Introduction
Colorectal cancer (CRC) is a significant public health concern, ranking fourth in terms of incidence and second in mortality among cancers in the United States. Recent trends show varied changes in different age groups: rising rates under 50, declining in the 50-64 age range, and a notable reduction in the ≥65 group due to effective screening. Disparities persist, with higher rates in males and non-Hispanic Black individuals. Effective screening strategies play a pivotal role in balancing the detection of lesions while minimizing potential harms. These strategies encompass diverse methods, ranging from stool tests like FIT, gFOBT, and sDNA, to visualization techniques such as colonoscopy, flexible sigmoidoscopy (FS), and computed tomography colonography (CTC). The American College of Physicians (ACP) reviewed guidelines and evidence to help clinicians decide on CRC screening for asymptomatic average-risk adults.1
Recommendations1
Recommendation 1: Initiation of Screening
Clinicians should initiate screening for colorectal cancer in asymptomatic average-risk adults when they reach the age of 50 years. It is a pivotal starting point for timely and proactive screening efforts that can contribute to the early detection and management of CRC.
Recommendation 2: Age Group 45-49
Clinicians should exercise caution when considering screening for asymptomatic average-risk adults aged between 45 and 49 years. The uncertainties surrounding the balance of benefits and potential harms in this age group warrant careful discussion between clinicians and patients to arrive at informed decisions.
Recommendation 3: Age and Life Expectancy Factors
Screening for colorectal cancer in asymptomatic average-risk adults aged 75 years and older or those with a life expectancy of 10 years or less is not recommended. The potential benefits of screening may diminish in these cases, necessitating a personalized approach that prioritizes patient well-being.
Recommendation 4a: Collaborative Decision-Making
Clinicians are advised to share decision-making with their patients to select the most appropriate screening test for colorectal cancer. This decision-making process should consider a holistic assessment of factors, including benefits, potential harms, costs, test availability, screening frequency, and individual patient values and preferences.
Recommendation 4b: Screening Test Options
Among the available screening options, clinicians can consider faecal immunochemical tests (FIT) or high-sensitivity guaiac faecal occult blood tests every two years, colonoscopy every ten years, or a combination of flexible sigmoidoscopy every ten years along with a faecal immunochemical test every two years. These tests provide viable avenues for effective screening while accommodating varying patient preferences and logistical considerations.
Recommendation 4c: Non-Recommended Tests
Clinicians should exercise discretion and refrain from utilizing stool DNA tests, computed tomography colonography, capsule endoscopy, urine-based tests, or serum-based tests for colorectal cancer screening. These modalities lack sufficient evidence to support their efficacy and may not yield reliable results for early detection.
Evidence Gaps and Research Needs1
Although the existing recommendations offer valuable insights, there are specific gaps in comprehension that warrant additional research. Investigating the benefits and potential harms of screening individuals below 50 years and those above 75 years can contribute to refining the optimal intervals for CRC screening initiation and cessation. Comparative trials focusing on the selection and frequency of screening tests within specific intervals (e.g., colonoscopy every 10 or 15 years) and between tests (e.g., FIT versus stool DNA) can enhance our evidence-based approach to CRC screening.
Emerging Evidence1
While this guidance statement has primarily relied on existing guidelines and evidence, one notable study require attention. The NordICC trial, a randomized pragmatic clinical trial, evaluated the effectiveness of screening colonoscopy. The trial demonstrated no significant difference in colorectal cancer incidence or all-cause mortality between the screening colonoscopy and usual care groups at a ten-year follow-up. Importantly, the findings emphasized the need for high adherence to screening protocols to optimize outcomes. The NordICC trial underscores the importance of ongoing research, including comparative studies, to inform future updates to CRC screening guidelines and evidence reviews.
Conclusion
Screening for colorectal cancer in asymptomatic average-risk adults is a complex endeavour that requires a nuanced approach to balance benefits and potential harms. The ACP’s comprehensive guidance statement draws from carefully examining guidelines and evidence to provide clinicians with actionable recommendations for making informed screening decisions. By considering age, life expectancy, patient preferences, and emerging evidence, clinicians can contribute to reducing the burden of colorectal cancer through effective screening strategies. As research continues to evolve, these recommendations offer a foundation for clinicians to engage in shared decision-making and optimize the health outcomes of their patients.
References
- Qaseem A, Harrod CS, Crandall CJ, et al. Screening for colorectal cancer in asymptomatic average-risk adults: a guidance statement from the American College of Physicians (Version 2). Ann Intern Med 2023. DOI: 10.7326/M23-0779.
