ERBB2 and breast cancer: In the ribociclib group, 146 patients (44%) had prior (neo)adjuvant chemotherapy and 175 patients (52%) had prior (neo)adjuvant ET (Conte P et al. First-line ribociclib + letrozole in patients with HR+/HER2– advanced breast cancer who received prior (neo)adjuvant therapy: a subgroup analysis of the MONALEESA-2 trial.