Liz O’Riordan (a consultant breast surgeon)and Trish Greenhalgh (a professor of primary care and well-known writer on evidence-based medicine) both developed breast cancer in 2015. Whilst both authors were already ‘experts’ in aspects of breast cancer, they quickly found that their academic and surgical knowledge did not prepare them well for being breast cancer patients. As they went through treatment, they acquired a new form of knowledge – around the lived experience of serious illness and its management – which helped them manage both the physical and the emotional aspects of the disease. They later wrote a book for other patients with breast cancer, containing all the things they had wanted to know the day they were diagnosed (which became a bestseller and is now widely recommended by oncologists and breast surgeons). This presentation will offer an account of patient-relevant evidence on breast cancer (much of it experiential) and invite discussion from the audience.