Striking a balance: Deciding the optimal age to cease surveillance for colorectal neoplasia
BY PETR PROTIVA, MD, MPH
The appropriate age to stop surveillance for colorectal neoplasia remains uncertain. Screening for average-risk individuals is typically stopped at age 75, but personalized screening with shared decision-making may continue until age 85.1 Evidence suggests that any survival benefit of screening past age 86 would be outweighed by the harm of screening and/or natural mortality. Nevertheless, determining the optimal age for surveillance in those with a history of neoplasia still poses some challenges. The issue is confounded as many clinicians use the terms “screening” and “surveillance” interchangeably. It should be noted that screening implies the individual is at average risk, while surveillance refers to those at elevated risk because of a personal history of colonic adenomas or cancer
Dr. Petr Protiva
Comorbidities and life expectancy
Despite recent staggering setbacks and a drop in the average life expectancy in the United States, the proportion of individuals older than 65 years old has been steadily increasing to a currently estimated 58.9 million – 16.8% of the U.S. population – and is projected to increase in the future.2 However, the prevalence of comorbidities also increases with age, and these are crucial factors to weigh in the decision-making process. Severe comorbid conditions, such as chronic obstructive pulmonary disease, cirrhosis, chronic hepatitis, chronic renal failure, dementia, and congestive heart failure can limit a patient’s ability to undergo surveillance and diminish or negate its benefits. There are online tools that help clinicians estimate life expectancy and time to benefit (that is, time between the intervention and its benefit), such as the Lee or Schonberg index.3 Consensus on time to colorectal screening benefit is about 9-10 years, but may be much shorter for surveillance. Striking a balance between the potential benefits of continued surveillance and the risks and burdens imposed on older adults with limited life expectancy is essential for making well-informed decisions.
Age-related risk increase and risk of neoplasia in the surveillance population:
The absolute risk of developing colorectal cancer is dependent on age. In adults aged 45-49, it is 33.4/100,000, rising to 135.6 in those 70-74 years old; in persons aged 85 and older, it is 234.7/100,000.4 A significant challenge in determining the appropriate age to stop surveillance is the additional individual risk based on baseline polyp characteristics. It seems reasonable to treat low-risk adenomas similarly to screening and stop surveillance by 85 or 86 years old in most cases. The decision process is less clear in individuals with advanced lesions or a personal history of colon cancer. The prevalence of advanced adenomas on the baseline exam is about 15% and greater than 20% on the follow-up exam if the index adenoma(s) were at least 20 mm in diameter. For five or more adenomas at baseline, the prevalence of advanced lesions on follow-up exam is about 20%. On the other hand, a negative surveillance colonoscopy (that is, no polyps found) is associated with far fewer advanced lesions on follow-up.
Colonoscopy
The safety of colonoscopy in older adults should be considered. The colonoscopy procedure is generally very safe, but is associated with a higher risk of post-procedure complications after outpatient colonoscopy in patients 75 years and older. In addition, comorbidities such as anemia, cardiac arrhythmia, heart failure, hypertension, chronic kidney disease, liver disease, smoking history, and obesity are also risk factors. It should be noted that high-quality colonoscopy is key to the detection and full removal of neoplastic lesions and risk reduction. The inability to achieve adequate colon preparation for any reason or undertaking colonoscopy in patients at high risk for complications reduces its benefit.
Who should oversee surveillance, the primary care physician or gastroenterologist
Should a gastroenterologist oversee the decision on surveillance in older adults based on a combination of age, estimated procedure risk and benefits, patient preferences, and current guidelines? Certainly, it seems appropriate and that this is what most specialists think, according to a recent survey of gastroenterologists and primary care physicians (PCPs) on this topic.5 Perhaps, not surprisingly, most PCPs disagreed – PCPs are thoroughly familiar with their patients’ up-to-date comorbidities, functional status, and preferences, and they have the benefit of knowing them for a long time. They also integrate diagnostic results from multiple subspecialists, sometimes from different states. The role of PCPs is critical in centers that offer open-access colonoscopy. Gastroenterologists may be the most appropriate authority to evaluate older individuals for continued surveillance, but in most busy practices these patients are seen by mid-level practitioners. Specialists play an important role if the PCP is uncertain whether surveillance is still indicated or in older patients with a history of advanced adenoma. Therefore, the colonoscopy report or subsequent communication after pathology results are returned should include a recommendation for future surveillance and a clear provision for discontinuing the surveillance in case of future health decline.
Conclusion
Determining the optimal age to discontinue surveillance for colorectal neoplasia involves evaluating multiple factors. Although the age limit is clearer for average-risk screening and low-risk lesion surveillance, uncertainty remains for individuals with advanced neoplasia history. Significant factors in this decision-making process include subsequent neoplasia risk, comorbidities, life expectancy, and age-related risks associated with colonoscopy. Cooperation between PCPs and subspecialty physicians is essential in making surveillance decisions for older adults. PCPs are well positioned to consider detailed patient comorbidities, functional status, and patient preferences, especially with the help of online life-expectancy estimators for most elderly or comorbid patients. To assist in this process, gastroenterologists should state clearly in their procedure report and subsequent pathology letters whether surveillance is recommended and that it is conditional on future comorbidities and should be discontinued if the patient’s health significantly declines.
Dr. Protiva is associate professor of medicine, Yale University, and director of the colon cancer screening program, VA Connecticut Healthcare System, West Haven. Dr. Protiva has no relevant disclosures.
References
1. Patel SG et al. Gastroenterology. 2022;162:285-99
2. U.S. Census Bureau. Measuring America’s People, Places, and Economy
3. University of California, San Francisco. ePrognosis. 4. Siegel RL et al. CA Cancer J Clin. 2023 May-Jun;73(3):233-54.
5. Schoenborn NL et al. Am J Gastroenterol. 2023; 118(3):523-30.
