Primary Central Nervous System Lymphoma in Elderly Patients: Clinical Outcomes and Prognosis
Authors: Dahiya Saurabh , Xie Hao , Hill Brian T. , Peereboom David , Stevens Glen H , Murphy Erin , Chao Samuel , Suh John , Ahluwalia Manmeet S 
Published: October 2019

Abstract
Abstract 5083
In this retrospective study, we sought to describe the demographics, diagnoses, management, and outcomes of elderly patients with primary CNS lymphoma (PCNSL) at a single institution.

Patients and Methods
After obtaining IRB approval, the Cleveland Clinic Brain Tumor and Neuro-Oncology Center's database was used to identify patients with newly diagnosed PCNSL who were older than 60 years between 1986 and 2010. We excluded patients who were HIV positive or had systemic lymphoma. During individual chart review, we confirmed the diagnosis and collected information of patients' demographics, disease presentation, diagnostic procedures, initial and salvage therapy, and clinical outcome.

Results
A total of 84 patients were older than 60 years of age when they were diagnosed with PCNSL at our institution from 1986 to 2010. The median age was 67. 9 years (range: 60. 3–89. 2 years). The median Karnofsky performance status (KPS) of these patients at the diagnosis was 70 (range: 20–90), which stayed the same at the subsequent disease relapses. The median duration of symptoms was 1. 5 months (range: 0. 1–13 months).
The initial treatment regimens included whole brain radiation therapy (WBRT), chemotherapy with or without consolidation WBRT. Five patients (6%) received WBRT alone. 43 patients (51%) received chemotherapy alone. Six patients (7%) received chemotherapy followed by consolidation WBRT. Among the patients who received chemotherapy with or without WBRT, 40 of them (48%) received methotrexate-based therapy; 9 patients (11%) received non-methotrexate-based therapy.
Among the patients who received initial treatment, 20 of them (37%) achieved complete response (CR), while 19 patients (35%) had disease progression during the treatment. The median progression free survival (PFS) was 8. 0 months (95% CI 2. 7–22 months). The median overall survival (OS) was 15. 5 months (95% CI 6. 6–38. 5 months). We also compared the benefit of individual initial treatment regimens although the reason of their allocation was not determined. It turned out that patients with chemotherapy followed by consolidation WBRT had significantly higher response rate and longer survival than patients with WBRT alone (Figure 1). Unfortunately, no patient who received WBRT alone achieved CR. In addition, the methotrexate-based chemotherapy offered significantly longer PFS than non-methotrexate-based chemotherapy (P = 0. 0008).
In univariate analysis, we evaluated potential prognostic factors such as gender, age, KPS, symptom duration, prior malignancy, year of diagnosis, symptoms, and multiple site involvement for response rate, PFS, and OS. Recursive partitioning analysis identified 70 years as the cutoff point for age and 70 as the cutoff point for KPS. We found that no factors can predict response to therapy. However, younger age, higher KPS, more recent diagnosis, and the presence of ocular symptoms were favorable factors for longer OS. Age is the only favorable prognostic factor for PFS, although higher KPS has a trend (P = 0. 08) toward longer PFS. When these factors were subjected to multivariable analysis, age older than 70 years and KPS less than 70 were the only poor prognostic factors for both OS and PFS. With this information in hand, we divided the patients into three prognostic groups based on the number of poor prognostic factors (Table 1). The median OS and PFS for the group with no poor prognostic factors were 65 months and 24 months, respectively. The median OS and PFS for the group with all poor prognostic factors were 1. 0 month and 0. 6 month, respectively.

Conclusions
Chemotherapy followed by consolidation WBRT had significantly higher response rate and longer survival than patients with WBRT alone. Age and performance status were the only independent predictor of either PFS or OS.

Disclosures:
No relevant conflicts of interest to declare.