The study stems from the need to detect adverse events arising after the administration of Antibody-Drug Conjugates (ADCs) used in the treatment of metastatic breast cancer in a real life context and to correlate the same with the quality of life reported by patients.

The study stems from the need to detect adverse events arising after the administration of ADCs used in the treatment of metastatic breast cancer in a real life context and to correlate the same with the quality of life reported by patients.Through the findings of toxicities related to the ADCs, it will be possible to highlight which are the issues that most affect patients undergoing these cancer treatments. The analysis of the data collected will also make it possible to highlight any toxicities not yet considered or/and of new onset. In addition useful elements may emerge from responses to the quality of life questionnaire, to cope with the difficulties expressed by patients regarding daily life activities, social relations, work and family. Such contributions will be fundamental to the construction of integrated care pathways, the aim of which is to involve a specialized nurse as part of a multidisciplinary team.

Inclusion Criteria:

• Female gender;
• Age ≥ 18 years;
• Signature of consent to participate in the study and to the processing of personal data (Privacy);
• Diagnosis of stage IV breast cancer;
• Systemic treatment with T-DM1, T-DXD or SG as monotherapy;
• Absence of cognitive decline, expressed by a score greater than or equal to 4 on the Six Item Screener questionnaire;
• Good understanding of the Italian language;
• Willingness and ability to adhere to scheduled visits, treatment plan, laboratory tests and study procedures.

Exclusion Criteria:

• All patients who do not meet the above criteria will be excluded from the study.

92 patients diagnosed with stage IV breast cancer treated at the Department of Medical Oncology and Cancer Prevention, IRCCS National Cancer Institute of Aviano and at the other involved clinical centers considered eligible for the study will be enrolled, after providing written informed consent.