Long-term outcome comparing histological grades of follicular lymphoma patients treated with immunochemotherapy as first-line therapy: A retrospective analysis from two institutions.

OBJECTIVES: To clarify the impact of histological grades in follicular lymphoma. METHODS: We retrospectively analysed 250 patients diagnosed with FL treated with chemoimmunotherapy: 188 patients were grades 1-2 and 62 grade 3A. RESULTS: In our series, grade 3A FL patients were older, higher proportion of localised disease and lower bone marrow infiltration at diagnosis comparing grades 1-2 FL patients. Estimated six-year progression-free survival and time to progression showed no differences between both groups [grade 3A: 56% (95%CI: 39%-73%) and 51% (95%CI: 41%-61%) vs grades 1-2:55% (95%CI: 46%-63%) and 57% (95%CI: 49%-65%), P = .782 and P = .521, respectively]. Estimated six-year overall survival was lower, 76% (95%CI: 64%-88%) for the grade 3A group than grades 1-2 83% (95%CI: 77%-89%); P = .044. In addition to that, cumulative incidence curves of death not related to lymphoma at 10 years between groups were as follows: [0.26 (95%CI: 0.25-0.27) and 0.05 (95%CI: 0.04-0.06) for G3AFL and G1-2FL, respectively], P = .010. Grade 3A FL showed in PFS curve no relapses after 6 years. These results were absolutely reproduced in 199 patients receiving R-CHOP regimen as induction. CONCLUSIONS: Our results indicate similar long-term outcomes in terms of progression-free survival and time to progression in grades 1-2 and 3A. No relapses were observed in G3AFL group after 6 years.