Abstract
73 Background: Eligibility criteria may disproportionately affect black patients and contribute to their underrepresentation in clinical trials. We studied this potential barrier by examining clinical trials in prostate cancer, a disease in which black men face higher incidence and mortality. Specifically, we investigated the use of serum creatinine (sCr) alone instead of race-adjusted measurements for renal function, and the use of an absolute neutrophil count (ANC) threshold that could exclude men with benign ethnic neutropenia, which afflicts 6.7-8% of black patients and could lead to the exclusion of patients despite having healthy immune systems. Methods: We identified 401 interventional prostate cancer clinical trials with an overall survival endpoint. The list of trials was collected on January 16, 2017 from clinicaltrials.gov using the following criteria – study type: interventional studies; conditions: prostate cancer; interventions: drug; outcome measures: overall survival. Characteristics gathered from each trial included sponsor type, phase, accrual goal, start year, and toxicity. Results: Overall, 47.9% (192) of these trials used either sCr alone and/or required participants to have ANC ≥1.5×109 cells/L. Specifically, 25.2% (101) of the trials used sCr alone to determine eligibility, and 41.4% (166) of the trials required patients to have an ANC ≥1.5×109 cells/L. Conclusions: Of clinical trials in prostate cancer, 47.9% used criteria that disproportionately excluded black patients. The reevaluation of these two eligibility criteria could improve minority trial enrollment. First, lowering the ANC cutoff for patients with benign ethnic neutropenia would increase the number of eligible black participants, as 89% of these patients have an ANC ≥1.0×109 cells/L. Second, using race-adjusted equations for renal function would take into account racial differences in creatinine. While adopting race-based differences in trial criteria may add slight logistical challenges when ensuring patients meet trial eligibility, these adjustments would prevent healthy patients from being excluded solely because of benign laboratory differences caused by their race.
