Inflammatory bowel disease associated with primary sclerosing cholangitis (PSC-IBD) may have a high prevalence of rectal sparing, backwash ileitis, and colorectal neoplasia.
Dr Loftus and colleagues from Maine in America undertook a study in order to describe the clinical features and outcomes of PSC-IBD and compare these to a group of chronic ulcerative colitis patients.
The researchers evaluated medical records of all patients with PSC-IBD from the Mayo Clinic Rochester between 1987 and 1992.
The investigators analyzed information on endoscopic and histological features, colorectal neoplasia, surgery, and other clinical outcomes.
The research team excluded patients referred for colorectal neoplasia and those who did not undergo colonoscopy with biopsies.
The researchers identified a control group of chronic ulcerative colitis patients matched for sex, duration of IBD at first clinic visit, and calendar year of first clinic visit.
The team abstracted similar information from these control participants.
|Rectal sparing and backwash ileitis were more common in the PSC-IBD group than in controls|
The researchers identified a total of 71 PSC-IBD patients and 142 chronic ulcerative colitis patients without primary sclerosing cholangitis.
The research team found that rectal sparing and backwash ileitis were more common in the PSC-IBD group (52% and 51%, respectively) than in controls (6% and 7%, respectively).
In addition, the researchers noted that overall, colorectal neoplasia developed in 18 cases and 15 controls, including 11 cancers (7 cases and 4 controls).
An increased risk of colorectal neoplasia or death was not detected in a matched analysis.
The research team found that although the cumulative incidence of colorectal neoplasia was higher in cases (33%) than in controls (13%) at 5 years, this was of borderline statistical significance.
Overall survival from first clinic visit was significantly worse among cases (79% v 97%) at 5 years.
Dr Loftus concluded, "PSC-IBD is frequently characterized by rectal sparing and backwash ileitis."
"Colorectal neoplasia develops in a substantial fraction and overall survival is worse. PSC-IBD may represent a distinct IBD phenotype."