The science of prevention: novel strategies for and new insights into central nervous system prophylaxis in patients with cancer.

r t o c t r h a w n b p n unanticipated consequence of recent successes in the treatment of non–central nervous system (CNS) malignancies has been a steady ncrease in the frequency of brain and spinal fluid elapse. This pattern has been well-documented in paients with breast cancer, small cell and non-small cell ung cancer, and non-Hodgkin lymphoma (NHL) and ay well emerge in other common (colorectal cancer) nd less common (melanoma) tumor types. Unfortuately, the treatments available for brain metastases nd neoplastic meningitis have not evolved as quickly s those for non-CNS disease. In general, these are imited to cranial irradiation of various types, intraerebrospinal fluid (CSF) chemotherapy with a very ew available agents, and an even shorter list of systemcally administered drugs with good CNS penetrance. n general, treatment of CNS relapse, regardless of the nderlying malignancy, has been only modestly successul because of the restricted access of some drugs to the NS, because of resistance of the CNS metastases to vailable therapies, and because the risk of treatmentelated CNS toxicity imposes limits on the aggressiveness f therapy. For all of these reasons, interest in preventing NS metastases, ie, CNS prophylaxis, has become an ncreasing focus of basic and clinical research. In 2007, an international symposium attended by ome of the world’s leading neurologists, hematoloists, oncologists, and basic scientists was convened o discuss the scientific underpinnings of CNS prohylaxis and their implementation in clinical pracice. This supplement provides an updated overview f their presentations, and the discussions they enendered. The opening article reviews both the hisory and the current therapeutic state-of-the-art in he two diseases— childhood acute lymphoblastic eukemia and very aggressive NHL—in which CSF rophylaxis has been an unmitigated success. This nd subsequent articles review the evidence for and gainst CSF prophylaxis in other forms of NHL, in a ariety of solid tumors, and in malignant primary rain tumors, both those where intra-CSF chemo-