Primary CNS Lymphoma in a HIV Negative Population: A Review of Clinicopathologic Characteristics, Therapy, and Outcomes of 59 Patients

Primary central nervous system lymphoma (PCNSL) is a rare aggressive variant of diffuse large B cell lymphoma (DLBCL) with a poor prognosis. Optimal therapeutic strategies have not been defined yet in primary CNS lymphoma. High dose Methotrexate (HD MTX) is an effective chemotherapeutic agent with superior outcomes compared to historical studies using whole brain radiation therapy (WBRT). The combination of HD MTX with WBRT showed improved response rates compared to chemotherapy (CT) alone, but was associated with greater risk of neurotoxicity in patients >60 years old.

To review clinicopathologic characteristics, therapy and outcomes of 59 patients with primary CNS DLBCL without HIV.

This was a single center retrospective review of pts with confirmed diagnosis of primary CNS DLBCL from 1999 to 2012. Data was extracted from the Moffitt Cancer Center (MCC) electronic records. Baseline demographics, clinical, pathological and treatment data were collected and analyzed. Patients were stratified according to their treatment regimens including HD MTX (3g/m2) alone or in combinations and WBRT alone or in combination with CT.

Descriptive statistical analyses were utilized. Chi square analysis and t- test were performed to compare categorical and continuous variables. Kaplan-Meier method was used to estimate OS and log rank test was used to compare the groups. All data was analyzed using SPSS version 19.0 statistical software.

59 patients who underwent CT and/or WBRT for PCNSL between 1999 and 2012 were identified. The age range at diagnosis was 17–85 years with median age of 64. 35 of 59 patients (59%) were ≥ 60 years old. Male to female ratio was 1.27:1 (33:26). The median ECOG PS was 1. A majority of patients presented with motor deficits, 29 out of 59. The most common location of lymphoma was in the cerebral hemispheres. The median survival of the entire cohort was 37 months. 18 of 59 pts (25%) survived ≥ 60 months. In the cohort of pts that survived ≥ 60 months, a majority 16 of 18 (89%) received HD MTX. Patients treated with initial WBRT and chemotherapy revealed inferior overall survival (OS) compare to patients treated with induction chemotherapy alone (OS 37 months vs. 66 months) (p=0.011). Patients over the age of 60 had worse outcomes compared to patients who were less than the age of 60 (OS 33 months versus 70 months) (p=0.023).

HD MTX was the most frequently utilized CT regimen in the cohort of patients surviving > 60 months. Administering WBRT combined with chemotherapy was associated with worse outcomes in this retrospective analysis. Patients with primary CNS lymphoma who are older than 60 have worse outcomes in this retrospective analysis compared to patients younger than 60.

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