Shared Decision Making in Surveillance for Distant Metastasis in Breast Cancer

\[Background\] 1. Shared decision making between patients and physicians when breast cancer patients encounter decision making in the initial treatment process has already been included in the recommendations for breast cancer treatment in each country. However, in the follow-up stage using various imaging tests after the initial breast cancer treatment, the evidence of decision making is very poor and the patient who understands this well and actively participates in the process of deciding the follow-up strategy are almost none. 2. Major guidelines including NCCN, ASCO and ESMO recommend surveillance with routine imaging such as sonography and mammography, and does not recommend advanced imaging tests for asymptomatic patients. These guidelines are based on two prospective randomized trials conducted in 1994. Despite many international medical recommendations, many institutions around the world are increasingly using distant metastasis tests in belief of improving the survival rate through early detection of distant metastasis and of improving the emotional stability of doctors and patients. 3. In this study, clinical impacts of shared decision making in strategy of surveillance for asymptomatic patients on quality of life would be investigated by prospective randomized pragmatic trial. Additionally, oncological results would be analyzed and real world data of patients preference would be gathered \[Study design\] Prospective, single-institutional, randomized pragmatic trial \[Statistical considerations\] With 5% significance level and 90% power, 132 patients are needed in each group. Assuming a 28% drop out rate, 368 patients need to be recruited. \[Randomizations\] Web-based randomization would be conducted stratified to subtypes. \[Objectives\] 1. Primary objective \- QoL (when enrollment, after 1 and 2 year - FACT-B score) 2. Secondary objectives * Depression - anxiety scale (HADS score) * Recurrence-free survival * Patients' preference for surveillance in SDM group * Cross over rate in SDM group