Brain metastases as a first site of recurrence in patients on chemotherapy with controlled systemic cancers: An increasingly urgent clinical scenario.

Abstract

e13590 Background: As the treatment of non-central nervous system (CNS) malignancies improves, brain metastases (BM) are occurring more often in patients with controlled primary disease. In a retrospective analysis of 1953 patients with BM, 44.7% had a controlled primary tumor at the time of BM diagnosis. Given that prognosis after BM remains dismal, it is necessary to identify groups who might benefit from improved delivery of initial systemic therapy across the blood brain barrier (BBB). Methods: A retrospective literature review was conducted to estimate the proportion of patients with non-small cell lung cancer (NSCLC), breast cancer, and melanoma treated with chemotherapy in whom BM was the initial site of recurrence. Only studies explicitly reporting CNS metastasis with controlled extra-cranial (EC) disease on chemotherapy or reporting the first site of recurrence after chemotherapy were included. Results: Four studies of advanced NSCLC reported an average of 23% of patients who developed BM as an initial site of recurrence. Breast cancer cases varied by subtype with a range of 4 - 19%. In four papers reporting HER-2 status, an average of 14% of patients treated with traztuzumab had CNS metastasis with controlled EC disease. In three papers assessing patients with metastatic melanoma on chemotherapy, 4 – 25% initially progressed in the CNS. Conclusions: Of the 1024 patients treated with chemotherapy and achieving controlled systemic disease in this retrospective review, first recurrence in the brain was common: 23% in NSCLC, 12% in breast cancer, and 12% in melanoma. While chemotherapy controlled non-CNS disease, concentrations of these drugs were clearly subtherapeutic in the CNS. Preventing BM in patients with NSCLC, breast cancer, and melanoma will require novel therapeutic approaches designed to facilitate drug entry through an intact BBB early in the treatment of the primary tumor. [Table: see text]