CAT rs1001179 Single Nucleotide Polymorphism Identifies an Aggressive Clinical Behavior in Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia (CLL) is characterized by an extremely variable clinical course. Although several parameters have been shown to be associated with clinical outcomes in patients with CLL, there remains substantial intragroup clinical heterogeneity in otherwise molecularly and staging homogeneous CLL subgroups. We have recently shown that high catalase (CAT) expression identifies patients with an aggressive clinical course and that higher CAT expression is associated with the presence of the rs1001179 single nucleotide polymorphism (SNP) T allele in the CAT promoter. Herein, we genotyped CLL patients for CAT rs1001179 SNP in an exploratory study (n = 235) and in a sequential independent validation study (n = 531). Time-to-event modeling analyses for time-to-first-treatment (TTFT) from the two patients' cohorts showed that TT genotype was associated with a shorter TTFT, independently of other currently used prognostic parameters in CLL. Moreover, the TT genotype identifies CLL patients with a faster clinical progression even within subgroups of patients with low-risk biological and clinical hallmarks. In conclusion, our data show that the TT genotype identifies CLL patients with a shorter TTFT, pointing to this SNP as a possible prognostic factor, which can improve patients' risk stratification leading to better patient management and personalized therapeutic choices.