[Epidemiology of brain metastases]

The most frequent intracranial brain tumours are brain metastases. All types of cancer can develop brain metastases but two thirds of brain metastases occurring in adult patients are secondary to one of these three cancers: lung cancer, breast cancer and melanoma. In accordance with these data, this review is focusing on the epidemiology of these three types of cancer. We report here the incidence, risk factors, median time of brain metastases occurrence after diagnosis of the primary cancer, prognosis and median survival for these three types of cancer. We also discuss the clinical implications of these data. The second part of this review is focusing on the Graded Prognostic Assessment scores in all types of primary cancer with brain metastases, how they can be applied in clinical research for a better stratification of patients, and to some extent in clinical practice to guide decisions for personalized treatments. These scores provide a better understanding of the different profiles of clinical evolution that can be observed amongst patients suffering from brain metastases according to the type of primary cancer. We highlighted the most remarkable and useful clinical implications of these data.