Imaging of young-onset colorectal cancer: what the radiologist needs to know.

Young-onset colorectal cancer (YOCRC) refers to colorectal cancer diagnosed in individuals under the age of 50. Whilst the overall incidence of colorectal cancer is decreasing, YOCRC cases are increasing and now accounts for up to 10% of all colorectal cancers. YOCRC more frequently presents with acute symptoms, where radiologists play an important role in identifying malignancy and distinguishing it from benign colonic pathologies. Risk factors associated with YOCRC, such as inflammatory bowel disease and hereditary syndromes, may exhibit specific imaging manifestations. In addition, YOCRC is frequently associated with a mucinous histopathological subtype which may be identifiable based on the presence of specific imaging features. Given their younger age, these patients are more likely to undergo aggressive treatment and complex surgical interventions. Specific considerations such as fertility preserving surgical techniques must be factored in when managing these patients. As the incidence of YOCRC increases, guidance for colonoscopy screening protocols may need revision. This includes evaluating the role of ionising imaging techniques in both diagnosing and follow-up to balance early detection and minimising radiation exposure in this younger patient population.