Q&A: ACP issues new guidance on colorectal cancer screening
The ACP has issued a new evidence-based guidance statement on screening for colorectal cancer screening in asymptomatic adults with average risk.
Because multiple organizations differ on recommendations for screening age, methods and screening intervals, the “ACP offers guidance that attempts to reconcile the different guidelines,” Michael Pignone, MD, MPH, chair of the department of medicine in the Dell Medical School at the University of Texas, wrote in an accompanying editorial.
The authors of the ACP guidance statement said they evaluated cancer screening guidelines published by U.S. organizations between June 2014 and May 2018. ACP guidance statements are based on evidence used and referenced in the guidelines that scored the highest in their clinical appraisal, and do not include new findings. They arrived at their own recommendations based primarily on the U.S. Preventive Services Task Force and Canadian Task Force on Preventive Health Care guidelines.
The ACP recommends that average-risk adults should be screened between 50 and 75 years of age; that clinicians discuss the harms and benefits of different screening methods with patients; and that clinicians stop screening for colorectal cancer in average-risk patients aged older than 75 years or patients who have a life expectancy of less than 10 years.
Amir Qaseem, MD, PhD, MHA, lead author of the guidance statement and vice president of clinical policy at ACP, discussed the recommendations with Healio Primary Care. – by Erin Michael
Q: Why is the ACP guidance for colorectal cancer screening in asymptomatic average-risk adults based primarily on USPSTF and Canadian Task Force on Preventive Health Care (CTFPHC) guidelines?
A: We reviewed and evaluated available guidelines using the AGREE (Appraisal of Guidelines for Research and Evaluation) instrument. We selected two guidelines — CTFPHC and USPSTF — as they scored highest overall. Differences between high and low scoring guidelines were mostly due to methodological rigor and editorial independence. According to the National Academy of Medicine and the Guidelines International Network, a rigorous and high-quality process is a critical component of a trustworthy guideline.
Q: What is the importance of discussing colorectal cancer screening test options with patients?
A: Colorectal cancer is the second leading cause of cancer-related death in both men and women in the United States. Considering that the screening rates in the eligible population are hovering around mid-60%, it is critical to increase screening to reduce overall and cancer-specific mortality and morbidity.
Q: Why should asymptomatic patients at average risk begin colorectal cancer screening at 50 years old?
A: Regular screening for colorectal cancer in average-risk adults reduces colorectal cancer-specific mortality and even though the median age for colorectal cancer diagnosis is 67 years, persons aged 65 to 75 years derive the most direct benefit from screening for colorectal cancer. Colorectal cancer mortality decreases from screening.
Q: The guidance advises clinicians to stop screening in those aged older than 75 years or with a life expectancy of 10 years or less. What risks are involved with continued screening in these groups?
A: Harms of screening vary, depending on the type of test. For colonoscopy, it can be perforations, major and minor bleeding, cardiopulmonary complications, inconvenience, discomfort, harms and inconvenience of bowel preparation and conscious sedation. Fecal immunochemical testing is associated with false-positive and false-negative results and harms stemming from a subsequent colonoscopy for false-positive results or identified lesions. Guaiac-based fecal occult blood test also has false-positive and false-negative results, and harms associated with subsequent colonoscopy. Flexible sigmoidoscopy is associated with perforations, major and minor bleeding (rare), and any harms caused by a subsequent colonoscopy, discomfort and harms of bowel preparation.
Clinicians should discontinue screening in average-risk adults older than 75 years or in adults with a life expectancy of 10 years or less because harms of screening increase with age. Also, it takes on average 10 years to see the benefit of screening, meaning evidence shows that it takes 10 years to prevent one death from colorectal cancer for every 1,000 patients screened. We understand that accurate life expectancy is difficult to predict but for a 75-year-old man or woman in the U.S., average life expectancy is 9.9 years and 12 years, respectively. If we add serious comorbid conditions, the benefit from screening is reduced further, and the patient would undergo unnecessary, burdensome, potentially harmful and costly screening tests.
Q: What efforts are needed to implement ACP guidance in clinical practice?
A: Implementation of this guidance or any guideline is a complex topic and takes a lot of effort, planning and an organized approach. Strategies include dissemination using various outlets — such as this piece in Healio — patient education, including developing resources, clinician education and training, quality indicators and measures, integration into clinical decision support system, social interaction, etc.
Disclosures: Pignone reports being a former member of the USPSTF and participating in the development of the USPSTF colorectal cancer screening recommendation. Qaseem reports no relevant financial disclosures.