Good news if you’ve got Crohn’s and PSC?

As we know, patients with PSC and ulcerative colitis are at a greater risk of getting colon cancer or colorectal dysplasia than those with ulcerative colitis alone. But what about if you have Crohn’s and PSC? Is there a difference?

Dr Roger Chapman has now published research1 supporting what he has said all along; that there are different types of PSC. In what is probably the largest study of PSC/Crohn’s Disease (CD) to date (yet still a small study), he found that patients with PSC/CD seemed to have a unique disease phenotype. They conclude: “Unlike PSC/UC (ulcerative colitis), PSC/CD has an equal gender distribution and a higher preponderance of small duct disease. There is significant negative association between a history of smoking and PSC/CD, suggesting a possible protective role of smoking against the development of PSC in patients with CD.”

Although the distribution of disease in PSC/UC is usually total, the clinical course is generally milder than in patients with total colitis without PSC. This has also been suggested of PSC/CD but Chapman et al demonstrated that PSC/CD does not run a milder course than CD in isolation. “This study suggests a better prognosis in patients with PSC/CD compared to those with PSC/UC, with a significant difference in major event-free survival (cancer, liver transplantation or death) observed, (p=0.04)”, that is, PSC/CD patients are less likely to progress to cancer, liver transplantation or death when compared with those with PSC/UC. PSC Support helped fund this study.

Braden et al2, with Roger Chapman as senior author, then went on to look at the relationship between PSC/CD and cancer and found that PSC was not a risk factor for colorectal dysplasia or cancer in patients with Crohn’s disease. They demonstrated no increased risk of colorectal neoplasia in patients with PSC and Crohn's colitis, in contrast to that found in patients with PSC and ulcerative colitis. They also found less cancer overall than expected, and the team hypothesize that this finding could be due to better/more frequent colonoscopies, and taking Urso. Roger discusses the findings in a podcast via American Gastroenterological Association.

Annual colonoscopy from the time of diagnosis of UC or CD is still recommended in patients with PSC, although Chapman suggests that for PSC/CD patients, it may be more effective to limit surveillance to those patients with additional risk factors, such as family history of colorectal cancer, but would welcome further studies to confirm his findings. Roger's clinic at the John Radcliffe Hospital, Oxford, now offers colonoscopies for some PSC/CD patients once every two years.

References
1 Halliday,et al, (2012). A unique clinical phenotype of primary sclerosing cholangitis associated with Crohn's disease. Journal of Crohn's and Colitis (2012) 6, 174–181
2 Braden et al. (2012) Risk for Colorectal Neoplasia in Patients With Colonic Crohn's Disease and Concomitant Primary Sclerosing Cholangitis. Clinical Gastroenterology and Hepatology, 10 (3): 303-308.