Ursodeoxycholic acid as a chemopreventive agent in patients with ulcerative colitis and primary sclerosing cholangitis

Autoimmune liver diseases and recurrence after orthotopic liver transplantation: what have we learned so far?

Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) may all recur after liver transplant. Diagnosis of rPBC is defined by histology; rAIH by serology, biochemistry and histology; rPSC by histology and/or imaging of the biliary tree and exclusion of other causes of nonanastomotic biliary strictures. Criteria for recurrent disease (RD) may differ from those used in similar disease in the native liver: frequent use of immunosuppressive therapy changes the pattern and natural history of RD and can co-exist with other transplant-related causes of graft damage. RD may occur in the presence of normal liver tests; the reported incidence will depend on the way in which diagnostic tests (especially protocol biopsies) are applied. The risk of RD increases with time, but does not correlate with the rate of graft loss. Treatment is largely unproven: ursodeoxycholic acid will improve serology and may slow progression of rPSC and rPBC; introduction or increased dose of corticosteroids may reduce progression of rAIH. Risk factors for rPBC include use of tacrolimus compared with cyclosporine; for rPSC include absence of colon peri-transplantation and for rAIH possible associations with some HLA haplotypes have been suggested.

Effects of common haplotypes of the ileal sodium dependent bile acid transporter gene on the development of sporadic and familial colorectal cancer: a case control study

BACKGROUND

The genetics of sporadic and non-syndromic familial colorectal cancer (CRC) is not well defined. However, genetic factors that promote the development of precursor lesions, i.e. adenomas, might also predispose to CRC. Recently, an association of colorectal adenoma with two variants (c.507C>T;p.L169L and c.511G>T;p.A171S) of the ileal sodium dependent bile acid transporter gene (SLC10A2) has been reported. Here, we reconstructed haplotypes of the SLC10A2 gene locus and tested for association with non-syndromic familial and sporadic CRC compared to 'hyper-normal' controls who displayed no colorectal polyps on screening colonoscopy.

METHODS

We included 150 patients with sporadic CRC, 93 patients with familial CRC but exclusion of familial adenomatous polyposis and Lynch's syndrome, and 204 'hyper-normal' controls. Haplotype-tagging SLC10A2 gene variants were identified in the Hapmap database and genotyped using PCR-based 5' exonuclease assays with fluorescent dye-labelled probes. Haplotypes were reconstructed using the PHASE algorithm. Association testing was performed with both SNPs and reconstructed haplotypes.

RESULTS

Minor allele frequencies of all SLC10A2 polymorphisms are within previously reported ranges, and no deviations from Hardy-Weinberg equilibrium are observed. However, we found no association with any of the SLC10A2 haplotypes with sporadic or familial CRC in our samples (all P values > 0.05).

CONCLUSION

Common variants of the SLC10A2 gene are not associated with sporadic or familial CRC. Hence, albeit this gene might be associated with early stages of colorectal neoplasia, it appears not to represent a major risk factor for progression to CRC.

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

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

Extraintestinal manifestations of inflammatory bowel disease

Inflammatory bowel disease (IBD) is associated with a variety of extraintestinal manifestations (EIMs) that may produce greater morbidity than the underlying intestinal disease and may even be the initial presenting symptoms of the IBD. As many as 36% of patients with IBD have at least one EIM. Some are more common related to active colitis (joint, skin, ocular, and oral manifestations). Others are especially seen with small bowel dysfunction (cholelithiasis, nephrolithiasis, and obstructive uropathy), and some are nonspecific disorders (osteoporosis, hepatobiliary disease, and amyloidosis). Patients with perianal Crohn's disease are at higher risk for developing EIMs than other IBD patients. Also the presence of one EIM appears to confer a higher likelihood of developing other manifestations than would be expected by chance alone. The identified pathogenetic autoimmune mechanisms include genetic susceptibility antigenic display of autoantigen, aberrant self-recognition, and immunopathogenetic autoantibodies against organ-specific cellular antigen(s) shared by colon and extra-colonic organs. Microbes may play an important role, probably by molecular mimicry. Early recognition of these extraintestinal manifestations should help guide therapy that will reduce overall morbidity in affected patients. This paper reviews the diagnosis, therapy and management of the more common EIMs.

Probiotics in primary sclerosing cholangitis: a randomized placebo-controlled crossover pilot study

BACKGROUND

Beneficial effects of probiotics have been reported in liver disease. Inflammatory bowel disease concurs in 90% of primary sclerosing cholangitis (PSC) patients, suggesting that substances originating from the inflamed gut may damage the biliary tree.

OBJECTIVE

To assess potential beneficial effects of probiotics on serum liver tests, pruritus and fatigue in PSC.

METHODS

Fourteen patients (13 male/one female, mean age 45 years), with concurrent inflammatory bowel disease were randomized to treatment with probiotics (Ecologic 641, containing four Lactobacillus and two Bifidobacillus strains; Winclove Bio Industries, Amsterdam, The Netherlands) or placebo during 3 months in a double-blind fashion. After a 1-month washout period, crossover was made.

RESULTS

No changes in pruritus, fatigue and stool frequency were noted during placebo or probiotics. No significant differences were observed between treatment with probiotics and placebo in bilirubin (at end of probiotic vs. placebo period: -13 vs. -15% change from baseline; P=0.89), alkaline phosphatase (-9 vs. -9%; P=0.99), gamma glutamyl transpeptidase (-11 vs. -5%; P=0.60), aspartate aminotransferase (-16 vs. -15%; P=0.99), alanine aminotransferase (-27 vs. -26%; P=0.97), prothrombin, albumin or bile salts.

CONCLUSION

Our data do not support beneficial effects of probiotics on symptoms, liver biochemistry or liver function in PSC.

The challenges in primary sclerosing cholangitis--aetiopathogenesis, autoimmunity, management and malignancy

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease, characterized by progressive inflammation and fibrosis of the bile ducts, resulting in biliary cirrhosis and is associated with a high risk of cholangiocarcinoma. The majority of patients are young, male and have coexisting inflammatory bowel disease. PSC is found with a prevalence of 10/100,000 in Northern European populations. The pathophysiology of PSC is a complex multistep process including immunological mechanisms, immunogenetic susceptibility and disorders of the biliary epithelia. The diagnosis is primarily based on endoscopic cholangiography although magnetic resonance imaging is increasingly used; biochemistry and immunoserology as well as histology play only a minor role. Due to the high risk of developing cholangiocarcinoma and also other tumours of the GI tract, surveillance strategies are essential, however they have yet to be established and evaluated. Biochemical parameters, clinical risk factors, endoscopic procedures and imaging techniques contribute to the early identification of patients at risk. Since medical therapy of PSC with ursodeoxycholic acid does not improve survival, to date, liver transplantation is the only option with a cure potential; if transplantation is accurately timed, transplanted PSC patients have an excellent rate of survival. However if cholangiocarcinoma is detected, a curative treatment is not possible in the majority of cases. The present review critically summarizes the current knowledge on the aetiopathogenesis of PSC and gives an overview of the diagnostic approaches, surveillance strategies and therapeutic options. Primary sclerosing cholangitis is a disease of unknown aetiology and without any further curative treatment options apart from liver transplantation. Therefore it may be regarded as the greatest challenge in hepatology today.

