Primary central nervous system lymphoma: the role of consolidation treatment after a complete response to high-dose methotrexate-based chemotherapy

BACKGROUND: The most effective treatment for a new diagnosis of primary central nervous system lymphoma is high-dose methotrexate (MTX)-based chemotherapy followed by whole-brain radiation therapy (WBRT). However, this combined modality treatment carries an increased risk of delayed neurotoxicity. For patients who achieve a complete response (CR) after induction that uses high-dose MTX-based chemotherapy, it is not clear if consolidation treatment is necessary. Therefore, a retrospective study was conducted to assess the impact of consolidation treatment after a CR to initial induction chemotherapy on disease control and survival. METHODS: The authors retrospectively analyzed 122 patients who achieved a CR after initial MTX-based chemotherapy. The benefit of consolidation WBRT, high-dose cytarabine (HDAC), or both on failure-free (FFS) and overall survival (OS) was assessed. RESULTS: With a median follow-up of 60 months, FFS was longer in patients who received WBRT plus HDAC as consolidation treatment (P = .03 by univariate analysis); there was no difference in OS observed among patients who received no consolidation treatment, HDAC alone, WBRT plus HDAC, or WBRT alone. Age and Karnofsky performance scale (KPS) were the only independent prognostic factors. Patients who received WBRT alone or in combination with HDAC had higher rates of neurotoxicity. CONCLUSIONS: Consolidation treatment with WBRT, HDAC, or both does not appear to improve survival in patients who achieved a CR with induction MTX-based therapy. Age, KPS, and risk of delayed neurotoxicity must be considered in the choice of consolidation regimens.