Uncovering Social Disparities in Early-Onset Colorectal Cancer
A recent study reveals rising early-onset colorectal cancer rates, highlighting disparities and the need for improved screening and early detection strategies.
Microscopic image of colon cancer cell - Generated with Google Gemini AI
While colorectal cancer rates have declined in older adults, there has been a significant rise in early-onset colorectal cancer in patients diagnosed before age 50. This prompted a large-scale real-world study by Ontada, presented by Jessica Paulus, ScD, senior director of Observational Research, at the recent American Society of Clinical Oncology (ASCO) Annual Meeting.
The research, drawing from a vast community oncology network, aimed to shed light on the characteristics, disparities, and outcomes of early-onset disease, particularly through the lens of social determinants of health.
Unpacking the Scale of Early-Onset Colorectal Cancer
The retrospective cohort study analyzed data patients with colorectal cancer within The US Oncology Network. Of these, almost 15,000 patients were diagnosed with early-onset colorectal cancer, making this one of the largest analyses of this relatively rare but growing population.
The study unveiled several critical insights. The early-onset group showed an overrepresentation of certain racial and ethnic subgroups compared with the average-onset group. Specifically, there were higher percentages of patients who identified as Black (11% vs 8%), American Indian or Alaskan Native (1.3% vs 0.9%), of a documented race other than White (20% vs 15%), and of Hispanic/Latino ethnicity (11% vs 8%) compared with those in the average-onset CRC cohort.
A striking difference was observed in the stage of cancer at initial diagnosis. The early-onset group was more likely to present with stage III (37% vs 34%) or stage IV (34% vs 28%) disease compared with the average-onset group. This is a crucial finding, as advanced stages are strongly associated with worse survival outcomes. Additionally, regardless of age at diagnosis, the stage of disease at initial diagnosis was the strongest predictor of overall survival. This underscores the urgent need for earlier detection in younger patients, who are currently more likely to be diagnosed at later stages.
Additional findings showed that 11% of patients in the early-onset cohort and 10% of those in the average-onset cohort were current smokers at time of diagnosis, and more than one-third of the early-onset group was obese (36%) vs 31% in the average-onset group. Early-onset patients were more commonly located in urban areas than those in the average-onset group (69% vs 63%).
Looking at the 2,810 patients with Distress Thermometer data, those in the early-onset group were more likely to report high or moderate distress (29% vs 22%) and less likely to report low distress (71% vs 78%). The 5-year OS probability was 72% (95% CI, 71-73) in the early-onset group vs 64% (95% CI, 63-64) in the average-onset group.
Implications for Clinical Practice and Screening Guidelines
Paulus emphasized that current colorectal cancer screening guidelines in the US, which recommend screening at age 45, are falling short for early-onset cases.
"Half of our early-onset patients were actually younger than age 45 at diagnosis, so they are not being helped by those current population-level screening," she noted.
For clinicians, Paulus stressed the need to reduce diagnostic delays. Younger patients often experience longer intervals—anywhere from 4 to 8 months longer—between their first symptoms and a definitive diagnosis, as they often "ping-pong" between different providers. One oncologist, she shared, suggested that all gastrointestinal symptoms compatible with neoplasm should be considered cancer until proven otherwise, lowering the threshold for colonoscopy referrals.
Looking ahead, Paulus sees opportunities for noninvasive or less-invasive screening approaches for younger populations. Furthermore, she advocated for risk-based screening models, similar to those used effectively in non–small cell lung cancer, to identify younger patients who warrant a very low threshold for colonoscopy or other screening methods. Such models could significantly improve early detection and ultimately, survival outcomes.
