The stem cell transplantation utilization rate in the United States increased from 2008 to 2014, but was lower among Hispanics and non-Hispanic blacks compared with non-Hispanics whites.
The stem cell transplantation utilization rate (STUR) in the United States increased from 2008 to 2014, but was lower among Hispanics and non-Hispanic blacks compared with non-Hispanics whites, according to data from a study published recently in Cancer. Despite this difference in utilization, race/ethnicity did not affect transplantation outcomes.
“With clear data demonstrating no differences in outcomes and a clear difference in transplantation utilization by ethnic groups, it is crucial that we now perform additional studies to understand why a disproportionate number of black and Hispanic patients fail to undergo transplantation for multiple myeloma,” wrote researcher Jeffrey R. Schriber, MD, of the Cancer Transplant Institute, Virginia Piper Cancer Center, Scottsdale, Arizona, and colleagues. “It is also important that race and ethnicity should be clearly delineated as factors that do not impact outcomes in terms of proceeding to transplantation.”
Undergoing upfront hematopoietic stem cell transplantation is an important part of the treatment of patients with newly diagnosed multiple myeloma; however, studies suggest that only about one-third of patients with myeloma undergo transplantation. With this study, Schriber and colleagues wanted to explore possible barriers to transplantation among these patients, and outcomes based on race/ethnicity.
Using the Center for International Blood and Marrow Transplant Research database, the researchers identified 28,450 patients who received transplant for myeloma between 2008 and 2014. They then calculated the incidence of myeloma using data from SEER 18 registries, and taken together, these data gave them the STUR.
Among the included patients there were 18,046 non-Hispanic whites, 4,123 non-Hispanic blacks, and 1,933 Hispanic patients. The overall STUR estimate was 19.1% in 2008 and increased to 30.8% in 2014. The STUR increased across all groups during the study period; however, the increase was substantially lower among Hispanics and non-Hispanic blacks compared with non-Hispanic whites.
“Despite an almost doubling of the STUR from 8.6% to 16.9% among Hispanics and a 70% increase in the STUR among blacks from 12.2% to 20.5%, the rate remained substantially lower than that among non-Hispanic whites, for whom it rose from 22.6% to 37.8%,” the researchers wrote.
The group of Hispanic patients in the study was significantly younger (P < .001). The researchers also found that fewer patients older than 60 years of age underwent transplantation who were Hispanic (39%) or non-Hispanic black (42%) compared with non-Hispanic whites (56%).
“This is particularly poignant in patients with multiple myeloma, because the median age at diagnosis of multiple myeloma is 69 years,” the researchers wrote. “This finding may also account in part for some differences in the STUR across race/ethnicities.”
More Hispanic patients (57%) were diagnosed with stage III disease compared with non-Hispanic blacks (54%) and non-Hispanic whites (52%; P < .001).
The researchers observed no difference in post-transplantation outcomes between the different racial/ethnic groups for transplantation-related mortality, progression-free survival, or overall survival. A multivariate analysis showed that race/ethnicity had no influence on survival.
“Further education on early referral to transplantation centers for all populations is critical, and efforts should be made to expand community outreach across racial and ethnic groups,” the researchers wrote.