GSTM1 and breast carcinoma: Breast cancer-specific mortality demonstrated a different pattern, with carriers of GSTT1 null mutation/GSTM1 present/GSTP1105Ile/Ile genotypes associated with a reduced risk (HR=0.12; 95% CI 0.01-1.16) compared to participants with GSTM1 present/GSTT1 present/homozygous wild-type for GSTP1. However this association was not significant (P=0.06).