The long-term efficacy and safety of high-dose chemotherapy with autologous stem cell transplantation in the treatment of primary central nervous system lymphoma: A real-world report from the Polish Lymphoma Research Group

BACKGROUND: The aim of this prospective, observational study was to evaluate the safety and efficacy of high-dose chemotherapy (HDC) with carmustine, etoposide and thiotepa (BET) followed by autologous stem-cell transplantation (ASCT) for transplant eligible primary central nervous lymphoma (PCNSL) patients. METHODS: High-dose chemotherapy with autologous stem-cell transplantation (HDC-ASCT) is a recommended consolidation strategy for eligible primary CNS lymphoma patients; however, more data on its efficacy and safety in real-world patients are still needed. We report the outcomes of 60 patients treated in five hemato-oncology centers within the Polish Lymphoma Research Group, considered eligible for HDC-BET-ASCT after R-MIV (rituximab, methotrexate, ifosfamide, vincristine) induction with one cycle of AT (cytarabine and thiotepa) at the end of induction. The median age (range) was 58 (19-70) years, with 24 (40%) patients aged ≥ 60 years. RESULTS: Two patients (3.3%) died from transplant-related toxicity. At a median follow-up of 51 months, 4-year progression-free (PFS) and overall survival (OS) were 66% and 74%, respectively. Fifteen (25%) patients relapsed: 10 within the first 12 months, while 2 patients (13.3%) 3.6 years and 7 years after ASCT. Five patients (33%) achieved a second complete remission, with two patients eligible for a second HDC-ASCT. Eighteen patients were transplanted during the COVID-19 pandemic, with more relapses shown during this period (44.4% vs. 16.6%), but with no impact on 4-year OS (p = 0.49) and PFS (p = 0.1) compared to patients treated outside the pandemic. CONCLUSION: Strategy based on R-MIV induction and HDC-BET-ASCT was feasible and had acceptable safety in daily practice.