Incidence, Risk Factors And Prognosis Of Transformation In Follicular Lymphoma: A Multicentre Retrospective Analysis Of 1763 Patients From The Geltamo Spanish Lymphoma Cooperative Group

INTRODUCTION Follicular lymphoma (FL) may, over time, transform into an aggressive lymphoma, usually diffuse large B-cell lymphoma (DLBCL). Transformed follicular lymphomas (tFL) have a worse prognosis due to poorer response to treatment than primary DLBCL. The incidence of transformation is estimated in ~3% per year, although it varies largely between different studies (24%-70% overall). These differences are mainly due to different criteria to define tFL, to lack of evidence of tFL by biopsy, absence of clonality studies discarding secondary de novo NHL, studies performed in the pre-Rituximab era, or different follow-up times among studies. With all this pitfalls, the actual incidence of transformation remains an open question. The aim of the present study is to analyse the incidence and prognostic impact of transformation in patients with FL in a large retrospective series of the Spanish group of Lymphomas (GELTAMO). PATIENTSM others, p 2 (p=0.002, HR: 2,1 95% CI: 1.3-3.4). In the multivariate analysis, factors predicting decreased OS after transformation included non-achievement of CR after first line therapy (p We analyzed separately the role of autologous stem cell transplantation (ASCT) in transformed FL patients. Patients that received ASCT were significantly younger ( CONCLUSIONS In this series, one of the largest reported in the rituximab era, high risk FLIPI (u003e=2) and non-response to FL first line therapy were associated with a higher risk of transformation.Only non-response to transformed FL treatment therapy and a high LDH at transformation were associated with a worse OS after transformation in the multivariate analysis. Autologous transplantation in transformed patients could have a benefit in terms of OS after transformation, but after the introduction of immunochemotherapy strategies, perhaps patients responding to treatment after transformation do not beneficiate from this strategy. *Equal contribution; ‡ Equal senior contribution Disclosures Sancho: CELLTRION, Inc.: Research Funding.