What the study found
Scientists from Dana-Farber Cancer Institute, Mass General Brigham and the Broad Institute have published a large analysis of colorectal tumors. They hope it will help explain why the disease is increasingly striking younger adults, according to The Boston Globe. The work appeared in the peer-reviewed journal Nature Medicine.
The team examined 189 tumors from patients whose ages ranged from their 20s to their 90s. Of those patients, 54 were diagnosed before turning 50. Using methods that read tissue at the level of individual cells, the researchers studied more than 850,000 cells in all.
Tumors from younger patients appeared to be built differently. They contained a much larger share of stromal cells, the connective and supporting cells that surround and sustain a tumor. According to the Globe, research on other solid cancers has tied these cells to resistance to chemotherapy. The scientists also saw differences in which genes were switched on in younger patients' tumors, a finding experts said could point toward new drug targets.
A rising problem
The study comes as colorectal cancer becomes more common among younger Americans. The American Cancer Society reports that rates among people under 50 climbed by nearly 3 percent each year from 2013 through 2022. The disease now causes more cancer deaths in that age bracket than any other cancer type.
Scientists have pursued a range of explanations. A growing body of evidence connects risk with diet, including ultra-processed foods, along with other lifestyle and environmental influences. The authors of the new study took a complementary approach. They looked at the biology of the tumors themselves, searching for traits that shift with a patient's age.
Dr. Kimmie Ng, a senior author and director of the Young-Onset Colorectal Cancer Center at Dana-Farber, said the analysis revealed subtle differences between younger and older patients. She said the dataset is the biggest assembled for colorectal cancer and includes the most young patients.
What the researchers are saying
Ana Anderson, a senior author affiliated with the Gene Lay Institute of Immunology and Inflammation at Brigham and Women's Hospital, described the earlier state of knowledge bluntly. “It’s been a bit of a black box,” she said. She added that the findings give investigators a direction to pursue, with the hope of eventually developing therapies tailored to young-onset disease.
Ng was similarly optimistic. “It gives a huge amount of hope,” she said, calling the dataset a guide for where future research should be directed.
Dr. John Paul Shen, an associate professor of gastrointestinal medical oncology at the University of Texas MD Anderson Cancer Center, was not part of the study. He said the data suggest clear experiments that labs around the world could run. “That’s hugely valuable,” Shen said.
Limits and next steps
Shen and other experts noted a caveat. Although the analysis goes deep at the cellular level, it draws on a relatively small number of people. Ng responded that the study group matches what is broadly understood about young-onset colorectal cancer patients worldwide.
Dr. Christina Annunziata, senior vice president of extramural discovery science at the American Cancer Society, said later work could build on the findings by studying other groups of patients. She described the dataset as “an essential first step.”
Experts cautioned that practical breakthroughs may take time. Annunziata said the research is needed to understand why people are developing cancer earlier in life and what can be done about it.
