Revalidation of FLIPI in patients with follicular lymphoma (FL) registered in the F2 study and treated upfront with immunochemotherapy

Abstract

8008 Background: The Follicular Lymphoma International Prognostic Index (FLIPI) has become a widely accepted tool for risk assessement of FL. However, the recent shift to upfront immuno-chemotherapy (ICHT) requires confirmation studies of FLIPI discriminant power to ensure that the advent of Anti-CD20 MoAb did not modify its predictive value. Methods: We looked for the role of rituximab and its impact on the predictive value of FLIPI in the group of 1,093 patients diagnosed with FL between January 2003 and May 2005 and registered by 69 European and American Institutions in the F2-study. We identified 827 patients = 18 years of age and treated with systemic therapy. For the purposes of the present examination the prognosis was investigated in terms of progression-free survival (PFS) and the impact of rituximab explored by Cox analysis. Results: Patients characteristics are as follows: median age 57 yrs (21–93), male 50.1%, advanced stage 77.2%, elevated LDH 22.3%. To date central pathology review has been performed in 406 cases and the diagnosis of FL was confirmed in 98.3%. Patients at low risk (LR), intermediate risk (IR) and high risk (HR) on the basis of FLIPI were 40.3%, 32.6% and 27.1% respectively. Five-hundred sixty patients (67.7%) received ICHT, and 267 (32.3%) were treated with CHT only. After a median follow-up of 26 months the 3-yr PFS is 63.0%. Overall, the FLIPI remains highly predictive, being the 3-yr PFS of 77.8%, 60.5% and 49.1% for patients at LR, IR and HR respectively. Moreover, the 3-yr PFS predicted from Cox analysis is 81%, 62%, and 50% for patients at LR, IR and HR treated with ICHT (p<0.001), and 76%, 56%, 43% in those treated with CHT only (p<0.001). Finally, the relative risk for progression adjusted by the use of Anti-CD20 MoAb confirmed the efficacy of rituximab in all risk groups. The relative risk of progression for patients at IR was 2.01 as compared to patients at LR (p<0.001), and that for patients at HR was 1.47 as compared to patients at IR (p=0.021). Conclusions: Our study demonstrates that the FLIPI remains a useful tool to predict outcome even in the era of ICHT. Moreover, rituximab added to upfront chemotherapy improves the outcome of patients with FL in any risk group and in association with any chemotherapy regimen. No significant financial relationships to disclose.