Analysis of Disparities in Time to Allogeneic Transplantation in Adults with Acute Myelogenous Leukemia

Abstract

While alternative donors extend transplant access, whether recipient ancestry impacts the time to allogeneic transplant is not established. We analyzed the likelihood of clinically significant delays to allograft by patient ancestry in 313 transplanted adult acute myelogenous leukemia (AML) patients. Non-European ancestry patients (n = 99) were more likely than Europeans (n = 214) to receive HLA-mismatched donor allografts (45% versus 24%, p < 0.001). Overall, the median time from transplant indication to allograft was 127 days (range 57-1,683). In multivariable analysis, non-Europeans had an increased risk of prolonged indication-transplant time > 180 days (OR 2.1, 95%CI:1.4-5.6, p = 0.012) due to significant delays in indication-consult > 90 days (OR 2.8, 95%CI:1.3-4.5, p = 0.005) and consult-transplant > 120 days (OR 2.4, 95%CI:1.2-3.7, p = 0.005). Compared to recipients of HLA-matched unrelated donors (URD), HLA-mismatched adult donor recipients were at increased risk of delayed indication-transplant whereas matched sibling and cord blood recipients were at lower risk. Sub-analysis showed more indication-transplant delays in non-European versus European 8/8 URD recipients (44% versus 19% > 180 days, p = 0.004). Finally, the pandemic further exacerbated delays for non-Europeans. In summary, while non-European AML patients are less likely to receive 8/8 URDs as expected, if they do their transplants are delayed. HLA-identical siblings and cord blood facilitate the fastest transplants regardless of patient ancestry whereas other adult donor transplants are delayed. Strategies to mitigate referral barriers, hasten donor evaluation, and utilize all alternative donor sources are critical to ensure timely transplantation for AML patients.