- HER2 positive by 2013 ASCO-CAP guidelines (IHC 3+ and/or FISH positive; IHC 2+ HER2 patients are eligible with reflex FISH positive testing with the ratio ≥ 2.0) breast cancer patients with untreated asymptomatic or minimally symptomatic brain metastasis by MRI. There is no upper or lower limit to the size or number of brain metastases.