Familial Adenomatous Polyposis-Risk of Cancer, Cancer Prevention, and Long-Term Consequences: Learnings from Five Decades with the Danish Polyposis Register.

Familial adenomatous polyposis (FAP) is a hereditary condition marked by the growth of hundreds to thousands of adenomatous polyps in the colon and rectum, significantly elevating the risk of colorectal cancer (CRC) if left untreated. Caused by pathogenic variants in the APC gene, FAP is typically identified in adolescence, often leading to the recommendation of prophylactic colectomy to reduce the risk of CRC. However, even with colectomy, FAP patients face higher risks for other cancers, notably in the duodenum and pancreas. Our studies emphasize the importance of lifelong endoscopic surveillance and tailored treatment strategies to detect and manage precancerous lesions in the gastrointestinal tract. Advances in genetic screening have also significantly improved early detection and family risk management, especially for at-risk relatives. The Danish Polyposis Register, for example, is a comprehensive, nationwide database enabling tracking and preventative care for FAP families, effectively prolonging life expectancy by facilitating early intervention and surveillance of cancer risks. Endoscopic evaluation may differentiate between classical FAP and attenuated FAP (AFAP), a milder form with fewer polyps and a delayed onset, although both types require consistent monitoring due to elevated cancer risks. Innovations in genetic research, including the use of whole-genome sequencing, continue to refine risk assessments, helping to prevent unnecessary surgical interventions while providing personalized management plans for each patient. The disease's impact extends beyond physical health; the hereditary nature of FAP leads to psychological stress, often resulting in higher anxiety, depression, and educational challenges among patients. Adolescents and young adults, in particular, might benefit from targeted psychological support and educational interventions to help manage the mental and social implications of living with a chronic, cancer-prone condition. Studies underscore the need for interdisciplinary care to support these aspects of patients' lives, as they face unique challenges not experienced by other populations. Overall, research suggests that FAP treatment must integrate comprehensive cancer surveillance, proactive genetic screening, mental health support, and tailored medical interventions. The success of multidisciplinary, national registers like Denmark's emphasizes the importance of such models worldwide and should encourage the development of similar programs to improve patient outcomes and support those at high risk for hereditary cancers.