High-dose thiotepa-based chemotherapy with autologous stem cell support in elderly patients with primary central nervous system lymphoma: a European retrospective study

In this retrospective multicentre study, we investigated the outcomes of elderly primary central nervous system lymphoma (PCNSL) patients (>= 65 years) who underwent high-dose chemotherapy followed by autologous stem cell transplantation (HDT-ASCT) at 11 centres between 2003 and 2016. End points included remission, progression-free survival (PFS), overall survival (OS) and treatment-related mortality. We identified 52 patients (median age 68.5 years, median Karnofsky Performance Status before HDT-ASCT 80%) who all underwent thiotepa-based HDT-ASCT. Fifteen patients (28.8%) received HDT-ASCT as first-line treatment and 37 (71.2%) received it as second or subsequent line. Remission status before HDT-ASCT was: CR 34.6%, PR 51.9%, stable disease 3.8% and progressive disease 9.6%. Following completion of HDT-ASCT, 36 patients (69.2%) achieved CR (21.2% first-line setting and 48.1% second or subsequent line setting) and 9 (17.3%) PR (5.8% first-line setting and 11.5% second or subsequent line setting). With a median follow-up of 22 months after HDT-ASCT, median PFS and OS were reached after 51.1 and 122.3 months, respectively. The 2-year PFS and OS rates were 62.0% and 70.8%, respectively. We observed two HDT-ASCT-associated deaths (3.8%). In selected elderly PCNSL patients, HDT-ASCT, using thiotepa-based conditioning regimes, is feasible and effective. Further prospective and comparative studies are warranted to further evaluate the role of HDT-ASCT in elderly PCNSL patients.