Differences in biomarkers
With regard to underlying molecular differences between Black and White patients, the investigators found that the most common mutations were in NPM1, FLT3-ITD, and DNM3TA. Mutations were detected in more than 20% of Black patients. Other commonly mutated genes were IDH2, NRAS, TET2, IDH1, and TP53, which were mutated in more than 10% of patients. “All of these genes are established commonly mutated genes in AML,” said Bhatnagar.
On univariable and multivariable outcome analyses, which were used to identify clinical or molecular features that had a bearing on outcome, FLT3-ITD and IDH2 mutations were the only mutations associated with a higher risk for death among Black patients.
“This is actually a very important finding, as both FLT3 and IDH2 are now targetable with small-molecule inhibitors,” said Dr. Bhatnagar. “In addition, it is also worth noting that other gene mutations that have known prognostic significance in AML, such as NPM1, as well as RUNX1 and TP53, did not remain in the final statistical model.
“Importantly, our study provides powerful evidence that suggests differences in underlying disease biology between young Black and White AML patients, as evidenced by differences in the frequencies of recurrent gene mutations, “ she said.
Understudied disparities
Although the study showed that Black patients had worse outcomes, “surprisingly, the authors found these outcomes hold even when the patients are participating in clinical trials,” noted Elisa Weiss, PhD, senior vice president of education, services, and health research for the Leukemia and Lymphoma Society.
“The study makes clear that the medical and science community need to do more to better understand the social, economic, environmental, and biological causes of these disparities,” she said in an interview. “In fact, the findings suggest that there are myriad complex and understudied causes of the identified disparities, and they are likely to lie at the intersection of all levels of the social ecology that impact an individual’s ability to access timely and unbiased care, maintain their mental and physical health, and receive needed social support and resources.”
She noted that the Leukemia and Lymphoma Society has an Equity in Access research program that aims to “advance study of underlying causes of inequitable access to care and identify policies, strategies, and interventions that have the potential to reduce inequities and increase access to health care, services, and programs for blood cancer patients and survivors.”
The research was supported in part by the National Cancer Institute of the National Institutes of Health, other institutions, and through several scholar awards. Dr. Bhatnagar has received advisory board honoraria from Novartis, Kite Pharma, Celgene, Astellas, and Cell Therapeutics. Dr. Weiss has disclosed no relevant financial relationships.
A version of this article originally appeared on Medscape.com.