Despite the fact that black men face higher rates of prostate cancer and are more at risk of dying from the disease, they are underrepresented in clinical trials. BWH investigators recently identified a potential barrier that may be disproportionately preventing black patients from enrolling in these trials: lab test results.
Clinical trials can offer patients access to cutting-edge treatments with the potential to extend their survival and shape the future standard of care. As of last year, more than 400 prostate cancer clinical trials were being conducted to find interventions for patients. BWH investigators found that nearly half of these studies used laboratory values that varied by race, disproportionately excluding black men. Their results are published in JAMA Oncology.
“Something as simple as a lab-value exclusion criteria may serve as yet another barrier to allowing African-American patients to take part in randomized trials,” said corresponding author Paul Nguyen, MD, of the Department of Radiation Oncology. “We hope that this message will reach researchers who are designing clinical trials and setting entry criteria: We need to be cognizant that the criteria we choose may inadvertently make it harder for African-American patients to participate.”
Lead author Marie Vastola, a research assistant in Radiation Oncology, and her colleagues examined prostate cancer trials collected from clinicaltrials.gov. Specifically, they investigated the use of two components measured in blood tests – serum creatinine (sCr) and absolute neutrophil count (ANC) – to determine a patient’s eligibility for the trial.
sCr is used as a measurement of kidney function, but average levels vary by race. Black patients tend to have higher sCr concentrations than white patients or patients of other races or ethnicities. ANC is measured to determine the health of a patient’s immune system. However, up to 8 percent of black patients may have benign ethnic neutropenia, a condition that decreases ANC levels but does not affect the immune system. Without adjusting for race, both measurements may disproportionately disqualify black patients from a clinical trial.
The team found that 47.9 percent of clinical trials used either sCr alone and/or required an ANC level that would exclude patients with benign ethnic neutropenia – two criteria that resulted in disproportionately excluding black patients from prostate cancer trials.
“Adjusting for race-based differences in clinical trial eligibility criteria may add slight logistical challenges, but these adjustments could prevent qualifying individuals from being excluded from trials solely because of laboratory differences caused by their race,” said Vastola.