This is an exploratory research study with the aim of identifying specific cancer biomarkers in various subtypes of breast cancer. Blood samples will be collected from 60 participants divided into 40 patients and 20 healthy donors. An amendment to the research has been proposed to enroll 24 additional participants divided into 12 patients and 12 healthy donors.

In this research study different commercial RUO (Research Use Only) antibodies will be purchased and then tested on blood samples obtained by participants affected by breast cancer and by healthy participants as control. Sixty participants will be enrolled belonging to different categories: 20 participants affected by early breast cancer, 20 participants affected by metastatic breast cancer, and 20 healthy volunteers to be used as negative control.

After signing the informed consent form, participants will be screened to evaluate if they meet the eligibility criteria. If all the criteria are met, participants will be enrolled into the study and will be asked to provide some demographic and other data. A 13 ml blood sample will be collected by the subjects and shipped to Tethis laboratories in order to be processed and analysed.

An amendment has been proposed to enroll 24 additional participants divided into 12 patients and 12 healthy donors. During the amendment, participants will be enrolled to test the analytical capacity of the antibodies evaluated in the first part on samples processed with different methods in order to select the optimal one for future development.

Inclusion Criteria:

• Participant is willing and able to give and sign a written informed consent for participation in the study.
• Female aged 18 years or above.
• Diagnosed with early breast cancer (stage I and II) or metastatic breast cancer.
• Healthy participants who visit the site for reason other than cancer diagnosis (including breast cancer).

Exclusion Criteria:

• History of other malignancies other than breast cancer (for healthy participants includes also breast cancer).
• Undergone surgery or treatment for breast cancer before enrollment (only for early breast cancer).
• Presence of known severe coagulation or haematological disorder
• Known Pregnancy
• Absence of written signed informed consent for participation in the study

Participants will be selected from among the people who visit the Breast Surgery department

This is a basic research study without an IPD information sharing plan