The percentage of cells with 17p deletion and the size of 17p deletion subclones show prognostic significance in chronic lymphocytic leukemia.

TP53 disruption is considered to be the most important prognostic factor in chronic lymphocytic leukemia (CLL), but not all patients with TP53 disruption have similar dismal outcomes. We evaluated the prognostic value of TP53 disruption in CLL patients without treatment indications. Data of 305 CLL patients were analyzed. 41 of them (13%) had TP53 disruption. Patients with lower percentage of cells with del(17p) had significantly better survival. Patients with mutated IGHV, β2-microglobulin ≤3.5 mg/L, wild-type TP53, age ≤65 years or without complex karyotype (CK) had relatively favorable outcomes in the del(17p) group. Furthermore, patients with del(17p) as a minor clone showed survival advantage compared with those with del(17p) as a major clone. These data suggest that the percentage of cells with del(17p), the size of the del(17p) subclone, CLL International Prognostic Index, and CK should be considered to build refined prognostication models for patients with TP53 disruption.