Genomic arrays identify high-risk chronic lymphocytic leukemia with genomic complexity: a multicenter study

Complex karyotype identified by chromosome-banding analysis has been shown to have prognostic value in chronic lymphocytic leukemia (CLL). Genomic arrays offer high-resolution genomewide detection of copy-number alterations (CNA) and could therefore be well equipped to detect the presence of a complex karyotype. Current knowledge on genomic arrays in CLL is based on outcomes of single-center studies, in which different cutoffs for CNA calling were used. To further determine the clinical utility of genomic arrays for CNA assessment in CLL diagnostics, we retrospectively analyzed 2,293 arrays from 13 diagnostic laboratories according to established standards. CNA were found outside regions captured by CLL fluorescence in situ hybridization probes in 34% of patients, and several of them, including gains of 8q, deletions of 9p and 18p ( P