Pemetrexed for primary central nervous system lymphoma in the elderly

The aim of this study was to evaluate the efficacy and safety of a consecutive series of elderly patients with primary central nervous system lymphoma (PCNSL) treated with single-agent pemetrexed without radiotherapy or intrathecal chemotherapy.

Twelve histologically confirmed newly diagnosed PCNSL patients older than 65 years were studied between 2008 and 2013. An induction chemotherapy was initially given (pemetrexed 600 mg/m(2) on day 1, every 3 weeks). Patients achieving a complete, partial response or stable disease proceeded to a maintenance phase (up to 6 cycles). Patients with progressive/recurrent disease (PD) were treated with whole brain radiotherapy on an individual basis.

Four patients presented complete response, six patients showed partial response and two patients presented progressive disease. The median progression-free survival (PFS) was 9.0 months [95 % confidence interval (CI) 2.0-45.3] and the median overall survival was 19.5 months (95 % CI 5.0-45.3). Adverse events included leukocytopenia, anemia, fatigue, rash and vomiting. No neurotoxicity or treatment-related death was observed. The estimated 1-year and 2-year survival rate was 66.7 and 41.7 %, respectively.

Our efficacy results demonstrate that the single-agent pemetrexed was feasible, active and well tolerated in elderly patients with PCNSL. Furthermore, this single-agent regimen results in higher response rates and less toxicity comparable with other chemotherapy or radiotherapy regimens. Prospectively, controlled studies are warranted to confirm such results.