Prophylactic Cranial Irradiation in Patients With HER-2-Positive Metastatic Breast Cancer

Though brain metastases are a risk in all patients with breast cancer, those with HER-2 overexpression are at significantly greater risk. One series estimated a 30% incidence of brain metastases in this population, while another study found an incidence of approximately 40%. Traditional systemic therapies do not cross the blood brain barrier to any significant degree or at all, but radiation treatment can be effective in the treatment of intracranial metastases.