Increased Risk of Colorectal Cancer and Mortality Associated with Advanced Adenomas
A new cohort study published in JAMA Network Open analyzing data from the Minnesota Colon Cancer Control Study has found that patients with both nonadvanced and advanced adenomas at colonoscopy face a significantly increased risk of developing colorectal cancer (CRC) compared with those with no adenomas.
The findings reinforce the importance of surveillance colonoscopy in patients with adenomas to reduce CRC-related morbidity and mortality.
The study included 10,584 participants who underwent colonoscopy following a positive fecal occult blood test. Over a 20-year period, the cumulative CRC incidence was 1.8% in patients with no adenomas, 3.9% in those with nonadvanced adenomas, and 5.5% in those with advanced adenomas. The presence of nonadvanced adenomas was associated with more than double the risk of CRC compared to individuals without adenomas (subdistribution hazard ratio [SHR], 2.24; 95% CI, 1.54-3.24; P < .001), while the presence of advanced adenomas increased the risk more than 3-fold (SHR, 3.24; 95% CI, 2.32-4.52; P < .001).
“Participants with nonadvanced and advanced adenomas at colonoscopy were at significantly increased risk of developing CRC compared with those with no adenomas,” the study states.
Patients with advanced adenomas also exhibited an increased risk of CRC mortality (SHR, 2.20; 95% CI, 1.36-3.57; P < .001) and all-cause mortality (hazard ratio [HR], 1.12; 95% CI, 1.03-1.21; P = .005). However, those with nonadvanced adenomas did not demonstrate a statistically significant increase in CRC mortality or all-cause mortality.
“Our finding of increased risk of all-cause mortality among those with advanced adenomas has not been previously reported,” the authors noted. The study suggests that shared risk factors, such as smoking, high body mass index, or genetic predispositions, may contribute to both advanced adenomas and increased mortality risk.
Limitations of the study include the older time period for colonoscopies and the absence of surveillance colonoscopy data. Nevertheless, the findings underscore the need for continued CRC surveillance in patients with adenomas and support current guidelines recommending more frequent follow-up for those with advanced adenomas.
Reference
Shaukat A, Goffredo P, Wolf JM, Rudser K, Church TR. Advanced adenoma and long-term risk of colorectal cancer, cancer-related mortality, and mortality. JAMA Netw Open. Published online February 3, 2025. doi:10.1001/jamanetworkopen.2024.59703
