Racial and Ethnic Disparities in European Breast Cancer Clinical Trials

Simple Summary Breast cancer is known to be associated with the race and ethnicity of patients regarding the tumor characteristics and patient survival. However, in worldwide clinical trials, the participation of Black and Hispanic patients is lower than expected based on the frequency of breast cancer in these populations. This article aims to assess race reporting and representation trends in European trials. Ninety-seven such trials conducted exclusively in Europe between 2010 and 2022 were identified in the PubMed and ClinicalTrials.gov databases. Race was reported in 10.31% of these, and mostly in trials carried out across multiple European countries. They featured a White-predominant population, with 1.08% Asian and 0.88% Black patients included. Race reporting trends in European trials are much lower than in worldwide or American-based trials on the same subject. Systematic race reporting among other patient demographics and adequate minority inclusion will ameliorate the quality of European clinical trials and promote equality in healthcare access.Abstract Breast cancer is the most prevalent female cancer worldwide with known correlations between the race and tumor characteristics of the patients and prognosis. International and US-based studies, however, have reported a disproportionate representation of Black and Hispanic patients in clinical trials. This is the first study assessing race and ethnicity reporting trends and inclusion in European breast cancer trials. The PubMed and ClinicalTrials.gov databases were systematically searched for trials on breast cancer treatment conducted exclusively in Europe between 2010 and 2022. Of the 97 identified trials, race was reported in 10.31%. Multinational participation, but not the study size or trial phase, was significantly associated with higher race reporting trends. These 10 trials featured a White-predominant population, with 1.08% Asian and 0.88% Black patients included. The acquisition of the race and ethnicity data of patients in European trials is lower compared to the U.S. or worldwide studies and does not permit extensive analysis of minority participation. In a limited analysis, the low rates of minority participation are concerning, based on population-based data on minorities in select European countries. These observations should encourage race reporting practices in European breast cancer trials and adequate minority participation to support the generalizability of the results of the studies and promote healthcare equity.