NCMP-13. Tolerance of High-Dose Methotrexate Treatment of Primary Central Nervous System Lymphoma (Pcnsl) Patients With Renal Impairment, Case Series and Review of Literature

Abstract

PCNSL in immune competent patients is a rare extra-nodal non-Hodgkin lymphoma that accounts for 3–4% of newly diagnosed CNS tumors. Treatment consists of high-dose methotrexate (HD-MTX) based polychemotherapy regimen with or without brain radiation. There are few reported cases supporting the use of HD-MTX as a treatment option in such patients with impaired renal function. The objective of this study was to analyze outcomes and tolerance of HD-MTX based chemotherapy regimen (HD-MTX, rituximab and temozolomide, MRT) in patients with PCNSL and renal impairment. We present five patients with median age 63 (range 40 – 67) at diagnosis, with varying degrees of renal impairments, were all treated with and tolerated well of MRT. They are all alive and have been on observation. Cases 2 & 3 had a one functioning kidney and achieved complete responses (CR) without toxicities. Case 1, with history of grade 3 renal insufficiency during his initial HD-MTX and received carboxypeptidase G2 rescue, tolerated re-treatment with MRT at PCNSL recurrence and achieved a partial response (PR) that has been stable for 44 months. Case 4, who had a cadaver-transplanted kidney, was able to get a CR after 8 treatment with MRT. Case 5, with grade 3 chronic kidney disease from type II diabetes mellitus, achieved CR with MRT with slowing down of his MTX clearance. Literature review for reports with PCNSL and renal impairment treated with HD-MTX through March 31, 2022 identified eight cases and their responses and adverse effects summarized. Due to the low number of published cases and limitation of a retrospective analysis, it is impossible to draw a conclusion on the impact of impaired renal function on the tolerance of HD-MTX treatment of PCNSL. However, our findings indicate that a subset of the patients may still benefit from treatment with HD-MTX based chemotherapy.