Breast cancer ranks as the top leading malignant tumors among females, and also accounts for the most common cause of tumor related mortality in females worldwide. Approximately, 20-30% of breast cancer cases develop metastasis, while 50% of patients will suffer from breast cancer liver metastasis. The proper indication for surgical treatment of breast cancer liver metastasis is still a matter of discussion. Surgery is becoming more practical and effective than conservative treatment in improving the outcomes of patients with breast cancer liver metastasis and liver metastasis surgery is included in an onco- surgical strategy.

Breast cancer ranks as the top leading malignant tumors among females, and also accounts for the most common cause of tumor related mortality in female's worldwide . Approximately, 20-30% of breast cancer (BC) cases develop metastasis, while 50% of patients will suffer from breast cancer liver metastases (BCLM) . The presence of liver metastasis has markedly worsened the prognosis of patients, and the median survival was reported to be 3.8-29 months.

Metastatic breast cancer is considered to be a disseminated disease and many oncologists remain reluctant to include surgery within the multimodal treatment strategy of these patients . Although systemic treatments can achieve approximately 60% of responses in breast cancer recurrence, long-term survival is exceptional only with medical treatment . Without liver resection, the average survival reported after the first onset of liver metastases is distributed over a range from 1 to 15 months. Surgery is becoming more functional and effective than conservative treatment in improving the poor outcomes of patients with BCLM . However, there is no generally acknowledged set of standards for identifying candidates who will benefit from surgery. The proper indication for surgical treatment is still a matter of discussion; surgical resection should be assessed when the following premises are met: low surgical risk, low metastasis number, complete macroscopic liver removal, absence of proven extrahepatic disease by positron emission tomography and computed tomography, objective response to chemotherapy before surgery, and long disease-free interval. Breast cancer liver metastasis surgery (BCLMS) is included in an onco-surgical strategy.

Most of the published series of patients with liver metastases of breast cancer who have undergone surgery come from a single center or few centers and there are hardly any long-term results, so we consider necessary to carry out a multicenter review of patients who underwent surgery in high volume centers across Europe belonging to the European-African Hepato-Pancreato-Biliary Association (E-AHPBA) to asses survival and disease-free survival and to determine which patients may benefit from surgery.

This retrospective multicenter cohort study in centers performing BCLMS aims to provide an assessment of the outcomes across E-AHPBA centers.

Inclusion Criteria:

• Patients ≥ 18 year old.
• Scheduled surgery for breast cancer liver metastases between January 1st 2010 and December 31st 2015
• American Society of Anesthesiologists (ASA) score I-III.
• They have signed the informed consent.

Exclusion Criteria:

• Patients under 18 year old.
• ASA ≥ IV.
• Urgent surgery.
• Patients who have not signed the informed consent.

All patients operated on in the participating European centers with breast cancer liver metastases during the study period (between January 1st 2010 and December 31st 2015) and that meet the inclusion criteria.