Temporal trends in colon neoplasms in patients with primary sclerosing cholangitis and ulcerative colitis

Bringing to Light the Risk of Colorectal Cancer in Inflammatory Bowel Disease: Mucosal Glycosylation as a Key Player

Colitis-associated cancer is a major complication of inflammatory bowel disease remaining an important clinical challenge in terms of diagnosis, screening, and prognosis. Inflammation is a driving factor both in inflammatory bowel disease and cancer, but the mechanism underlying the transition from colon inflammation to cancer remains to be defined. Dysregulation of mucosal glycosylation has been described as a key regulatory mechanism associated both with colon inflammation and colorectal cancer development. In this review, we discuss the major molecular mechanisms of colitis-associated cancer pathogenesis, highlighting the role of glycans expressed at gut epithelial cells, at lamina propria T cells, and in serum proteins in the regulation of intestinal inflammation and its progression to colon cancer, further discussing its potential clinical and therapeutic applications.

High Risk of Advanced Colorectal Neoplasia in Patients With Primary Sclerosing Cholangitis Associated With Inflammatory Bowel Disease

BACKGROUND & AIMS

Patients with inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC, termed PSC-IBD) are at increased risk for colorectal cancer, but their risk following a diagnosis of low-grade dysplasia (LGD) is not well described. We aimed to determine the rate of advanced colorectal neoplasia (aCRN), defined as high-grade dysplasia and/or colorectal cancer, following a diagnosis of indefinite dysplasia or LGD in this population.

METHODS

We performed a retrospective, longitudinal study of 1911 patients with colonic IBD (293 with PSC and 1618 without PSC) who underwent more than 2 surveillance colonoscopies from 2000 through 2015 in The Netherlands or the United States (9265 patient-years of follow-up evaluation). We collected data on clinical and demographic features of patients, as well as data from each surveillance colonoscopy and histologic report. For each surveillance colonoscopy, the severity of active inflammation was documented. The primary outcome was a diagnosis of aCRN during follow-up evaluation. We also investigated factors associated with aCRN in patients with or without a prior diagnosis of indefinite dysplasia or LGD.

RESULTS

Patients with PSC-IBD had a 2-fold higher risk of developing aCRN than patients with non-PSC IBD. Mean inflammation scores did not differ significantly between patients with PSC-IBD (0.55) vs patients with non-PSC IBD (0.56) (P = .89), nor did proportions of patients with LGD (21% of patients with PSC-IBD vs 18% of patients with non-PSC IBD) differ significantly (P = .37). However, the rate of aCRN following a diagnosis of LGD was significantly higher in patients with PSC-IBD (8.4 per 100 patient-years) than patients with non-PSC IBD (3.0 per 100 patient-years; P = .01). PSC (adjusted hazard ratio [aHR], 2.01; 95% CI, 1.09-3.71), increasing age (aHR 1.03; 95% CI, 1.01-1.05), and active inflammation (aHR, 2.39; 95% CI, 1.63-3.49) were independent risk factors for aCRN. Dysplasia was more often endoscopically invisible in patients with PSC-IBD than in patients with non-PSC IBD.

CONCLUSIONS

In a longitudinal study of almost 2000 patients with colonic IBD, PSC remained a strong independent risk factor for aCRN. Once LGD is detected, aCRN develops at a higher rate in patients with PSC and is more often endoscopically invisible than in patients with only IBD. Our findings support recommendations for careful annual colonoscopic surveillance for patients with IBD and PSC, and consideration of colectomy once LGD is detected.

Hepatobiliary manifestations of ulcerative colitis: an example of gut-liver crosstalk

The interaction between inflammatory bowel disease (IBD) and hepatobiliary manifestations represents a classic example of liver-gut crosstalk. The importance of liver-gut crosstalk in IBD is demonstrated in the pathogenesis and outcome of primary sclerosing cholangitis (PSC) in IBD patients. Immunoglobulin G4-associated cholangitis (IAC), which has recently been described in UC patients, may also illustrate the significance of gut-liver interaction in these patients. Presence of these hepatobiliary manifestations influences the outcome of associated IBD, in particular ulcerative colitis (UC), and vice versa. The pathogenesis of PSC is postulated to be related to gut inflammation in IBD that results in inflammation in the portal tracts (the 'leaky gut'). Enterohepatic circulation of lymphocytes from the gut to the liver is also of potential relevance to PSC pathogenesis and outcomes. The presence of PSC and gut inflammation in IBD influences the course and outcomes of both diseases. Further research is required, to understand the mutual effect of liver-gut crosstalk in the outcomes of UC patients, and highlights the importance of an interdisciplinary approach-involving gastroenterologists, hepatologists, advanced endoscopists and liver transplant surgeons-in the management of these patients.

