Correlation of the FLIPI score for follicular lymphoma with period of diagnosis and type of treatment.

OBJECTIVES: Follicular lymphoma (FL) is generally considered an indolent disorder but a significant subset of patients shows a worse outcome. Aim of this study was to validate the FLIPI score in an independent series of follicular lymphoma patients and to correlate prognostic categories with the period of diagnosis and the use of anthracycline.

METHODS: We evaluated the clinical characteristics, prognostic stratification, and outcome of 338 patients with follicular lymphoma consecutively diagnosed and followed at our Institution between 1975 and 2002.

RESULTS: The distribution of patients within the prognostic categories of the IPI and FLIPI score, while confirming the indolent outcome of follicular lymphoma, shows that a subset of patients has a worse prognosis. With the IPI score, 62% of patients are in the low risk, 26% in the low-intermediate, and 12% in the high (high-intermediate+high) risk group. With the FLIPI score, 48% of patients are categorized as low risk, 31% as intermediate risk, and 21% as poor risk. With the IPI score, median OS is 17.3 years for the low risk; 6.3 for the intermediate risk, and 5.2 years for the high risk group (p=0.0004). With the FLIPI system, median OS is 15.5 years for the low risk, 8.3 years for the intermediate risk, and 5.2 for the poor risk group (p=0.0002). Prognostic scores were calculated also after dividing patients according to the time of diagnosis: in three periods (before 1987, between 1988 and 1997, and from 1998), as well as in two periods (before and after 1998). In all the periods studied survival of patients classified according to IPI and FLIPI categories was significantly different.

CONCLUSION: This study shows in an independent series that the FLIPI score is a reproducible prognostic index of clinical utility for the initial assessment of patients with follicular lymphoma.