Multisite retrospective study of synchronous neoplasia rates at colonoscopic diagnosis of early-onset versus average-onset colorectal cancer

The incidence of early-onset colorectal cancer (diagnosed before age 50 years) continues to increase globally within high-income countries. A retrospective and cross-sectional study at Mayo Clinic sites and in the Mayo Clinic Health System compared synchronous neoplasia rates at colonoscopic diagnosis of early-onset versus average-onset colorectal cancer. Patients with early-onset colon cancer, but not rectal cancer, had significantly higher rates of synchronous advanced adenomas compared with patients with average-onset cancers. The authors conclude that these results suggest widespread field cancerization in patients with early-onset colon but not rectal cancer, indicating biological differences by primary tumor site.