Natural history of low grade dysplasia in patients with primary sclerosing cholangitis and ulcerative colitis

BACKGROUND AND AIM

Patients with ulcerative colitis (UC) and primary sclerosing cholangitis (PSC) are at increased risk of colon cancer. The aim of this study was to determine the natural history of LGD and its progression to high grade dysplasia (HGD)/colorectal cancer (CRC) in PSC-UC patients.

METHODS

Ten PSC-UC patients with LGD who underwent surveillance colonoscopy from 1996 to 2011 were evaluated. Raised dysplasia was defined as a discrete raised lesion located in an area involved by either quiescent or active colitis that was endoscopically resected, while flat dysplasia was defined as the absence of documentation of a raised lesion.

RESULTS

Of the 10 patients with LGD, 3 (30%) progressed to raised HGD over a mean follow-up of 13±11 months. Three of 10 patients had initial raised LGD while 7 had flat LGD. The location of HGD was in the proximal colon in all 3 patients. However all 3 patients who progressed to HGD had initial dysplasia located in the distal colon and had flat morphology. The incidence rate for detection of HGD/CRC was 9.4 cases per 100 person years at risk. Patients with LGD with flat morphology had an incidence rate of 17.8 cases per 100 person years at risk. HGD occurred more frequently within the first year of initial detection of LGD (23.5 per 100 patient years of follow-up).

CONCLUSIONS

One-third of patients with LGD progressed to HGD/CRC in PSC-UC. Most patients progress within the first year of diagnosis of LGD supporting early colectomy in PSC-UC patients with LGD.

Chronic ulcerative colitis and colorectal cancer

One of the most important consequences of chronically active ulcerative colitis (UC) or Crohn's disease (CD) - the two major forms of inflammatory bowel disease (IBD) - is the development of colorectal cancer (CRC). An increased risk for the occurrence of CRC in up to 30% of affected patients after 35years of UC has been reported. Recent evidence from population based studies indicates a lower risk. Nevertheless the incidence is still significantly increased as compared to individuals without chronic colitis. Colitis-associated CRC (CAC) does not display the adenoma-carcinoma sequence which is typical for sporadic CRC and the pathophysiology appears to be different. Chronic inflammation and the increased turnover of epithelial cells contribute to the development of low- and high-grade dysplasia which may further transform into CAC. Reactive oxygen species (ROS) generated by the inflammatory infiltrate are thought to contribute to the generation of dysplastic lesions. In sporadic CRC the sequence of mutations that finally lead to malignancy involves early activation of Wnt/β-catenin pathway (in 90% of cases) including mutations in adenomatous polyposis coli (APC) tumor suppressor gene, its regulating kinase GSK3β and β-catenin itself. β-catenin mutations are rarer in CAC and mutations in APC occur rather late during the disease progression, whereas there are earlier mutations in p53 and K-ras. Recent data indicate that the intestinal microbiome and its interaction with a functionally impaired mucosal barrier may also play a role in CAC development. CACs frequently show aggressive growth and early metastases. The treatment of CAC in patients with colitis always includes proctocolectomy with ileoanal anastomosis as meta- or synchronic lesions are frequent.

Outcome of patients with primary sclerosing cholangitis and ulcerative colitis undergoing colectomy

AIM: To study the outcomes of primary sclerosing cholangitis (PSC) patients with ulcerative colitis (UC) undergoing colectomy.

METHODS: We identified 193 patients with PSC and UC undergoing colectomy at the Mayo Clinic (Rochester, MN, United States), between January 1, 1995 and December 31, 2008 using a computerized record system. Eighty-nine patients were excluded due to unclear diagnosis, liver transplantation prior to colectomy, age less than 18 years, inadequate follow-up data or known cases of cholangiocarcinoma. We retrospectively reviewed data from patient medical records. Clinical information, date of colectomy, preoperative and follow-up liver tests and pathological findings of the colon were reviewed. The Mayo risk score at baseline was calculated to obtain survival estimates for up to 4 years of follow-up. The primary endpoint was defined by the presence of all-cause mortality and/or liver decompensation requiring liver transplantation. All patients who did not have a clinical note on December 31, 2008 were considered as patients with an incomplete follow-up unless they reached a study endpoint (death or underwent liver transplantation) prior to that date. The study was approved by the Institutional Review Boards of the Mayo Clinic.

RESULTS: Of the 2441 patients with PSC observed in this period, 104 patients (4.3%) had UC and underwent colectomy and were included. The median age was 43.2 years, and 67% were male. The leading indications for colectomy were severe colonic inflammation (49%), the presence of colonic dysplasia during routine surveillance (42%) and bowel perforation (3%). Twenty-six patients were lost to follow-up after a median duration of 3.9 years. The remaining 78 patients included 52 patients (66.7%) who were followed for a median duration of 5.5 years and 26 patients (33.3%) who developed primary endpoints including death (n = 13) or underwent liver transplantation (n = 13) with a median follow up of 2.6 years. For the secondary endpoint, the liver complications within 1 mo following the colectomy were found in 9 patients (8.6%) and included worsening liver tests (n = 3), liver failure requiring liver transplantation (n = 2), acute cholangitis (n = 3) and right hepatic vein thrombosis with hepatic infarct (n = 1). A multivariate logistic analysis demonstrated that only lower platelet count and lower albumin level preoperatively were significantly associated with more primary endpoints (OR = 0.99 and 0.05 respectively).

