The impact of race on outcome of autologous transplantation in patients with multiple myeloma

Abstract

17029 Background: Multiple myeloma (MM) is the most common hematologic malignancy in African-Americans (AA), with historically double the mortality of Caucasians (C). Monoclonal gammopathy of undetermined significance (MGUS) is also three times more frequent in AA than C. There has been limited data exploring racial differences in survival during the era of high dose chemotherapy with autologous stem cell transplantation (ASCT). Methods: We retrospectively analyzed the records of all C (n=55) and AA (n=36) MM patients who underwent ASCT over 10 years. Presenting demographic, clinical features and response to therapy by the Bladé criteria were obtained from medical records. Progression-free survival (PFS) and overall survival (OS) were analyzed by Kaplan-Meier method, and compared using the log-rank test. Results: The median age at diagnosis for AA was 52 years (30–75 years), compared to C at 56 years (39–79 years), p=0.006. There was no statistical difference in presenting ISS stage (AA: I- 50%, II- 28.1%, III- 21.9%; C: I- 51.2%, II- 20.9%, III- 27.9%), or values for presenting hemoglobin, calcium, and creatinine. There was a trend for increased skeletal involvement at diagnosis in the C group (82% vs. 69%, p=0.08). AA presented with an increased CRP (1.2 mg/dl vs. 0.25mg/dl, p=0.05). The most commonly used induction and conditioning regimen was VAD (78% AA vs. 70% C), and Mel 200 (72% AA vs. 65% C), respectively. Response to induction: CR: AA- 6%, C- 5%, p=1.00; PR: AA- 64%, C- 56%, p=0.519. Response to ASCT: CR: AA- 17%, C- 26%, p=0.438; PR: AA- 56%, C- 46%, p=0.519. At a median follow-up of 46.7 months, PFS was 60.5 months and 43.7 months (p=0.490), for AA and C, respectively; OS was 95.2 months and 68.5 months (p=0.421), for AA and C, respectively. Conclusion: In this series, AA with MM present at a younger age, with an increased CRP and a trend for less skeletal involvement than C at diagnosis. Despite a trend for less CR rates in AA, there was a trend for increased PFS and OS compared to C. This suggests there are biologic differences in MM between the races that may result in different therapeutic outcomes. One possible explanation would be the known higher frequency of MGUS in AA resulting in a reversion to a stable, indolent MGUS-like state after ASCT. These findings should be confirmed in larger studies. No significant financial relationships to disclose.