ERBB2 and breast cancer: Patients with TNBC and HER2 + BC had a worse CNS-PFS compared with HR + HER2-BC (TNBC versus HR + HER2: HR 1.8; 95% CI 1.2 to 2.7; p < 0.001; HER2 + BC versus HR + HER2-BC: HR 1.45, 95% CI 1.0 to 2.0, p = 0.03).