|The following article features coverage from the American Society of Hematology 2020 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
Black race was an independent predictor of death among patients with acute myeloid leukemia (AML), according to the results of an analysis of both the Surveillance Epidemiology End Results (SEER) Program and the Cancer and Leukemia Group B (CALGB)/Alliance for Clinical Trials in Oncology (Allliance) protocols, which were presented during the virtual 62nd American Society of Hematology (ASH) Annual Meeting and Exposition.
Previous studies have indicated that Black patients with AML have higher mortality rates compared with White patients.
“Gene mutation frequencies and [their] associated prognostic impact, which might be indicative of differences in AML tumor biology, have not been assessed in any large study that could potentially provide an explanation for the survival disparity as well,” Bhavana Bhatnagar, DO, of The Ohio State University, and presenter of the study, said during an ASH press briefing. The aim of this study was to determine if racial disparities in AML survival remain, and to assess if any cytogenetic or mutational differences between Black and White patients may contribute to any disparities.
The study evaluated data from 11,190 adults in the SEER program diagnosed with AML between 1986 and 2015. The molecular features of 1339 patients with AML treated in Alliance clinical trials with standard intensity cytarabine/anthracycline induction and consolidation between 1986 and 2015 was also analyzed.
In the SEER registry, there was a significantly greater risk for death among Black patients compared with White patients (hazard ratio [HR], 1.28). The 3-year overall survival (OS) was 32% among Black patients compared with 41% among White patients (P <.001).
“The survival disparity between Black and White AML patients has actually widened over the past 3 decades,” Dr Bhatnagar said.
Given that enrollment in a clinical trial better controls for similar treatment selection, a similar analysis was performed using the Alliance data to determine if access to care improved outcomes.
Rates of complete response (CR), relapse, and early death were similar between Black and White patients. However, Black patients — particularly those who were younger (younger than 60 years) — experienced shorter disease-free survival at a median of 0.8 years compared with 1.4 years among White patients (P =.02). This disparity was also present in older patients, but more marginal, whereas it was striking among younger patients. Median OS was also shorter for Black patients, at 1.2 years compared with 1.8 years among White patients (P =.02).
“We were very surprised to find that clinical trial enrollment did not alleviate survival disparities for young Black AML patients. Something happens between the time that these patients achieve remission and the time that they pass away,” Dr Bhatnagar said.
In the Alliance cohort, Black patients were less likely to have normal cytogenetics (P =.01), which was in contrast to previous, less modern studies, Dr Bhatnagar said. AML among Black participants was also less likely to harbor the favorable prognostic NP1 mutations (P =.04), but was more likely to have IDH2 mutations (P =.03), compared with White study participants.
Among patients whose disease had FLT3-ITD or IDH2 mutations, which are typically prognostically favorable, the survival disparity persisted. Black patients had shorter OS compared with White patients when FLT3-ITD was present (HR, 1.95; P =.03) or when IDH2 mutations were present (HR, 2.17; P =.008). This is actually a very important finding, as both FLT3 and IDH2 are now targetable with small-molecule inhibitors.
In a multivariate analysis, Black race was an independent predictor of poor OS among younger patients.
Dr Bhatnagar concluded by stating, “We were able to confirm the impact of socioeconomic factors, while also demonstrating that being Black in and of itself is prognostic for poor overall survival. In summary, our study demonstrates the delicate interplay between the variety of factors that influence survival disparities, particularly for younger Black AML patients,” Dr Bhatnagar said.
When asked by an attendee of the virtual meeting whether the study attempted to assess the impact of structural racism on disease outcomes, Dr Bhatnagar replied that their study supported the notion that structural racism was a factor, but that it did not examine this aspect directly — and that skilled social scientists would likely need to be involved to design a study that specifically investigated the role of these structural inequities.
Read more of Cancer Therapy Advisor‘s coverage of the ASH 2020 meeting by visiting the conference page.
Bhatnagar B, Zhao Q, Fisher JL, et al. Poor treatment outcomes of young (<60 years) African American patients (pts) diagnosed with acute myeloid leukemia (AML) (Alliance). Presented at: 62nd ASH Annual Meeting and Exposition; December 5-9, 2020. Abstract 6.