Hyperdiploidy as a rare event that accompanies poor prognosis markers in CLL

The presence of chromosomal gains other than trisomy 12 in chronic lymphocytic leukaemia (CLL) is unusual. However, some patients may show gains on several chromosomes simultaneously suggesting a hyperdiploid karyotype.

The objective of this study was to analyse by FISH the frequency and prognostic impact of hyperdiploidy in CLL.

A review of 1359 consecutive cases diagnosed with CLL referred for FISH analysis to a unique institution was carried out. Hyperdiploidy was considered when a gain of at least three of the five FISH probes used was observed.

Seven cases (0.51%) with hyperdiploidy were found, confirming that it is a rare event in this disease. Although most patients presented with early Binet stages at diagnosis, six of seven (86%) shortly progressed. The median of time to the first therapy (TTFT) and overall survival (OS) for the patients with hyperdiploidy were short (1.4 months and 20 months, respectively). Moreover, comparing them with a control group of patients (non-hyperdiploid) with completed follow-up data, TTFT and OS of the patients with hyperdiploidy were significantly shorter than the control group.

The presence of hyperdiploidy is uncommon and probably associated with poor prognostic markers in CLL.