With Familial Adenomatous Polyposis (FAP), what percentage of individuals will develop colorectal cancer without a colectomy?

Familial Adenomatous Polyposis (FAP) is a hereditary condition characterized by the development of numerous polyps in the colon and rectum, which significantly increases the risk of colorectal cancer. It is well established that virtually all individuals with untreated FAP will develop colorectal cancer if they do not undergo a colectomy, typically by the age of 40.

In this context, the answer being 100% indicates that every individual with FAP is at risk of colorectal cancer without surgical intervention. This highlights the importance of regular surveillance and early surgical management to prevent cancer in individuals diagnosed with FAP. The mechanism behind this progression is that the numerous adenomatous polyps can transform into cancerous lesions if left unchecked, leading to a near certainty of malignant transformation.

Thus, the understanding of this condition underscores the critical need for early detection and treatment, making the statistic that 100% of individuals will develop colorectal cancer without a colectomy accurate and crucial for patient care.