Real-world analysis of autologous stem cell transplantation in primary central nervous system lymphoma using Taiwan Blood and Marrow Transplantation Registry (TBMTR)

Although high-dose chemotherapy with autologous stem cell transplantation (HDC/ASCT) is an established consolidation strategy for primary central nervous system lymphoma (PCNSL), real-world data remain limited, especially in Asia. This retrospective multicenter study analyzed 65 PCNSL patients from the Taiwan Blood and Marrow Transplantation Registry (TBMTR) who underwent HDC/ASCT between 2012 and 2022. Patients were classified into the frontline (n = 47) and salvage (n = 18) HDC/ASCT groups. The 2-year overall survival (OS) and relapse-free survival (RFS) rates were 68.3% and 58.8% in the frontline group, and 69.8% and 58.4% in the salvage group, respectively. Thiotepa-based regimens showed no survival advantage; the 2-year OS was 58.3% for thiotepa recipients versus 76.6% for non-thiotepa recipients (p = 0.84). This finding may be attributed to limited access to thiotepa and the small number of patients who received thiotepa-based induction chemotherapy. Disease relapse or progression was the primary cause of mortality across all groups, whereas infection or other non-relapse mortality was infrequent. In this study, HDC/ASCT improved OS and RFS for PCNSL patients in both frontline and salvage settings, although the thiotepa-based conditioning regimen showed no survival benefit.