Primary Brainstem Lymphoma: A Population-Based Study.

Background: Primary brainstem lymphoma (PBSL) is rare and malignant. An understanding of this disease is lacking. We aimed to characterize clinical features, estimate survival, and explore survival-related factors of PBSL.

Methods: Patients with a histological diagnosis of primary lymphoma in the brainstem (C71.7) from 1975 to 2016 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) program. Log-rank tests and univariate and multivariate Cox proportional hazard analyses were used to identify survival-related factors.

Results: PBSL constituted 2.7% of brainstem malignancies. The median age of the PBSL patients was 59.5 years. Diffuse large B cell lymphoma ( = 49, 84.5%) was the most prevalent histology among the 58 cases with reported specific lymphoma subtype. The majority of PBSLs were localized ( = 46, 52.3%), at low Ann Arbor Stage (I/II,  = 63, 70.5%), and presented as a single primary ( = 71, 80.7%). Chemotherapy was applied in 50 (56.8%) cases. Three-year overall survival (OS) and disease-specific survival (DSS) rates were 42.7% and 53.5%, respectively. Multivariate analyses showed that independent predictive/prognostic factors for OS were age ( = 0.004), tumor number ( = 0.029), and chemotherapy ( = 0.001); DSS-related factors only included age ( = 0.014) and chemotherapy ( = 0.008).

Conclusions: We estimated survival rates for PBSL patients. Factors associated with OS and DSS were also identified. Our findings addressed the importance of chemotherapy in treating PBSL patients.