Analysis of Clinical Factors and Outcomes Associated with Nonuse of Collected Peripheral Blood Stem Cells for Autologous Stem Cell Transplants in Transplant-Eligible Patients with Multiple Myeloma.

Collection and storage of peripheral blood stem cells (PBSCs) for use in autologous stem cell transplantation (ASCT) upon first disease relapse is an accepted practice for eligible patients with multiple myeloma (MM). However, little is known about the factors and outcomes associated with nonuse of these collected and stored PBSCs by MM patients who intended to have a delayed ASCT. From January 1, 2004 to December 31, 2014 we identified 342 patients who underwent collection and storage of their PBSCs in anticipation of a delayed ASCT upon first disease relapse. Among these, 176 patients (11%) had not proceeded to a delayed ASCT at the time of this study analysis. The most common reason for not undergoing an ASCT was not experiencing a relapse on first-line therapy (53%, n = 94). However, 11% of patients (n = 37) who planned for a delayed ASCT were unable to undergo an ASCT at disease relapse. Comparison with a control group of MM patients who underwent an upfront ASCT suggested a worse overall survival from diagnosis in these patients who were ASCT ineligible at disease relapse (112 versus 80 months, P = .011). This study provides valuable data for patients and care providers to take into consideration when deciding on whether to pursue an upfront or a delayed ASCT.