Disease activity and cancer risk in inflammatory bowel disease associated with primary sclerosing cholangitis

AIM: To investigate the phenotype of inflammatory bowel disease associated with primary sclerosing cholangitis (PSC-IBD).

METHODS: Data from 75 PSC-IBD patients evaluated in our tertiary center between 1963 and 2006 were collected and compared to 150 IBD patients without PSC, matched for sex, birth date, IBD diagnosis date and initial disease location regarding ileal, different colonic segments, and rectum, respectively.

RESULTS: While PSC-IBD patients received more 5-aminosalicylates (8.7 years/patient vs 2.9 years/patient, P < 0.001), they required less immuno-suppressors (24% vs 46% at 10 years; P < 0.001) and less intestinal resection (10% vs 44% at 10 years, P < 0.001). The 25-year cumulative rate of colectomy was 25.1% in PSC-IBD and 37.3% in controls (P = 0.004). The 25-year cumulative rate of colorectal cancer was 23.4% in PSC-IBD vs 0% in controls (P = 0.002). PSC was the only independent risk factor for the development of colorectal cancer (OR = 10.8; 95% CI, 3.7-31.3). Overall survival rate without liver transplantation was reduced in PSC-IBD patients (67% vs 91% in controls at 25 years, P = 0.001).

CONCLUSION: This study confirms that patients with PSC-IBD have a particular disease phenotype independent of the initial disease location. Although their disease is less active and they use more 5-aminosalicylates, they present a higher risk of colorectal cancer.

Clinical features and management of primary sclerosing cholangitis

Primary sclerosing cholangitis is a chronic cholestatic liver disease characterized by inflammation and fibrosis of the bile ducts, resulting in cirrhosis and need for liver transplantation and reduced life expectancy. The majority of cases occur in young and middle-aged men, often in association with inflammatory bowel disease. The etiology of primary sclerosing cholangitis includes immune-mediated components and elements of undefined nature. No effective medical therapy has been identified. The multiple complications of primary sclerosing cholangitis include metabolic bone disease, dominant strictures, bacterial cholangitis, and malignancy, particularly cholangiocarcinoma, which is the most lethal complication of primary sclerosing cholangitis. Liver transplantation is currently the only life-extending therapeutic alternative for patients with end-stage disease, although recurrence in the allografted liver has been described. A PSC-like variant attracting attention is cholangitis marked by raised levels of the immunoglobulin G4 subclass, prominence of plasma cells within the lesions, and steroid responsiveness.

Current diagnosis and management of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is an important liver disease with major morbidity and mortality. The diagnosis of PSC is confirmed by magnetic resonance cholangiopancreaticography, and endoscopic retrograde cholangiopancreaticography is performed in patients needing therapeutic endoscopy. As a result of the unknown cause of the disease, current medical therapies are unsatisfactory. Nevertheless, high-dose ursodeoxycholic acid should be recommended for treatment of PSC patients because there is a trend toward increased survival. Dominant bile duct stenoses should be treated endoscopically. However, liver transplantation continues to be the only therapeutic option for patients with advanced disease. Estimation of prognosis and timing of liver transplantation should be determined individually for each PSC patient on the basis of all results. The diagnosis and treatment of cholangiocarcinoma (CC) still remain a challenge in PSC patients. Early diagnosis of CC certainly is a prerequisite for successful treatment with surgical resection or innovative strategies such as neoadjuvant radiochemotherapy with subsequent orthotopic liver transplantation. Therefore, endoscopic techniques such as cholangioscopy and/or intraductal ultrasound may be useful diagnostic tools in patients with stenoses suspicious for malignancy.

Cancer in inflammatory bowel disease

Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). Many of the molecular alterations responsible for sporadic colorectal cancer, namely chromosomal instability, microsatellite instability, and hypermethylation, also play a role in colitis-associated colon carcinogenesis. Colon cancer risk in inflammatory bowel disease increases with longer duration of colitis, greater anatomic extent of colitis, the presence of primary sclerosing cholangitis, family history of CRC and degree of inflammation of the bowel. Chemoprevention includes aminosalicylates, ursodeoxycholic acid, and possibly folic acid and statins. To reduce CRC mortality in IBD, colonoscopic surveillance with random biopsies remains the major way to detect early mucosal dysplasia. When dysplasia is confirmed, proctocolectomy is considered for these patients. Patients with small intestinal Crohn's disease are at increased risk of small bowel adenocarcinoma. Ulcerative colitis patients with total proctocolectomy and ileal pouch anal-anastomosis have a rather low risk of dysplasia in the ileal pouch, but the anal transition zone should be monitored periodically. Other extra intestinal cancers, such as hepatobiliary and hematopoietic cancer, have shown variable incidence rates. New endoscopic and molecular screening approaches may further refine our current surveillance guidelines and our understanding of the natural history of dysplasia.

Colorectal cancer and dysplasia in inflammatory bowel disease

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

Endoscopy in the management of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic, cholestatic liver condition characterized by progressive fibrosis and destruction of the intra- and extrahepatic biliary tree. PSC has a clear association with inflammatory bowel disease and is often progressive, leading to cirrhosis and end-stage liver failure. For many patients, liver transplantation offers the only hope of long-term survival. No effective medical treatment exists, and therapy is often aimed at treating complications of the disorder, including dominant biliary strictures, which may cause symptomatic jaundice, cholangitis, and pruritus. Studies on endoscopic therapy (eg, biliary dilation and/or stent insertion) have shown favorable results, although most studies have been small, retrospective, and uncontrolled. Up to 20% of patients with PSC develop cholangiocarcinoma; however, distinguishing between cholangiocarcinoma and benign strictures can be difficult. Ideally, randomized trials are required to determine the safest and most effective endoscopic management for symptomatic dominant strictures.

