Oligometastatic breast cancer is a condition in which breast cancer has spread to a small number of other parts of the body. Patients with this type of disease may live longer than those with more widespread metastases. In addition to standard treatments that act on the whole body, such as chemotherapy or hormonal therapy, these patients might also benefit from local treatments that directly target the cancer spots. One of these local treatments is stereotactic body radiotherapy (SBRT), a non-invasive radiation treatment that delivers high doses of radiation in a few sessions. In the past, most of the evidence about the benefit of local treatments came from surgery. More recently, there has been growing interest in SBRT because it does not require surgery. However, the results of studies so far have not been consistent.The goal of this multicenter retrospective study is to better understand whether SBRT can improve disease control and survival in patients with breast cancer that has spread to a limited number of sites outside the brain.

Inclusion Criteria:

• Patients ≥18 years
• Histological diagnosis of breast cancer
• Oligometastatic or oligoprogressive metastatic breast cancer
• SBRT delivered to a minimum dose of 50Gy EQD2 (αβ 10 Gy),in a maximum of 12 fractions as per Oligocare definition
• Ability to provide written informed consent

Patient with Oligometastatic or oligoprogressive metastatic breast cancer treated with SBRT