Clinicopathological and Molecular Characterization of Crohn’s Disease-Associated Small Bowel Adenocarcinomas.
J Crohns Colitis. 2019 Aug 07;:
Authors: Liao X, Li G, McBride R, Houldsworth J, Harpaz N, Polydorides AD
BACKGROUND AND AIMS: Small bowel adenocarcinoma (SBA) is a recognized complication of Crohn’s disease (CD) but its low absolute prevalence limits opportunities for clinicopathological characterization.
METHODS: We compared the clinical, pathological and molecular features of 48 SBA from patients with CD (CDSBA) and 29 SBAs from patients without CD (NSBA) who underwent treatment at our tertiary care center between 2000 and 2018.
RESULTS: Patients of CDSBA were younger than those of NSBA (mean age, 56 vs. 64, P=0.02). Males predominated in both groups. Most CDSBA (69%) occurred in the ileum whereas most NSBA occurred in the duodenum (38%) and jejunum (31%, P<0.001). Stage I tumors were more prevalent in the CDSBA (33% vs. 3%, P=0.002), although the rates of Stage IV disease and disease-specific mortality were similar in both groups. CDSBA were less likely to present a discrete mass (35% vs. 93%, P<0.001) and were more often stricturing or fistulizing (75% vs. 10%, respectively, P<0.001) than NSBA. Microscopically, CDSBA were relatively heterogeneous, exhibiting at least 3 distinct growth patterns in 39% compared with 1% of NSBA (P=0.01). Low-grade tubuloglandular adenocarcinoma was the predominant pattern in 19% of CDSBA compared with 0% of NSBA (P=0.003). CDSBA were more frequently DNA mismatch repair proficient (90% vs. 62%, P=0.04), exhibited similar profiles of frequently mutated genes as NSBA, except IDH1 (18%) and SMAD4 (12%) mutations that occurred uniquely in CDSBA.
CONCLUSIONS: These observations, based on the largest single center series described hitherto, establish that CDSBA is a distinct clinical, pathological and molecular entity.
PMID: 31388669 [PubMed – as supplied by publisher]