Outcomes of Non-Cryopreserved Versus Cryopreserved Peripheral Blood Stem Cells for Autologous Stem Cell Transplantation in Multiple Myeloma.

BACKGROUND Autologous stem cell transplantation (ASCT) has become a standard procedure in multiple myeloma (MM) patients. Cryopreservation (CRYO) of stem cells may be associated with adverse reactions of dimethyl sulfoxide. Previous studies showed that stem cell storage at 4°C (non-cryopreserved [NC] method) may have some advantages. This analysis focused on comparing the transplant-related outcomes of the 2 preservation methods. MATERIAL AND METHODS This was a cohort study of consecutive MM patients who underwent ASCT at Chiang Mai University from 2014 to 2019. Primary outcomes were time to neutrophil and platelet engraftment. Key secondary outcomes were the incidence of infusion reactions, duration of hospitalization, cost, and survival. RESULTS A total of 42 MM patients underwent ASCT. Of these, 26 patients and 16 patients underwent NC and CRYO stem cell collections, respectively. There was no difference in time to neutrophil engraftment (median 12 vs. 10.5 days, P=0.203) or platelet engraftment (median 14 vs. 12 days, P=0.809) between groups. The incidence of infusion reactions and duration of hospitalization were similar in both groups. The average cost of ASCT was 10% lower in the NC group. There was no difference in progression-free survival (median 16 vs. 22 months, P=0.701) or overall survival between NC and CRYO groups. CONCLUSIONS ASCT in MM using the NC preservation method is effective and safe compared to the CRYO method in both short-term and survival outcomes.