Evaluation of Improvements in Patient-reported Quality of Life

Inclusion Criteria: * Before patient registration, written informed consent must be given according to national and local regulations. * Participants have had histologically proven stage I-III breast cancer undergoing endocrine treatment (with or without prior chemotherapy) no more than 12 months prior to randomization. * Be between 18 and 75 years of age. * Have increased life expectancy beyond the initial 3 months post-treatment initiation. * Have the ability to understand protocol, participate in testing and willingness to sign a written informed consent. * Absence of any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule. Exclusion Criteria: * Patients that are not willing to sign an informed consent form