Large bowel cancer in the setting of inflammatory bowel disease

Inflammatory bowel diseases (IBDs) are a well-known risk factor for the development of colorectal cancer (CRC). This risk relates to different aspects of the disease, such as the duration, activity, and extension, and tends to increase in the presence of associated conditions, such as family history of CRC or some extra-intestinal manifestations. Rectal cancer (RC) in IBD has been poorly investigated.

We reviewed the scientific literature for data on the features and management of RC in the setting of IBD. Here, we provide a practical insight into the diagnosis and management of the condition.

Several genetic and environmental factors promote the development of CRC, including alterations of intestinal microflora and mutations in the genes responsible for the cell cycle and for DNA mismatch repair. Dysplasia is the main evidence of a clear conversion of normal epithelium to cancer. Dysplasia is often multifocal, in contrast to sporadic CRC, which explains the tendency toward the development of synchronous and metachronous CRC in patients with IBD. Other conditions that need attention are strictures, for which the threshold for surgery must be low. Treatment of RC in patients with IBD follows the same oncologic criteria as non-IBD-related RC, but patients are often diagnosed at more advanced stages, suggesting that this is frequently overlooked. This is ultimately associated with poorer outcomes in IBD patients.

There is a pressing need for more data on IBD-related RC. Implementing knowledge will result in optimization of survival for these patients.