Early stage breast cancer treatment and outcome of older patients treated in an oncogeriatric care and a standard care setting: an international comparison - de Boer, Anna Z.; van de Water, Willemien; Bastiaannet, Esther; de Glas, Nienke A.; Kiderlen, Mandy; Portielje, Johanneke E. A.; Extermann, Martine (Breast cancer research and treatment, 2020)