Deoxycholyltaurine rescues human colon cancer cells from apoptosis by activating EGFR-dependent PI3K/Akt signaling

Recent studies indicate that secondary bile acids promote colon cancer cell proliferation but their role in maintaining cell survival has not been explored. We found that deoxycholyltaurine (DCT) markedly attenuated both unstimulated and TNF-alpha-stimulated programmed cell death in colon cancer cells by a phosphatidylinositol 3-kinase (PI3K)-dependent mechanism. To examine the role of bile acids and PI3K signaling in maintaining colon cancer cell survival, we explored the role of signaling downstream of bile acid-induced activation of the epidermal growth factor receptor (EGFR) in regulating both apoptosis and proliferation of HT-29 and H508 human colon cancer cells. DCT caused dose- and time-dependent Akt (Ser(473)) phosphorylation, a commonly used marker of activated PI3K/Akt signaling. Both EGFR kinase and PI3K inhibitors attenuated DCT-induced Akt phosphorylation and Akt activation, as demonstrated by reduced phosphorylation of a GSK-3-paramyosin substrate. Transfection of HT-29 cells with kinase-dead EGFR (K721M) reduced DCT-induced Akt phosphorylation. In HT-29 cells, EGFR and PI3K inhibitors as well as transfection with dominant negative AKT attenuated DCT-induced cell proliferation. DCT-induced PI3K/Akt activation resulted in downstream phosphorylation of GSK-3 (Ser(21/9)) and BAD (Ser(136)), and nuclear translocation (activation) of NF-kappaB, thereby confirming that DCT-induced activation of PI3K/Akt signaling regulates both proproliferative and prosurvival signals. Collectively, these results indicate that DCT-induced activation of post-EGFR PI3K/Akt signaling stimulates both colon cancer cell survival and proliferation.

Treatment of primary sclerosing cholangitis

Aims of treatment for primary sclerosing cholangitis are as follows: prevention of progression of hepatobiliary disease, reduction of symptoms and consequences of cholestasis (pruritus, osteoporosis), and prevention of complications (colorectal cancer, hepatobiliary cancer). Ursodeoxycholic acid (UDCA) improves biliary secretion and laboratory parameters of cholestasis, but its effects on liver histology and survival are not clear. It reduces the incidence of dysplasias and carcinomas of the colon in patients with colitis and possibly has a beneficial effect on the incidence of bile duct carcinomas. At present, UDCA represents the most promising therapeutic option. Immunosuppressive treatment has not been proven to be effective; it appears to be indicated in the overlap syndrome with autoimmune hepatitis but may be harmful in bacterial cholangitis. Bacterial cholangitis is common in patients with dominant stenoses and requires antibiotic treatment. Endoscopic treatment of dominant stenoses improves cholestasis and prolongs survival in comparison to predicted survival. Pruritus represents a problem in some patients, and cholestyramine represents the first-line treatment. If ineffective, opioid antagonists, rifampin, or ondansetron may be tried. For treatment of osteoporosis and osteopenia, calcium and vitamin D supplementation are recommended, and in selected cases, bisphosphonates may be indicated. In patients with severe cholestasis and coagulation defects, parenteral supplementation of vitamin K may be indicated. During treatment, all patients should be regularly screened for colonic and bile duct carcinomas. Patients with cirrhosis of the liver and its complications are treated accordingly, and in end-stage disease, liver transplantation is indicated.

Emerging drugs for complications of end-stage liver disease

BACKGROUND

The prevalence of end-stage liver disease is rising rapidly and constitutes a major healthcare burden currently. Many cases are diagnosed at a later stage when liver transplantation is the only effective treatment option. There is thus an urgent need for novel treatments to reverse the earlier stages of cirrhosis as well as to treat the many associated life-threatening complications.

OBJECTIVES

To review the current drugs available for treating the complications of advanced liver disease. To address novel treatment strategies that are in development, with particular reference to the rapidly developing area of antifibrotic therapy. To assess how the obstacles that have so far impeded the development of effective new drugs for end-stage liver disease may be overcome in the future.

METHODS

The literature was reviewed to define current therapies and therapies in clinical trials. We used the current models of the molecular basis of liver fibrogenesis to determine potential new therapeutic targets for antifibrotic therapy.

CONCLUSIONS

Insights into the pathogenesis of liver injury and fibrosis have opened up new avenues for therapy and there are now candidates and targets with real potential for the development of a new generation of antifibrotic therapies.

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

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

Medical treatment of cholestatic liver disease

In most cholestatic liver diseases the cause of the disease is not known and therapy can only be directed toward suppression of the pathogenetic processes and amelioration of the consequences of cholestasis. The recognition of adaptive-compensatory responses to cholestasis has become of major importance. They tend to minimize retention of bile acids and other potentially toxic solutes in the hepatocyte by limiting hepatocellular uptake, reducing bile acid synthesis, stimulating detoxification, and up-regulating alternative pathways for excretion. Some of the drugs used for the treatment of cholestatic liver diseases in an empiric way turned out to be modulators of nuclear receptors, which regulate these adaptive-compensatory responses. New drugs are being designed and tested along these lines and may be regarded as treatment opportunities of the future.

Cancer in inflammatory bowel disease

Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). Many of the molecular alterations responsible for sporadic colorectal cancer, namely chromosomal instability, microsatellite instability, and hypermethylation, also play a role in colitis-associated colon carcinogenesis. Colon cancer risk in inflammatory bowel disease increases with longer duration of colitis, greater anatomic extent of colitis, the presence of primary sclerosing cholangitis, family history of CRC and degree of inflammation of the bowel. Chemoprevention includes aminosalicylates, ursodeoxycholic acid, and possibly folic acid and statins. To reduce CRC mortality in IBD, colonoscopic surveillance with random biopsies remains the major way to detect early mucosal dysplasia. When dysplasia is confirmed, proctocolectomy is considered for these patients. Patients with small intestinal Crohn’s disease are at increased risk of small bowel adenocarcinoma. Ulcerative colitis patients with total proctocolectomy and ileal pouch anal-anastomosis have a rather low risk of dysplasia in the ileal pouch, but the anal transition zone should be monitored periodically. Other extra intestinal cancers, such as hepatobiliary and hematopoietic cancer, have shown variable incidence rates. New endoscopic and molecular screening approaches may further refine our current surveillance guidelines and our understanding of the natural history of dysplasia.

