Observational study investigating Tolerance Of Anticancer Systemic Therapy In the Elderly (TOASTIE): a protocol oleh Sarah Taylor, Eleanor Smith, Christopher Mark Jones, Daniel Swinson, Mark A Baxter, Fiona Smith, R D Petty, Helen Dearden, Sally Martin, Michael Rowe, Kieran Zucker, Anna C Olsson-Brown, Clair Brunner, Anna Lewis, Lisa Rodgers, Anthea Cree