Improved survival with combined chemo-radiotherapy in primary central nervous system lymphoma

ABSTRACT

Primary CNS lymphoma [PCNSL] is an aggressive primary brain tumor. Cranial irradiation alone rarely results in long term disease control or prolonged survival. We retrospectively analyzed data on the effect of adding high-dose methotrexate [HDMTX] prior to whole brain irradiation [WBI]. All patients with PCNSL diagnosed and managed during 1991-2004 were identified and demographic characteristics, prognostic factors, treatment and outcome were reviewed. Of 62 patients, 10 were excluded [4 had WBI < 40 Gy and 6 had no treatment]. Radiation alone was considered curative with a dose > 40 Gy. Combined modality therapy included 3-4 cycles of HDMTX [3g/m2] followed by WBI. Of 52 patients analyzed for outcome, 36 had WBI [dose > 40 Gy], 16 received 3-4 cycles of HDMTX followed by WBI [combined modality therapy [CMT]]. Median age was 48.2 years; 42 years in the CMT group, 51 years in WBI. Patient characteristics were comparable between two groups except for higher multifocal tumor in the CMT group [92% vs. x22%, P=.029]. Median follow up was 12.83 +/- 6.4 months. The hazard ration for an event was 0.64 [95% CI, 0.52-0.98] and for death 0.58 [95% CI, 0.48-0.92], both in favor of CMT. Univariate regression analysis using one-way analyses of variance [ANOVA] and multivariate Cox regression analysis for prognostic factors including age [< 60 vs. >60], ECOG PS [0-2 vs. 3-4], extent of surgery [biopsy vs. debulking], solitary vs multifocal tumor and dose of radiation therapy [>50Gy vs. >50 Gy] failed to identify any prognostic factor. This retrospecitive comparison supports phase II trial results that indicate that high-dose methotrexate followed by WBI in PCNSL improves outcome: