ASCO 2025: Racial Disparities and Advanced Staging in Early-Onset Colorectal Cancer

At the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting, Jessica Paulus, ScD Epidemiology, senior director of observational research at Ontada, presented data that examined early-onset colorectal cancer using data from 105,000 patients, revealing significant racial disparities in diagnosis. In this interview with Pharmacy Times®, Paulus discusses that the study found that patients under the age of 50 are disproportionately represented by Black, Hispanic, and Latino populations and are more likely to be diagnosed at advanced stages (stages 3 and 4). Current screening guidelines starting at age 45 do not cover over half of early-onset patients, particularly those under the age of 44. The research emphasizes the need for risk-based screening algorithms, reduced diagnostic delays, and non-invasive screening methods to address these disparities.

Pharmacy Times: Can you start by introducing yourself?

Jessica Paulus: My name is Jess Paulus. I'm a cancer epidemiologist and a senior director of real-world research at Ontada, which is headquartered in Boston.

Pharmacy Times: Your research shows racial disparities in early-onset colorectal cancer. What might be driving these differences in diagnosis rates?

Paulus: The background of this work is that there's pretty growing recognition of the problem of what I'm really calling an epidemic of early-onset colorectal cancer. By early onset, I mean colorectal cancer that's diagnosed under age 50. There's growing recognition that the rates of early-onset colorectal cancer are rising both in the US and, now we understand, around the world. We've seen similar increases in low- and middle-income countries around the globe. There's been some attention to how social determinants of health, like patient race, ethnicity, and geography, may be partially underlying the rise in early-onset colorectal cancer, as well as may be associated with outcomes from this type of colorectal cancer. But to date, there have not really been any large-scale evaluations of early-onset colorectal cancer, as well as how that intersects with social determinants of health. That brings us to the impetus for this research project, which is that we were able to leverage real-world data from one of the largest community oncology networks in the US. In bringing that together, we were first seeking to characterize early-onset colorectal cancer versus what I'm calling average-onset colorectal cancer with respect to social determinants of health and other sociodemographic and clinical factors. Then the second piece is that we really want to describe the overall survival experience of patients with early-onset colorectal cancer, again, versus average-onset colorectal cancer. So that was a bit about kind of the impetus, or the motivation for the study. One of the reasons the study, I think, is distinguished is that I believe it's one of the largest studies of early-onset colorectal cancer to date. We were able to look at 105,000 patients with colorectal cancer, in total, 15,000 of whom had early-onset disease, again, initial diagnosis under the age of 50. It was just a very large-scale analysis that covered most of the geography of the US.

Pharmacy Times: You found early-onset patients are morely to be diagnosed at advanced stages. What clinical interventions could help catch these cancers earlier?

Paulus: One of the most significant things that came out of the descriptive comparison of early-onset versus later-onset colorectal cancer is that we found overrepresentation of patients of American Indian and Alaskan Native race as well as Asian and Black race and Hispanic and Latino ethnicity in the early-onset group, again, as compared to the average-onset group. As one example, over 11% of the early-onset cases were of Black race, versus only about 8% of the average-onset cases; 12% of the early-onset cases were of Hispanic or Latino ethnicity, as compared to only about 8% of the average-onset cases. We also saw increasing amounts of obesity at diagnosis or a BMI of 30 or greater in the early-onset cases versus the average-onset cases. Perhaps the most clinically striking finding of all is that we found that the early-onset patients were more likely to be diagnosed at stage 3 and stage 4 disease, again, at that initial diagnosis, as compared to the patients with an average onset of disease. We found about a 10% point difference in that early-onset cases had about a 10% greater chance of being diagnosed at stage 3 or 4 at initial diagnosis as compared to those average-onset cases of colorectal cancer. The difference in stage diagnosis is very concerning because one of the last pieces of our data that I wanted to point out is that we found that initial stage at diagnosis is really the strongest predictor of overall survival for all patients with colorectal cancer, regardless of whether you're diagnosed over or under 50 at initial diagnosis. And so, because we're seeing this sort of stage shift for the early-onset cases towards more advanced stages at diagnosis, that's very concerning from a patient outcome perspective and really points to some sort of practice and policy steps that we need to take to bridge this gap for those patients diagnosed earlier at younger ages.

Pharmacy Times: What do you see as the most critical next steps in addressing the rising epidemic of early-onset colorectal cancer?

Paulus: I think this work has some really critical practice and policy implications. One of the first things to be underscored by this work is that earlier detection is important for all patients. Advanced stage of disease at initial diagnosis has really dire prognostic consequences for patients. But what we're seeing here is a real disparity for the early-onset cases. From other research, we know that there is a greater diagnostic delay for the early-onset patients. I noticed a study that suggested that the early-onset patients had a 6-month greater duration from time of first symptom to definitive diagnosis as compared to patients who are older with colorectal cancer or the average-onset patients. That's something that we have got to reduce. We've got to figure that out. This is really a challenge for practitioners in the internal medicine or general medicine space before these patients get to oncology practice to consider how to reduce the time from symptom to diagnosis.

Pharmacy Times: Is there anything you would like to add?

Paulus: Also noteworthy is that in our study, over half of the early-onset patients were actually under the age of 44. Current population-based screening guidelines for colorectal cancer start at 45 years of age, and this was actually recently reduced down to 45 years of age, yet that still doesn't cover half of the early-onset patients. This really points to some strategies that we should think through about how to better screen patients who are younger. Population-wide screening for this group doesn't make sense, but we can consider risk-based algorithms for triage screening for those who might have the highest risk. Such as some of the risk factors that were pointed to in this research. I think there's also work to be done to promote more noninvasive screening modalities that could be used to increase the degree of screening, especially for younger patients.