Prognostic Factors Influencing Treatment Response in Primary Central Nervous System Lymphoma

Aims: The aim of this study was to determine the clinic pathological findings of patients with primary central nervous system lymphoma (PCNSL) as real-life data, examine their treatment approaches, and define the prognostic factors. Methods: Eighty-four patients who presented with a diagnosis of PCNSL between January 2008 and July 2021 were included in this study. The treatments received by the patients and their survival outcomes were retrospectively analyzed. Results: The median age at diagnosis was 55 (18-80 years). The median progression-free survival (PFS) was 16.8 months (12.421.2 months), while the median overall survival (OS) was 18 months (13.7-22.4 months) in all patients. The most commonly used chemotherapy was high-dose methotrexate based regimens, which were preferred in 68 (81%) patients. Objective response rate and disease control rate were 75% and 83.3%, respectively. Consolidation therapy was an independent prognostic factor for PFS (HR: 0.32, 95% CI, 0.18-0.55, p<0.001). There were 42 (50%) patients who had been treated by consolidation therapy. Patients who received consolidation therapy were observed to have a 67% reduction in mortality compared to those who did not (HR: 0.33, 95% CI, 0.19-0.57, p<0.001). Also, high risk in Memorial Sloan-Kettering Cancer Center (MSKCC) prognostic model was found to be associated with a 2-fold increase in mortality compared to the good risk group (HR: 2.04, 95% CI, 1.02-3.56, p=0.022). Toxicity of any grade was observed in 78 (92.9%) patients. There were 3 (3.6%) patients who died due to treatment toxicity. Conclusion: Consolidation therapy was found to be an independent predictive factor for both OS and PFS in PCNSL. In addition, high risk class according to MSKCC prognostic model was found to be associated with increased mortality.