HOUT-16. A RETROSPECTIVE ANALYSIS OF SURVIVAL OUTCOMES BASED ON CONSOLIDATION REGIMENS IN PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA Free

Currently, Primary Central Nervous System Lymphoma (PCNSL) is treated with induction therapy consisting of polychemotherapy followed by consolidation therapy. Besides the incorporation of high-dose methotrexate as the backbone of induction therapy, there is no accepted standard induction or consolidation regimen for patients with PCNSL in the US. In this study, we compared three consolidation techniques by analyzing overall survival (OS) and progression free survival (PFS) in patients treated for PCNSL.

Patients treated for newly diagnosed PCNSL at Huntsman Cancer Institute after July 1, 2012 with induction followed by consolidation therapy were retrospectively reviewed. Patients who completed one of the following regimens were included: rituximab/methotrexate/vincristine/procarbazine (R-MVP), rituximab/methotrexate/temozolomide (R-MT), or rituximab/methotrexate (R-M) for induction followed by consolidation with etoposide/cytarabine (EA), high-dose cytarabine (HIDAC), or autologous stem cell transplant (ASCT). Patients were excluded if there was evidence of systemic lymphoma on PET/CT or if the patient received radiation as consolidation therapy. Survival was calculated from the date of diagnosis and last date of known survival.

Twenty-three patients met eligibility criteria and received the following four treatment regimens: R-MT+EA (12), R-MT+ASCT (4), R-M+ASCT (1), and R-MVP+HIDAC (6). The median age of diagnosis was 61. Patients receiving ASCT (5) had a trend towards a more favorable OS (p=0.0675) compared to the other two consolidation therapies with no recurrence or death in those patients treated with ASCT. When comparing non-transplanted patients, R-MVP-HIDAC had a trend towards better OS and PFS compared to R-MT-EA.

This small retrospective review provides evidence that ASCT may be a superior treatment consolidation strategy in patients with PCNSL compared to EA and HIDAC, and that R-MT-EA may be less successful in practice than in published trials. These findings suggest that consolidation with ASCT should be strongly considered in all patients with PCSNL despite which induction therapy was received.