High-Dose Chemotherapy with Autologous Hematopoietic Stem Cell Transplantation in Relapsed or Refractory Primary CNS Lymphoma: A Retrospective Monocentric Analysis of Long-Term Outcome, Prognostic Factors, and Toxicity.

High-dose chemotherapy with autologous stem cell transplantation (HCT-ASCT) is reportedly an effective treatment strategy in relapsed or refractory primary CNS lymphoma (r/r PCNSL); however, only selected patients are eligible for this treatment. We retrospectively analyzed outcome, prognostic factors, and toxicity in 59 patients with r/r PCNSL planned to receive HCT-ASCT at our institution between January 2005 and December 2021 ( n = 33 < 65 years; n = 26 ≥ 65 years). Median follow-up was 65 months (95% CI 21-109). Median age was 63 years (range 29-76), median Karnofsky performance score (KPS) was 80 (range 30-100). In the entire cohort of 59 patients, median overall survival (OS) was 14 months (95% CI 0-37). In 50/59 (84.7%) patients who completed HCT-ASCT, median progression free survival (PFS) was 12 months (95% CI 3-21) and median OS 30 months (95% CI 0-87). 1-year, 2-year, and 5-year OS rates of 61.2%, 52.3% and 47.1%, respectively, were observed. Six patients (10.2%) died related to treatment (1 during induction treatment, 5 post HCT-ASCT). Age was not prognostic. On univariate analysis, KPS ≥ 80 ( p = 0.019) and complete or partial remission before HCT-ASCT ( p = 0.026) were positive prognosticators of OS; on multivariate analysis, KPS ( p = 0.043) and male gender ( p = 0.039) had an impact on OS. The 5-year OS rate in patients with progressive or stable disease after induction treatment was 32.7%. In summary, HCT-ASCT was effective and feasible in this cohort of r/r PCNSL patients. Clinical state, remission status before HCT-ASCT, and gender influenced survival, whereas age did not influence outcome in this study.