Clinicopathological and molecular landscape in colorectal cancer associated with colorectal polyps and inflammatory bowel disease.

Although inflammatory bowel disease (IBD) and colorectal polyps are considered as significant risk factors of colorectal cancer (CRC), the molecular mechanism associated with colorectal carcinogenesis is still explored. Unlike sporadic CRC, local persistent inflammation in IBD induces genetic and epigenetic alterations, leading to tumor development. Moreover, cumulative data indicate that colorectal polyps display a significant malignant potential. In this context, our study aimed to investigate the clinicopathological features of CRC associated with IBD and/or colorectal neoplastic polyps in a retrospective group of CRC cases. The clinical data and histopathological features of CRC cases have been collected from our files. Immunohistochemical examination of mismatch repair (MMR) proteins has been performed in a selected case. The study group comprised 40 patients, 72.5% men and 27.5% women, with a median age of 64.73±9.09 years. Out of the cases with double association, 62.5% of CRC cases displayed colorectal polyps, while 32.5% of patients were diagnosed with both CRC and IBD, which encompassed both ulcerative colitis (UC) and Crohn's disease (CD). Two patients included in our study group exhibited a triple association of IBD, colorectal polyps, and CRC, one of them showing defective MMR (dMMR) phenotype. Although our results provide significant data on the relationship between IBD, colorectal polyps, and colorectal carcinogenesis, future cohort studies are needed to improve our understanding on the complex mechanism of colorectal carcinogenesis, ultimately guiding improved prevention, diagnosis, and treatment strategies for these patients.