Background: The aim of our study was to analyze changes over time in the characteristics, treatment, and outcome of patients with primary central nervous system lymphoma (PCNSL).
Methods: Data on 315 patients with histologically proven PCNSL undergoing radiotherapy between 2005 and 2009 were collected from 20 Japanese institutions using a questionnaire. These data were then compared with data on 273 patients treated during the period 1995-2004 and those on 466 patients treated during the period 1985-1994.
Results: In terms of patient and tumor characteristics, we found a significant increase in mean patient age in the 2005-2009 period compared to the 1985-2004 period (63 vs. 58-59 years, respectively) and in the percentage of patients with better performance status (PS) during the 2005-2009 period compared with the 1995-2004 period (World Health Organization PS 0-2: 73 vs. 65 %, respectively). Regarding treatment, relative to the 1995-2004 period, significant changes in the 2005-2009 period were (1) decreased rate of attempting tumor resection (23 vs. 44 %); (2) increased use of chemotherapy (78 vs. 68 %), and (3) increased use of methotrexate (MTX)-containing regimens (84 vs. 53 %). The 5-year overall survival rates were 15.3, 30.1, and 36.5 % for patients seen during the 1985-1994, 1995-2004, and 2005-2009 periods, respectively, but relapse-free survival did not improve between the 1995-2004 and 2005-2009 periods (26.7 vs. 25.7 % at 5 years, respectively). Patients receiving MTX-containing chemotherapy had 5-year survival rates of 19, 50, and 44 % during these three periods, respectively.
Conclusions: Although patient backgrounds differed among the study periods, recent trends were a high patient age, better PS, avoidance of extensive tumor resection, more frequent use of chemotherapy, and improved survival. The recent improvement in survival may be due to improvements in second-line treatment and supportive care.