Chemoradiotherapy for fistula-related perianal squamous cell carcinoma with Crohn's disease.

The reports of chemoradiotherapy for anal squamous cell carcinoma with Crohn's disease are few. Severe toxicity related to radiotherapy is concerned in patients with inflammatory bowel disease. We report a case of chemoradiotherapy for locally advanced fistula-related perianal squamous cell carcinoma in a patient with long-standing Crohn's disease which was controlled by a maintenance therapy. The patient completed standard chemoradiotherapy using intensity-modulated radiotherapy without severe toxicity, and achieved complete remission. Standard chemoradiotherapy using intensity-modulated radiotherapy may be feasible and effective treatment for this population when Crohn's disease is controlled.