Significance of MYC rearrangement and chemotherapy type on survival outcomes of patients with central nervous system lymphoma.
7548 Background: Central nervous system lymphoma (CNSL) has a poor prognosis and an optimal treatment regimen has not been established. Due to the rarity of this disease and frequently poor performance status at diagnosis, there have been few prospective therapeutic clinical trials in this patient population. We therefore performed a retrospective analysis of prognostic factors and treatment outcomes of patients with CNSL treated at a single institution. Methods: Pathology records were used to identify patients diagnosed with CNSL from 1/1/2005 to 9/1/2016 at the University of North Carolina Cancer Hospital. Information about demographics, disease characteristics, treatment, and outcomes was gathered from the electronic medical record. Overall (OS) and progression free survival (PFS) were estimated using the Kaplan-Meier method. Results: We identified 100 patients with CNSL. 49% had primary CNSL (PCNSL). 78% of cases were diffuse large B cell lymphoma. Out of 51 patients evaluated for MYC translocation by FISH, 13 were positive (3 PCNSL and 10 secondary CNSL). Out of 74 patients treated with chemotherapy, 51% received methotrexate (MTX), procarbazine, and vincristine (MPV), with or without rituximab, 28% were treated with other high dose MTX based regimens, with or without rituximab, and 20% received a non-MTX based regimen. There was no significant difference in OS between PCNSL and secondary CNSL (13.7 vs 7.9 months, p = 0.97). Patients with MYC translocation had a worse OS compared to those without MYC translocation (5.1 vs 29.5 months, p = 0.004). Patients treated with MPV had a longer PFS compared to those treated with other high dose MTX based regimens or those who were treated with a non-MTX based regimen (19.1 vs 10.9 vs 3.9 months, p = 0.05), but difference in OS did not reach statistical significance (29.5 vs 22.4 vs 10.6 months, p = 0.12). Conclusions: In this single institution analysis of CNSL, MYC translocation was associated with worse survival. MPV was associated with improved PFS compared to other chemotherapy regimens. Further prospective studies are needed comparing MPV to other MTX-based regimens in CNSL.