Study Finds Non-Hispanic African American Patients Have Worse allo-, autoHCT Outcomes

According to study results published in Blood Advances, survival outcomes following treatment with autologous hematopoietic cell transplant (autoHCT) and allogeneic hematopoietic transplant (alloHCT) have improved over time across different racial groups. However, non-Hispanic African American (NHAA) patients continue to have worse outcomes.¹

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AutoHCT uses a patient’s own stem cells to restore the body’s ability to make normal blood cells following high doses of chemotherapy, whereas alloHCT can potentially cure patients with life-threatening blood cancers, sometimes using stem cells from a donor. The study authors note that although prior research has demonstrated improvements in post-transplant outcomes, the conducted studies were either small or did not have strong enough data covering patients of different races.¹

“This is certainly the largest study to look at the state of the science in terms of use of transplants by racial/ethnic minorities, involving over 145,000 transplants over a 10-year period. We wanted to see if improvements translated proportionally for all patients,” said lead study author Nandita Khera, MD, MPH, professor of medicine in the Division of Hematology/Oncology at Mayo Clinic in Phoenix, AZ, in a press release.¹

The observational study included data from 79,904 patients who received autoHCT and 65,662 who received alloHCT and were in 1 of 4 racial groups: non-Hispanic White (NHW), NHAA, and Hispanic patients across 5 2-year cohorts from 2009 and 2018. Overall survival (OS) following transplant was examined as well as the volume and rates of change of HCT over time, with rates of change being compared using the Poisson model.²

The study results demonstrated that, although OS improved following both autoHCT and alloHCT over time for all 4 racial groups, both NHAA adults and children undergoing alloHCT had an approximate 13% (HR 1.13; 95% CI 1.04-1.22; p = 0.004) and 62% (HR 1.62; 95% CI 1.3-2.03; p < 0.001) increased risk of death, respectively, compared to their NHW counterparts. Even after adjustments for known risk factors—including age, treatments received, disease status, and donor type—NHAA patients still had worse outcomes. Additionally, the rate of change for the use of autoHCT and alloHCT was shown to be higher in the enrolled NHAA and Hispanic populations compared with the NHW population.^1,2

“Overall, we saw that the volume of transplants and survival increased for everyone, but not at the same rate…This suggests the need to better understand the reasons for these disparities through qualitative studies exploring the impact of social determinants of health on outcomes,” said Khera in the press release.¹

The study authors also noted that positive trends in survival outcomes for Hispanic patients were noticeable, with trends being as good as NHW patients. The authors acknowledge that, outside of the study, improvements in transplant volume is potentially because of greater awareness of alloHCT and autoHCT, better access to alloHCT donors, and policy changes resulting from the expansion of Medicaid and the Affordable Care Act.¹

Further, the authors emphasize that there are limitations to the study, including the lack of Asian or mixed-race populations. Additionally, the study only captured patients who are coming out of transplant and did not include those who never gained access to it. According to the authors, another study to examine the true use of alloHCT and autoHCT is currently ongoing.^1,2

“This study helps justify efforts for continued investments in research, training, practice, and community engagement to address the disparities in access and outcomes of these highly expensive and complex medical technologies so that everyone can enjoy the benefits of scientific progress equally,” said Khera in the press release.¹

References

1. American Society of Hematology. Stem Cell Transplants and Survival Rates on the Rise Across All Racial and Ethnic Groups. News release. April 25, 2024. Accessed April 30, 2024. https://www.hematology.org/newsroom/press-releases/2024/stem-cell-transplants-and-survival-rates-on-the-rise-across-all-racial-and-ethnic-groups#:~:text=Survival%20after%20both%20autologous%20hematopoietic,results%20published%20in%20Blood%20Advances

2. Khera N, Ailawadhi S, Brazauskas R, et al. Trends in Volumes and Survival After Hematopoietic Cell Transplantation in Racial/Ethnic Minorities. Blood Adv. Published online April 25, 2024. doi:10.1182/bloodadvances.2023012469