Anorectal Cancer in Crohn’s Disease Has a Poor Prognosis Due to its Advanced Stage and Aggressive Histological Features: a Systematic Literature Review of Japanese Patients

Background Patients with Crohn’s disease (CD) are generally known to be at an increased risk of cancer. The anorectal area is the most frequent cancer site in Japanese CD patients. However, the risks are not well defined. The aim of this study was to clarify the clinicopathological characteristics of Japanese CD-associated anorectal carcinoma patients and to explore screening methods for the detection of cancer at earlier stages.