A Prognostic Model Incorporating Age and Systemic Inflammation Response Index for Primary CNS Lymphoma

Background: Here, we propose a novel predictive scoring system incorporating age and the systemic inflammation response index (SIRI), which is calculated using neutrophil, monocyte, and lymphocyte counts, for patients with newly diagnosed primary central nervous system lymphoma (PCNSL). Methods: The study included 55 consecutive patients with sufficient blood test data and follow-up at our institution between November 2006 and May 2022. Age and SIRI were identified as prognostic factors and incorporated into a predictive multivariate Cox proportional hazards model. A scoring system of 0–2 points was created, with 1 point each assigned to age ≥ 65 years and high SIRI score (≥1.43 × 109/L). We subsequently validated the predictive scoring system in an independent external validation cohort. Results: Patients with 0, 1, and 2 points were assigned to groups 1, 2, and 3, respectively. The median overall survival (OS) was 35.9 months in the entire training cohort and 57.8, 37.2, and 16.1 months in groups 1, 2, and 3, respectively. The three groups showed significant differences in median OS (p < 0.001), with lower scores corresponding to longer survival times. The performance of our new scoring system was significant in the training cohort and in the external validation cohort. Conclusion: Our new scoring system incorporating age and SIRI may serve as a preliminary prognostic model for predicting OS in patients with PCNSL. This score may be beneficial for disease risk stratification and clinical decision-making in the future.