Colitis-associated colorectal neoplasia in ulcerative colitis with primary sclerosing cholangitis: a nationwide study

Background/Aims: Ulcerative colitis (UC)-associated colorectal neoplasia (UCAN) in patients with UC and primary sclerosing cholangitis (PSC) has not been studied well in Japan. This retrospective study examined the clinicopathological features and prognosis of UCAN in patients with PSC-UC. Methods: A total of 808 patients with UCAN were enrolled from 1983 to 2020 and categorized into PSC (PSC-UCAN, n = 26) and no PSC (UCAN-alone, n = 782) groups. Clinicopathological features were compared between the 2 groups, and the 10-year overall survival (OS) and cancer-specific survival (CSS) were analyzed. Results: The PSC-UCAN group had a shorter UC duration before UCAN diagnosis (12.8 years vs. 16.9 years, P= 0.044), were younger at UCAN diagnosis (47.8 years vs. 53.3 years, P= 0.046), and developed UCAN more frequently in the right-sided colon (34.6% vs. 15.9%, P= 0.028) than the UCAN-alone group. The PSC-UCAN group showed a trend toward a lower proportion of high-grade dysplasia (19.2% vs. 30.7%) and a higher proportion of early-stage cancers (53.9% vs. 31.2%). The 10-year OS (64.6% vs. 79.3%, P=0.080) and CSS (80.8% vs. 83.9%, P=0.60) were comparable. Conclusions: Patients with PSC-UCAN showed earlier and younger development of UCAN than patients with only UCAN, with a high prevalence in the right-sided colon. Early-stage cancer was more frequently observed in the PSC-UCAN group, despite the shorter duration of UC. Patients with PSC-UC probably benefit from early initiation of surveillance colonoscopy.