For a patient with a first-degree relative who has colon cancer, how often should colonoscopy screening be performed?

When there is a first-degree relative with a history of colon cancer, it increases the individual's risk of developing the disease. The recommendations for screening in such scenarios take family history into account to ensure earlier and more frequent screening. In this case, starting screening with colonoscopy at age 40 and repeating it every 5 years is appropriate. This time frame allows for early detection and intervention, which is crucial in managing colon cancer that may arise due to genetic factors related to family history.

In contrast, starting colonoscopy at age 50 every 10 years is usually reserved for populations with an average risk of colon cancer without significant family history. Screening starting too early with an annually basis or at age 30 might be unnecessary or overly aggressive, as the current guidelines focus on the high-risk nature posed by first-degree relatives, and screening should generally start no earlier than age 40. The alternative option of beginning at age 45 doesn't adequately address the risk factor amplification that comes with having a first-degree relative affected by colon cancer, thus would not align with the recommended guidelines.