After both stages, only one SNP was significantly associated with an increased risk of breast cancer - the PGR-12 (rs1042638) V660L valine to leucine polymorphism [VL heterozygotes (odds ratio, 1.13; 95% confidence interval, 1.03-1.24) and the LL homozygotes (odds ratio, 1.30; 95% confidence interval, 0.98-1.73), P(het) = 0.008, P(trend) = 0.002].