Background: The risk of cancer increases as people age, and yet, participants in oncology clinical trials have historically been younger than those in the general population with the respective tumor type, thus limiting our understanding of the safety and efficacy of trial results in the real world. The US Food and Drug Administration (FDA) has issued guidance on multiple occasions on the inclusion of older adults in clinical trials. We sought to evaluate whether there has been progress in the representativeness of older adults in oncology trials.
Methods: For oncology drug approvals since 2002, we searched for registration trials and collected data on the median age of study participants. We then searched SEER*Explorer to find the median age of the general population with the respective cancer type. We assessed linear trends to see if there were age gaps between the median ages of trial participants and SEER participants, and we assessed differences in time frames when guidance was issued.
Results: The age gap between registration trials and SEER data for all 22 years was 5 years (62 years for registration trials vs. 67 years for SEER). The age gap has declined over time (Beta = -0.22, p = 0.004) but still persists. Between 2002 and 2012, the age gap between registration trials and the SEER population was 7 years (59 vs. 66 years, p < 0.001); between 2013 and 2019, it was 5 years (62 vs. 67 years, p < 0.001); and between 2020 and 2024, the age gap was 4 years (63 vs. 67 years, p < 0.001).
Conclusion: We found that the age gap between registration trial participants and the general population with the respective tumor type has declined over time, but the age-gap persists, despite guidance issued by the FDA. Efforts to include more representative study participants in clinical trials should be intensified, possibly through greater enforcement through regulatory oversight.
Keywords: age gap; oncology; real‐world; registration trials.
© 2025 The American Geriatrics Society.