With an annual rate of more than 12 million global diagnoses and 7.6 million deaths, the societal and economic burden of cancer cannot be overstated. Brain metastases are the most common malignant tumors of the central nervous system, yet their incidence appears to be increasing in spite of the advancement of cancer therapies. While much is known about primary cancers (including primary brain tumors), less work has been done to uncover the roots of metastatic disease. Brain Metastases from Primary Tumors Volume 1 fills that gap, serving as the first reference to focus primarily on the link between primary cancers and brain metastases. This link is explored for the most common cancer types – lung, breast, and melanoma. Additionally, biological background as well as therapy for CNS metastases is addressed. Age and gender related trends are also discussed, as is the use of biomarkers for early detection.