Addition of endocrine therapy to dual anti-HER2 targeted therapy in initial treatment of HER2 + /HR + metastatic breast cancer

Matthew Loft, Sheau Wen Lok, Richard de Boer, Laeeq Malik, Sally Greenberg, Belinda Yeo, A. Antón, Michelle Nottage, Vanessa Wong, Louise Nott, Ian Collins, Javier Torres, Frances Barnett, Janine Lombard, Peter Gibbs, Lucy Gately