Abstract:To investigate the prognostic role of the platelet-lymphocyte ratio (PLR) in primary central nervous system lymphoma (PCNSL) and to find a modified IELSG scoring system suitable for the Asian PCNSL population. Methods:The clinical data of 72 patients with PCNSL from the First Affiliated Hospital of Nanjing Medical University from June 2011 to December 2021 were retrospectively analyzed. We also performed Kaplan-Meier method, univariate and multivariate Cox regression analysis for survival analysis and prognostic factors evaluation. Results: Median progression-free survival (PFS) and overall survival (OS) were 17 months and 39 months, respectively. Univariate Cox regression analysis confirmed PLR ≥107 (P=0.022, P=0.038), age 54≥ years (P=0.043,P=0.027), LDH/ULN>2(P=0.080,P=0.064), CSF protein/ULN>2 (P=0.051,P=0.023), ECOG评分≥2 ((P=0.029,P=0.027)) and modified IELSG high-risk group ((P=0.064,P=0.001) were associated with shorter PFS and OS. Multivariate Cox regression analysis confirmed PLR ≥107 (P=0.011, P=0.022) and ECOG≥2 (P=0.013, P=0.015) were independent risk factors for PFS and OS. Conclusion: PLR may be used as an indicator to evaluate the prognosis of PCNSL.