Primary sclerosing cholangitis, autoimmune hepatitis and overlap syndromes in inflammatory bowel disease

Primary sclerosing cholangitis (PSC) is a chronic progressive disorder of unknown aetiology characterised by chronic inflammation and stricture formation of the biliary tree. Symptoms include itch and lethargy and in advanced cases cholangitis and end-stage liver disease, however increasing numbers of asymptomatic individuals are being identified. The disease is rare in the general population but is strongly associated with inflammatory bowel disease (IBD) affecting up to 5% of patients with Ulcerative Colitis, with a slightly lower prevalence (up to 3.6%) in Crohn's disease. The strength of this association means that the vast majority (> 90%) of patients with PSC also have IBD, although many may have only mild gastro-intestinal symptoms. Usually IBD presents before PSC, although vice-versa can occur and the onset of both conditions can be separated in some cases by many years. Mean age of diagnosis of PSC is in the fifth decade of life with a strong male predominance. Risk is increased in those with a family history of PSC, suggesting a genetic predisposition and the disease is almost exclusive to non-smokers. The ulcerative colitis associated with PSC is characteristically mild, runs a quiescent course, is associated with rectal sparing, more severe right sided disease, backwash ileitis and has a high risk of pouchitis post-colectomy. Most worrisome is the high risk of colorectal malignancy which necessitates routine colonoscopic surveillance. Cholangiocarcinoma is also a frequent complication of PSC with a 10%-15% lifetime risk of developing this condition. Treatment with high dose ursodeoxycholic acid offers some chemoprotective effects against colorectal malignancy and may decrease symptoms, biochemical and histological progression of liver disease. Small duct PSC patients characteristically have normal cholangiography, and liver biopsy is required for diagnosis, it appears to have a more favourable prognosis. Autoimmune Hepatitis (AIH) is also more prevalent in patients with IBD, with up to 16% of patients with AIH also having ulcerative colitis. A small subgroup of patients have a AIH-PSC overlap syndrome and the management of these patients depends on liver histology, serum IgM levels, autoantibodies, degree of biochemical cholestasis and cholangiography as some of these patients may respond to immunosupression.

Ursodeoxycholic acid: Mechanism of action and novel clinical applications

Ursodeoxycholic acid (UDCA) is used in the treatment of cholestatic liver diseases, gallstone dissolution, and for patients with hepatitis C virus infection to ameliorate elevated alanine aminotransferase levels. The efficacy of UDCA treatment has been debated and the mechanisms of action in humans have still not defined. Suggested mechanisms include the improvement of bile acid transport and/or detoxification, cytoprotection, and anti-apoptotic effects. In this review, we summarize the proposed molecular mechanisms for the action of UDCA, especially in hepatocytes, and also discuss the putative future clinical usage of this unique drug.

Incidence, diagnosis, and therapy of cholangiocarcinoma in patients with primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) can lead to the development of cholangiocarcinoma (CCA). The tumor may present as an intrahepatic focal cholangiocellular carcinoma but more often as a ductal infiltrating desmoplastic lesion. CCA is found synchronously with the diagnosis of PSC in 20-30% and within 1 year in 50%. During later follow-up, the yearly developmental rate of CCA is 0.5-1.5%. Most patients with PSC and CCA do not yet have cirrhosis but present with a severe stenosis at the hilum of the liver. This type of tumor is difficult to diagnose by imaging techniques.(18)F-FDG-PET scanning and CEA or CA 19-9 are not early diagnostic tools. Regular MRI, multislice CT, and repeated endoscopically obtained brush cytology of stenotic lesions are recommended. The recent use of more extensive surgical resection techniques in patients with CCA results in 5-year survival rates of > or =50%. If tumors are small or incidental findings, liver transplantation leads to a 3- to 5-year survival rate of 35%. Pretransplant radiotherapy with 5-FU chemosensitization followed by endoscopic brachytherapy with iridium-192 seems to greatly improve the outcome of transplantation. Treatment with ursodeoxycholic acid may prevent development of CCA.

Identification of aberrant forms of alkaline sphingomyelinase (NPP7) associated with human liver tumorigenesis

Alkaline sphingomyelinase (alk-SMase) is expressed in the intestine and human liver. It may inhibit colonic tumorigenesis, and loss of function mutations have been identified in human colon cancer. The present study investigates its expression in human liver cancer. In HepG2 liver cancer cells, RT–PCR identified three transcripts with 1.4, 1.2 and 0.4 kb, respectively. The 1.4 kb form is the wild-type cDNA with five translated exons, the 1.2 kb product lacks exon 4 and the 0.4 kb form is a combination of exons 1 and 5. Genomic sequence showed that these aberrant transcripts were products of alternative splicing. Transient expression of the 1.2 kb form showed no alk-SMase activity. In HepG2 cells, the alk-SMase activity is low in monolayer condition and increased with cell polarisation. Coexistence of 1.4 and 1.2 kb forms was also identified in one hepatoma biopsy. GenBank search identified a cDNA clone from human liver tumour, which codes a protein containing full length of alk-SMase plus a 73-amino-acid tag at the N terminus. The aberrant form was translated by an alternative starting codon upstream of the wild-type mRNA. Expression study showed that linking the tag markedly reduced the enzyme activity. We also analysed human liver biopsy samples and found relatively low alk-SMase activity in diseases with increased risk of liver tumorigenesis. In conclusion, expression of alk-SMase is changed in hepatic tumorigenesis, resulting in loss or marked reduction of the enzyme function.

Ursodeoxycholic acid versus sulfasalazine in colitis-related colon carcinogenesis in mice

PURPOSE

Inflammation influences carcinogenesis. In the current study, we investigated whether ursodeoxycholic acid (UDCA) can inhibit colitis-related mouse colon carcinogenesis and compared it with the effects of sulfasalazine.

EXPERIMENTAL DESIGN

Male CD-1 mice were given a single i.p. injection of azoxymethane followed by 1-week oral exposure of 1% dextran sodium sulfate in drinking water. They are then maintained on a basal diet mixed with UDCA (0.016%, 0.08%, or 0.4%) or sulfasalazine (0.05%) for 17 weeks. At week 20, the tumor-inhibitory effects of both chemicals were assessed by counting the incidence and multiplicity of colonic neoplasms. The immunohistochemical expression of the proliferating cell nuclear antigen labeling index in colonic epithelial malignancies was also assessed. Finally, at week 5, the mRNA expressions for cyclooxygenase-2, inducible nitric oxide synthase, peroxisome proliferator-activated receptor-gamma, and tumor necrosis factor-alpha were measured in nontumorous mucosa.

RESULTS

Feeding the mice with UDCA at all doses significantly inhibited the multiplicity of colonic adenocarcinoma. The treatment also significantly lowered the proliferating cell nuclear antigen labeling index in the colonic malignancies. UDCA feeding reduced the expression of inducible nitric oxide synthase and tumor necrosis factor-alpha mRNA in the colonic mucosa, while not significantly affecting the expression of cyclooxygenase-2 mRNA and peroxisome proliferator-activated receptor-gamma mRNA. Sulfasalazine caused a nonsignificant reduction in the incidence and multiplicity of colonic neoplasia and did not affect these mRNA expression.

CONCLUSIONS

Our findings suggest that UDCA rather than sulfasalazine could serve as an effective suppressing agent in colitis-related colon cancer development in mice.

