The genotype distribution of this variant increased the breast cancer risk in patients with HER2-positive status (OR = 2.13, 95% CI = 1.10–4.13, p = 0.025); however, it showed a protective association among those who had grade 2 cancer (OR = 0.38, 95% CI = 0.19–0.75, p = 0.006) and a positive lymph node status (OR = 0.55, 95% CI = 0.30–0.98, p = 0.043). This evidence concerns the gene ERBB2 and breast cancer.