The dataset is slightly older but the results are slightly more favorable:
"Overall survival, NS, and RS are improved in patients with HER2+ tumors, relative to those with HER2− lesions, and HER2 amplification is independently associated with increased survival in patients with BM from breast cancer. Our findings suggest that the prognosis of HER2+ patients may be better than that of otherwise similar patients who are HER2− and that stereotactic radiosurgery may be beneficial for some patients with HER2+ lesions."
Relationship Between HER2 Status and Prognosis in Women With Brain Metastases From Breast Cancer
http://www.redjournal.org/article/S0...abstract?cc=y=