A new study published in JAMA Network Open reveals a significant barrier to cancer treatment for individuals of African and Middle Eastern ancestry. Researchers from the Dana-Farber Cancer Institute found that many cancer clinical trials automatically exclude participants based on blood neutrophil levels, which are naturally lower in people with the Duffy null blood group – a common trait among those of African and Middle Eastern descent.
The study, led by Dr. Andrew Hantel, examined 289 Phase III clinical trials for the five most common cancers in the U.S. The results showed that 76.5% of these trials excluded individuals with neutrophil levels typical of the Duffy null phenotype. Colorectal cancer trials had the highest exclusion rate at 86.4%, while prostate cancer trials had the lowest at 47.8%.
Dr. Hantel explained, “People with the Duffy-null phenotype are equally able to fight off infections compared to others.” However, their naturally lower neutrophil counts often fall below the cut-off points for trial participation, despite not indicating an increased risk of infection.
This exclusion has far-reaching consequences. As Dr. Hantel noted, “The treatment guidelines set by the National Comprehensive Cancer Network, or NCCN, are based on the clinical trials in which those drugs were tested.” Consequently, standard therapies may be inappropriately modified for these patients, potentially leading to lower survival rates.
The study’s authors conclude that these practices “structurally discriminate against patients of African and Middle Eastern ancestry.” They advocate for changing the exclusion criteria to allow these individuals access to potentially life-saving cancer clinical trials, while acknowledging the need for further research on appropriate dosing for people with the Duffy null phenotype.
See “Cancer Trials Exclude Individuals of African and Middle Eastern Ancestry Due to Duffy Blood Group” (September 11, 2024)