Chemoprophylaxis of colorectal cancer in inflammatory bowel disease: current concepts

Ulcerative colitis and Crohn's disease both confer an increased risk of developing colorectal cancer. The use of 5-aminosalicylate as a remission-inducing agent has been long accepted. Its use as a potential chemoprophylactic agent has been proposed and is used by some practitioners. This review examines the most recent data on 5-aminosalicylate as a chemoprophylactic drug as well as ursodeoxycholic acid, folic acid, azathioprine, and 6-mercaptopurine.

[Medicinal prevention of gastrointestinal tumors: aspirin, Helicobacter and more?]

Despite the huge number of drugs on the market and recent advances in pharmacotherapy, only a few substances are available for the prevention of gastrointestinal tumors--most of which are not approved for this indication or not validated in appropriately designed randomized trials. General recommendations include lifestyle modifications such as avoidance of smoking, only moderate consumption of alcohol, regular physical exercise and a nutrition rich in fresh fruits and vegetables with limited meat. A global eradication therapy for Helicobacter pylori would be desirable to prevent gastric carcinoma, but this does not seem feasible from the socio-economic point of view. Therefore, at least patients at high risk should be screened and this pathogen eradicated, preferentially in their youth. Hepatitis B vaccination of newborns to prevent the development of hepatocellular carcinoma has already been established in Germany; a specific antiviral therapy should be offered to all patients with hepatitis B or C infections, taking into consideration the risks associated with this treatment. The use of non-steroidal anti-inflammatory drugs (NSAIDs) to prevent gastrointestinal malignancies cannot generally be recommended and should be restricted to patients at high risk and to clinical studies. However, the appropriate substance, dose and duration of NSAID therapy are still being debated.

Cancer and pediatric inflammatory bowel disease

Cancer in children may be mistakenly diagnosed as inflammatory bowel disease (IBD), and specific cancers may develop in patients who truly have IBD. Ulcerative colitis patients historically carry an increased risk of colorectal adenocarcinoma, but current practices of surveillance and early surgery may have an impact on this. Crohn's disease patients require surveillance for colon cancer, but are also likely to be at increased risk for small bowel tumors and lymphoma. Some malignancies affecting IBD patients are sequelae of immunomanipulation, performed in the interest of IBD therapy itself. Knowing the cancer risks associated with IBD and those associated with agents used for IBD treatment, and practicing long-term surveillance for these tumors, are central components of caring for patients with IBD. Lessons learned from the fields of oncology and bone marrow transplantation may provide future directions and potential cures in IBD.

The incidence of cholangiocarcinoma in primary sclerosing cholangitis after long-time treatment with ursodeoxycholic acid

BACKGROUND/AIMS

Cholangiocarcinoma represents a serious complication of primary sclerosing cholangitis. Ursodeoxycholic acid may possibly influence the incidence of cholangiocarcinoma in man. The aim of this study was to evaluate the incidence rate of cholangiocarcinoma in a large group of primary sclerosing cholangitis patients after long-time treatment with ursodeoxycholic acid.

PATIENTS AND METHODS

From May 1987 up to May 2005 a total of 150 patients with primary sclerosing cholangitis but without evidence of cholangiocarcinoma at entry were included in the study. All patients were treated with ursodeoxycholic acid and controls were performed in at least yearly intervals.

RESULTS

The median treatment time of the 150 patients was 6.4 years. Altogether five patients developed a cholangiocarcinoma during treatment yielding a rate of 3.3%. The patients developed 0.58 cholangiocarcinoma per 100 patient-years in years 0-2.5, 0.59 cholangiocarcinoma in years 2.5-8.5, and no cholangiocarcinoma thereafter up to 18 years after entry into the study. The Kaplan-Meier estimate of cholangiocarcinoma incidence during ursodeoxycholic acid treatment reached a plateau after 8.3 years.

SUMMARY AND CONCLUSION

The annual incidence rate of cholangiocarcinoma in primary sclerosing cholangitis treated with ursodeoxycholic acid is lower than expected and decreases with time of treatment.

Risk factors for colorectal neoplasia in inflammatory bowel disease: a nested case-control study from Copenhagen county, Denmark and Olmsted county, Minnesota

OBJECTIVES

Population-based data on risk factors and protective factors for colorectal dysplasia and cancer in patients with inflammatory bowel disease (IBD) are sparse. We conducted a nested case-control study of such factors in two well-described IBD cohorts from Copenhagen County, Denmark and Olmsted County, Minnesota.

METHODS

Forty-three neoplasia cases were matched on six criteria to 1-3 controls (N = 102). Medical records were scrutinized for demographic and clinical data. For each variable, the odds of neoplasia were estimated using conditional logistic regression.

RESULTS

Primary sclerosing cholangitis (PSC) (odds ratio [OR] 6.9, 95% confidence interval [CI] 1.2-40), percentage of disease course with clinically active disease (OR [per 5% increase] 1.2, 95% CI 0.996-1.4), and >or=1 yr of continuous symptoms (OR 3.2, 95% CI 1.2-8.6) were associated with neoplasia, whereas a borderline association with median number of small-bowel x-rays (OR 1.3, 95% CI 0.96-1.6) was observed. We did not observe a protective effect of frequency of physician visits (OR 1.4, 95% CI 0.96-2.0), number of colonoscopies (OR 1.4, 95% CI 1.0-2.1), cumulative dose of sulfasalazine (OR [per 1,000 g] 1.1, 95% CI 1.0-1.3) and mesalamine (OR [per 1,000 g] 1.3, 95% CI 0.9-1.9), or partial intestinal resections (OR 1.5, 95% CI 0.3-7.1).

CONCLUSIONS

Subgroups of IBD patients-those with PSC, severe long-standing disease, and exposure to x-ray-were at greater risk of colorectal neoplasia. The protective effect of close follow-up, colonoscopy, and treatment with 5-aminosalicylates was questionable.

High-dose ursodeoxycholic acid for the treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease that results in progressive fibrosis of intrahepatic and extrahepatic bile ducts. No effective therapy currently exists for this disease. Ursodeoxycholic acid (UDCA), a hydrophilic bile acid, is the most promising treatment option because of its benign side effect profile and documented benefit in the treatment of other cholestatic liver diseases, including primary biliary cirrhosis. Multiple studies using standard-dosage (8-15 mg/kg/d) and high-dosage (20-30 mg/kg/d) UDCA generally show improvement in liver chemistries in PSC patients, and several show improvement in liver histology. However, the majority of trials using UDCA in PSC are underpowered and fail to show improvements in clinically relevant endpoints, such as delayed progression to cirrhosis, portal hypertension, liver transplantation, development of cholangiocarcinoma, or death.

