IMPORTANCE Precision oncology is revolutionizing cancer care, allowing for personalized treatments to improve outcomes. Cancer research has benefitted from well-designed studies incorporating precision medicine objectives, but it is unclear if these studies are representative of the diverse cancer population. OBJECTIVETo evaluate racial and ethnic representation in breast, prostate, lung, and colorectal cancer studies incorporating precision oncology objectives in the Clinicaltrials.gov registry and compare with the incidence of these cancer types in racial and ethnic minority groups in the US population. DESIGN, SETTING, AND PARTICIPANTSThis cross-sectional study identified US-based breast, prostate, lung, and colorectal cancer studies incorporating precision oncology objectives for reporting of race and ethnicity. The Surveillance, Epidemiology, and End Results and US Census databases were used to determine cancer incidence by race and ethnicity, linked with cancer type and median year of enrollment for each trial. Data were collected and analyzed between December 2020 and April 2021. MAIN OUTCOMES AND MEASURESThe expected number of participants per study by each racial and ethnic group was calculated based on the corresponding US-based proportion. Under-and overrepresentation was defined as the ratio of the actual number of enrolled cases to the expected number of cases for each trial by cancer type. Ratios above 1 indicated overrepresentation while a ratio below 1 indicated underrepresentation. Random-effects meta-analysis of representation ratios of individual trials was performed to weigh each individual study. RESULTSOf 93 studies encompassing 5867 enrollees with race and ethnicity data; 4826 participants (82.3%) were non-Hispanic White, 587 (10.0%) were Black, and 238 (4.1%) were Asian.Per observed-to-expected ratios, White participants were overrepresented in all studies, with a ratio of 1.35 (95% CI, 1.30-1.37), as well as Asian participants, with a ratio of 1.46 (95% CI, 1.28-1.66), while Black participants (ratio, 0.49; 95% CI, 0.45-0.54), Hispanic participants (ratio, 0.24; 95% CI, 0.20-0.28), and American Indian and Alaskan Native participants (ratio, 0.43; 95% CI, 0.24-0.78) were underrepresented. By individual cancer site, White participants were consistently overrepresented in all studies, while Black and Hispanic participants were underrepresented.CONCLUSIONS AND RELEVANCE This analysis found that precision oncology studies for breast, lung, prostate, and colorectal cancers vastly underrepresent racial and ethnic minority populations relative to their cancer incidence in the US population. It is imperative to increase diversity among enrollees so that all individuals may benefit from cancer research breakthroughs and personalized treatments.

IMPORTANCEThe 2012 US Preventive Services Task Force (USPSTF) Grade D recommendation against prostate-specific antigen (PSA) screening for all men has been controversial, with data documenting a shift to a higher stage of disease at diagnosis. The association between the Grade D recommendation and prostate cancer-specific mortality (PCSM) among contemporary cohorts, however, is unclear.OBJECTIVE To evaluate PCSM rates between 1999 and 2019, comparing trends in rates before and after the change in the 2012 USPSTF screening guideline to assess its association with PCSM. EXPOSUREThe 2012 USPSTF Grade D recommendation against PSA screening for all men.

Biorepositories enable precision oncology research by sharing clinically annotated genomic data, but it remains unknown whether these data registries reflect the true distribution of cancers in racial and ethnic minorities. Our analysis of Project Genomics Evidence Neoplasia Information Exchange (GENIE), a real-world cancer data registry designed to accelerate precision oncology discovery, indicates that minorities do not have sufficient representation, which may impact the validity of studies directly comparing mutational profiles between racial/ethnic groups and limit generalizability of biomarker discoveries to all populations.