Should IGHV status and FISH testing be performed in all CLL patients at diagnosis? A systematic review and meta-analysis.

Since the first description of the natural history of chronic lymphocytic leukemia (CLL) by David Galton in 1966, the considerable heterogeneity in the disease course has been well recognized. The Rai and Binet staging systems described ∼40 years ago have proven to be robust prognostic tools. Over the past 2 decades, several novel biological, genetic, and molecular markers have been shown to be useful adjuncts to the Rai and Binet staging systems. In this systematic review, we examined the role of immunoglobulin heavy-chain variable region gene (IGHV) mutation status and genetic abnormalities determined by interphase fluorescence in situ hybridization (FISH) in patients with newly diagnosed CLL. The cumulative evidence presented in this systematic review is sufficient to recommend that FISH and IGHV be performed as standard clinical tests for all patients with newly diagnosed CLL in those countries with the resources to do so. In addition to clinical stage, these parameters could represent the minimal standard initial prognostic evaluation for patients with CLL. This approach will allow the application of powerful, recently developed prognostic indices (all of which are dependent on IGHV and FISH results) to all patients with newly diagnosed CLL.