γ knife radiosurgery of brain metastasis from breast cancer

The incidence of brain metastasis in patients with metastatic breast cancer ranges from 14 to 16%.Age, number of metastatic sites, short disease-free survival and molecular subtypes are associated with the occurrence of brain metastasis. Patients classified in the triple-negative group more frequently presented brain metastasis as the first site (26%) than those in the human epidermal growth factor receptor 2 (HER2)-positive (6%) or luminal (12%) subtypes. Whole brain radiation therapy (WBRT) is still the standard treatment for breast cancer patients with brain metastasis. The 1- and 2-year survival rates of patients with brain metastasis were 25 and 10%, respectively, with a median survival of 6 months. In selected patients with single brain metastasis, majority of lung cancer, three randomized controlled trials underlined the significant survival benefit in adding local treatment such as surgery or stereotactic radio surgery to WBRT. Similarly, the upfront stereotactic radiosurgery (SRS) alone did not affect survival rate in three other randomized studies and represents an alternative treatment for patients with stage 1-4. Metastatic breast cancer patients with Karnofsky Performance Scale ≥70, single or oligometastatic brain metastases and well-controlled extracranial disease or favorable disease-specific graded prognostic assessment group presented a median overall survival of 16 months. Delaying WBRT could spare patients of neurocognitive toxicity due to full-dose whole brain irradiation. Nevertheless, the real WBRT neurocognitive impact is still unclear. These patients should be followed with serial magnetic resonance image every 3 months and treated with WBRT or additional SRS at recurrence to control brain disease.