Inpatient vs outpatient autologous hematopoietic stem cell transplantation for multiple myeloma

Background: High-dose chemotherapy and autologous hematopoietic stem cell transplantation (auto-HCT) are commonly performed for multiple myeloma (MM) patients and may be as safe in the outpatient setting as in the inpatient setting. Methods: We performed a single-center retrospective analysis of all MM patients undergoing auto-HCT between January 2008 and December 2012. We categorized patients as outpatient vs inpatient auto-HCT and compared clinical characteristics and outcomes between the groups. Results: One thousand and forty-six patients were included (669 inpatients, 377 outpatients). Patients transplanted as outpatients were significantly younger (58 [34-78] vs 62 [31-82], P <.001) and more likely to have an hematopoietic stem cell comorbidity index (HCT-CI) score <2 (P =.003) and creatinine <2 (P <.001). There were no differences in treatment-related mortality (TRM) but the inpatient group experienced significantly more grade 2-5 (P =.003) and grade 3-5 (P =.003) adverse events (AEs). 2 year progression-free survival (PFS) was significantly longer in the outpatient group (60% vs 50%, HR =HR 0.7, 95% CI 0.6-0.9, P =.005). 2 year OS was also longer in the outpatient group (83% vs 77%, HR 0.6, 95% CI 04-0.9, P =.01). Conclusion: Outpatient auto-HCT can be safely performed for selected patients with MM. Differences in outcomes are likely related to baseline clinical characteristics rather than choice of treatment setting.