Risk factors and survival outcome in cerebral metastatic breast cancer

The development of brain metastases (BM) of primary breast cancer patients leads to limited survival. HER2-positive and triple-negative status are risk factors for the development of BM. Estrogen receptor (ER)/progesterone receptor (PR)/HER2 are important prognostic markers and are essential for effective treatment decisions. We retrospectively analyzed the impact of known risk factors and the outcome after the development of BM. Eighty consecutive patients, treated between January 1, 2001, and June 30, 2012, on the basis of primary non-metastatic operable breast cancer and who developed BM, were enrolled. Clinical parameters (TNM; ER, PR, HER2) and their impact on the occurrence of BM and additionally their prognostic influence after the occurrence of BM were investigated. A small tumor size, ductal histology, grade 3, hormone receptor-negative, triple-negative and HER2+ tumors were associated with BM. Median time from breast cancer diagnosis to BM was 35 months (range 26.2-43.8). Grade 3 versus 2 has significantly negative prognostic impact with earlier development of BM (median 23 vs. 41 months; p=0.033). HER2-positive patients had significantly longer survival after the occurrence of BM than HER2-negative patients (p=0.009). The risk of BM varies significantly by subtype. In high-risk patients, the occurrence of BM must be considered, and possibly, general screening in these patients is warranted. The survival advantage of HER2-positive breast cancer patients compared with HER2-negative patients after the occurrence of BM is possibly explainable by systemic control of disease. Standard of care for patients with BM is whole-brain radiotherapy, with/without surgery, or stereotactic radiosurgery. Perhaps novel therapies may additionally improve survival in these patients.