Screening for Colorectal Cancer and Evolving Issues for Physicians and Patients: A Review.

Importance: Colorectal cancer (CRC) is the second-leading cause of cancer death in the United States. Screening can reduce CRC mortality and incidence, and numerous screening options, although available, complicate informed decision making. This review provides evidence-based tools for primary care physicians to identify patients with higher-than-average-risk and engage patients in informed decision making about CRC screening options. Observations: Recently, the US Preventive Services Task Force recommended any of 8 CRC screening approaches for average-risk individuals, beginning at age 50 years. Only 2 methods have been shown in randomized clinical trials to reduce mortality: fecal occult blood testing and flexible sigmoidoscopy. Of the 8 programs, screenings using the fecal immunochemical test annually and colonoscopy every 10 years are now the most commonly used tests in the United States and among the most effective in reducing CRC mortality as determined by decision models. With the exception of primary screening using colonoscopy, all of the other screening approaches have multiple steps. Adherence to each phase of a multistep program is critical to achieving maximal effectiveness of the screening program. It is likely that each of the recommended programs can reduce CRC mortality, but other key outcomes may differ such as lifetime burden of colonoscopy, complications, patient acceptance, and cost. Decisions about the timing of screening cessation should be individualized. Conclusions and Relevance: CRC screening is effective if patients adhere to the steps in each screening program. There is no evidence that one program is superior to another. Informed decision-making tools are provided to assist patients and clinicians with the goal of improving adherence to effective screening.