Most adolescents and young adults diagnosed with colorectal cancer already have advanced disease, according to a multicenter study that highlights the challenges of detecting a cancer rarely suspected in younger patients.
Presented at the American Academy of Pediatrics 2026 National Conference & Exhibition, the research found that 80 percent of patients aged 21 or younger had stage III or IV colorectal cancer at diagnosis. More than one-third subsequently experienced disease recurrence.
Researchers from the Pediatric Surgical Oncology Research Collaborative reviewed medical records from 84 patients diagnosed between 2012 and 2023 across 34 institutions. Patients with previously diagnosed hereditary cancer predisposition syndromes or inflammatory bowel disease were excluded.
The median age at diagnosis was 16.5 years. Only 20 percent reported a first- or second-degree relative with colorectal cancer, suggesting that family history alone would have failed to identify most patients.
Common presenting symptoms included abdominal or back pain (74 percent), changes in bowel habits (45 percent), weight loss (43 percent), and rectal bleeding (38 percent).
The median duration of symptoms before diagnosis was 12 weeks, while the median time to colonoscopy was 13 weeks.
Pathological examination revealed aggressive tumor characteristics in many patients. Approximately 42 percent had poorly differentiated tumors, one-third showed signet ring features, and 39 percent had mucinous features.
Disease recurrence occurred in 37 percent of patients, typically within 11 months. Recurrence was associated with lymph node involvement, poor tumor differentiation, and signet ring features. Overall, 45 percent died from colorectal cancer during the study period.
For diagnostic services, the findings emphasize the importance of investigating persistent gastrointestinal symptoms in younger patients, even without a known hereditary predisposition.
They also highlight the value of histopathological assessment in identifying aggressive tumor features associated with recurrence, alongside the potential role of genetic evaluation. Among patients who underwent germline testing, variants involving mismatch repair genes, TP53, and APC were identified.
The retrospective study cannot establish whether colorectal cancer incidence is increasing or determine the causes of delayed diagnosis. However, its findings reinforce the need for timely investigation and coordinated pediatric and adult oncology care.
Newsletters
Receive the latest pathologist news, personalities, education, and career development – weekly to your inbox.
