In White women, an increased risk of breast cancer was observed for COX2-rs689470 (OR: 2.02, 95% CI: 1.16–3.53) in the dominant model and ALOX5-rs1487562 (OR: 1.80, 95% CI: 1.02–3.18) in the recessive model, while the association among Black women was essentially null. This evidence concerns the gene PTGS2 and breast cancer.