluding patients who had undergone surgery, only 65% of patients with ulcerative colitis had been prescribed a 5-aminosalicylate in the previous 6 months and good treatment adherence was suggested in only 42% of ulcerative colitis patients taking a 5-aminosalicylate. Prescribing of aminosalicylates was more common in patients under specialist or shared care than those under general practitioner care only; this remained significant in a regression model also including extent of disease (P < 0.0001).

CONCLUSIONS

General practitioners play an important role in caring for patients with IBD and may need relevant education and support. Aminosalicylates appear to be under-used in patients with ulcerative colitis.

Does the use of 5-aminosalicylates in inflammatory bowel disease prevent the development of colorectal cancer?

OBJECTIVES

There is increased interest in determining whether 5-aminosalicylate (5-ASA) use can prevent the development of colorectal cancer (CRC) among patients with inflammatory bowel disease (IBD). The aim of this study was to determine whether use of 5-ASA was associated with a reduced risk of CRC in these patients.

METHODS

We extracted from our population-based University of Manitoba Inflammatory Bowel Disease Epidemiology Database the number of patients with a new diagnosis of CRC between the years 1997 and 2000. From within our Inflammatory Bowel Disease Epidemiology Database we extracted a control group of IBD patients who did not develop CRC matched to the case group who did develop CRC by age, sex, diagnosis, year of diagnosis, and geographic area of residence. We linked cases and controls with Manitoba Health's Drug Program Information Network to study 5-ASA use within 2 yr before CRC diagnosis. The Drug Program Information Network database is a population-based database that was established in 1995 and that records all prescription drugs.

RESULTS

There were 25 cases of IBD identified as having CRC. These were matched with 348 cases of IBD who did not develop CRC. CRC cases were more likely to be exposed to 5-ASA (odds ratio = 1.46; 95% CI = 0.58-3.73) but this result was not statistically significant. The mean total days of use was 400.9 days +/- 185.9 among CRC cases versus 420.2 days +/- 241.7 among non-CRC cases (p = 0.92). The prescribed daily dose was 2295 mg/day +/- 1041 mg among CRC cases and 1811 mg +/- 520 mg among controls (p = 0.21).

CONCLUSIONS

These data do not support 5-ASA as protective in preventing CRC.

Survival and cause-specific mortality in ulcerative colitis: follow-up of a population-based cohort in Copenhagen County

BACKGROUND & AIMS

A population-based cohort from Copenhagen County comprising 1160 patients diagnosed with ulcerative colitis between 1962 and 1987 was followed-up until 1997 to describe survival and cause-specific mortality.

METHODS

Observed vs. expected deaths were presented as standardized mortality ratio (SMR) with exact 95% confidence intervals (CI) calculated by using individually registered person-years at risk and Danish 1995 mortality rates. Cumulative survival curves were calculated.

RESULTS

A total of 261 deaths occurred, not significantly different from the expected number of 249 (SMR, 1.05; 95% CI, 0.92-1.19). The median age at death among men was 70 years (range, 6-96 years) and among women 74 years (range, 25-96 years). Twenty-five deaths (9.6%) were caused by complications to ulcerative colitis, mostly infectious and cardiovascular postoperative complications. Patients older than 50 years of age at diagnosis and with extensive colitis showed an increased mortality within the first 2 years because of ulcerative colitis-associated causes. The mortality from colorectal cancer was not increased and that of cancer in general was significantly lower than expected: 50 vs. 71 (SMR, 0.70; 95% CI, 0.52-0.93). A significantly increased mortality from pulmonary embolism and pneumonia was found. Among women only, death from genitourinary tract diseases and suicide was significantly increased.

CONCLUSIONS

Despite an overall normal life expectancy for patients with ulcerative colitis, patients >50 years of age and with extensive colitis at diagnosis had increased mortality within the first 2 years after diagnosis, owing to colitis-associated postoperative complications and comorbidity.

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Colorectal cancer and high grade dysplasia complicating ulcerative colitis in Italy. A retrospective co-operative IG-IBD study

BACKGROUND

Ulcerative colitis is a well-known risk factor for colorectal cancer.

AIM

To take a census of the cases of colorectal cancer in ulcerative colitis patients observed in Italy and to evaluate the clinical presentation of neoplastic complication.

PATIENTS AND METHODS

Experts from 28 Italian centres specialised in the management of inflammatory bowel disease or malignancies participated to the study. They were invited to send clinical data of patients with ulcerative colitis complicated by colorectal cancer or high-grade dysplasia consecutively observed between 1985 and 2000. One hundred and twelve patients (92 with cancer and 20 with high-grade dysplasia) were collected. Fourteen of them had undergone colectomy and ileo-rectal anastomosis for ulcerative colitis. Data of surgical patients were analysed separately.

