Concomitant systemic and central nervous system non-Hodgkin lymphoma: the role of consolidation in terms of high dose therapy and autologous stem cell transplantation. A 60-case retrospective study from LYSA and the LOC network.

The purpose of our study is to determine the outcome of patients with systemic non-Hodgkin lymphoma presenting with neurologic localization at diagnosis, as well as the impact of consolidation in terms of high-dose therapy followed by autologous stem cell transplantation. Newly diagnosed non-Hodgkin lymphoma patients with concomitant systemic and neurological involvement at diagnosis were included in this study. Sixty patients (37 males; 25 females) were included. Median age was 61 years (23-85 years). Histological subtype was mainly diffuse large B-cell lymphoma (n = 54; 90%). The International prognostic index was over 2 in 41 (72%) patients. Median number of extranodal sites was 2 (range: 1-5). Central nervous system involvement alone was documented in 48 patients. Paravertebral involvement with epidural mass and cord compression and positive cerebrospinal fluid were present in 7 patients. Five patients had both central nervous system and epidural involvement. First-line chemotherapy was mainly anthracycline-based (88%) plus high-dose methotrexate (74%) with or without cytarabine. Consolidation with high-dose therapy followed by autologous stem cell transplantation was performed in 19 patients. For the whole population, overall response rate after induction chemotherapy was 76%. Three-year progression-free survival and overall survival were 42 ± 7% and 44 ± 7%, respectively. For patients under 66 years of age, consolidation strategy using high-dose therapy followed by autologous stem cell transplantation positively impacted 3-year overall survival and progression free survival (P = 0.008) and (P = 0.003), respectively. In multivariate analysis, high-dose therapy had a positive impact on 3-year overall survival and progression-free survival for the whole population as well as for patients under 66 years old in CR after induction therapy (OS [HR=0.22 (0.07-0.67)] and progression-free survival [HR = 0.17 (0.05-0.54)]). In conclusion, non-Hodgkin lymphoma prognosis with concomitant systemic and neurological involvement at diagnosis is poor with a high risk of relapse when treated with conventional chemotherapies alone. This retrospective study supports the feasibility and the potential benefit of a consolidative strategy with high-dose therapy followed by autologous stem cell transplantation in this subset of patients. This strategy and the best intensive chemotherapy regimen remain to be validated in prospective trials.