Ursodeoxycholic acid modulates histone acetylation and induces differentiation and senescence

Agents that can modulate colonic environment and control dysregulated signaling are being evaluated for their chemopreventive potential in colon cancer. Ursodeoxycholate (UDCA) has shown chemopreventive potential in preclinical and animal models of colon cancer, but the mechanism behind it remains unknown. Here biological effects of UDCA were examined to understand mechanism behind its chemoprevention in colon cancer. Our data suggests that UDCA can suppress growth in a wide variety of cancer cell lines and can induce low level of apoptosis in colon cancer cells. We also found that UDCA treatment induces alteration in morphology, increased cell size, upregulation of cytokeratin 8, 18 and 19 and E-cadherin, cytokeratin remodeling and accumulation of lipid droplets, suggesting that UDCA induces differentiation in colon carcinoma cells. Our results also suggest significant differences in UDCA and sodium butyrate induced functional differentiation. We also report for the first time that UDCA can induce senescence in colon cancer cells as assessed by flattened, spread out and vacuolated morphology as well as by senescence marker beta-galactosidase staining. We also found that UDCA inhibits the telomerase activity. Surprisingly, we found that UDCA is not a histone deacytylase inhibitor but instead induces hypoacetylation of histones unlike hyperacetylation induced by sodium butyrate. Our results also suggest that, although UDCA induced senescence is p53, p21 and Rb independent, HDAC6 appears to be important in UDCA induced senescence. In summary, our data shows that UDCA modulates chromatin by inducing histone hypoacetylation and induces differentiation and senescence in colon cancer cells.

Matrix metalloproteinase-7-catalyzed release of HB-EGF mediates deoxycholyltaurine-induced proliferation of a human colon cancer cell line

Prior evidence indicates that bile acids stimulate colon cancer cell proliferation by muscarinic receptor-induced transactivation of epidermal growth factor receptors (EGFR). To explore further the mechanism underlying this action, we tested the hypothesis that bile acids activate a matrix metalloproteinase (MMP) that catalyzes release of an EGFR ligand. Initial studies showed that non-selective MMP inhibitors blocked the actions of deoxycholyltaurine (DCT), thereby indicating a role for MMP-catalyzed release of an EGFR ligand. DCT-induced cell proliferation was reduced by increasing concentrations of EGFR kinase inhibitors, by antibodies to the ligand binding domain of EGFR, by neutralizing antibodies to heparin binding-EGF-like growth factor (HB-EGF) and by CRM197, an inhibitor of HB-EGF release. These findings and our observations with more selective MMP inhibitors suggested that MMP-7, an enzyme known to release HB-EGF, plays a key role in mediating bile acid-induced H508 colon cancer cell proliferation. We observed that recombinant HB-EGF and MMP-7 mimicked both the signaling and proliferative actions of bile acids. Strikingly, reducing MMP-7 expression with either neutralizing antibody or small interfering RNA attenuated the actions of DCT. MMP-7 expression in H508 cells was confirmed using quantitative reverse transcription PCR. DCT stimulated a greater than 10-fold increase in MMP-7 gene transcription. Co-localization of pro-MMP-7 and pro-HB-EGF at the cell surface (immunofluorescence microscopy) was demonstrated, indicating proximity of the enzyme to its substrate. These findings provide strong evidence that in H508 human colon cancer cells, DCT-induced transactivation of EGFR is mediated by MMP-7-catalyzed release of the EGFR ligand HB-EGF.

Chemoprevention in gastrointestinal cancers: current status

Chemoprevention, pharmacological intervention for disease prevention, aims to intervene in pathways that lead to clinical disease before the disease occurs. Cancer chemoprevention is a relatively new field, but for gastrointestinal cancers, clinical trials have highlighted the chemopreventive potential of several agents. For colorectal neoplasia, trials with aspirin and other non-steroidal anti-inflammatory drugs (NSAIDS) and calcium have demonstrated the most significant reductions of risk. In observational studies, NSAIDs also consistently appear to protect against oesophageal and gastric cancer. Calcium, and perhaps vitamin D, are also promising and have the advantage of being inexpensive, safe interventions. For the prevention of oesophageal cancer, antitumour-B and retinamide have provided hopeful results, although it is not clear that these findings can be extrapolated from the study populations in Asia to western countries. Evidence from China suggests that a combination of beta-carotene, alpha-tocopherol and selenium may protect against oesophageal cancer, but the relative importance of each agent is unclear, and, again, their effects in other populations has not yet been assessed. Mass immunization against hepatitis B seems to be the most effective means of reducing the incidence of hepatocellular cancer worldwide. In addition, treatment with interferon alpha in patients chronically infected with hepatitis C virus shows considerable promise, given the increasing prevalence of hepatitis C virus carriage in recent years. TJ-9, polyprenoic acid and anti-aflatoxin compounds are also possible avenues that deserve future research.

Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown aetiology characterised by inflammation and fibrosis of the biliary tree. The mean age at diagnosis is 40 years and men are affected twice as often as women. There is a reported annual incidence of PSC of 0.9-1.31/100,000 and point prevalence of 8.5-13.6/100,000. The onset of PSC is usually insidious and many patients are asymptomatic at diagnosis or have mild symptoms only such as fatigue, abdominal discomfort and pruritus In late stages, splenomegaly and jaundice may be a feature. In most, the disease progresses to cirrhosis and liver failure. Cholangiocarcinoma develops in 8-30% of patients. PSC is thought to be immune mediated and is often associated with inflammatory bowel disease, especially ulcerative colitis. The disease is diagnosed on typical cholangiographic and histological findings and after exclusion of secondary sclerosing cholangitis. Median survival has been estimated to be 12 years from diagnosis in symptomatic patients. Patients who are asymptomatic at diagnosis, the majority of whom will develop progressive disease, have a survival rate greater than 70% at 16 years after diagnosis. Liver transplantation remains the only effective therapeutic option for patients with end-stage liver disease from PSC, although high dose ursodeoxycholic acid may have a beneficial effect.

Resistance to ursodeoxycholic acid-induced growth arrest can also result in resistance to deoxycholic acid-induced apoptosis and increased tumorgenicity

BACKGROUND

There is a large body of evidence which suggests that bile acids increase the risk of colon cancer and act as tumor promoters, however, the mechanism(s) of bile acids mediated tumorigenesis is not clear. Previously we showed that deoxycholic acid (DCA), a tumorogenic bile acid, and ursodeoxycholic acid (UDCA), a putative chemopreventive agent, exhibited distinct biological effects, yet appeared to act on some of the same signaling molecules. The present study was carried out to determine whether there is overlap in signaling pathways activated by tumorogenic bile acid DCA and chemopreventive bile acid UDCA.

METHODS

To determine whether there was an overlap in activation of signaling pathways by DCA and UDCA, we mutagenized HCT116 cells and then isolated cell lines resistant to UDCA induced growth arrest. These lines were then tested for their response to DCA induced apoptosis.

