Peripheral blood involvement in patients with follicular lymphoma: a rare disease manifestation associated with poor prognosis. (26th November 2013) - Sarkozy, Clémentine
Summary Follicular Lymphoma (FL) is the second most common non‐Hodgkin lymphoma (NHL) subtype and its course is heterogeneous. At diagnosis, some patients with FL manifest a detectable leukaemic phase (FL‐LP), but this feature has been seldom described and is poorly characterized. Among 499 patients diagnosed with FL in Lyon‐Sud hospital, 37 (7·4%) had characteristic FL‐LP (by cytological blood smears and flow cytometric analysis). In addition, 91/1135 FL patients from the PRIMA study presented FL‐LP at study entry. In order to evaluate the outcome of this Lyon‐Sud cohort, FL‐LP patients were matched with 111 newly diagnosed FL without LP according to the Follicular Lymphoma International Prognostic Index (FLIPI) score, age and treatment. Presence of FL‐LP was associated with shorter progression‐free survival (PFS) and overall survival (OS) (P = 0·004 and P = 0·031, respectively). Presence of FL‐LP and high FLIPI score remained independent prognostic factors in a Cox model for time to progression (TTP). A number of circulating lymphoma cells (CLC) >4 × 109/l was the most significant predictor for a shorter TTP in this Cox model. The prognostic impact of FL‐LP on TTP was validated in the PRIMA cohort (P = 0·0004). In conclusion, FL‐LP is a rare event associated with shorter PFS and patients with CLC >4 × 109/l have a poorer outcome. These patients should be monitored carefully to consider alternative therapeutic options.