Treatment of diffuse large B-cell lymphoma with secondary central nervous system involvement: encouraging efficacy using CNS-penetrating R-IDARAM chemotherapy.

Diffuse large B-cell lymphoma with secondary involvement of the central nervous system (SCNS-DLBCL) is a rare condition carrying a poor prognosis. No optimal therapeutic regimen has been identified. We retrospectively analysed 23 patients with SCNS-DLBCL treated with R-IDARAM (rituximab 375mg/m(2) IV day 1; methotrexate 125mg by intrathecal injection day 1; idarubicin 10mg/m(2)/day IV days 1 and 2; dexamethasone 100mg/day IV infusion over 12h days 1-3; cytosine arabinoside 1000mg/m(2)/day IV over 1h days 1 and 2; and methotrexate 2000mg/m(2) IV over 2h day 3. Ten out of 23 (44%) patients had CNS involvement at initial presentation (new disease'), 10/23 (44%) had relapsed disease and 3/23 (13%) had primary refractory disease. 14/23 (61%) of patients responded - 6 (26%) complete response, 8 (35%) partial response. Grade 3-4 haematological toxicity was seen in all cycles, with no grade 3-4 or long-term neurological toxicity. Median follow-up for surviving patients was 49months. At 2years, estimated progression-free survival (PFS) was 39% and overall survival (OS) was 52%. Encouraging outcomes were reported in patients with new disease, with 5-year estimated PFS of 50% and OS 75%. R-IDARAM is a well-tolerated regimen with encouraging efficacy in patients with SCNS-DLBCL, although patients with relapsed or refractory disease continue to fare poorly.