Shared decision-making in metastatic breast cancer: discrepancy between the expected prolongation of life and treatment efficacy between patients and physicians, and influencing factors.

Treatment decisions in oncology are based on a balance between the efficacy of therapy and its side effects. Patients with metastases and patients with a limited prognosis are a particular challenge, since communication about the disease situation and the expected therapeutic benefit is difficult not only for patients, but also for physicians. The aim of this study was therefore to compare the benefits expected of therapy by patients and physicians. Questionnaires were sent to 9,000 breast cancer patients and to 6,938 physicians. The questionnaires described 10 cases of breast cancer in the metastatic setting. The patients and physicians were asked to state the treatment benefit they would require to decide for the therapy options chemotherapy, endocrine therapy, antibody therapy, radiotherapy, and bisphosphonates. Additionally, the participants provided data on patient and physician characteristics. Expected treatment benefits were compared between patients and physicians, and influencing factors that modified the expected benefit were identified. Patients expected much greater benefits from the therapies offered than the physicians. For all treatment modalities, about 50 % or more of patients expected more than a 12-month increase in overall survival from all therapies. Among the doctors, this proportion ranged from 7 to 30 %. Among patients, previous experience of side effects and having young children in the family were the strongest influencing factors. Among the doctors, age and level of education had a strong influence on the expected prognostic improvement to indicate a therapy option. As expectations of treatment differ greatly between patients and doctors, a structured approach to solving this conflict is required. There appear to be some indicators that might help address the problem, such as the physicians' level of training and experience and the patients' specific social circumstances.