A study of adolescents diagnosed with colorectal cancer in the United States between 2012 and 2023 found that 80% of patients were not diagnosed until their cancer had reached Stage 3 or Stage 4. The research, which identified 84 cases, will be presented at the American Academy of Pediatrics’ national conference in San Diego.

The median age of the patients in the study was 16.5 years old. In the cohort, 29% of patients had Stage 4 cancer at the time of diagnosis. The study has not yet been published in a peer-reviewed journal.

Outcomes for the group were poor, with 38 patients, or 45.2%, dying from colorectal cancer. The cancer returned in about 37% of patients in the study. When colorectal cancer is caught in stage 1 and stage 2, the five year survival rate is about 90%.

Dr. Danielle Cameron, director of pediatric surgical oncology at Mass General Brigham Cancer Institute in Boston, worked on the study. She noted that this demographic faces distinct challenges compared to older adults. "The adolescent and the youngest of the young adults are at particular risk for bad outcomes and are a unique and vulnerable population even compared to people in their 30s and 40s," Cameron said. "They are at higher risks for more aggressive types of colorectal cancers and more opportunities for diagnostic delays."

Cameron suspects that the rise in colorectal cancer in young people likely has to do with DNA changes brought on by environmental exposures during childhood. This aligns with broader trends showing that worldwide, rates of colorectal cancer are rising among people in their 20s and 30s. A person born in the 1990s is four times more likely to be diagnosed with colorectal cancer before age 50 than people born in the 1960s were.

Jo Henderson, an 18-year-old from Seekonk, Massachusetts, experienced these diagnostic challenges firsthand. She was diagnosed with advanced colorectal cancer at age 17. Henderson was not part of the study, and Dr. Cameron was not her doctor.

"I was expecting a gluten allergy, lactose intolerance," Henderson said. "Literally anything but cancer."

By the time Henderson's cancer was found, it had spread to her ovaries. In December 2025, she underwent a partial colectomy and bilateral oophorectomy, followed by five months of chemotherapy. A colonoscopy in August 2026 showed no signs of cancer for Henderson.

She is currently a freshman in the Powers College of Business at Clemson University and is on hormone replacement medicine. Henderson will need annual colonoscopies moving forward. Her oncologist is Dr. Kimmie Ng, director of the Young-Onset Colorectal Cancer Center at Dana-Farber Cancer Institute in Boston.

The symptoms reported in the study mirror those Henderson experienced. In the study, about 74% of people reported back or abdominal pain. About 45% of people reported changes in bowel habits, and about 32% of people had rectal bleeding.

Dr. Tara Henderson, chair of the department of pediatrics at the Yale School of Medicine, was not involved in the research and is not related to Jo Henderson. "There are a lot more common things that cause those symptoms," Tara Henderson said. "But taking symptoms seriously is important."

Genetic factors also played a role in the study cohort. About half of the patients underwent genetic testing. Genetic testing revealed a handful of genetic mutations that can raise the risk of cancer in about half of the study patients.

Tara Henderson noted that family history is not always present. "Despite there being no family history, they may still have a genetic predisposition," she said.

Colorectal cancer in people younger than 20 accounts for fewer than 100 cases per year in the United States. The incidence of colorectal cancer in people younger than 20 is approximately one in a million. However, the rate is increasing across age groups.

Over the past two decades, colorectal cancers have increased fivefold among children ages 10 to 14. Over the past two decades, colorectal cancers have more than tripled among teens aged 15 to 19. Over the past two decades, colorectal cancers have nearly doubled among young adults ages 20 to 24.

Why It Matters

The study shows a shift in the demographics of colorectal cancer, with incidence rates rising sharply among adolescents and young adults. While the absolute number of cases remains low, with fewer than 100 cases per year in people under 20, the relative increase is substantial. The high rate of late-stage diagnosis and mortality reflects the difficulty in identifying the disease in this age group, where symptoms often mimic common benign conditions.

Experts point to a combination of genetic predisposition and environmental factors as potential drivers of this trend. The data suggests that early-life exposures may contribute to DNA changes that lead to cancer development later in adolescence. Understanding these mechanisms is critical for improving screening guidelines and reducing diagnostic delays for a population that is currently considered low-risk by standard medical protocols.

Timeline

In December 2025, Jo Henderson had a portion of her colon removed. A colonoscopy in August 2026 showed no signs of cancer for Jo Henderson. The research will be presented at the American Academy of Pediatrics’ national conference in San Diego.