Affiliation:
1. Department of Oncology Queen’s University Kingston Ontario Canada
2. Division of Cancer Care and Epidemiology Queen’s Cancer Research Institute Kingston Ontario Canada
3. School of Population Health Faculty of Medicine and Health University of New South Wales Sydney New South Wales Australia
4. Centre Hospitalier Universitaire de Quebec‐Université Laval Hôpital Saint‐Sacrement Centre des Maladies du Sein Deschênes‐Fabia Quebec Quebec Canada
5. Department of Medical Oncology and Haematology Princess Margaret Hospital University of Toronto Toronto Ontario Canada
Abstract
AbstractBackgroundOver one half of cancer diagnoses occur in patients aged 65 and older. The authors quantified how treatment effects differ between older and younger patients in oncology registration trials.MethodsThe authors performed a retrospective cohort study of registration trials supporting US Food and Drug Administration approval of cancer drugs (from January 2010 to December 2021). The primary outcome was differential treatment effect by age (younger than 65 years vs. 65 years or older) for progression‐free survival and overall survival. Random effects meta‐analysis and a pairwise comparison of outcomes by age group also were performed.ResultsAmong 263 trials that met the inclusion criteria, 120 trials with 153 end points and 83,152 patients presented age‐specific outcome data. Among the included randomized patients, 38% were aged 65 years and older compared with an incidence proportion of 55% in data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program. Studies evaluating prostate cancer had the highest representation of patients aged 65 years or older (73%), whereas breast cancer studies had the lowest (20%). There were no changes in the proportion of patients aged 65 years or older over time (p = .86). Only 7% of end points showed a statistically significant interaction between outcome and age group. In a pooled analysis, there was an association between treatment effect and age for progression‐free survival that approached but did not meet significance (hazard ratio, 0.95; p = .06), and there was no difference for overall survival (hazard ratio, 0.97; p = .79).ConclusionsOlder adults remain under‐represented in oncology registration trials. Significant differences in outcomes by age group were uncommon in individual trials and pooled analyses. However, clinical trial participants differ from real‐world patients older than 65 years, and increased enrollment and ongoing research into differential treatment effects by age are needed.