Association between single nucleotide polymorphism-genotype and outcome of patients with chronic lymphocytic leukemia in a randomized chemotherapy trial

Background There is variability in the outcome of patients with chronic lymphocytic leukemia with apparently the same stage of disease. Identifying genetic variants that influence patients' outcome and response to treatment may provide important insights into the biology of the disease. Design and Methods We investigated the possibility that genetic variation influences outcome by conducting a genome-wide analysis of 346,831 single nucleotide polymorphisms in 356 patients entered into a phase III trial comparing the efficacy of fludarabine, chlorambucil, and fludarabine with cyclophosphamide as first-line treatment. Genotypes were linked to individual patients' outcome data and response to chemotherapy. The association between genotype and progressionfree survival was assessed by Cox regression analysis adjusting for treatment and clinicopathology. Results The strongest associations were shown for rs1949733 (ACOX3; P=8.22x10 ^-7), rs1342899 (P=7.72x10 ^-7) and rs11158493 (PPP2R5E; P=8.50x10 ^-7). In addition, the 52 single nucleotide polymorphisms associated at P<10 ^-4 included rs438034 (CENPF; P=4.86x10 ^-6), previously correlated with cancer progression, and rs2255235 (B2M; P=3.10 x 10 ^-5) and rs2064501 (IL22RA2; P=4.81x10 ^-5) which map to B-cell genes. Conclusions Our findings provide evidence that genetic variation is a determinant of progression-free survival of patients with chronic lymphocytic leukemia. Specific associations warrant further analyses.