During a 2-year period, 758 patients newly diagnosed with breast cancer will be screened for inclusion at the Section of Breast Surgery at Rigshospitalet, Copenhagen. Of these 324 participants enter the randomized controlled trial (RCT) and are randomized in a computer-generated sequence of 1:1 to the intervention (nurse-navigation) or control group (standard care). A total of 432 participants will enter an observational questionnaire study. All participants are followed for 1,5 years.