Epidemiologic Characteristics, Prognostic Factors and Treatment Outcomes in Primary Central Nervous System Lymphoma: A SEER-Based Study

Objective: To study the clinical characteristics, prognostic factors and treatment outcomes in patients with primary central nervous system lymphoma (PCNSL).Materials and Methods: The data of total 5166 PCNSL patients diagnosed between 2000 and 2018 from the Surveillance, Epidemiology, and End Results (SEER) database was obtained.Results: The mean age was 63.1±14.9 years, with a male to female of 1.1:1.0. The most common histologic subtype was diffuse large B-cell lymphoma (DLBCL) (84.6%). The 1-, 3-, and 5-year OS were 50.1, 36.0 and 27.2% and corresponding to DSS were 54.4, 41.3 and 33.5%, respectively. Multivariate analysis with Cox regression showed that race, sex, age, marital status, surgery, chemotherapy and radiotherapy were independent prognostic factors for OS, but radiotherapy no longer for DSS. Nomograms specially for DLBCL were established to predict the possibility of OS and DSS. The concordance index (C-index) of OS and DSS were 0.704 (95% CI 0.687-0.721) and 0.698 (95% CI 0.679-0.717), suggesting the high discrimination ability of the nomograms.Conclusion: Surgery or/and chemotherapy was favourably associated with better OS and DSS. However, radiotherapy did not benefit to OS and DSS in the long-term. A new predictive nomogram and a web-based survival rate calculator we developed showed favorable applicability and accuracy to predict the long-term OS for DLBCL patients specifically.