Impact of Race on Progression-Free Survival and Overall Survival in Patients with Multiple Myeloma

Background: Multiple myeloma (MM) is a disorder of plasma cells. Management typically includes induction therapy, autologous stem-cell transplantation (ASCT) and maintenance therapy. Despite significant progress in treatment modalities and improved survival and response rates in patients diagnosed with MM, it remains an incurable disease with a poor outcome, especially in high-risk groups. Black patients have been shown to have a higher incidence of MM than white patients. Multiple studies have been done to examine racial disparities among white and black patients, specifically in overall survival (OS) and progression free survival (PFS). However, data has been overall inconclusive with some studies suggesting there is a difference in survival based on race, while other studies suggesting the opposite. Thus, racial disparities among white and black patients' needs to be further investigated. In our retrospective chart review we reviewed all adult patients with advanced MM within Henry Ford Cancer Institute in the last 10 years to determine the impact of maintenance therapy on PFS and overall survival OS.

Methods: We conducted a retrospective chart review of adult patients with MM who underwent autologous stem cell transplantation (ASCT) between January 1, 2012 to December 31, 2022. Those who received maintenance chemotherapy after transplant were included in the study. Patients who were lost to follow-up or who had largely incomplete records were excluded. Data points including age, gender, race, date of transplant, maintenance chemotherapy regimen, last follow-up, and date of death (if applicable) were recorded. Kaplan-Meier plots were used to illustrate overall survival and time to relapse between various races. Statistical significance was set at p<0.05.

Results: There were 158 patients included in the study. Of the 158 patients, 82 (51.9%) were male, and 76 (48.1%) were female. The average age of patients included was 61.66 + 9.30 years, spanning from 32 to 78 years old. There were 71 (44.9%) White patients, 76 (48.1%) Black patients, and 11 (7.0%) patients that were of another race. There was no statistical significance in PFS and OS between Black, White and Other race categories.

Conclusions: We did not see a difference in outcome based on race and believe all patients would derive equal benefit from maintenance therapy. Further prospective studies are warranted to examine racial disparities in patients with multiple myeloma.