Primary Central Nervous System Lymphoma

The Cleveland Clinic experience with primary central nervous system lymphoma

BACKGROUND

The rarity and difficulty of conducting large trials limit the evaluation of various treatment options for primary central nervous system lymphoma (PCNSL). In this study, we sought to describe the demographics, diagnoses, management, and outcomes of patients with PCNSL at a single institution.

METHODS

This is a retrospective study of 153 patients with PCNSL between 1986 and 2010. Prognostic factors identified by univariate and multivariable survival analyses were used by recursive partitioning analysis to generate a prognostic model.

RESULTS

The median age was 61 and Karnofsky performance status (KPS) was 70. The progression-free survival was 9.3 months; the overall survival was 27 months. The diagnosis of PCNSL was established mainly by stereotactic brain biopsy (80%), cerebrospinal fluid analysis (7.2%), and vitrectomy (2.6%). Methotrexate-based chemotherapy with or without consolidation whole-brain radiation therapy offered better response rate and survival in the initial treatment than whole-brain radiation therapy alone. However, this observation was not present in the subsequent salvage treatments. Multivariable Cox proportional hazards regression identified age and KPS as the only prognostic indicators. Recursive partitioning analysis categorized the patients into 3 groups. Patients with KPS >70 had a favorable outcome compared with patients with KPS ≤70. This held true especially for patients age 60 and younger.

CONCLUSIONS

The Cleveland Clinic experience with management of PCNSL demonstrated successful disease control with methotrexate-based regimens. The survival and prognostic indicators approximate those reported previously and provide independent validation for a simple yet powerful prognostic model using age and KPS to predict survival.

The role of radiation therapy in the management of primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is an aggressive neoplasm with a poor prognosis. Early studies of whole brain radiation therapy (WBRT) alone revealed a robust initial response but high rates of local recurrence with long-term follow-up. The addition of high-dose methotrexate (HDMTX)-based chemotherapy improved the durability of disease control. However, delayed neurotoxicity emerged as an important complication, mainly in elderly patients. Therefore, researchers have investigated eliminating WBRT or reducing its dose. Multiple studies of chemotherapy alone have demonstrated inferior disease control. On the other hand, a phase III trial reported that WBRT may be deferred until relapse without compromising survival; however, this trial is fraught with flaws. A recent study of immunochemotherapy and dose-reduced WBRT demonstrated excellent outcomes. Currently, this regimen is being studied in a multi-institutional trial by the Radiation Therapy Oncology Group. WBRT maintains an important position in the armamentarium against PCNSL. This article aims to describe its evolving role.