Long-term Outcomes in Primary CNS Lymphoma Following R-MVP and High Dose Chemotherapy With Autologous Hematopoietic Stem Cell Transplant

Background: Primary central nervous system lymphoma (PCNSL), a rare central nervous system malignancy, is usually treated with high-dose methotrexate in the first line setting, typically followed by consolidation therapy. Due to the broad range of currently available treatments for PCNSL, comparability in long-term follow up studies is limited and the data are scattered across small studies.

Methods: Here we report the long-term survival of patients with newly diagnosed, immunocompetent PCNSL, enrolled in a phase II trial from June 2005 to September 2011. Patients were treated using rituximab, methotrexate, vincristine, and procarbazine (R-MVP) chemotherapy followed by high dose chemotherapy (HDC) and autologous stem cell transplant (ASCT) in those with partial or complete response to R-MVP. In a post hoc analysis, clinical and imaging features were evaluated in those still alive.

Results: 26 of 32 patients underwent HDC-ACST consolidation. Of these, 3 patients died from treatment related toxicity, and 2 due to disease progression within one year of ASCT. None of the remaining 21 patients had disease progression with a median follow-up of 12.1 years and were included in the analysis. Compared to the post HDC-ASCT assessment, at last follow up there was no significant difference in the median Karnofsky Performance Status (KPS) (80 (range: 60-100) versus 90 (range: 70-100)), the median Neurologic Assessment in Neuro-Oncology (NANO) score (1 (range: 0-4) versus 1 (range 0-5)) and leukoencephalopathy score (1 (range 0-3) versus 1 (range: 1-4)).

Conclusion: Long-term follow up demonstrated that treatment was well tolerated in most patients enrolled in this study, with stable leukoencephalopathy on imaging and stable clinical performance status. Disease recurrence was not observed beyond 2 years after HDC-ASCT consolidation.