RESULTS

The mean age at diagnosis of ulcerative colitis and colorectal cancer patients was 39.3 and 53.2 years, respectively, and the mean duration between diagnosis of ulcerative colitis and cancer was 13.9 years (range 0-53). Inflammation was proximal to the splenic flexure in 71 cases (76.3%). One hundred and three colorectal cancers were registered (93 patients with single lesion and five patients with two synchronous cancers), with 76.7% of cancers being located in the left colon. As to the surgical patients, the mean age at diagnosis of ulcerative colitis and cancer was 28.9 and 47.0 years, respectively, and the mean diagnostic interval for ulcerative colitis and cancer was 18.1 years. Only 51 out of 112 patients were in follow-up. An early diagnosis of neoplasia (high grade dysplasia, stage A or B sec. Dukes) occurred in 72.5% of patients who were subjected to endoscopic surveillance and in 48.0% of patients who did not undergo endoscopic surveillance (p=0.02).

CONCLUSIONS

These data show an earlier diagnosis of cancer in patients who had undergone endoscopic surveillance. The poor compliance to the follow-up program, however, reduces its effectiveness. Moreover, total colectomy allows an easier follow-up, with only the rectum being controlled. Colectomy with ileo-rectal anastomosis or proctocolectomy with ileo-anal anastomosis, could represent a valid alternative in patients at high risk of cancer who refuse endoscopic surveillance.

Review article: mechanisms of action of mesalazine in preventing colorectal carcinoma in inflammatory bowel disease

A series of epidemiological, experimental and preliminary clinical trials strongly suggest that mesalazine or 5-aminosalicyclic acid (5-ASA) may have antineoplastic and potentially prophylactic chemopreventive properties. It is assumed that mesalazine may have similar genetic and molecular targets as nonsteroidal anti-inflammatory drugs (NSAIDs), which is further supported by its close similarity with aspirin, differing only in its structure by the presence of an amino group at position 5 of the benzene ring. The putative chemopreventive actions include the inhibition of inflammatory cascades and/or reactions involved in cell growth and proliferation, such as cyclo-oxygenase (COX-1 and COX-2), which regulate cell proliferation through the formation of prostaglandins; lipoxygenase; nuclear factor kappaB (NFkappaB), responsible for the subsequent expression of pro-inflammatory molecules; MAP kinases and Bcl-2, as well as the activation of apoptotic processes, such as the stimulation of intestinal sphingomyelinase. The peroxisome-proliferator-activated receptor delta (PPARdelta), which also regulates gene transcription, is thought to play a role in both inflammatory and non-inflammatory driven carcinogenesis. This may be another significant target. It is hypothesized that 5-ASAs may prevent the enhancing effect of prostaglandins on PPARdelta binding to DNA by its COX inhibitory properties, decreasing proliferation of colorectal mucosal cells in non-inflammatory bowel disease patients with sporadic polyps of the large bowel.

Chemoprevention of colorectal cancer in ulcerative colitis

BACKGROUND

Patients with ulcerative colitis (UC) are at greater risk of developing colorectal cancer (CRC) than the general population. Both duration and extent of UC are important risk factors for CRC, as is the presence of primary sclerosing cholangitis, family history of CRC, and (in some studies) early age at diagnosis of UC. Efforts to reduce this risk have focused on colonoscopic surveillance as the best alternative to the more definitive, but less appealing, approach of prophylactic colectomy. However, spurred on by findings in the sporadic CRC literature, there has been a growing interest in a possible role for chemoprevention of CRC in patients with UC.

EMPIRICAL STUDIES

Published evidence to date indicates that 5-aminosalicylic acid agents are protective against the development of dysplasia and CRC. Oral, but not topical, steroids also appear to be chemoprotective, but their chronic use cannot be recommended for this indication. Ursodeoxycholic acid has been shown to reduce the risk of neoplasia in UC patients with primary sclerosing cholangitis. Evidence suggests, but does not prove, that folic acid is chemopreventive in patients with UC. Further studies are needed to fully define the chemoprotective role of these and other agents.

