Efficacy and safety of HD-MTX based systemic chemotherapy regimens: retrospective study of induction therapy for primary central nervous system lymphoma in Chinese

We performed a retrospective study of 49 patients with newly diagnosed primary central nervous system lymphoma (PCNSL), to compare the efficacy and safety of different high-dose methotrexate (HD-MTX) based systemic chemotherapy regimens as induction therapy. 25 patients received AB ± R alternative regimen (consist methotrexate, ifosfamide, vindesine, dexamethasone, carmustine and teniposide), while others received HD-MTX ± R regimen. The complete response rate and overall response rate of AB ± R group and HD-MTX ± R group were 36.83% vs. 33.33%, and 68.42% vs. 71.43%, while the 2-year OS and PFS rate were 71.43% vs. 74.62%, and 42.86% vs. 54.64%, respectively. In Age > 60 subgroup, the 2-year OS and PFS rate of AB ± R group and HD-MTX ± R group were 81.82% vs. 33.33%, and 54.55% vs. 33.33%. No significant differences were found in grade 3 or 4 toxicity rate. Generally, HD-MTX ± R regimen was not inferior to AB ± R alternative regimen, but AB ± R alternative regimen seemed achieving more survival benefits in the elderly. We suggest to adjust HD-MTX ± R regimen by changing the dose-reduction strategy especially in elderly patients and adding other powerful drugs that can well penetrate blood-brain barrier to improve the efficacy.