Moving from prognostic to predictive factors in chronic lymphocytic leukaemia (CLL)

Many prognostic factors have been identified in chronic lymphocytic leukaemia (CLL). Based on the assessment of B cell receptor (BCR) structure and function, a subdivision into subtypes is possible (e.g., immunoglobulin heavy chain variable gene segment (IGHV) unmutated and mutated, V3-21 usage) with distinct biological and clinical characteristics. Recurrent genomic aberrations (i.e., 11q and 17p deletion) and gene mutations (i.e., TP53 and ATM) help to define biological and clinical subgroups. In addition, serum markers (e.g., thymidine kinase (TK) and ß2-microglobulin (ß2-MG)), cellular markers (e.g., CD38 and ZAP70) and clinical staging have an impact on outcome in CLL. The biological characterisation of CLL has not only led to progress in outcome prediction but also has begun to be translated into novel treatment strategies. Nonetheless, most factors associated with prognosis have not been thoroughly interrogated for their predictive value in the light of different therapeutic approaches. With a growing number of agents acting on specific biological targets and being used in different clinical situations, the future is likely to bring the identification of predictive factors in CLL.