Race and Medicine

Race and Medicine

Disclosures: Hadidi reports no relevant financial disclosures. Please see the study for all other author’s relevant financial disclosures.
June 23, 2020
2 min read

African Americans underrepresented in cancer trials that led to FDA approvals

Disclosures: Hadidi reports no relevant financial disclosures. Please see the study for all other author’s relevant financial disclosures.
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African Americans have been routinely underrepresented in clinical trials supporting FDA approval of drugs for all types of cancer, according to results of a retrospective study published in Annals of Internal Medicine.

Further research is needed to better understand the discrepancies in trial participation and how to address their consequences, researchers noted.

Samer Al Hadidi, MD, MS

“Some barriers are related to socioeconomic factors, [whereas] others are related to distrust of the medical system based on a previous history of research misconduct related to African American persons,” Samer Al Hadidi, MD, MS, clinical researcher in the section of hematology and oncology at Baylor College of Medicine, told Healio. “Some previous studies have also indicated that researchers may not offer clinical trials based on bias that African American persons may be less compliant with research protocols and studies.”

African Americans have the highest death rates of any racial or ethnic group in the United States for most types of cancer.

Lack of trial participation among the African American community has been attributed to a lack of information about trials and concern about trial conditions, an aversion to the randomization required for participation, suspicion of health care providers’ attitudes, and distrust of medical research related to historical events, including the Tuskegee study.

Hadidi and colleagues sought to evaluate whether these factors had an impact on participation of African Americans in trials that supported 75 new oncologic drug approvals between 2014 and 2018.

Researchers calculated participation-to-prevalence ratios (PPRs) by dividing the percentage of African Americans among trial participants by the percentage of African Americans among individuals with disease. A PPR of 1 indicated identical representation of African Americans in the trial and disease populations, and PPRs between 0.8 and 1.2 indicated similar representation, according to the researchers.

Results showed that among 61,763 patients enrolled in the pivotal trials, 7.44% were African American, which equated to a PPR of just 0.31 for this population for all cancer types combined.

Researchers observed consistent underrepresentation of African Americans in these trials across major disease subtypes, including breast cancer (PPR = 0.29), prostate cancer (PPR = 0.18), lung cancer (PPR = 0.15) and hematologic cancers (PPR = 0.12).

“Drug approvals are based on clinical trials that primarily enroll whites and their results are directly applied to African Americans and other minorities,” Hadidi told Healio. “In retrospect, when we start using the drugs to treat patients, we may see that African Americans either respond less or more to the drug.


“The ideal way of [conducting trials in the future] is to enroll minorities with the same prevalence they have in the community,” Hadidi added. “This may be done by asking each clinical trial to enroll specific number of African Americans or other minorities, so the results of such trials that result in a subsequent drug approval will be a real reflection of the activity of the drug in the community.”

For more information:

Samer Al Hadidi, MD, MS, can be reached at hadidi@bcm.edu.