Validation of Modified Breast Graded Prognostic Assessment for breast cancer patients with brain metastases: extra-cranial disease progression is an independent risk factor

Central nervous system (CNS) metastases are a serious complication of solid organ tumours, resulting in significant morbidity and mortality (1). Breast cancer (BC) is the second most common cause of brain metastases (BM) (2). Previously regarded as having a uniformly dismal prognosis, advances in treatment have resulted in the recognition that BC patients with BM are heterogeneous with widely differing survival (3-5). Factors found to prognosticate survival in these patients include performance status, age, number of BM, tumour histology, receipt of local or systemic therapy and extra-cranial disease status (6-10). Various prognostic instruments incorporating these factors have been developed (11-14)