Eligibility Requirements Exclude Black Patients From Prostate Cancer Clinical Trials

Black patients with prostate cancer are underrepresented in clinical trials due to eligibility requirements that exclude patients with benign ethnic neutropenia, according to a new study published in JAMA Oncology.

Researchers studied the potential barriers of entry into prostate cancer clinical trials for black patients, a community that experiences higher incidence and mortality than any other community. A list of trials was collected from ClinicalTrials.gov based on their characteristics, such as sponsor type, phase, accrual goal, start year, and toxicity. The authors sought out interventional studies on prostate cancer that measured the overall survival of patients after drug treatment.

It was assumed that measuring the use of serum creatinine (sCr) for renal function could exclude black men, who have higher sCr for any given renal function. The use of an absolute neutrophil count (ANC) threshold could also exclude 6.7% to 8% of black patients with benign ethnic neutropenia despite healthy immune systems.

A total of 401 interventional prostate cancer clinical trials were included in the study. Almost 48% of the trials used sCr alone and/or ANC thresholds as requirements for patients to participate. These requirements that determined eligibility were more common in trials that were sponsored by academic investigators or cooperatives groups, were phase 1 or 2, had lower accrual, and incorporated at least one treatment considered to be high toxicity.

The authors concluded that 41.4% of prostate cancer clinical trials excluded patients with benign ethnic neutropenia, a condition that effects almost always black men and has been proven to have no increased risk of infection in the patient. An approach to fix this is by lowering the ANC cutoff to allow more black participants in clinical trials.

It was also noted that 25.2% of trials used sCr alone to measure eligibility for clinical trials, despite black patients inherently having higher sCr levels. A race-adjusted equation would take into account insignificant racial differences.

“While adopting race-based differences in trial criteria may add slight logistical challenges when ensuring that patients meet trial eligibility, these adjustments would prevent healthy individuals from being excluded solely because of benign laboratory differences caused by their race,” the authors said.

References

Vastola ME, Yang DD, Muralidhar V, et al. Laboratory eligibility criteria as potential barriers to participation by black men in prostate cancer clinical trials. JAMA Oncol. Published online February 08, 2018. Accessed February 9, 2018. doi:10.1001/jamaoncol.2017.4658