QOL of Women With HR-Positive Metastatic BC Treated in the First-line Setting: Comparison Between Public and Private Institutions.

Inclusion Criteria: * Patients who agree to participate by signing a document of free and informed consent (ICF), indicating that the research participant was informed about all relevant aspects of the study; * Female patients ≥ 18 years of age; * Patients diagnosed with hormone receptor positive, human epidermal growth factor receptor-type 2 -negative metastatic breast cancer; in first-line treatment (metastatic de novo disease or patients with recurrence during adjuvant endocrine therapy). * First-line treatment can be considered as cytotoxic chemotherapy, isolated endocrine therapy or endocrine therapy in combination with 4/6 cyclin inhibitors. * Patients on treatment for at least three (3) months and no more than eighteen (18) months. * Have performance status Eastern Cooperative Oncology Group (ECOG scale) of 0-2. * Do not present other concomitant neoplasms. Exclusion Criteria: * Patients who refuse to participate. * Illiterate patients, with low levels of education or cognitive deficits that make it difficult to answer the questions of the data collection instrument. * Patients with life expectancy \<3 months. * Treatment with any product under investigation during the last 28 days.