Colorectal cancer in inflammatory bowel disease: review of the evidence

Inflammatory bowel disease (IBD)-related colorectal cancer (CRC) is responsible for approximately 2% of the annual mortality from CRC overall, but 10–15% of the annual deaths in IBD patients. IBD-related CRC patients are also affected at a younger age than sporadic CRC patients, and have a 5-year survival rate of 50%. Despite optimal medical treatment, the chronic inflammatory state inherent in IBD increases the risk for high-grade dysplasia and CRC, with additional input from genetic and environmental risk factors and the microbiome. Recognizing risk factors, implementing appropriate surveillance, and identifying high-risk patients are key to managing the CRC risk in IBD patients. Chemoprevention strategies exist, and studies evaluating their efficacy are underway. Once dysplasia or invasive cancer is diagnosed, appropriate surgical resection and postoperative treatment and surveillance are necessary. Here, we discuss the current state of IBD-related CRC, prevalence, risk factors, and evidence for surveillance, prophylaxis, and treatment recommendations.