Increasing incidence of early-onset colorectal cancer (review)
This review explains the rise of colorectal cancer in adults under 50, what is known about its causes and distinct features, and how screening ages and clinical management have responded.
Overview
Review of the epidemiology of colorectal cancer diagnosed before age 50, including birth-cohort effects, proposed risk factors (obesity, diet, microbiome, antibiotics), clinical and molecular features (left-sided and rectal predominance, later stage at diagnosis, similar mutational profiles in sporadic cases), germline findings, and implications for screening and treatment.
The early-onset colorectal cancer page's emphasis on investigating rectal bleeding at any age, universal germline testing and avoiding treatment escalation on age alone follows this framing.
- Causes remain hypotheses; no single exposure explains the trend.