Early-onset colorectal cancer: Rising incidence in young adults, diagnostic delay, and surgical outcomes

Abstract

Early-onset colorectal cancer (EOCRC), usually defined as colorectal cancer diagnosed before 50 years of age, has become a clinically important epidemiologic problem because incidence is rising across multiple regions while rates in older screened populations have declined. This narrative review critically examines the increase in incidence, mechanisms of diagnostic delay, and surgical outcomes in young adults. PubMed/MEDLINE and guideline sources were searched in 2026 using terms related to EOCRC, incidence, symptoms, diagnostic intervals, surgery, postoperative complications, recurrence, and survival. Population-based studies, systematic reviews, international guidance, and surgical cohorts were prioritized. Evidence shows that EOCRC is disproportionately distal or rectal and is often diagnosed at stage III or IV. Hematochezia, abdominal pain, altered bowel habits, and iron deficiency anemia are recurrent warning features, yet diagnostic intervals of several months remain common. Delay creates missed opportunities for diagnosis but does not fully explain advanced presentation, which also reflects tumor biology and the absence of routine screening for many younger adults. Surgical treatment should follow standard oncologic principles rather than age alone. Younger patients generally tolerate resection well and have lower medical morbidity and short-term mortality, although anastomotic leak and reoperation risks remain clinically relevant. Long-term outcomes are dominated by stage and pathological risk rather than chronological age. Earlier symptom recognition, risk-based assessment, germline testing, and timely colonoscopy are therefore central to reducing preventable late diagnoses.