Population: Patients over 18 with breast cancer and bone metastasis.
Inclusion criteria:
* Patient over 18 years of age.
* Patient diagnosed with breast cancer (BC) and bone metastases (BM).
* Patient who has granted informed consent in writing to participate in the study.
* Patient capable of understanding and completing the questionnaires.
Exclusion criteria:
* Patient with another type of disease that, in the investigator's opinion, could mask the study results.
* Patients with a life expectancy of less than 8 months.
* Patient who is participating in a clinical trial with an unregistered drug at the start of the study.
