Is There a Role for Systemic Chemotherapy in the Treatment of Brain Metastases?

Abstract

AbstractBrain metastases (BM) are the most common metastatic complication of systemic cancer to the central nervous system (CNS). Treatment is most often with radiotherapy (whole brain radiotherapy (WBRT), stereotactic radiotherapy (SRT) or a combination) and in selected patients (for example solitary metastasis) resective surgery. The role for chemotherapy in the treatment of BM is difficult to define due to a paucity of clinical trials the majority of which are nonrandomized, retrospective studies and case reports. Two factors influence the efficacy of chemotherapy in BM; the intrinsic chemosensitivity of the tumor and chemotherapy drug delivery. Several generalizations can be made regarding chemotherapy of BM based on the limited literature. Response to chemotherapy reflects inherent chemosensitivity of the primary tumor with best responses seen with small cell lung cancer, intermediate responses seen with non-small cell lung cancer and breast cancer and low response rates with melanoma. Response to chemotherapy is in addition determined by prior chemotherapy exposure as front-line chemotherapy has higher response rates than second- or third-line chemotherapy. Response to chemotherapy as compared to WBRT or SRT is inferior and less durable. The use of chemotherapy for the treatment of BM is most often limited to patients having failed radiotherapy (often both WBRT and SRT) and with multiple lesions. Emerging data suggests that targeted therapies may play an increasing role in the treatment of BM.KeywordsBrain MetastasisSmall Cell Lung CancerEpidermal Growth Factor Receptor InhibitorHER2 Positive Breast CancerCentral Nervous System MetastasisThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.