The prognostic significance of 13q14 deletions in chronic lymphocytic leukemia

Abstract

Although chronic lymphocytic leukemia (CLL) is the most common leukemia in adults, little is known about the molecular abnormalities underlying it and their prognostic significance. Using a battery of six microsatellite markers from 13q12.3-14.3 between BRACA2 gene and the Rb gene, we assayed loss of heterozygosity (LOH) in 78 CLL patients. We found deletion in 13q14 in 29 patients (37%) between D13S153 and the AFMa 301wb5. Classical cytogenetics was less sensitive, as it detected the 13q14 deletion in only one out of 69 patients (1%) in whom adequate metaphases were obtained. We found no significant difference in survival between patients with and patients without 13q14 LOH. In subset of patients with low β 2-microglobulin levels, those with 13q14 LOH had significantly shorter survival than did patients with low β 2-microglobulin levels but no 13q14 LOH. Also patients in early Rai stages (0–II) with 13q14 LOH had shorter survival period ( P=0.05) than did patients without LOH. These data confirm the prevalence of 13q14 deletion in CLL and suggest that this deletion may help identify more aggressive disease in patients presenting with early stage disease.