Prospective Validation of the FLIPI: Baseline Distribution and Correlates in Newly Diagnosed Follicular Lymphoma (FL) Patients from the US: First Report of the National LymphoCare Study.
Authors: Link Brian K. , Cerhan James R. , Dillon Hildy , Farber Charles M. , Feliciano Susan , Friedberg Jonathan W. , Hainsworth John , Steis Ron , Vose Julie M. , Zelenetz Andrew D. 
Published: April 2020

Abstract
Background: FL comprises one quarter of lymphoma in the United States, presents in a heterogeneous fashion, and generates substantial debate regarding optimal management strategies. The recently published clinical prognostic index (FLIPI, BLOOD104:1258) facilitates outcome evaluation and may guide therapeutic strategy. The National LymphoCare Study (NLCS) is an ongoing disease-based longitudinal observational study designed to assess patterns of initial disease presentation including prognosis, long term treatment choices, and clinical outcomes in FL patients.
Methods: Beginning March, 2004, pts were recruited from U.S. community practices and academic centers. Pts with FL diagnosed within 6 months with no prior lymphoma history are eligible for enrollment. Collected data includes histology, staging and prognostic evaluation, serial management strategies including drug choices but not doses, response to treatment, and events including relapses and death. There is no study-specific prescribed treatment regimen or intervention. The treating physician determines management for FL according to clinical judgment.
Results: 992 pts were enrolled from 207 sites through April, 2005. 182 community sites enrolled 86% of subjects. Pt characteristics include median age 62y, 52.5% female, 90.6% Caucasian, 40% Gr1, 26% Gr2, 19% Gr3, 13% NOS, with highest determined Ann Arbor stage = 17% I, 15%II, 26% III, 33%IV, 8% Unk. The demographic characteristics are similar to pts in the national SEER registry (median age 64, 51% F, 91.3% Caucasian) but clinical characteristics are notable for a higher fraction of advanced stage disease. 686/992 (69%) patients had calculable FLIPI scores based on initial investigator workup. Of factors contributing to FLIPI scores, LDH was collected by investigators in 78% of pts. When correlated with age, geography, and academic/community sites, LDH collection rates differ with 90% in academic sites vs 76% in community sites (p = .0002). Distribution of FLIPI among 686 pts with complete scores are shown in Table1, and show remarkable consistency across grades.
Summary: The NLCS is an ongoing study with a large and rapidly growing database combining clinical and treatment data and is the first database investigating initial workup, prognosis, and outcomes of pts in a predominantly community based U.S. population. FL pts enrolled in NLCS are similar to those in the SEER database, and should be widely generalizable to the US population. FLIPI continues to define three distinct groups in the NLCS and is independent of histologic grade. Current evaluation patterns result in 31% incomplete FLIPI scores, suggesting this useful prognostic index is underutilized.
FLIPI distribution (%) Low 36 37 37 38 34 81 14 Intermed 37 31 32 28 37 14 40 High 27 32 31 34 29 5 46 Solal Celigny n=1795 NLCS n=686 NLCS Gr1 n=276 NLCS Gr2 n=188 NLCS Gr3 n=136 Stage I/II n=234 Stage III/IV n=452