Management of leptomeningeal metastases: Prognostic factors and associated outcomes.

Limited data are currently available to direct treatment recommendations in the management of leptomeningeal metastases (LM). Here we review treatment modalities clinicians should understand in order to manage patients with LM. We first describe our institution's experience with the treatment of LM and use this dataset to frame the discussion of LM management. Between 1999 and 2014, 1361 patients with central nervous system metastases were reviewed, 124 (9.1%) had radiographic evidence of LM, and these patients form the cohort for this analysis. Mean age at diagnosis of LM was 52years. Median survival for the entire cohort was 2.3months. The most common primary malignancies were non-small cell lung cancer (25.8%), breast cancer (17.7%), small cell lung cancer (16.9%) and melanoma (8.9%). Univariate analyses demonstrated that greater Karnofsky Performance Status (KPS) (p=0.001) and administration of systemic chemotherapy (p<0.001) resulted in improved median survival. Multivariate Cox analyses revealed that receipt of chemotherapy and a complete course of whole brain radiotherapy (WBRT) (median dose 30Gy in 10 fractions, range 24-40Gy) were predictive of longer survival, (p=0.013 and 0.019, respectively). These data suggest that there is a group of patients with good KPS who may experience significantly longer median survival than expected. Multivariate analysis from this single institution retrospective study demonstrated a benefit for WBRT and chemotherapy in individuals with good KPS. These findings provide contemporary data from a large cohort of LM patients, which may be utilized to guide treatment recommendations, assist in patient counseling and direct future investigations into optimization of treatment regimens.