Review article: the data supporting a role for aminosalicylates in the chemoprevention of colorectal cancer in patients with inflammatory bowel disease

The chemoprevention of colorectal cancer (CRC) with long-term sulfasalazine and 5-aminosalicyclic acid (5-ASA) treatment has been demonstrated through epidemiological and experimental studies, in patients with ulcerative colitis. In a large case-controlled study, there was a trend for long-term nonsteroidal anti-inflammatory consumption to be protective against CRC in patients with inflammatory bowel disease (IBD) (OR, 0.84). Sulfasalazine treatment over a 3-month period was shown to be protective (OR, 0.38), independently of disease activity. A longer-term study of sulfasalazine also revealed a relationship with treatment compliance, where 3% of compliant patients developed CRC compared with 31% of the noncompliers. Treatment with 5-ASA was associated with an increase in apoptosis, a decrease in proliferation of colorectal mucosa and has been shown to lower the rate of spontaneous mutation. In a retrospective, matched case-control study conducted in the UK, 102 patients with ulcerative colitis and CRC were matched with ulcerative colitis patients without CRC. Incidence was correlated to treatment protocols, family history and other risk factors. Mesalazine was the only treatment to be associated with a statistically significant reduction in the risk of developing cancer. Even after adjusting for variables, mesalazine at doses > 1.2 g / day reduced the risk of cancer by 81% (P = 0.006). Frequent visits to the clinician were also associated with a protective effect.

Review article: colitis-associated cancer -- time for new strategies

Colorectal cancer (CRC) remains a feared and potentially life-threatening complication of both ulcerative colitis and Crohn's colitis. Currently, the main preventive strategy is a secondary one, i.e. surveillance colonoscopy usually after 8 years of disease duration, when the risk for neoplasia begins to increase. Despite its widespread acceptance, dysplasia and cancer surveillance is unproven in terms of reducing mortality or morbidity and there is a remarkable lack of uniformity in the manner in which it is practised. In this review article, the pitfalls of dysplasia surveillance are summarized and the need for novel chemopreventive and perhaps pharmabiotic approaches for prevention are highlighted.

Aminosalicylates and colorectal cancer in IBD: a not-so bitter pill to swallow

Inflammatory bowel disease (IBD) is associated with an increased risk of developing intestinal cancer at sites of chronic inflammation. Aminosalicylates, including both sulfasalazine and mesalamine, are the most commonly prescribed anti-inflammatory agents prescribed in IBD. On balance, the body of literature to date suggests that aminosalicylates confer some protection against the development of colonic neoplasia in patients with IBD and in a variety of models, including in the noninflamed gut. This latter observation implies that aminosalicylates may be of chemopreventive value in normal as well as IBD individuals. The current review examines and gives an overview of the evidence from a variety of sources, including epidemiological, in vivo and in vitro studies that have investigated the potential anticancer effects of aminosalicylates.

Studies of compliance with delayed-release mesalazine therapy in patients with inflammatory bowel disease

BACKGROUND

Non-compliance with maintenance mesalazine therapy may be a risk factor for relapse in inflammatory bowel disease, but the prevalence and determinants of non-compliance are unknown.

AIM

To study the prevalence and determinants of non-compliance in patients with inflammatory bowel disease.

METHODS

Out-patients receiving delayed-release mesalazine were studied. Compliance was determined by direct enquiry and by analysis of urine samples for 5-aminosalicylic acid/N-acetyl-5-aminosalicylic acid. Potential determinants of compliance were assessed.

RESULTS

Ninety-eight patients were studied. Forty-two patients (43%) reported taking <80% of their prescribed dose. Logistic regression revealed the independent predictors of non-compliance to be three-times daily dosing [odds ratio (OR), 3.1; 95% confidence interval (CI), 1.8-8.4] and full-time employment (OR, 2.7; 95% CI, 1.1-6.9). Urine from 12 patients (12%) contained no detectable 5-aminosalicylic acid/N-acetyl-5-aminosalicylic acid, and 18 patients (18%) had levels below those expected. Depression was the only independent predictor of complete non-compliance (OR, 10.5; 95% CI, 1.8-79.0), and three-times daily dosing was the only independent predictor of partial non-compliance (OR, 3.7; 95% CI, 1.8-8.9). Self-reporting correctly identified 66% of patients judged to be non-compliant on urinary drug measurement.

CONCLUSIONS

Non-compliance with maintenance mesalazine therapy is common in patients with inflammatory bowel disease. Three-times daily dosing and full-time employment are predictors of partial non-compliance, whilst depression is associated with complete non-compliance. Self-reporting detects most non-compliant patients.

Does monitoring prevent cancer in inflammatory bowel disease?