CONCLUSION: One third of patients with PSC and UC undergoing colectomy died or underwent liver transplantation within 2.6 years. PSC patients with lower platelet counts and lower albumin levels were significantly more likely to have a poorer outcome.

Inflammatory bowel disease in primary sclerosing cholangitis: a robust yet changing relationship

BACKGROUND

Primary sclerosing cholangitis (PSC) has a well-established association with inflammatory bowel disease (IBD) and may represent a distinctive phenotype. It is unknown whether changes in the clinical and endoscopic presentation of newly diagnosed IBD among patients with PSC might have occurred over time.

METHODS

Initial clinical and endoscopic presentations of IBD in PSC were studied for 2 different time periods: 1993 to 1997 (early cohort) compared with 2003 to 2007 (recent cohort).

RESULTS

The baseline characteristics were similar in the 57 early cohort and 72 recent cohort patients. Compared with the recent cohort, alkaline phosphatase concentrations were higher in the early cohort (7.1 versus 2.6 × upper limit of normal, P = 0.0001). PSC was diagnosed before IBD in the recent cohort compared with the early cohort (50% versus 35%, P = 0.0009). The initial clinical and endoscopic presentations of IBD were similar in the 2 cohorts. The majority of patients had mild pancolitis, whereas rectal sparing and backwash ileitis were detected in one third and one fourth of patients, respectively. In addition, no differences in IBD outcomes or PSC characteristics were revealed. Immunomodulators and biological treatments were more commonly used in the recent cohort when compared with the early cohort (90% versus 56%, P = 0.03, and 13% versus 4%, P = 0.08, respectively).

CONCLUSIONS

IBD in PSC has unique characteristics, and the clinical features of this unique presentation have remained stable over time. A shift in the timing of diagnosis of the 2 diseases has occurred in recent years, with PSC being more often diagnosed first.

Circulating CD4+CD25+ regulatory T cells in the pathobiology of ulcerative colitis and concurrent primary sclerosing cholangitis

BACKGROUND

Immunopathogenetic features of primary sclerosing cholangitis (PSC) in ulcerative colitis (UC) still remains unclear. Peripheral blood CD4+CD25+ regulatory T cells have a key role in the induction and maintenance of peripheral self-tolerance and inhibit several organ-specific autoimmune diseases. Therefore, CD4+CD25+ T cells are believed to play an essential role in autoimmune diseases. The aim of the present study is to analyze the role of CD4+CD25+ T cells in the pathogenesis of UC-associated PSC.

METHODS

This study evaluated the levels of CD4+CD25+ T cells in peripheral blood mononuclear cells (PBMC) of 27 UC patients with PSC and 20 UC patients as controls. CD4+CD25+ T cells were isolated from PBMC with a direct immunofluorescence technique, using mice monoclonal antibodies namely FITC-labeled anti-CD4 and PE-labeled anti-CD25. In each patient, CD4+CD25+ T cells percentage in PBMC were studied by flow cytometry, and then the number of CD4+CD25+ T cells were calculated.

RESULTS

Twenty-seven UC patients with PSC and 20 UC patients without PSC as controls were enrolled in the present study. The percentage of CD4+CD25+ regulatory T cells among PBMC were significantly elevated in UC + PSC patients compared with UC patients without PSC (p = 0.04).

CONCLUSIONS

CD4+CD25+ T cells were found to be elevated in UC patients with PSC suggesting a partial role of activated T cell response in the disease pathophysiology. Our findings imply that CD4+CD25+ regulatory T cells may play a key role in the immunopathogenesis of UC-associated PSC and may affect the therapeutic management of these diseases.

Inflammatory bowel disease cancer risk, detection and surveillance

Ulcerative colitis (UC) is a chronic and relapsing inflammation of the colonic mucosa with variable extension from the rectum towards the cecum. The aim of medical treatment is to induce and maintain clinical remission. If no remission can be achieved, continuous inflammation may repeatedly destroy the epithelial cells. This has to be compensated by epithelial increased proliferation which finally can lead to inflammation-associated colorectal cancer (CRC). The risk of colitis-associated CRC is increased after a long disease duration, especially in patients with chronic active disease. This risk may be lower if long-lasting mucosal healing can be achieved. To detect the development of dysplasia/intraepithelial neoplasia and colitis-associated CRC early, surveillance programs have been installed. However, the evidence of success for those surveillance programs is limited. This is partially due to problems of detecting precancerous lesions in the colonic mucosa during those surveillance programs. The specific problems of surveillance programs for the prevention of CRC and specific aspects of patient care in UC are reviewed in this article.