High-dose methotrexate, high-dose cytarabine and temozolomide for the treatment of primary central nervous system lymphoma (PCNSL).

Treatment of primary central nervous system lymphoma (PCNSL) associates with low response rates and poor survival using conventional radio and chemotherapy. Due to its favorable toxicity profile, temozolomide has emerged as a new option for treatment of PCNSL in young patients. In this study, we report a series of PCNSL patients treated with an innovative regimen combining high dose of both cytarabine and methotrexate with temozolomide without radiotherapy or intrathecal chemotherapy. To evaluate a new intensive chemotherapy with temozolomide, trying to assess response and progression-free survival rates and if the results are promising, we are aiming at evaluating the overall survival (OS) taking into consideration the toxicity profile. The study was performed at Al Mowassa Charity Hospital in Damascus (Syria). Forty patients with histologically confirmed PCNSL median age 52 years (range 20-65) years were included. Biopsies were cultured, and a karyotyping was made in 32 patients. An induction chemotherapy was started, and methotrexate 3 gr/m² over 12 h on day 1, cytarabine 3 gr/m² every 12 h on day 1 and temozolomide 150 mg/m² from day 2 through day 6 with a total of 6 cycles were given on a monthly basis. Among the 40 patients included in the study, a complete response was observed in 34 patients (85%) and a partial response in the remaining 6 patients (15%). Disease progressed in 8 out of 40 patients (20%) while 32 patients are still living at 5 years making the OS reaching 77%. Grade II nephrotoxicity was observed in 2 patients while grade III and IV hematotoxicity was observed in 5 patients. High dose of both Ara-C and MTX combined with temozolomide appears to be a good choice in the treatment of PCNSL, in the light of good response and OS rates, taking into consideration the acceptable toxicity profile. However, a larger trial is needed to make it an acceptable new combination as a first line for PCNSL patients.