Adenocarcinoma associated with perianal fistulas in Crohn's disease.

AIM The purpose of the present study was to examine the possible relation between anorectal carcinoma and infliximab therapy for Crohn's disease. PATIENTS AND METHODS This study reviewed the medical records of patients with perianal Crohn's disease, who have required surgical intervention at the Tohoku University Hospital since May 2002, when infliximab was approved as a remedy for Crohn's disease in Japan. RESULTS Ninety-two patients underwent surgery due to perianal Crohn's disease between May 2002 and December 2011. Four out of 92 patients were diagnosed as having anorectal carcinoma associated with perianal fistula. All four patients had advanced carcinoma, and received infliximab before the diagnosis of cancer was made. Infliximab was administered due to an exacerbated anal lesion in three patients. CONCLUSION Careful inspection and obtaining of a biopsy sample under anesthesia is recommended for patients with Crohn's disease who have long-standing anal fistulas, especially before infliximab administration due to a possible exacerbation of anal symptoms.