RESULTS

We found that a majority of the cell lines resistant to UDCA-induced growth arrest were also resistant to DCA-induced apoptosis, implying an overlap in DCA and UDCA mediated signaling. Moreover, the cell lines which were the most resistant to DCA-induced apoptosis also exhibited a greater capacity for anchorage independent growth.

CONCLUSION

We conclude that UDCA and DCA have overlapping signaling activities and that disregulation of these pathways can lead to a more advanced neoplastic phenotype.

Primary sclerosing cholangitis: summary of a workshop

Primary sclerosing cholangitis (PSC) is a rare but important liver disease that leads to cirrhosis and need for liver transplantation in a high proportion of cases. The disease occurs in approximately 1 per 100,000 population per year, usually presents in adulthood, and affects men more often than women. Typical serum biochemical results, autoantibodies and liver biopsy are suggestive but not diagnostic of PSC, the diagnosis requiring cholangiographic demonstration of stricturing and dilatation of the intra- and/or extra-hepatic bile ducts. The natural history of PSC is variable, the average survival being 12 to 17 years. The cause of PSC is still unknown. Although considered an autoimmune disease, PSC has several atypical features and a strong genetic component. The therapy of PSC is unsatisfactory. Standard doses of ursodeoxycholic acid (UDCA) lead to improvements in biochemical abnormalities but not in histology, cholangiographic appearance or survival. Several innovative therapies have been tried in PSC, but with scant evidence of benefit. For patients with high grade strictures, endoscopic dilatation is beneficial. Liver transplantation is successful for end-stage liver disease due to PSC and improves survival. PSC may recur after transplantation but is rarely progressive. The most dreaded complication of PSC is cholangiocarcinoma. Diagnosis of this highly malignant tumor is difficult, and there are no biomarkers for its early detection. Liver transplantation for cholangiocarcinoma has an exceedingly poor outcome, although transplantation with neoadjuvant chemoirradiation holds promise in selected patients. Thus, significant opportunities remain for basic and clinical research into the cause, natural history, and therapy of PSC.

Chemoprevention: risk reduction with medical therapy of inflammatory bowel disease

The ideal chemopreventative agent, in addition to being efficacious in the prevention of cancer, must be easily administered, affordable, safe, and well tolerated, with minimal side effects. In the past decade, a growing body of literature has emerged on the prevention of CRC in patients with long-standing CD and UC. The data are not definitive and consist almost exclusively of retrospective case-control and cohort studies rather than the more rigorous prospective RCTs. 5-ASA compounds have been most thoroughly studied, and most of the existing data support the use of 5-ASA in the prevention of CRC. Although the precise dose and duration are unclear, studies suggest that chronic systemic administration of 5-ASA at a dose of at least 1.2 g/d is most likely to be effective. A beneficial effect of folate, albeit not statistically significant, has been consistently shown in every study performed for this purpose. Folate supplementation, which is safe and affordable, should also be recommended for all patients with IBD, especially those taking sulfasalazine. UDCA has been shown to exert a protective effect in most studies on patients with UC and concomitant PSC. Because this patient population is at particularly high risk for CRC, it is advisable to consider UDCA in all patients with colitis complicated by PSC. For patients without PSC, sufficient data do not exist to recommend it for the purpose of cancer prevention. Five of the six corticosteroid studies have found a beneficial effect of systemic steroids, although most did not reach statistical significance. Regardless, given the frequent and serious adverse effects associated with chronic steroid use, systemic corticosteroids should not be prescribed for this indication. Budesonide, an oral corticosteroid with minimal systemic absorption, is a potential alternative, although it has not yet been studied as a chemopreventative agent. Similarly, until the long-term safety of chronic NSAID use can be demonstrated in patients with IBD, the role of NSAIDs in chemoprevention remains undefined. Although the data are conflicting, immune-modulating medications, such as AZA, do not seem to confer any reduction in the risk of dysplasia or CRC. The data on calcium supplementation and statin use are still too limited to endorse their use for the prevention of colitis-related CRC. Chemoprevention is an area that holds great promise in the reduction of morbidity and mortality associated with IBD. Further studies, including prospective trials when possible and cost-effectiveness analyses, need to be performed to develop an optimal strategy for the reduction of cancer risk in patients with IBD.

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

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

Extraintestinal manifestations and complications in inflammatory bowel diseases

Crohn’s disease (CD) and ulcerative colitis (UC) are chronic inflammatory bowel diseases (IBD) that often involve organs other than those of the gastrointestinal tract. These nonintestinal affections are termed extraintestinal symptoms. Differentiating the true extraintestinal manifestations of inflammatory bowel diseases from secondary extraintestinal complications, caused by malnutrition, chronic inflammation or side effects of therapy, may be difficult. This review concentrates on frequency, clinical presentation and therapeutic implications of extraintestinal symptoms in inflammatory bowel diseases. If possible, extraintestinal manifestations are differentiated from extraintestinal complications. Special attention is given to the more recently described sites of involvement; i.e. thromboembolic events, osteoporosis, pulmonary involvement and affection of the central nervous system.

Effects of a 3-mo consumption of short-chain fructo-oligosaccharides on parameters of colorectal carcinogenesis in patients with or without small or large colorectal adenomas

Intervention studies of colorectal adenoma recurrence have demonstrated the need for surrogate markers of the cancer risk. Short-chain fructo-oligosaccharides (sc-FOS) have protective actions on colon carcinogenesis in animal models. We investigated differences in biological markers between adenoma and adenoma-free subjects, before and after 3 mo of daily intake of 10 g sc-FOS, within a multicenter study. After a full colonoscopy, 3 groups were studied at baseline and after 3 mo: 26 subjects with small colorectal adenoma(s), 18 with large adenoma(s), and 30 with no adenoma. At baseline, the mean fecal butyrate concentration was significantly lower in the adenoma groups than in the adenoma-free group (12.01 +/- 5.08 vs. 17.28 +/- 7.34 mmol/g dry weight) but was significantly increased in that group after 3-mo ingestion of sc-FOS (15.7 +/- 8.0 mmol/g; P = 0.02). In subjects without adenoma, sc-FOS ingestion was associated with a decrease in fecal lithocholic acid (P = 0.02) and an increase in cholic acid (P = 0.02), chenodeoxycholic acid (P = 0.04), total primary bile acids (P = 0.03), and ursodeoxycholic acid (P = 0.05). Fecal pH, blood parameters, and crypt cell proliferation were not significantly modified by sc-FOS ingestion in either group. In subjects with and without adenoma, sc-FOS affects some aspects of the colonic environment, which may be involved in prevention of colorectal neoplasia.

