Prolonged Survival with Low Incidence of CNS Relapse and Late Toxicities in a Retrospective Series of 278 Young Patients with High-Risk (aa-IPI 2–3) Diffuse Large B-Cell Lymphoma Treated with Intensified Chemotherapy with or without Rituximab At Diagnosis

Abstract

1606 Introduction. Diffuse Large B-cell Lymphoma (DLBCL) patients at high-risk (age-adjusted International Prognostic Index (aa-IPI) 2–3), had a dismal prognosis if treated with conventional chemotherapy. The introduction of intensive regimens and the addition of monoclonal antibody anti-CD20, improved prognosis, but some issues remain unresolved such as: the risk of central nervous system (CNS) relapses and the incidence of late toxicities. We analyzed a series of young DLBCL patients at high-risk consecutively treated in four prospective trials by the Italian Lymphoma Foundation (FIL) with the aim to assess the risk of CNS relapses and late toxicities in this series of patients with a prolonged follow-up Methods. From 1986 to 2006, 278 patients with DLBCL with aa-IPI 2–3 at diagnosis, were enrolled in four consecutive trials previously reported. Thirty-two into a phase II study, treated with 12 weekly infusion of MACOP-B; 39 into a phase II trial with eight weekly MACOP-B infusions followed by high-dose cytarabine, mitoxantrone and dexamethasone (MAD) plus standard BEAM and autologous stem cell transplantation (ASCT); 95 in a phase III trial that randomized high-dose sequential (HDS) chemotherapy plus ASCT (45 patients) vs six courses of dose-dense intensified CHOP (iCHOP) (50 patients); 112 into a phase II trial with four courses of iCHOP in combination with Rituximab followed by Rituximab-MAD + BEAM and ASCT. CNS prophylaxis was not mandatory in the four protocols. Updated data regarding of survival, CNS relapses and late toxicities were recorded on June 2011. Results. Clinical characteristics were: aa-IPI 2 in 55%, aa-IPI 3 in 45%, PS > 2 in 66%, LDH upper normal value in 89%, number of extranodal sites > 2 in 35%, bone marrow involvement in 27% of patients, with no statistical differences between the four trials. With a median follow-up of five years, 5-year Overall Survival (OS) was 63% (95% CI: 57–69%) in the whole series; 5-year OS by treatment was 41% (95%CI: 24–74%) in MACOPB, 54% (95%CI: 37–68%) in MACOPB+MAD+BEAM and ASCT; 53% (95%CI: 38–67%) in HDS+ASCT; 58% (95%CI: 43–70%) in iCHOP; 79% (95%CI: 70–86%) in R-iCHOP+R-MAD+BEAM and ASCT. In a multivariate analysis, the risk of death was significantly reduced in R-iCHOP+R-MAD+BEAM and ASCT (p<.001) and was adversely influenced by age with a progressive increase of five years at diagnosis (p.008) or aa-IPI3 (p.001). Four patients experienced CNS relapses, three of them in R-iCHOP+R-MAD+BEAM and ASCT and one in MACOPB. Only one of the four patients received CNS prophylaxis with intrathecal Methotrexate, even if all of them were at risk for CNS relapse according to Italian Society of Hematology guidelines (Barosi, Hematol 2006). Cumulative incidence of CNS recurrence at 10 years for R-iCHOP+R-MAD+BEAM and ASCT regimen was 3.6% (0 to 7.8). Most frequent late toxicities were dyslipidemia and secondary amenorrhea. Regarding to secondary malignancies, myelodisplasia or acute myeloid leukemia were recorded in three patients, two of them treated with R-iCHOP+R-MAD+BEAM and ASCT, at a median time of seven years off therapy. The actuarial risk of secondary malignancies at 10 years for R-iCHOP+R-MAD+BEAM and ASCT was 4.2% (0 to 10). Conclusions. The addition of Rituximab to dose-dense iCHOP plus high-dose chemotherapy plus BEAM and ASCT improved the outcome in young untreated DLBCL patients at poor prognosis, with an acceptable risk of secondary malignancies and late toxicities. A careful identification of patients at risk could avoid the risk of CNS relapse. Disclosures: Vitolo: Roche Italy: Speakers Bureau; Celgene: Speakers Bureau; Jannsen-Cilag: Speakers Bureau.