Less Than 5% of Older Adults Joined Blood Cancer Trials, Study Shows

Older adults bear the brunt of hematologic malignancies, yet their complex comorbidities, functional limitations, and logistical barriers often prevent them from enrolling in clinical trials. These obstacles contribute not only to underrepresentation in clinical research but, more importantly, a critical evidence gap that limits guidance for their care.

Inna Gong, MD, PhD and colleagues sought to quantify these gaps with data from the Surveillance, Epidemiology, and End Results (SEER)–Medicare linked database. Their retrospective cohort study of patients with hematologic malignancies aged 66 years or older, published in Cancer in December 2025, confirmed a strikingly low rate of clinical trial participation in this population: around 4% at 5 years.¹

In an interview with Targeted Oncology, Dr Gong, hematologist at the Princess Margaret Cancer Centre in Toronto, Canada and lead author, discussed key findings from the study and offered insights for practical, patient-centered strategies to improve trial participation in this population.

Targeted Oncology: What led you and your group to investigate these disparities, specifically in this population of older adults with hematologic malignancies?

Inna Gong, MD, PhD: First of all, we know that [treatment of] hematologic malignancies has seen a rapid shift in terms of moving beyond chemotherapies to integrating novel targeted treatments as well as immunotherapies. So, I think the question is more ripe than ever to answer… are the clinical trials enrolling patients that could be generalized to the general oncology population that we see in the United States?

One of the aspects that really motivated us is that although disparities in trial enrollment have been studied previously, most of those studies relied on trial-level data detailed patient-level demographic data that limits our ability to understand the specific factors influencing participation among older adults with hematologic malignancies. And so we really wanted to be able to leverage individual patient-level data through the SEER–Medicare linked database to estimate clinical trial participation to examine the influence of demographic, geographic, and comorbidity factors on trial participation.

Could you summarize the major findings of the study?

What we found was that, using this national SEER–Medicare data, trial participation among older adults was strikingly low, only 4.3% at 5 years, and that participation drops sharply with increasing age, Black race, female sex, lower income, greater distance from major [National Cancer Institute; NCI] centers. These [findings] suggest that there's underrepresentation in those demographic groups, and we need targeted solutions and evidence guiding…improvement in clinical trial representation that reflects…the broader [population of] patients that we treat.

What was your reaction to this low rate of participation or any of the associations you found?

We did find it surprising. I think that perhaps some of the literature suggests that the rates of participation should have improved over time. Especially during the years that we had looked at, we might have expected a slightly better participation incidence just based on the policies that have been suggested. For example, in 2000, the Medicare national coverage determination provided coverage for routine care costs in clinical trials and we might have expected that clinical trial enrollment improved since that time. As well, certainly organizations, including NCI, [American Society of Clinical Oncology], and [American Society of Hematology] have all called for improved trial access and greater inclusion. Given these efforts, we may have anticipated higher participation rates, which underscores why contemporary, patient-level data are still needed to understand where gaps in enrollment persist.

How can interventions like navigator programs and decentralized trials facilitate participation in this population?

I think…the solution is unlikely to be one-size-fits-all. The current evidence suggests that a clinical trial navigation program could be helpful in order to align the patients in need of a clinical trial, or seeking to participate in a clinical trial, and being able to navigate to the appropriate centers and…navigate barriers that are preventing them from going on a clinical trial. For example, one effective approach has been Blood Cancer United’s [formerly Leukemia & Lymphoma Society] Clinical Trial Support Center, a free, nurse-led navigation service that helps patients identify trials and navigate barriers like travel and insurance.

I think that the other aspect—decentralized trial designs—are critically important. These models leverage the partnership with community hospitals and treatment centers closer to patients’ home. [Such designs would be] allow sharing some of the logistics of enrollment and follow up with centers that are closer for the patient, so reducing the geographical burden of…clinical trial participation.

I think one important aspect that we wanted to highlight as well is…eligibility criteria. We know that eligibility criteria can be quite variable across trials, and there have been studies to show that if you reduce the eligibility criteria and certain organ function requirements to ensure that only the most relevant are included, that could be another strategy to improve the clinical trial participation rate. We did find that certain comorbidities, specifically pulmonary and renal disease, were associated with lower participation, and there's literature to support that a [slight] loosening [of] the eligibility criteria for those comorbidities could be another evidence-based approach. For example, the FDA’s Project Optimus, which focuses on optimizing dose selection for oncology therapies, has the potential to expand trial access by including older adults and patients with comorbidities.

With these disparities brought to light, are there any efforts you would like to see being made in terms of increasing participation in these trials?

Ultimately, I think…the most important aspect that we need to consider for oncology trials is, if we want the trial population to reflect real-world patients, then we also need to design trials around the individual patients that we're treating and their lives. We need to…think about the fact that the reality is that many patients do have to reorganize their lives around clinical trial participation just because of the number of visits and requirements to participate in trials. This burden is particularly pronounced for patients living far from trial sites—our data showed that patients living 250 miles or more from NCI centers had 36% lower odds of participation.

So, I think we should take a patient-centered approach, or strive to do so, to reduce the barriers—for example, the barriers that we've identified here with regards to social demographics—and providing more support for those patients. [This includes] identifying specific barriers to certain racial demographics and…connect[ing] them with physicians and trial navigators that can provide the necessary education around clinical trials and…connect[ing] with the patient in a more culturally sensitive way.

Then…reduc[ing] the geographical burden [through] decentralized approaches to clinical trial participation. [Finally], considering comorbidities and reducing the strict eligibility criteria in order to expand access.

REFERENCES

1. Gong IY, Soto MJ, Rafinejad‐Farahani B, et al. Disparities in clinical trial participation among older adult Medicare beneficiaries with hematologic malignancies from 2006 to 2019: A SEER–Medicare analysis. Cancer. 2025;131(24). doi:10.1002/cncr.70204