Clinicopathological risk factors for a poor prognosis of primary central nervous system lymphoma in elderly patients in the Tohoku and Niigata area: a multicenter, retrospective, cohort study of the Tohoku Brain Tumor Study Group.

Clinicopathological risk factors for a poor prognosis were investigated in elderly patients with malignant lymphoma of the central nervous system. A total of 82 pathologically confirmed, CD20-positive, diffuse large B-cell lymphoma patients aged 71 years or older who underwent therapeutic intervention in the Tohoku and Niigata area in Japan were retrospectively reviewed. A univariate analysis was performed by the log-rank test using the Kaplan-Meier method. A Cox proportional hazards model was used for multivariate analysis of risk factors. Of the 82 patients, 39 were male and 43 were female, and their median age at onset was 75 years. At the end of the study, there were 34 relapse-free patients (41.5%), 48 relapse cases (58.5%), median progression-free survival was 18 months, and median overall survival (OS) was 26 months; there were 41 deaths and 41 survivors. Multivariate analysis of median OS showed that Karnofsky Performance Status less than 60% 3 months after treatment (p = 0.022, hazard ratio (HR) = 2.591) was the clinical risk factor, and double expressor lymphoma (p = 0.004, HR = 3.163), expression of programmed death-ligand 1 in tumor infiltrating lymphocytes or tumor-associated macrophages (p < 0.001, HR = 5.455), and Epstein-Barr virus infection (p = 0.031, HR = 5.304) were the pathological risk factors.