Response-adapted treatment with upfront high-dose chemotherapy followed by autologous stem-cell transplantation rescue or consolidation phase high-dose methotrexate for primary central nervous system lymphoma: a long-term mono-center study.

Treatment regimens for primary central nervous system lymphoma (PCNSL) include high-dose methotrexate (HD-MTX)-based chemotherapy, with or without radiotherapy and are based on studies of selected patient groups. This retrospective study assessed a consistent strategy of response-adapted protocol applied for patients including age >65 years in a cancer center for 10 years longitudinally. Case notes were studied of 61 consecutively treated patients with PCNSL histologically diagnosed between 2003 and 2013. Clinical follow-up during and after treatment included neurologic examination and magnetic resonance imaging. Of the patients studied, 14.8 % (9/61) were clinically unfit for chemotherapy; the remaining 85.2 % (52/61) of patients were treated with HD-MTX. Of these patients, 58 % (30/52) achieved an initial complete response, with a median survival of 100.1 months. Of these response-adapted patients, 33 % (10/30) were <65 years and were treated with upfront high-dose chemotherapy and autologous stem-cell transplantation (HDC-ASCT). The remaining response-adapted patients included 53 % (16/30) who were ≥65 years underwent consolidation with HD-MTX, and 14 % (4/30) who chose radiotherapy. The median survival of patients with HDC-ASCT had not yet been reached compared with 67.6 months for patients with HD-MTX consolidation treatment (p = 0.26). At the end of the study, 75 % (39/52) of patients had died mainly owing to progression or relapse of PCNSL. Multivariate analysis showed that age younger than 65 years (p = 0.02) and complete response for up-front HD-MTX (p = 0.001) were independent prognostic indicators of overall survival. In conclusion, this single-center retrospective clinical study has shown that treatment of PCNSL with upfront HDC-ASCT and consolidation phase HD-MTX monotherapy may be feasible, even for elderly patients in a routine clinical setting, using the three-step selection by eligibility and response to initial HD-MTX, and age threshold of 65 years for ASCT.