ATLANTA — More non-Hispanic whites underwent hematopoietic stem cell transplant for initial therapy for multiple myeloma compared with non-Hispanic blacks, non-Hispanic Asians and Hispanics, according to study results presented at the ASH Annual Meeting and Exposition.
Modifiable factors should be addressed to minimize disparities within racial subgroups, including minorities, the research showed.
“Overall, we know that stem cell transplants are a standard of care for treatment of multiple myeloma patients and, clearly, the transplants have improved patient outcomes significantly,” Sikander Ailawadhi, MD, medical oncologist in the division of hematology-oncology at Mayo Clinic in Jacksonville, Florida, said during his presentation. “We also know there are already racial disparities with respect to survival and outcomes in myeloma, so patients from different racial/ethnic groups will have different outcomes.”
Research on trends has shown that HSCT use has increased for all racial and ethnic groups over time; however, racial minorities remain less likely to undergo the procedure than whites.
Ailawadhi and colleagues sought to identify factors that determine HSCT use within any given racial/ethnic group.
Researchers used the 2016 National Cancer Data Base to identify 111,799 patients diagnosed with multiple myeloma between 2004 and 2013. Of them, 15,021 (13.4%) received HSCT as part of initial therapy, 77.5% of whom were non-Hispanic white, 15.1% non-Hispanic black, 5.2% Hispanic, 2% non-Hispanic Asian and less than 1% were classified as other.
Researchers used multivariate GEE logistic regression analysis to find any association between use of HSCT as part of initial treatment of multiple myeloma and sociodemographic factors.
Results showed a significant reduced likelihood of receiving HSCT for every 10-year increase in age at diagnosis for all racial subgroups (P < .001); no differences occurred by gender.
Non-Hispanic Asians represented the only subgroup who did not have a significant year-wise increase over time in likelihood of receiving HSCT.
HSCT use significantly increased as median income increased among non-Hispanic whites and Hispanics, but not for non-Hispanic blacks and non-Hispanic Asians. Higher education level was associated with a significant increase in HSCT use for non-Hispanic whites and non-Hispanic blacks, but not for Hispanics or non-Hispanic Asians.
An increase in great circle distance from the treatment center (P = .013), as well as a lower Charlson-Deyo comorbidity index, appeared associated with increased likelihood of receiving HSCT for all racial groups.
Insurance payer status impacted likelihood of receiving HSCT among all races. Private insurance appeared associated with greater likelihood of HSCT receipt among non-Hispanic whites (OR = 5.22; 95% CI, 4.08-6.68), non-Hispanic blacks (OR = 5; 95% CI, 3.46-7.25) and Hispanics (OR = 9.51; 95% CI, 4.09-22.11). Other insurance payer types were associated with greater HSCT likelihood among non-Hispanic Asians (OR = 8.74; 95% CI, 1.83-41.62).
Analyses examining treatment center characteristics showed patients of all races appeared likely to receive HSCT if treated at an academic/research facility or centers with highest quartile of patient volume seen (P = .046).
Pertaining to geographical region, non-Hispanic whites and non-Hispanic Asians had the highest likelihood of receiving HSCT in the mountain region, but no impact of geography occurred for non-Hispanic blacks or Hispanics.
“There are disparities that exist even within a racial ethnic subgroup when it comes to stem cell transplant utilization for multiple myeloma,” Ailawadhi said. “We feel there are different factors that play a role for different racial groups. So, interventions should be much more targeted. These differences must be addressed to try and ensure maximum access to transplant and based on that, step towards decreasing any racial disparities.” – by Melinda Stevens
Ailawadhi S, et al. Abstract 860. Presented at: ASH Annual Meeting and Exposition; Dec. 9-12, 2017; Atlanta.
Disclosures: Ailawadhi reports honoraria and consultant roles with Amgen, Novartis and Takeda; as well as research funding from Pharmacyclics. One other author reports research funding from LAM Therapeutics, Inc.