Worldwide Efforts Needed to Close Regional HSCT Utilization Gap Worldwide Efforts Needed to Close Regional HSCT Utilization Gap

NEW ORLEANS — Although acute myeloid leukemia is on the rise worldwide, and the use of hematopoietic stem cell transplants (HSCT) as a treatment has increased overall, in some countries fewer than 5% of patients are offered this option.

The use of HSCT, the main curative option for AML, “remains unacceptably low,” commented Molly Tokaz, MD, a hematology/oncology fellow at the Fred Hutchinson Cancer Center, Seattle, Washington.

She was presenting the findings from a study of worldwide HSCT utilization here at the American Society of Hematology annual meeting.

Globally, the incidence of AML has increased 16.2% from 101,867 cases in 2009 to 118,404 in 2016, she noted. This in turn has led to a 54.9% increase in the worldwide use of HSCT for AML, from 9659 to 14,965 transplants per year over the same period.

North America and Europe have the highest utilization rates of allogeneic HSCT for AML, but even so fewer than 40% of patients have the procedure, raising a “question of how [well] we are prioritizing the use of HSCT even in these resource-abundant health systems,” Tokaz said.

Meanwhile, in Africa, South America, and the Eastern Mediterranean, fewer than 5% of AML patients undergo transplant. Although “resource-constrained regions have the largest growth in HSCT use” in recent years, utilization rates remain abysmally low, “which has profound effects on the expected outcomes for patients in these regions,” she said.

Overall, “patients from lower- and middle-income countries face substantial barriers to accessing stem cell transplantation for AML,” commented Chancellor Donald, MD, a hematologist/oncologist at Tulane University, New Orleans, who moderated the session.

The “stark regional differences” illustrate “inequities in the delivery of stem cell transplants” but also opportunities “to improve access to this potentially curative treatment,” he said.

The goal of the study was to establish a global baseline of HSCT utilization to help focus future expansion efforts aimed at closing regional access gaps. It shows there is much work to be done, Tokaz said.

An international effort is needed to address the issue, including better data collection, implementation of regional HSCT programs, increased representation of ethnic and racial minorities in international donor registries, and other measures. In many cases, telemedicine can help with sharing cross-border expertise.

In short, what’s needed is a “comprehensive global effort to improve outcomes for patients with AML” worldwide, Tokaz said.

Timing of transplant is similar across regions, generally coming during the first complete remission, and there’s also been a global shift toward collecting stem cells from peripheral blood.

There has also been a marked shift away from autologous procedures and toward allogeneic transplants, she said.

A key difference between regions, however, is that whereas over half of transplants are from unrelated donors in Europe and North America, almost all are from related donors in Africa and the Eastern Mediterranean, with an increasing proportion of haploidentical donors. In addition, the majority of transplants in Asia, the western Pacific, and South America are from related donors.

The use of related donors has implications for HSCT treatment algorithms and outcomes, Tokaz said.

The estimates of AML incidence were obtained from the 2019 Global Burden of Disease study. Data on HSCT utilization came from the Worldwide Network for Blood and Marrow Transplantation. No funding source was reported. Tokaz reports no relevant financial relationships, but some co-authors had  numerous industry ties. Donald reported no relevant financial relationships.

American Society of Hematology 2022 Annual Meeting: Abstract 3638 Presented December 7, 2022.

M. Alexander Otto is a physician assistant with a master’s degree in medical science and a journalism degree from Newhouse. He is an award-winning medical journalist who worked for several major news outlets before joining Medscape. Alex is also an MIT Knight Science Journalism fellow. Email: aotto@mdedge.com

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