The current status of clinical trials on cancer and age disparities among the most common cancer trial participants

Objective To illustrate the status of all cancer clinical trials and characterize clinical trial enrollment disparities in the most common cancer. Methods Clinical trial data were extracted from ClinicalTrials.gov website. All searched clinical trials were included in the current status analysis of clinical trials on cancer. Among all the clinical trials, only trials addressing single disease sites of breast, prostate, colorectal, or lung (BPCRL) cancer were included in the age disparities analysis. The difference in median age (DMA) between the trial participant median age and the population-based disease-site-specific median age was calculated for each trial. Results A total of 7747 clinical trials were included in the current status analysis of clinical trials on cancer. The number of registered trials had been increasing from 2008 to 2021 (AAPC = 50.60, 95% CI 36.60, 66.00, P < 0.05). Of the 7747 trials, 1.50% (116) of the studies were clinical trials for the elderly aged 60 years or older. 322 trials were included in the age disparities analysis. For all trials, the median DMA was − 8.15 years ( P 25 , P 75 , − 10.83 to − 2.98 years, P < 0.001). The median DMA were − 9.55 years ( P 25 , P 75 , − 11.63 to − 7.11 years), − 7.10 years ( P 25 , P 75 , − 9.80 to − 5.70 years), − 9.75 years ( P 25 , P 75 , − 11.93 to − 7.35 years), 3.50 years ( P 25 , P 75 , 0.60 to 4.55 years), respectively, for breast cancer, colorectal cancer, lung cancer and prostate cancer. Conclusion The numbers of registered clinical trials show an upward trend. Age disparities between trial participants and diagnosed disease population are present in BPCRL cancer trials and appear to be increasing over time. Equitable participation in clinical trials on the basis of age is crucial for advancing medical knowledge and evaluating the safety and efficacy of new treatments that are generalizable to aging populations.