Early-Onset Colorectal Cancer Disparities Highlighted at ASCO Annual Meeting

CHICAGO – New research presented at the ASCO Annual Meeting reveals notable disparities in early-onset colorectal cancer diagnoses within community oncology settings.

Analyzing real-world data from over 100,000 colorectal cancer patients, the study demonstrated a higher representation of Black, Asian, and American Indian/Alaskan Native individuals, as well as those of Hispanic ethnicity, among patients with early-onset disease compared to those with average-onset disease.

The study also found that patients with early-onset colorectal cancer are more likely to be diagnosed with stage III or stage IV disease.

Stage at diagnosis is the most significant significant predictor of death in all patients with colorectal cancer. This underscores how critical it is for earlier detection and avoiding diagnostic delays for all patients, but especially for younger patients given we see such marked disparities.

Jessica K. Paulus, ScD, senior director of real-world research at Ontada

Early-onset colorectal cancer, defined as diagnoses in individuals under 50, is on the rise, while incidence rates are declining among adults aged 50 and older.

Previous research has explored potential drivers of this trend, but the impact of social determinants of health, such as race, ethnicity, and geographic location, remains understudied.

Researchers analyzed electronic health record data from a large, diverse network of U.S. community oncology practices to identify sociodemographic and clinical factors associated with early-onset versus average-onset colorectal cancer.They also examined overall survival (OS) based on age at diagnosis.

the retrospective study included data from 104,281 adults with colorectal cancer within the US Oncology Network and other non-network practices using the same EHR system, all diagnosed between 2000 and 2024.

The majority (86%) had average-onset colorectal cancer,diagnosed at age 50 or older (median age 67). The remaining 14% had early-onset disease, diagnosed before age 50 (median age 44).

Patient characteristics were obtained using iKnowMed, an oncology-specific electronic health record system.

The study revealed a higher proportion of Black/African American (11.1% vs. 8.2%),American Indian/Alaskan Native (1.3% vs. 0.8%), and Asian (4.8% vs. 3.4%) individuals in the early-onset group.Hispanic/Latino ethnicity was also more prevalent in the early-onset group (12% vs. 8.8%).

Individuals with early-onset disease were more likely to reside in urban areas (69% vs. 63%).

A greater percentage of those with early-onset colorectal cancer had obesity at diagnosis (36% vs. 31%).

Stage analysis at diagnosis showed a higher percentage of early-onset cases diagnosed at stage III (37% vs. 34%) or stage IV (34% vs. 28%).

Taken together, this corresponds to a nearly 10 percentage point difference in the burden of advanced stage at diagnosis between the two age groups.

Jessica K. Paulus, ScD

Patients with early-onset disease also reported higher levels of distress (31% vs. 21%), as measured by the National Thorough cancer Network Distress Thermometer scores.

The study indicated poorer overall survival among those with average-onset disease compared to early-onset disease (HR = 1.54; 95% CI, 1.46-1.62), with a higher 5-year OS probability in the early-onset group (72% vs. 64%).

Stage IV disease at initial diagnosis was identified as the strongest predictor of survival, regardless of age, increasing the risk of death nearly fivefold (HR = 4.78; 95% CI, 4.79-4.98).

Researchers acknowledged limitations, including the potential for sociodemographic factors to be specific to the community oncology populations studied and associated referral patterns.

These results may not represent the true magnitude of disparities in different settings in the U.S.

Jessica K. Paulus, ScD