ERBB2 and breast cancer: They did not observe any association with the HR-positive/HER2-positive subtype (n = 74 cases, 10+ years of use: RR = 1.47, 95% CI 0.76–2.82; fewer than 10 years of use: RR = 1.40, 95% CI 0.79–2.51) or for the receptor-negative subtypes (n = 174 cases), or for breast cancer overall [16, 17].