Aim of this study is to optimize an adherence increasing intervention designed for metastatic Breast Cancer (BC) patients by applying a full factorial design in order to evaluate the optimal combination of three different intervention components.

Today different types of Oral Anticancer Agents (OAA) are commonly prescribed to Breast Cancer (BC) patients. Patients are reported to prefer the oral modality of administration over the intravenous one for its convenience, flexibility, and easier assumption; nonetheless, the phenomenon of medication non-adherence is well-documented.

Although several interventions have been designed and tested in order to foster medication adherence among BC patients, the great majority of them were focused on adherence to endocrine therapy for early-stage BC patients, with only few exceptions involving metastatic BC patients or considering adherence to other types of OAA.

The aim of this work is to optimize an adherence increasing intervention designed for metastatic BC patients. This will be achieved by applying a full factorial design in order to evaluate the optimal combination of three different intervention components (informative documentation, personalized reminders and feedback).

Inclusion Criteria:

• Patients with a diagnosis of metastatic BC
• Patients with a prescription for any OAA (i.e. oral chemotherapy, endocrine therapy, and Cyclin-Dependent Kinase 4/6 Inhibitors)
• Age >18 years old
• Patients with a personal smart phone with internet access
• Willingness and ability to comply with scheduled visits and other trial procedures
• Understanding and speaking Italian language
• Written informed consent

Exclusion Criteria:

• Psychiatric disorders or conditions that might impair the ability to give informed consent
• Comorbidity that may impact on compliance to study procedures

Metastatic breast cancer patients with a prescription for any Oral Anticancer Agent