Background: Patients with extended, colonic inflammatory bowel diseases (IBD) have an increased risk for development of colorectal cancer (CRC) mainly due to the chronic, uncontrolled mucosal inflammation in the bowel. The aim of our nationwide study was to evaluate the demographic characteristic, the clinical features and the molecular pathogenetic alterations of IBD-associated CRCs in a relatively large cohort of patients.
Methods: Electric medical databases, personal queries and IBD registries have been used for data collection regarding clinical and demographic characteristic of IBD-related CRC. Gene expression profiles of p53, MLH1, MSH2, β-catenin, PTEN, APC, K-ras, Cox-2, NOS, NFκB and VEGF were also investigated with tissue microarray technique (TMT) in the tumour in selected cases.
Results: In our retrospective observational study between 1976 and 2016, we identified 14 Crohn's disease (CD) and 26 ulcerative colitis (UC) patients with histologically confirmed adenocarcinoma. CRC occurred at a median age of 50 years (min.–max. 34–78) and 56 years (min.–max. 24–87) in patients with CD (female n=5, male n=9) and UC (female n=5, male n=21), respectively. Median time elapsed between IBD diagnosis and the diagnosis of CRC was 18 years. Duke's A, B, C and D stage carcinomas were represented in 18.4%, 39.5%, 21.1% and 21.1%. Among UC patients, 76.9% (n=20) of carcinomas were localized in the rectosigmoideum, 15.4% (n=4) in the other part of the colon and 7.7% (n=2) of the carcinomas were multifocal. Among CD patients, 28.6% (n=4) of the carcinomas localized to the rectosigmoideum, while 71.4% (n=10) in the more proximal part of colon. Overall, 61.9% and 28.5% of UC patients demonstrated extended colitis and left-sided colitis, respectively (mean disease durations of 23 and 18 years). Altogether, 87.5% of UC- and 33.3% of CD-associated CRC seem to be IBD-related according to TMT. The timing between the last endoscopy and the diagnosis of CRC was average 6.5 (1–30) years in those 18 patients, when these data were available.
Conclusions: CRC occurs earlier in IBD than that in general population after a long disease duration and mainly in pancolitis. UC-associated CRC seems to be more distal and disease related, while CD-associated CRC may be more proximal and mainly sporadic. Lack of regular screening can increase the chance of advanced CRC.