Ursodeoxycholic acid treatment of vanishing bile duct syndromes

Vanishing bile duct syndromes (VBDS) are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Ursodeoxycholic acid (UDCA), a hydrophilic dihydroxy bile acid, is the only drug currently approved for the treatment of patients with PBC, and anticholestatic effects have been reported for several other cholestatic syndromes. Several potential mechanisms of action of UDCA have been proposed including stimulation of hepatobiliary secretion, inhibition of apoptosis and protection of cholangiocytes against toxic effects of hydrophobic bile acids.

Colorectal cancer in inflammatory bowel disease: Molecular and clinical considerations

Adenocarcinoma of the colon is an accepted and feared complication of chronic ulcerative colitis (UC) and colonic Crohn's disease (CD). When cancer is identified, surgery is necessary, and unlike with sporadic colorectal cancer (CRC), in which partial colectomy is effective, proctocolectomy is required. As CRC is a rare complication of these diseases, studies of the pathogenesis are limited primarily to observational studies; thus, the mechanism and molecular events that lead to neoplastic change are not fully understood or well known. Precancerous dysplasia has been associated with concurrent or future CRC in UC and, although less studied, in CD, and is therefore considered a marker of cancer risk in inflammatory bowel disease (IBD). Risk factors for dysplasia and CRC in IBD include longer duration of disease, greater extent of disease, younger age at diagnosis, diagnosis with primary sclerosing cholangitis (PSC), family history of CRC, and possibly backwash ileitis and degree of inflammation of the bowel over time. Prevention of cancer in IBD has been focused on secondary measures of identifying dysplasia in flat mucosa or protruding lesions during surveillance colonoscopy with random biopsies and, when confirmed, performing proctocolectomy. Studies of primary prevention of dysplasia and CRC using chemopreventive agents have suggested a possible benefit with a number of agents. These include ursodeoxycholic acid (in patients with PSC and UC), aminosalicylates, and possibly statins.

Risk factors for colorectal cancer in Crohn's colitis: a case-control study

BACKGROUND

Few data exist regarding exposures associated with colorectal cancer (CRC) in patients with Crohn's colitis. The aim of this study was to identify exposures that alter the risk of CRC in patients with Crohn's colitis.

METHODS

The Research Patient Database Registry at Massachusetts General Hospital was searched to identify cases and controls. Cases had a confirmed diagnosis of Crohn's disease involving at least one third of the colon and a confirmed diagnosis of colorectal adenocarcinoma. Matched controls were randomly chosen from the same source population. Paired univariate analysis was performed to develop an odds ratio (OR) for each exposure.

RESULTS

Twenty-seven patients were found to have Crohn's colitis and CRC. Colonoscopy performed for screening or surveillance was associated with an OR of 0.21 (95% CI 0.04-0.77; P=0.02). Nonsignificant trends for a protective effect included prior appendectomy (OR 0.30; 95% CI 0.05-1.17; P=0.10) and regular 5-aminosalicylate use (OR 0.30; 95% CI 0.05-1.17; P=0.10). Smoking history was associated with a 4-fold-increased risk for CRC, but this was not statistically significant (OR 4.00; 95% CI 0.80-38.67; P=0.11).

CONCLUSIONS

We found that having a colonoscopy for an indication of surveillance or screening is associated with decreased risk of CRC in the setting of Crohn's colitis. These data underscore the importance of CRC surveillance for Crohn's colitis in addition to ulcerative colitis and should prompt further study in this area.

Predictive and protective factors associated with colorectal cancer in ulcerative colitis: A case-control study

BACKGROUND & AIMS

Predictive and protective factors associated with colorectal cancer in chronic ulcerative colitis are not well described. Surveillance colonoscopy and 5-aminosalicylic acid therapy may mitigate cancer risk, but there is debate because these variables have not been evaluated in the same study. The presence of postinflammatory pseudopolyps and use of other anti-inflammatory medications may be important variables that influence risk, but data are sparse.

METHODS

Variables associated with colorectal cancer were registered in 188 patients with ulcerative colitis-related cancer and matched controls. Conditional logistic regression, adjusted for age at colitis diagnosis and colitis duration, identified a final set of variables independently associated with colorectal cancer.

RESULTS

In the final multiple variable model, the most important factors associated with colorectal cancer were a history of pseudopolyps (OR, 2.5; 95% CI: 1.4-4.6), 1 or 2 surveillance colonoscopies (OR, 0.4; 95% CI: 0.2-0.7), smoking (OR, 0.5; 95% CI: 0.2-0.9) and use of corticosteroids (OR, 0.4; 95% CI: 0.2-0.8), aspirin (OR, 0.3; 95% CI: 0.1-0.8), nonsteroidal anti-inflammatory drugs (OR, 0.1; 95% CI: 0.03-0.5), and 5-aminosalicylic acid agents (OR, 0.4; 95% CI: 0.2-0.9), although the latter was not statistically significant after 5 years. Primary sclerosing cholangitis and immunosuppressive use were not statistically significant.

CONCLUSIONS

These results suggest that, in a population matched for extent and duration of chronic ulcerative colitis, surveillance colonoscopy and use of anti-inflammatory medications may reduce the risk of colorectal cancer. A history of postinflammatory pseudopolyps appears to be a predictive factor for cancer.

Prevention of colitis-associated carcinogenesis in a mouse model by diet supplementation with ursodeoxycholic acid

Bile acids in the intestinal lumen contribute to the homeostatic regulation of proliferation and death of the colonic epithelial cells: Deoxycholic acid (DCA) appears to enhance and ursodeoxycholic acid (UDCA) to attenuate the process of chemically induced carcinogenesis. We studied the effects of UDCA on colitis-related colorectal carcinogenesis. Three groups of 25 mice were given 0.7% dextran sulphate in drinking water for 7 days and pure water for 10 days and were fed a standard diet containing double iron concentration. In 2 groups, the diet was supplemented with 0.2% cholic acid (CA), the precursor of DCA, or with 0.4% UDCA. After 15 cycles, the histology, the expression of MUC2, beta-catenin, p27 and p16 and the fecal water concentration of DCA and UDCA were investigated. All animals showed colitis with similar severity and histologic as well as immunophenotypic alterations, resembling those of human colitis. Among the animals fed the nonsupplemented diet, 46% developed colorectal adenocarcinomas and 54% anal-rectal squamous cell carcinomas. The prevalence of dysplasia and carcinomas did not change significantly in the animals given CA. Among the mice fed with UDCA, none developed adenocarcinomas and 20% squamous carcinomas. Dysplastic lesions were found in 88%, 67% and 40% of each group, respectively. The prevalence of dysplasia as well as of carcinoma showed an inverse relationship to the UDCA concentration in the fecal water. These data indicate that UDCA suppresses colitis-associated carcinogenesis. This model is suitable for investigation of the mechanism of the anticarcinogenic effect of UDCA in vivo.