ERBB2 and breast cancer: A meta-analysis of 97 studies by Erickson et al. showed that HER2-targeted therapy was associated with improved overall survival (OS) (hazard ratio (HR) 0.47; 95% confidence interval (CI) 0.39–0.56) in patients with HER2-positive breast cancer and intracranial metastases compared to the nontargeted therapy group.