Table.

Trial Factors Associated With Age Disparities

Trial Factor	No. of Trials	Mean DMA (SE), years	P Value
All included trials	302	‒6.49(0.34)	<.001a
Industry funding of trial
Yes	249	‒6.84(0.38)	.002
No	53	‒4.72 (0.79)
Cooperative group trial
Yes	74	‒6.24(0.73)	.34
No	228	‒6.57(0.39)
Age restriction enrollment criterionb
Yes	26	‒10.20(1.46)	.001
No	276	‒5.71(0.34)
ECOG PS restriction criterion
Yes (restricted to PS 0–1)	117	‒7.40(0.42)	.01
No (not restricted to PS 0–1)	103	‒5.35(0.66)
Molecular profile restriction criterionc
Yes	45	‒9.99(0.60)	<.001
No	257	‒5.88 (0.38)
Disease site
Breast	107	‒7.76(0.52)	.001
Colorectal	36	‒6.96(0.57)
Lung	105	‒8.98(0.35)
Prostate	54	2.66(0.48)
Modality
Systemic therapy	247	‒6.89(0.38)	.04
Radiotherapy	7	‒3.64(1.88)
Surgery	2	‒12.10(11.10)
Supportive care	45	‒4.76(0.83)
Systemic therapy subgroup
Cytotoxic chemotherapy	85	‒5.30(0.78)	.01
Targeted therapy	162	‒7.72(0.39)
Trial success (PEP met)
Yes	130	‒6.40(0.58)	.73
No	120	‒6.67 (0.49)

Abbreviations: DMA, difference in median age (trial minus population); ECOG, Eastern Cooperative Oncology Group; PEP, primary end point; PS, performance status.

^aFor all included trials (N = 302), the P value provided represents the results of a 1-sample t test comparing the mean DMA for all trials against a hypothetical population average DMA of 0. All other P values provided reflect Mann-Whitney U tests or Kruskal-Wallis tests for each trial factor listed.

^bTrials that included a restriction on the upper limit of enrollees were classified as having an “age restriction” enrollment criterion.

^c“Molecular Profile Restriction” trials were those that included an enrollment criterion that selected for younger patients based on the molecular profile of patients’ tumors; this included trials specifically for patients with triple-negative breast cancer, HER2-overexpressing breast cancer, ALK-rearranged non–small-cell lung cancer, or EGFR-mutant non–small-cell lung cancer, all molecular subtypes of each disease site associated with a younger patient population. Modality addressed the primary intervention as part of the randomization in the trial. Systemic therapy modality trials included those testing chemotherapy, targeted systemic agents, immunotherapy, and others; these trials all used systemic therapies to improve disease-related outcomes such as overall and disease-free survival. Supportive care trials included those where the intervention aimed to decrease or prevent disease-related or treatment-related toxicity as the primary end point (rather than survival/disease-control outcomes as discussed previously). Systemic therapy trials were further subdivided into cytotoxic chemotherapy and targeted therapy; the latter includes monoclonal antibodies, small molecule inhibitors, and similar agents. Fifty-two trials were excluded from analysis of trial success (whether the PEP was met) because the primary end point had not been published for these trials at time of analysis.