Primary Central Nervous System Lymphoma (PCNSL): Intent-to-Treat Analysis of Monocenter Long-Term Experience.

Background This is a retrospective, long-term single-center analysis of immunocompetent patients with PCNSL treated at our institution.

Methods All 72 consecutive patients diagnosed with PCNSL between January 1994 and February 2005 were scheduled to receive high-dose methotrexate (HDMTX; 1.5–4 g/m2) based chemotherapy.

Results The median age of the patients was 62 years, the median Karnofsky performance status (KPS) was 70%. Twelve patients did not receive HDMTX based chemotherapy due to poor physical condition or renal insufficiency. Of 60 patients treated with HDMTX based chemotherapy, 9 were followed by whole brain irradiation (WBI). Of 54 patients evaluable for response 35 (65%) responded (52% CR and 13% PR), and 19 (35%) did not. At a median follow-up of 58.7 months, median progression-free survival (PFS) was 9 months, and median overall survival (OAS) was 41.4 months. Eight patients have survived 60 months or longer (median age 48, range 19–76; median KPS 80, range 40–100), 5 of whom relapsed after primary therapy at a median of 5 months (range, 3–39.7) after initial diagnosis. According to the Memorial Sloan-Kettering Cancer Center (MSKCC) prognosis score, patients could be divided into three groups with significantly different OAS: 52.9 months for patients younger than 50 years, 42.4 months for patients ≥50 years and with KPS ≥70, and 5.2 months for patients ≥50 years and KPS <70 (p=0.009; log-rank test). Eleven of 17 patients alive without cerebral lymphoma after 27–84 months tested exhibited clinical deficits attributable to late neurotoxicity.

Conclusions This study providing long-term data shows that a relatively moderate HDMTX-based chemotherapy can result in prolonged survival and probably cure even in older and early relapsing patients. However, the probability of late neurotoxicity with prolonged survival is considerable. The comparison of our results to other retrospective studies underscore the importance of treating PCNSL patients preferably at experienced institutions. The MSKCC score proved useful to predict survival.