Assess the quality of life in patients with hormone receptor positive, human epidermal growth factor receptor-type 2 negative metastatic breast cancer treated in first line (patients with new metastasis or recurrence during adjuvant endocrine therapy): comparison between public and private institutions. The hypothesis to be evaluated is that patients treated in private institutions have a better quality of life when compared to patients treated in public institutions.

The main objective of the study is to assess the quality of life using the EORTC-QLQ-C30 (EORTC Quality of Life Questionnaire) and the EORTC-QLQ-BR23 (EORTC Quality of Life Questionnaire - Breast Cancer) of a patient with metastatic breast cancer hormone receptor positive human epidermal growth factor receptor-type 2 negative receiving treatment in the first-line scenario, comparing 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.

Patients treated at the oncology outpatient clinic of Hospital Beneficência Portuguesa in São Paulo and Hospital Perola Byington