摘要
This letter discusses the incidence of anal cancer among Crohn's disease(CD)-related malignancies.Patients with CD have been demonstrated to be at a higher risk of developing small bowel and colorectal cancers than healthy individuals.Although CD-associated anal cancer is relatively rare,patients with CD accom-panied by anal or perianal lesions are at increased risk of anal cancer.Addi-tionally,compared to ulcerative colitis,which is also an inflammatory disease,CD-related anal cancer is often detected at an advanced stage owing to the complexity of CD and is associated with a poor prognosis with frequent local recurrences.Therefore,the detection of early-stage cancer is crucial for improving the prognosis.However,the surveillance methods recommended for CD-related malignancies in the United States and Europe are similar to those for ulcerative colitis.They are not appropriate for detecting CD-related malignancies in the recto-anal region.Therefore,there is an urgent need for surveillance programs aimed at the early detection of malignant anorectal lesions in patients with CD.