Two first-degree relatives diagnosed with colorectal cancer at any age: when should they start screening colonoscopy?

Two first-degree relatives diagnosed with colorectal cancer at any age: when should they start screening colonoscopy?

• A. Start at 50
• B. Start at 40
• C. Start at 10 years younger than earliest
• D. Start at 40 or 10 years younger than earliest diagnosis, whichever comes first

Answer: (D)

Having two first-degree relatives with colorectal cancer places you at a higher familial risk, so screening starts earlier than the general population. The starting point is the earlier of age 40 or 10 years younger than the age at which the earliest relative was diagnosed. In other words, begin at the minimum of 40 and (earliest diagnosis age − 10). This targets you earlier when a relative was diagnosed younger, while still ensuring a practical minimum age like 40 when the earliest diagnosis was older. For example, if the earliest relative was diagnosed at 45, you’d start at 35; if the earliest was diagnosed at 65, you’d start at 40. After starting, colonoscopy is typically repeated every 5 years due to the increased risk.

Having two first-degree relatives with colorectal cancer places you at a higher familial risk, so screening starts earlier than the general population. The starting point is the earlier of age 40 or 10 years younger than the age at which the earliest relative was diagnosed. In other words, begin at the minimum of 40 and (earliest diagnosis age − 10). This targets you earlier when a relative was diagnosed younger, while still ensuring a practical minimum age like 40 when the earliest diagnosis was older. For example, if the earliest relative was diagnosed at 45, you’d start at 35; if the earliest was diagnosed at 65, you’d start at 40. After starting, colonoscopy is typically repeated every 5 years due to the increased risk.