Intermediate prognosis of 6q deletion in chronic lymphocytic leukemia

Cytogenetic features have an important role in the definition of distinct disease subsets in CLL. The deletion of 6q is known to occur at a relatively low frequency in CLL, and the detailed analysis of hematologic and clinical features of patients with CLL with 6q deletion is limited. To verify the incidence and prognostic significance of 6q deletion in Chinese patients with CLL, fluorescence in situ hybridization (FISH) was used in 240 patients with CLL. del(6q23) was found in 18 patients (7.5%), and only five patients had deletion in 6q23 as the sole abnormality. Strong correlations between del(6q23) and clinical parameters were not found. A difference in terms of survival in patients with del(6q23) as compared with patients without this anomaly was not able to be demonstrated. However, a significant difference was found when comparing the del(6q23) group with the del(17p13) or del(11q22.3) group (p = 0.023), or isolated del(13q14) group (p = 0.019). Our findings place the del(6q23) cytogenetic subset of CLL in an intermediate prognosis position between patients with del(11q22.3) or del(17p13), and patients with isolated del(13q14). FISH probes to detect deletions of 6q might be useful in clinical practice in the work-up of patients with CLL.