Colorectal Cancer Screening — ABIM Board MCQ

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HardColorectal Cancer ScreeningABIM Board

A 46-year-old man presents for preventive care. He has no hematochezia, iron-deficiency anemia, change in bowel habits, inflammatory bowel disease, or known hereditary cancer syndrome. His mother underwent colonoscopy at age 55, and he brings her endoscopy and pathology reports, which document complete removal of a 12-mm tubular adenoma without villous histology or high-grade dysplasia. The patient underwent a high-quality colonoscopy at age 41; the examination was normal. He is willing to undergo further colonoscopy and has no contraindication to the procedure. Which of the following is the most appropriate colorectal cancer screening plan?

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Reveal the answer and explanation

Correct answer: B — Colonoscopy now and every 5 years if normal

Explanation lettering: D = shown as A · A = shown as D

The mother’s adenoma is advanced despite its tubular histology and absence of high-grade dysplasia because it measures at least 10 mm. The documented advanced adenoma occurred in a first-degree relative before age 60, placing this patient in an increased-risk family-history category. The US Multi-Society Task Force recommends colonoscopy every 5 years, beginning at age 40 or 10 years before the relative’s diagnosis, whichever is earlier. Here, those thresholds are ages 40 and 45, respectively; therefore, age 40 governs. Because his normal colonoscopy was performed 5 years ago, repeat colonoscopy is due now. ([asge.org](https://www.asge.org/docs/default-source/education/practice_guidelines/piis0016510717318059.pdf?sfvrsn=0)) Annual FIT (A) is an alternative when a patient in this risk group declines the recommended colonoscopy; this patient accepts colonoscopy. A 10-year interval (C and E) is appropriate after a normal examination in many average-risk adults but not for this documented high-risk family history. Waiting until age 50 (D) incorrectly applies a later initiation threshold and would also extend the interval since his previous examination to 9 years. The relative’s exact pathology report is important: an undocumented family report of a nonspecific “polyp” should not automatically be treated as an advanced adenoma.

Reference: Colorectal cancer screening: Recommendations for physicians and patients from the U.S. Multi-Society Task Force on Colorectal Cancer (2017) — https://www.asge.org/home/resources/publications/guidelines/colorectal-cancer-screening-recommendations-for-physicians-and-patients-from-the-u.s.-multi-society-task-force-on-colorectal-cancer Improving Adherence to the 2017 Multi-Society Task Force on CRC Screening Recommendations for First-Degree Relatives of Patients with an Advanced Adenoma (January 3, 2025) — https://www.asge.org/home/resources/key-resources/blog/view/the-huddle/2025/01/03/qi-spotlight--improving-adherence-to-the-2017-multi-society-task-force-on-crc-screening-recommendations-for-first-degree-relatives-of-patients-with-an-advanced-adenoma