MDM2 SNP309 promoter polymorphism, an independent prognostic factor in chronic lymphocytic leukemia.

BACKGROUND

The single nucleotide polymorphism SNP309 with a change from T to G in the promoter region of the MDM2 gene is shown to increase the MDM2 protein levels and attenuate the p53 levels and associates with disease progression in several tumors.

OBJECTIVE

In this study, the role of the polymorphism was investigated with regard to the clinical outcome in B-cell chronic lymphocytic leukemia (B-CLL).

PATIENTS

A total of 210 patients with B-CLL were followed for up to 19 yr.

RESULTS

The overall survival (OS) of patients with at least one G-allele was significantly shorter when compared with those with two T-alleles (P = 0.024) with a more pronounced difference in patients below the median age. Age at onset of B-CLL was similar irrespective of MDM2 status. The presence of a G-allele in combination with TP53 mutations or unmutated IgVH gene status resulted in an additive risk of death.

CONCLUSION

In this report, with a high proportion of B-CLL patients with an advanced Binet stage and with an unmutated IgVH gene, MDM2 SNP309 was found to be independently associated with OS. The survival difference was more pronounced in younger patients.