Sporadic colorectal cancer in adolescents often presents at advanced stage

Most patients 21 years or younger with sporadic colorectal cancer (CRC) presented with stage III or IV disease, and few had a known family history, according to research presented at the American Academy of Pediatrics (AAP) 2026 National Conference & Exhibition in San Diego, California.¹^,² By the end of the study period, 45.2% of the 84 patients included had died of CRC.²

The study authors noted CRC is increasing among adolescent and young adult patients, and the press release described the disease in this population as distinct from CRC diagnosed in older adults.¹^,² Because CRC is uncommon in young people, symptoms such as abdominal pain and rectal bleeding are often overlooked, according to the press release.¹

"Colorectal cancer is, unfortunately, becoming more common in adolescents and young adults and represents a different disease than colorectal cancer diagnosed in older adults," Erica Arnold, MD, a pediatric surgical oncology research fellow in the Center for Surgical Outcomes Research at Nationwide Children’s in Columbus, Ohio, said in a press release. "When diagnosed, it is often aggressive, presenting with late-stage disease and associated with high rates of disease relapse and mortality."

Delayed diagnosis common in adolescents with sporadic colorectal cancer

Investigators with the Pediatric Surgical Oncology Research Collaborative retrospectively reviewed records of patients 21 years or younger diagnosed with CRC between 2012 and 2023 at 34 institutions.² Patients with a known CRC predisposition syndrome were excluded, including those with genetic syndromes or with inflammatory bowel disease diagnosed before CRC.²

Of the 84 patients identified, 65 (77.4%) had colon adenocarcinoma and 19 (22.6%) had rectal adenocarcinoma.² Median age at diagnosis was 16.5 years (IQR, 14.0-19.0), and 47 patients (56.0%) were male. Seventeen patients (20.2%) reported a first- or second-degree relative with CRC.²

Back or abdominal pain was the most common presenting symptom, reported by 62 patients (73.8%).² Other common symptoms included change in bowel habits (45.2%; n = 38), weight loss (42.9%; n = 36), and rectal bleeding (38.1%; n = 32).²

Symptoms lasted a median of 12 weeks (IQR, 2.0-24.0) before diagnosis, and median time to colonoscopy was 13 weeks (IQR, 6.0-32.0).² Most patients presented with stage III (51.0%; n = 43) or stage IV (29.0%; n = 24) disease.²

Aggressive histology linked with relapse in young patients with colorectal cancer

Sixty-two patients (73.8%) underwent upfront resection, 15 (17.9%) received neoadjuvant chemotherapy, and three (3.6%) received definitive chemoradiation.² In four patients (4.8%), attempted resection resulted only in ostomy creation because the disease was unresectable.²

On pathology, 28 patients (33.3%) had signet ring features, 33 (39.3%) had mucin, and 41.6% had poorly differentiated histology.² Of the 46 patients (54.8%) who underwent germline testing, four (8.6%) had a TP53 mutation, two (4.3%) had an APC mutation, and eight (17.4%) had a mismatch repair mutation.²

Relapse occurred in 31 patients (36.9%) at a median of 11 months (IQR, 10.0-21.0), and 96.8% of these patients had stage III or IV disease at diagnosis.² Compared with patients without relapse, those with relapse more often had positive lymph nodes (90.3% vs 50.9%; P = .0004), poorly differentiated histology (64.5% vs 28.3%; P = .0047), and signet ring features (61.3% vs 17.0%; P = .0002).² All patients with relapse had received adjuvant chemotherapy.²

The authors concluded children and adolescents without known predisposition syndromes experience delays in diagnosis, and most do not have a known family history.² They recommended clinicians include CRC in the differential for symptoms such as abdominal pain and rectal bleeding in adolescents without an alternative diagnosis.²

The press release also emphasized coordination between adult and pediatric care teams, along with carefully tailored treatment regimens, as early-onset cancers are diagnosed in increasingly younger patients.¹

The study was a retrospective review of patients treated at institutions in the collaborative and was not designed to measure changes in CRC incidence over time. Findings apply to sporadic disease, since patients with known predisposition syndromes were excluded.

References

1. American Academy of Pediatrics. Colorectal cancer on the rise in adolescent patients. Eurekalert. October 2, 2026. Accessed October 2, 2026. https://www.eurekalert.org/news-releases/1145234

2. Arnold E. Clinical presentation and epidemiology of pediatric and adolescent colorectal carcinoma: a Pediatric Surgical Oncology Research Collaborative study. Abstract presented at: American Academy of Pediatrics 2026 National Conference & Exhibition; October 2-6, 2026; San Diego, CA.