What is the typical time range for an adenomatous colon polyp to progress to colorectal cancer?

• A. 5-10 years
• B. 10-15 years
• C. 10-20 years
• D. 20+ years

Answer: (C)

Progression from an adenomatous colon polyp to colorectal cancer happens through the adenoma-carcinoma sequence, a stepwise process in which genetic changes accumulate over many years. An early APC mutation creates a small adenoma, and as additional mutations (such as KRAS activation and p53 loss) accumulate, the lesion grows from a benign polyp to an advanced adenoma and eventually to invasive cancer. Because these changes accrue gradually, the typical time frame from polyp formation to cancer is on the order of a decade to a couple of decades. In clinical terms, about 10 to 20 years best captures the common range, recognizing that individual polyps can progress faster or slower depending on size, histology, and molecular features.