Controversial fluorescence in situ hybridization cytogenetic abnormalities in chronic lymphocytic leukaemia: new insights from a large cohort.

The significance of rarer cytogenetic abnormalities in chronic lymphocytic leukaemia ( CLL) remains controversial. We performed fluorescence in situ hybridization ( FISH) prior to initial therapy on 618 CLL patients seen at our centre between 2005 and 2012. With a median follow-up of 5·6 years, we found that 55 patients harbouring 14q32 rearrangements without t(14;18) had a shorter time to first treatment ( TTFT) (median 26 months, P = 0·03) than patients with t(14;18) (median not reached). Patients with mono- or bi-allelic del(13q) as a sole abnormality had a similarly long TTFT (median not reached). Those patients who harboured 3 or more FISH abnormalities without del(17p) had a short TTFT (4·6 months), comparable to patients with del(17p) (8 months); however, the overall survival for patients with 3 or more FISH abnormalities was longer than for patients with del(17p) with 0 or 1 additional abnormalities (median not reached vs. 54 months). FISH cytogenetics remains a useful genetic tool in the clinic, even in the era of next generation sequencing and, as such, our data provide valuable new insights for counselling patients. [ABSTRACT FROM AUTHOR]