Age Disparities Among Patients in Cancer Clinical Trials and Patients With Cancer in the General Population
In a study reported in JAMA Oncology, Ludmir et al found that the median age of patients with common cancers enrolled in clinical trials was substantially lower than the median age of patients with the same cancers in the general population. Age disparity was greater in industry-funded trials.
Study Details
The study involved data from 302 phase III multiarm randomized clinical trials in breast (107 trials), prostate (54 trials), colorectal (36 trials), and lung cancer (105 trials) identified through ClinicalTrials.gov. Of these, 249 trials (82.5%) were industry-funded. The trials included a total of 262,354 patients. The difference in median age between the trial participant median age and the population-based disease site–specific median age was determined for each trial. Population-based median age for each disease site was determined from Surveillance, Epidemiology, and End Results (SEER) data matched to time of trial enrollment.
Key Findings
For all trials, the median age of trial participants was a mean of 6.49 years younger than the population median age (P < .001).
Mean difference in median age was greater among industry-funded trials vs non–industry-funded trials (-6.84 vs -4.72 years (P = .002). There was no difference between industry-funded and non–industry-funded trials with regard to percentage with age (8.4% vs 9.4%, P = .75) or performance status restriction (53.5% vs 50.0%, P = .70).
There was no difference in difference in median age for cooperative group vs non–cooperative group trials (-6.24 vs -6.57 years, P = .34).
Among all trials, difference in median age was larger in trials with enrollment criteria restricting upper age vs those without such restriction (-10.20 vs -5.71 years, P = .001) or restricting patients to Eastern Cooperative Oncology Group performance status of 0 or 1 vs those without such restriction (-7.40 vs -5.35 years, P = .01).
Difference in median age was greater among trials of targeted systemic therapy vs cytotoxic chemotherapy (-7.72 vs -5.30 years, P = .01), and was greater in industry-funded targeted therapy trials (-7.94 vs -4.33 years, P = .01).
Difference in median age was greatest in lung cancer trials: -8.98 years. In breast cancer trials, it was -7.76 years, -6.96 years in colorectal cancer trials, and +2.66 years in prostate cancer trials (overall P = .001).
Difference in median age was greater in trials with vs without molecular profile restriction criteria (-9.99 vs -5.88 years, P < .001); restricted trials were more likely to be industry-funded vs unrestricted trials (93.3% vs 81.2%, P = .045).
Linear regression modeling indicated an increasing difference between trial and population median ages over time, with an estimated rate of -0.19 years annually (P = .04).
The investigators concluded, “Age disparities between trial participants and the incident disease population are pervasive across trials and appear to be increasing over time. Industry sponsorship of trials is associated with heightened age imbalances among trial participants. With an increasing role of industry funding among cancer trials, efforts to understand and address age disparities are necessary to ensure generalizability of trial results as well as equity in trial access.”
C. David Fuller, MD, PhD, of The University of Texas MD Anderson Cancer Center, is the corresponding author for the JAMA Oncology article.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
