Risk-assessment in diffuse large cell lymphoma at first relapse. A study by the Italian Intergroup for Lymphomas.

BACKGROUND AND OBJECTIVES: Our aim was to identify risk factors in adults with diffuse large cell lymphoma at first relapse.

DESIGN AND METHODS: We studied 474 patients observed at 45 centers in Italy. Median time from diagnosis to relapse was 395 days, median age at relapse was 55 years and median follow-up from relapse was 3.3 years. Salvage therapy consisted of polychemotherapy in 79% of patients, monochemotherapy and/or radiotherapy and/or surgery alone in 16%, and palliative therapy in 5%. Salvage treatment was intensified with high-dose chemotherapy + stem cell transplant in 20% of patients. OS and PFS were compared by sex, International Prognostic Index at diagnosis, histology, B/T phenotype, initial treatment, salvage therapy, and features at relapse: time from diagnosis, LDH, stage, performance status and bone marrow involvement. Cox models, adjusted for salvage therapy, were performed with factors related to overall survival (OS) and progression-free survival (PFS).

RESULTS: Overall response (complete + partial) was 63%, OS at 3 years 35% and PFS at 3 years 26%. Relapse within 12 months from diagnosis, elevated serum lactic dehydrogenase (LDH), advanced stage and poor performance status were independent adverse factors for OS and PFS. The cumulative number of adverse factors is proposed as prognostic index for DLCL at first relapse since it identifies risk groups (p<0.0001) and has been validated (p=0.01). Moreover, it predicts OS and PFS in the selected group of patients with a responsive relapse (p<0.0001).

INTERPRETATION AND CONCLUSION: Delay from initial diagnosis, LDH, stage and performance status at relapse should be balanced in comparative studies of salvage therapy of adults with DLCL. Patients with more than 2 adverse factors are one third of all cases and deserve more effective salvage treatments.