Colorectal cancer in Crohn's colitis is comparable to sporadic colorectal cancer.

ABSTRACT

PURPOSE: It is now recognized that Crohn's disease (CD), similar to ulcerative colitis (UC), carries an up to 20-fold higher cancer risk, and the development of colorectal carcinoma (CRC) is a major long-term complication. Once CRC is present, molecular profiling is one of the components in selecting appropriate treatment strategies; however, in contrast to UC, genetic alterations in Crohn's colitis-associated CRC are poorly understood. METHODS: In a series of 227 patients with Crohn's colitis, we identified 33 cases of CRC (~14 %) and performed targeted mutational analysis of BRAF/KRAS/NRAS and determined microsatellite status as well as immunophenotype of the tumors. RESULTS: In the CRC cohort, the median age at time of cancer diagnosis was 58 (range 34-77 vs. 59.5 in sporadic; P = 0.81) and the median CD duration was 29 years (range 6-45). As a group, CRC complicating Crohn's colitis is BRAF (97 %) and NRAS (100 %) wild type and the vast majority is microsatellite stable (94 %); KRAS-mutations were found in six cases (18 %). Stage grouping, anatomic distribution, and overall survival were similar to sporadic CRC; however, long-standing CD (≥25 years) as well as gastric-immunophenotype (MUC5AC+) was associated with significantly shorter overall survival (P = 0.0029; P = 0.036, respectively). CONCLUSION: In summary, the clinicopathological and molecular profile of CD-associated CRC is similar to that observed in sporadic CRC.