However, given the relatively low incidence of CNS metastases, we cannot identify differences between the incidence of CNS metastases in different treatment groups of the trials, e.g., between lapatinib- and trastuzumab-treated patients with HER2-positive breast cancer or in the cohort of triple-negative patients with carboplatin therapy compared to patients without carboplatin therapy. Here, ERBB2 is linked to breast cancer.