Shah SC, et al. - Researchers performed this study to ascertain the rate of advanced colorectal neoplasia (aCRN), defined as high-grade dysplasia and/or colorectal cancer, following a diagnosis of indefinite dysplasia or low-grade dysplasia (LGD) in patients with primary sclerosing cholangitis (PSC) associated with inflammatory bowel disease (IBD). Based on the findings, PSC remained a strong independent risk factor for aCRN. Compared to patients with only IBD, aCRN developed at a higher rate and was more often endoscopically invisible in patients with PSC once LGD was detected. The findings supported the recommendation for careful annual colonoscopic surveillance for patients with IBD and PSC, and consideration of colectomy once LGD was detected.

Methods

• A retrospective, longitudinal study was performed.
• The study comprised of 1,911 patients with colonic IBD (293 with PSC and 1,618 without PSC) who underwent more than 2 surveillance colonoscopies from 2000 through 2015 in the Netherlands or the United States (9,265 patient-years of follow up).
• For this study, the researchers collected data on clinical and demographic features of patients, as well as data from each surveillance colonoscopy and histologic reports.
• The severity of active inflammation was documented for each surveillance colonoscopy.
• A diagnosis of aCRN during follow up was the primary outcome.
• Furthermore, they examined factors associated with aCRN in patients with or without a prior diagnosis of indefinite dysplasia or LGD.

Results

• Comped to patients with IBD only, patients with PSC-IBD had a 2-fold higher risk of developing aCRN.
• The researchers found no significant difference in mean inflammation scores between patients with PSC-IBD (0.55) vs patients with only IBD (0.56) (P=0.89), nor in proportions of patients with LGD (21% of patients with PSC-IBD vs 18% of patients with only IBD) (P=0.37).
• However, in patients with PSC-IBD (8.4 per 100 patient-years), the rate of aCRN following a diagnosis of LGD was significantly higher than patients with only IBD (3.0 per 100 patient-years) (P=0.01).
• Independent risk factors for aCRN were 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).
• In patients with PSC-IBD, dysplasia was more often endoscopically invisible than in patients with only IBD.