Pharmacogenetic association between GSTP1 genetic polymorphism and febrile neutropenia in Japanese patients with early breast cancer

Background: Genetic risk factors for febrile neutropenia (FN), the major adverse event of perioperative chemotherapy for early breast cancer, remain unclear. Methods: This study retrospectively explored pharmacogenetic associations of single nucleotide polymorphisms (SNPs) of the uridine glucuronosyltransferase 2B7 (UGT2B7, rs7668258), glutathione-S-transferase pi 1 (GSTP1, rs1695), and microcephalin 1 (MCPH1, rs2916733) genes with chemotherapy-related adverse events in 102 Japanese women who received epirubicin and cyclophosphamide as perioperative chemotherapy for early breast cancer. Results: The allele frequencies for all of the SNPs were in concordance with the Hap-Map data of Japanese individuals. Among the 24 patients who had FN at least once during all courses of chemotherapy, 23 had the A/A genotype, and 1 had the A/G genotype of the GSTP1 polymorphism (rs1695, P = 0.001); 23 of the 70 patients with the A/A genotype had FN, as compared with only 1 of the 32 patients with the A/G and G/G genotypes. The genotype distributions of the UGT2B7 and MCPH1 polymorphisms did not differ between the patients who had FN or grade 3/4 neutropenia and those who did not. Conclusion: Among Japanese women who received epirubicin and cyclophosphamide as perioperative chemotherapy for early breast cancer, those with the A/A genotype of the GSTP1 polymorphism (rs1695) were more likely to have FN.