Thus, we cannot exclude the possibility that differences in outcome might appear over a longer follow-up period because the curve of event onset is expected to occur later in patients with ER-positive ERBB2-negative BC than in patients with triple-negative or ERBB2-positive disease.32,33 Therefore, we have planned to continue the follow-up with a formal analysis after 10 years. Here, ERBB2 is linked to breast cancer.