Real-World Outcomes of Patients with Primary CNS Lymphoma (PCNSL): A Report from the Australasian Lymphoma Alliance (ALA).

Aim: Primary Central Nervous System Lymphoma (PCNSL) [i.e. diffuse large B-cell lymphoma of the CNS] is a rare and poor-prognosis disease occurring predominantly in older patients (median age >60 years old). Prospective studies of two commonly used chemoimmunotherapy (CIT) protocols, MATRix and MPV/Ara-C (+/- rituximab), have reported 2-year PFS and OS of 57-61% and 69-81% respectively. Our aim was to evaluate registry-reported outcomes of frontline CIT strategies employed at Australasian sites. Method(s): A retrospective study of consecutive, immunocompetent, adult PCNSL patients (WHO criteria: 2017) treated with curative-intent CIT, from 10 sites (9 Australian, 1 Singaporean) between 1 st January 2009 and 31 st December 2018 (i.e. ten-year period). Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier (log-rank) method. Univariate associations were derived using a Cox model with variables p<0.10 entered stepwise into a multivariate model. Result(s): Data was collected on 207 patients, 189 of whom met WHO diagnostic criteria for PCNSL (i.e. diffuse large B-cell lymphoma of the CNS). We excluded patients with insufficient data (6), non-DLBCL histology (6), secondary PCNSL (3) and post-transplant lymphoproliferative disorder (3). Of these, 176 (93%) received curative-intent CIT. The majority (66%) were over 65 years of age (median: 65, range: 25-87); ECOG performance status was >= 2 in 31% (data not available for 14% of patients). The majority were male (55%) and had deep structure involvement (64%). International Extranodal Lymphoma Study Group (IELSG) risk criteria could not be calculated in many patients due to missing data (predominantly LDH and CSF protein). CSF involvement was rare (n=23, 13%) but data was only available for 60% of patients. Of the 159 with documented renal function, 26% had renal impairment (defined as Cockroft-Gault creatinine clearance <60ml/min or eGFR <90ml/min). Five CIT regimens were used: MATRi