Breast cancer brain metastases: a review of the literature and a current multidisciplinary management guideline.

Breast cancer represents the second most frequent etiology of brain metastasis (BM). It is estimated that 10-30 % of patients with breast cancer are diagnosed with BM. Breast cancer BM are increasing due to the aging population, detection of subclinical disease, and better control of systemic disease. BM is a major cause of morbidity and mortality affecting neurocognition, speech, coordination, behavior, and quality of life. The therapy of BM remains controversial regarding use and timing of surgical resection, application of whole-brain radiotherapy, stereotactic radiosurgery and systemic drugs in patients with particular tumor subtypes. Despite numerous trials, the range of interpretation of these has resulted in differing treatment perspectives. This paper is a review of the state of the art and a multidisciplinary guideline on strategies to improve the therapeutic index in this situation.

Individualization of treatment strategies.

This section focuses on different aspects of the individualization of hormone treatment in breast cancer. This includes tumor-related biological factors such as expression of hormone receptors, HER-2, and Ki-67; host-related factors such as CYP2D6 or body mass index, and risk and/or development of specific toxicities and treatment adherence. The best predictor of response to hormonal interventions is the expression of hormone receptors, in particular, estrogen receptors. Treatment adherence and compliance are key factors and strategies aiming to identify and intervene when patients are at risk of abandoning treatment. Currently, routine assessment of CYP2D6 is not recommended to guide tamoxifen treatment. Likewise, there are no criteria regarding bone mass density, lipid profile, or arthralgias to recommend one class of agent versus another. Aromatase inhibitors should not be administered to patients who are pre- or perimenopausal.