DDEL-07. Blood-brain barrier disruption (BBBD) treatment is related to better survival in primary CNS lymphoma

Abstract INTRODUCTION Primary central nervous system lymphoma (PCNSL) is an aggressive malignancy affecting central nervous system (CNS). In treatment, blood-brain barrier (BBB) sets a challenge for chemoterapeutic penetration to CNS. A cornerstone of treatment is high-dose metotrexate (HD-MTX) combined with other immunochemotherapeutic agents. Currently, in many European countries, a standard care has been HD-MTX based immunochemotherapy combination (MATRIx). Autologous stem cell transplantation (ASCT) and radiotherapy have been used as consolidation therapy. Few centers in the world, like Oulu University Hospital in Finland, have also used blood-brain barrier disruption (BBBD) based treatment. In BBBD, the BBB is first opened with intra-arterial mannitol and chemotherapeutic agents are infused directly to cerebral arteries, enabling significantly higher drug concentrations in the CNS. Aim of this study was to compare treatment outcomes of MATRIx and BBBD treated real-life patients. MATERIAL AND METHODS Data were collected retrospectively from eight Finnish hospitals. Total of 82 PCNSL patients treated with MATRIx (37) and BBBD (45) were included. Secondary lymphomas were excluded. MATRIx therapy was given per protocol. BBBD therapy contained five chemotherapeutic agents (HD-MTX, cytarabine, carboplatin, cyclophosphamide and etoposide) with rituximab. Some patients received ASCT as consolidation therapy. RESULTS Patients’ median age for MATRIx was 69 years and for BBBD 63 years. Respective median WHO performance status classifications were 1 and 2. Two-year and five-year progression-free survival rates for MATRIx were 47% and 39%. Respective rates for BBBD were 79% and 69% (P=0.002). Two-year and five-year overall survival rates for MATRIx were 49% and 42%, and respective rates for BBBD were 80% and 70% (P=0.002). Five-year disease-spesific survival rate for MATRIx was 54% and for BBBD it was 76% (P=0.021). CONCLUSIONS This retrospective real-life study reports better survival of PCNSL patients with BBBD therapy compared to MATRIx therapy in terms of progression-free survival, overall survival, and disease-spesific survival.