Surveillance colonoscopy for patients who have inflammatory bowel disease with colonic involvement has gained widespread acceptance. From an evidence-based perspective, however, the foundation for this practice remains weak. There are no randomized controlled trials, prospective cohort studies, or case-control studies that definitively prove a benefit for surveillance colonoscopy (i.e., reduction in colorectal cancer-related mortality). Nevertheless, circumstantial evidence indirectly suggests a benefit. This article reviews risk factors for colorectal cancer in inflammatory bowel disease and the evidence supporting the practice of colonoscopic surveillance. The benefits of frequent physician visits and compliance with medication regimens with regard to reduction in colorectal cancer risk are also reviewed.

Radical causes of cancer

Free radicals are ubiquitous in our body and are generated by normal physiological processes, including aerobic metabolism and inflammatory responses, to eliminate invading pathogenic microorganisms. Because free radicals can also inflict cellular damage, several defences have evolved both to protect our cells from radicals--such as antioxidant scavengers and enzymes--and to repair DNA damage. Understanding the association between chronic inflammation and cancer provides insights into the molecular mechanisms involved. In particular, we highlight the interaction between nitric oxide and p53 as a crucial pathway in inflammatory-mediated carcinogenesis.

Role of mesalazine in acute and long-term treatment of ulcerative colitis and its complications

BACKGROUND

Sulfasalazine, consisting of 5-aminosalicylic acid bound to sulfapyridine by a diazo bond, was first used for treatment of ulcerative colitis in the early 1940s and later found effective in placebo-controlled trials for acute disease and for long-term maintenance of remission. Later studies found that the active moiety is 5-ASA (mesalazine, mesalamine) and the sulfapyridine moiety acts as a carrier molecule but causes many of the symptomatic adverse reactions.

METHODS

Review of the literature.

RESULTS

The finding that 5-ASA in the active motility led to the development of mesalazine prodrugs, olsalazine (Dipentum) and balsalazide (Colazide, Colazal), and targeted release mesalazine preparations, such as Asacol, Pentasa, and Salofalk, as well as enemas and suppository preparations for distal disease. Most patients with adverse effects from sulfasalazine will tolerate mesalazine. Mesalazine has been shown equivalent or superior to sulfasalazine, and superior to placebo, with a dose-response benefit, in inducing remission of acute disease. and comparable to sulfasalazine and superior to placebo for long-term maintenance of remission. Better tolerance of mesalazine and the ability to use higher doses favor its use in patients intolerant of sulfasalazine and in patients failing to respond to usual doses of sulfasalazine. Adverse effects from mesalazine are uncommon, but include idiosyncratic worsening of the colitis symptoms and renal toxicity. Mesalazine is safe to use during pregnancy and for nursing mothers. As maintenance therapy, mesalazine may reduce the risk of developing colorectal carcinoma.

CONCLUSION

Mesalazine represents effective and well-tolerated first-line therapy for mildly to moderately acute disease as well as for the long-term maintenance treatment in the patient with ulcerative colitis.

Is your patient taking the medicine? A simple assay to measure compliance with 5-aminosalicylic acid-containing compounds

BACKGROUND

Poor compliance with 5-aminosalicylic acid therapy has been reported amongst patients with inflammatory bowel disease. Currently, there is no easy method to monitor 5-aminosalicylic acid; however, the chemical similarity between 5-aminosalicylic acid and salicylate might provide a solution.

AIM

To determine the feasibility of using salicylate levels to monitor compliance with 5-aminosalicylic acid medication.

METHODS

Thirty-six patients with inflammatory bowel disease, taking maintenance 5-aminosalicylic acid, provided either a paired serum and urine sample or an intestinal biopsy. Samples were split into two: half were sent to the hospital biochemistry department for salicylate measurement, and half were analysed for 5-aminosalicylic acid and its metabolite, N-acetyl-5-aminosalicylic acid, using high performance liquid chromatography. Correlation between the results was calculated.

RESULTS

Serum and urine were available for 25 patients. Serum salicylate was undetectable, but urinary salicylate ranged from 31 to 3254 microg/mL. The correlations between urinary salicylate and 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid were 0.96 (95% confidence interval, 0.91-0.98) and 0.9 (95% confidence interval, 0.77-0.96), respectively. Sixteen biopsies were available from 13 patients. The 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid concentrations were 0.2-657 ng/mg and 1.6-1598 ng/mg, respectively; there was no correlation with bowel salicylate.

CONCLUSIONS

The close correlation between 5-aminosalicylic acid and salicylate levels offers a simple method to assess compliance with 5-aminosalicylic acid therapy.