Inferior prognosis in poor mobilizing myeloma patients

Introduction: Induction treatment followed by autologous stem cell transplantation (ASCT) has been accepted as the standard treatment for multiple myeloma (MM) patients. Granulocyte colony stimulating agent (G-CSF), chemotherapy or agents likes plerixafor are being used for the mobilization of stem cells from bone marrow. In this study, we evaluated the impact of the mobilization methods on the outcome of MM patients after ASCT. Method: The data of 205MM patients who underwent ASCT at our center between December 2009 and January 2019 were retrospectively analyzed. Patients were divided into 2 groups as good mobilizers (patients who were mobilized with G-CSF alone) and poor mobilizers (patients who were failed to mobilize with G-CSF alone and mobilized with G-CSF + cylophosphomide or G-CSF + plerixafor). Results: The median progression free survival (PFS) was 18.27 +/- 3.22 months in good mobilizers and 14.22 +/- 3.7 months in poor mobilizers. In G-CSF + cyclophosphamide method median PFS was 15.4 +/- 4.9 months wheras it was only 4 months in G-CSF + plerixafor method. We did not find a statistically significant difference between good and poor mobilizers regarding median PFS (p: 0.342). The median overall survival (OS) was found 34.48 +/- 4.2 months in good mobilizers and 15.13 +/- 5.78 months in poor mobilizers. In GCSF+ cyclophosphamide method median OS was 17 +/- 14.01 months wheras it was 10.66 +/- 7.68 months in G-CSF+ plerixafor method. We found a statistically significant difference between good and poor mobilizers regarding median OS (p: 0.007*). Conclusion: Our study shows that difficulty in stem cell mobilization is correlated with worse outcome.