[703] Young Age and High Frequency of Multiplicity, Well Differentiation, Crohn's-Like Reaction, Tumor Heterogeneity, and Signet Ring Differentiation in Inflammatory Bowel Disease-Associated Colorectal Adenocarcinoma

Xiuli Liu, Michael Landau, John R Goldblum, Zijing Zhao, Jingmei Lin. Cleveland Clinic, Cleveland, OH; Indiana University School of Medicine, Indianapolis, IN

Background: Longstanding inflammatory bowel disease (IBD), either ulcerative colitis (UC) or Crohn's disease (CD), is associated with a high risk of developing IBD-associated colorectal adenocarcinoma (CAC). It is unclear if these patients should be screened for hereditary nonpolyposis colorectal cancer syndrome (HNPCC). We hypothesize that IBD-associated CAC is morphologically different from sporadic microsatellite stable CAC.
Design: We evaluated the demographic and morphological features of 108 IBD-associated CAC, including UC-associated (n=95) and CD-associated CACs (n =13), compared to 70 control cases of microsatellite stable sporadic CACs. Clinicopathologic features, including age, tumor multiplicity, tumor differentiation, tumor heterogeneity, the presence of signet ring differentiation, and CD-like reaction were compared between the two groups.
Results: The mean age of patients with IBD-associated CAC was 50 years, significantly younger compared to the mean age of 61.4 years in the control group (p<0.05). Two or more synchronous CACs were noted in 20.2% patients with IBD-associated CACs but only in 7.1% of the control group (p <0.05). Well differentiation of tumors, CD-like reaction, tumor heterogeneity, and the presence of signet ring differentiation were significantly more common in IBD-associated CACs compared to the control group (p <0.05).
Conclusions: IBD-associated CAC occurs 10 years earlier compared to that of non-IBD related sporadic microsatellite stable CAC and it is more commonly associated with synchronous tumors. Morphologically, IBD-associated CACs share the pathologic features seen in HNPCC, such as well differentiation, CD-like reaction, tumor heterogeneity, and signet ring cell differentiation. The young age and morphological similarity between IBD-associated CAC and HNPCC suggest that an age and morphology-based strategy prior to the screening test for HNPCC may be less effective in IBD-associated CAC than in the non-IBD population.
Category: Gastrointestinal

Monday, March 19, 2012 1:00 PM

Poster Session II # 124, Monday Afternoon

 

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