Older individuals had a higher risk of complications 30 days after undergoing a colonoscopy as an outpatient procedure compared with a younger group of colorectal cancer screening–eligible individuals, according to recent research published in JAMA Network Open.
Natalia Causada-Calo, MD, MSc, division of gastroenterology, at St. Michael’s Hospital, University of Toronto, and colleagues performed a retrospective cohort study of 38,069 patients in Ontario administrative databases who underwent colonoscopy between April 2008 and September 2017. The patients included were older than 50 years (mean age, 65.2 years) with a majority (73.1%) undergoing their first colonoscopy. Those with inflammatory bowel disease and hereditary colorectal cancer syndromes were excluded. Researchers divided patients into groups based on age, placing patients aged 50-74 years into a colorectal cancer–screening eligible group (30,443 patients), and individuals 75 years or older into an “older cohort” (7,627 patients). Dr. Causada-Calo and colleagues analyzed 30-day admission to hospital or emergency department, and also examined 30-day all-cause mortality and incidence of colorectal cancer.
Among individuals in the older cohort, 515 of 7,627 patients (6.8%) experienced complications after colonoscopy compared with 795 of 30,443 patients (2.6%) in the screening-eligible cohort (P less than .001). Older age was an independent risk factor for postcolonoscopy complications, with individuals older than 75 years having twofold greater odds of complications after colonoscopy (odds ratio, 2.3; 95% confidence interval, 2.0-2.6) compared with individuals aged 50-74 years.
Other independent risk factors for complications included liver disease (OR, 4.7; 95% CI, 3.5-6.5), heart failure (OR, 3.4; 95% CI, 2.5-4.6), smoking history (OR, 3.2; 95% CI, 2.4-4.3), obesity (OR, 2.3; 95% CI, 1.2-4.2), chronic kidney disease (OR, 1.8; 95% CI, 1.1-3.0), cardiac arrhythmia (OR, 1.7; 95% CI, 1.2-2.2), anemia (OR, 1.4; 95% CI, 1.2-1.7), and hypertension (OR, 1.2; 95% CI, 1.0-1.5). Individuals who had previously undergone colonoscopy had a lower risk of complications after the procedure (OR, 0.9; 95% CI, 0.7-1.0).
There was a significantly higher incidence of colorectal cancer treated with surgery in the older group (119 of 7,626; 1.6%) compared with the younger (144 of 30,443; 0.5%) group (P less than .001). Mortality from any cause was also significantly higher in the older group (20 patients; 0.2%) compared with the younger (39 patients; 0.1%) group (P less than .001).
“In accordance with our findings, the decision to perform colonoscopy should be considered carefully in older patients, particularly in the presence of comorbidities,” Dr. Causada-Calo and colleagues wrote.
Aasma Shaukat, MD, MPH, GI section chief at Minneapolis VA Health Care System and professor of medicine at University of Minnesota, said in an interview that screening colonoscopy in a population older than 75 years should be an individualized discussion with a patient who has minimal comorbidities, and the decision to move forward with a colonoscopy should be considered only if a patient’s life expectancy is at least 10 years.
“This study shows that diagnostic colonoscopy is associated with high risk of complications and quantifies the risk, to frame the discussion with the patient about going forward,” she said. “Colorectal cancers are slow growing. In individuals age 75 and older, competing health risks and risk of the colonoscopy often outweigh the small benefit they may derive. Older individuals should thus focus on other health priorities.”
Physicians should make their older patients aware that there is a risk for serious adverse events, including death, which increases after age 75. “[The] risk-benefit ratio for performing colonoscopy needs to carefully weighed,” Dr. Shaukat said. “[T]he patient should be presented with options, including the option of no screening.”
The American Cancer Society advocates “for individualized decision-making regarding screening for individuals after 75 but [does] not give any firm recommendations,” while the U.S. Preventive Services Task Force noted in its recommendations on colorectal cancer screening that the “harms are large and benefits are small” after 75 years of age, and choice to screen for colorectal cancer in that age group is an individual one, Dr. Shaukat said.
Robert A. Smith, PhD, senior vice president of cancer screening at the American Cancer Society, said in an interview that while colonoscopy is the dominant screening test for colorectal cancer, it is not known how often physicians and their older patients discuss noninvasive colorectal cancer screening methods. Noninvasive screening methods such as a high-sensitivity stool test should be a consideration even for older adults with mild chronic conditions, “especially if they have a history of screening with negative results,” he said. “[A] history of regular screening with normal test results should be a basis for considering cessation of screening after age 75, or at least transition to a test with lower risks of complications.”
Future research in this area could use a hybrid model of screening, such as using different tests among various age groups or risk groups, to see whether an invasive or noninvasive method would lower a complication rate, Dr. Smith said. “Further, we need to have a greater understanding of when individuals can confidently stop getting screened, based on their underlying risk and history of prior screening results,” he noted.
Dr. Shaukat said future studies should focus on randomized trials for individuals 75 years and older to assess the benefits and harms of screening, “[d]eveloping risk stratification tools that factor in an individual’s risk of colon cancer, their life expectancy, and guide individualized decision making to undergo screening.”
Dr. Armstrong is the chair of the National Colon Cancer Screening Network for the Canadian Partnership Against Cancer and the past president of the Canadian Association of Gastroenterology. Dr. Albashir has received honoraria and speaker fees from Janssen, and grants from AbbVie and ATGen. Dr. Shaukat and Dr. Smith report no relevant conflicts of interest.
SOURCE: Causada-Calo N et al. JAMA Netw Open. 2020;3(6):e208958.