[Commentary on development of the prognostic factors concept in chronic lymphocytic leukaemia: the route from prognostic factors to therapy response predictors].

Chronic lymphocytic leukaemia (CLL) is a lymphoproliferative disorder with variable clinical course. Determination of disease prognosis is based on the identification of different prognostic factors. The concept of CLL prognostic factors is still developing and has undergone several fundamental changes. Traditional (old) prognostic factors and staging systems are useful in describing the extent of the disease at any given moment, in determining clinical progression and in the identification of patients who need to start treatment. However, traditional prognostic factors are not sufficient for predicting a long-term prognosis because they are not able to identify potentially aggressive forms of CLL in the early stages. Nevertheless, clinical staging systems maintain their importance and in contrast to other traditional factors also their independent prognostic role. Otherwise, traditional prognostic factors play the role of disease activity descriptors rather than the role of actual prognostic factors. CLL risk profile determination is based on the identification of so-called new prognostic factors, the most relevant of which are chromosomal aberrations, TP53 gene mutations, mutational status of IgVH genes, ZAP-70 and CD38 expression. These factors are able to predict the prognosis already at the time of the initial diagnosis. In contrast to previous ideas, they are not incorporated into recommendations regarding indications for treatment. This is due to the risks associated with early treatment and the lack of data validated in prospective clinical trials demonstrating the justifiability of such procedure. In patients being treated, new prognostic factors may be useful for predicting the response to the therapy and some of them may directly influence the choice of treatment regime. New CLL treatment modalities have also raised the question of their influence on the prognostic and predictive power of new prognostic factors.