This study aimed to investigate the association of the GSTP1 gene polymorphism with the outcomes and toxicities of treatments in breast cancer. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for the association of GSTP1 polymorphism with tumour response and toxicities, and the hazard ratios (HRs) and 95% CIs were calculated for the association between GSTP1 polymorphism and overall survival (OS). The statistical analysis showed that the GSTP1 polymorphism was not associated with tumour response or OS. A significant increase in the incidence of toxicities was observed (GA vs. AA OR = 1.45, 95% CI = 1.04-2.01, P = 0.028; GG vs. AA OR = 1.47, 95% CI = 1.03-2.10, P = 0.036; recessive model OR = 1.54, 95% CI = 1.13-2.09, P = 0.006; and allele model OR = 1.35, 95% CI = 1.07-1.71, P = 0.011), especially in the chemotherapy ± surgery group (GA vs. AA OR = 1.64, 95% CI = 1.05-2.56, P = 0.030; recessive model OR = 1.72, 95% CI = 1.17-2.54, P = 0.006; and allele model OR = 1.57, 95% CI = 1.11-2.21, P = 0.010). Our results indicate that the GSTP1 polymorphism may be associated with increased toxicity, especially in patients treated with chemotherapy ± surgery.
Keywords: GSTP1; breast cancer; meta-analysis; toxicities; treatment outcome.