The presence of high- or low-risk adenomas at screening colonoscopy could help physicians determine how long to make surveillance intervals, according to study results.
“Ideally, surveillance recommendations are based on the risk of developing and dying from colorectal cancer after adenoma removal,” Jeffrey K. Lee, MD, MAS, of the department of gastroenterology at Kaiser Permanente San Francisco, and colleagues wrote. “Yet most studies that serve as the basis for the guidelines have either been small in size, performed under highly standardized conditions or with selected populations, lacked long-term follow-up and colonoscopy quality data, evaluated broad time intervals, or focused on advanced adenomas rather than colorectal cancer incidence and mortality as the primary outcome.”
Researchers analyzed data from 64,422 individuals who underwent baseline colonoscopies from 2004 to 2010. They separated their findings into three groups — no adenoma, low-risk adenoma and high-risk adenoma — and followed the individuals until the earliest diagnosis of CRC, death, disenrollment from the health plan or Dec. 21, 2017. They then compared risk for CRC and related deaths between the adenoma groups and the no adenoma group.
Compared with the no adenoma group (n = 45,881), Lee and colleagues found that patients in the high-risk group (n = 7,563) had a higher risk for CRC (HR = 2.61; 95% CI, 1.87–3.63). They also had a higher risk for CRC-related death (HR = 3.94: 95% CI, 1.9–6.56).
Researchers determined that patients in the low-risk adenoma group were not at significantly increased risk for CRC (HR = 1.29; 95% CI, 0.89–1.88) or related death (HR = 0.65; 95% CI, 0.19–2.18) compared with the no adenoma group.
Lee and colleagues wrote that their findings help expand the understanding of CRC risk and related deaths after the removal of low-risk adenomas at a baseline colonoscopy.
“This finding suggests that guidelines recommending comparable follow-up for low risk adenomas and normal examinations, such as lengthening the surveillance interval to [more than 5 years] and possibly 10 years, may provide comparable cancer incidence and mortality benefits for these two groups,” they wrote. “Additional studies, potentially including randomized trials, on the natural history of low-risk adenoma and normal findings without intervening surveillance exams before 10 years are needed to help guide future surveillance practices.” – by Alex Young
Disclosure s: The authors report no relevant financial disclosures.