Abstract
Purpose: Crohn’s disease (CD) exists in an environment of chronic intestinal inflammation, but rarely develops into cancer. In Japan, cancer associated with CD is usually reported in the anorectal region, while small intestinal cancer is uncommon. Herein, we review small intestinal cancer cases associated with CD from our hospital and other reports in Japan. Materials and Methods: The subjects were 43 patients (52 lesions), including 17 who underwent surgery at our hospital between January 2011 and December 2022, and 26 cases reported elsewhere. The clinicopathological characteristics, diagnosis, and treatment were examined. Result: There were 31 males and 12 females, the mean age at the time of cancer diagnosis was 49 years, and the average time after onset of CD was 18.0 years. The CD type was small intestinal (n=13 cases), small and large intestinal (n=26), and unknown (n=4). Surgical indications were stricture (n=27 cases), fistula (n=11), cancer (n=6), and perforation (n=3). Six cases were diagnosed with small intestinal cancer preoperatively, 4 were diagnosed intraoperatively, and 33 were diagnosed by postoperative pathological examination. One lesion of small intestinal cancer was found in the jejunum, with all others in the ileum. The most common macroscopic lesion was type 5 (n=11 lesions), followed by types 0 and 3 (n=5 each), and types 1, 2 and 4 (n=1 each); with 28 lesions of unknown type. The histological types included well-differentiated adenocarcinoma (n=26 lesions), moderately differentiated adenocarcinoma (n=14), poorly differentiated adenocarcinoma (n=6), signet ring cell carcinoma (n=4), and mucinous carcinoma (n=2). The depth of invasion was pTis+T1 (n=10 cases), pT2 (n=9), pT3 (n=14), and pT4 (n=15). Lymph node metastasis was observed in 3/20 cases, and distant metastasis in 5/38 cases. The 5-year survival rate was 63.8%. Conclusion: Small intestinal cancer associated with CD is difficult to diagnose preoperatively. Thus, in most cases, surgery was performed as a common Crohn’s disease-related stricture or fistula.
