Circulating epithelial tumor cell analysis in CSF in patients with leptomeningeal metastases.

OBJECTIVE: The primary objective was to determine the sensitivity and specificity of epithelial cell adhesion molecule (EpCAM) immunoflow cytometry circulating tumor cells (CTC) analysis in CSF in patients with suspected leptomeningeal metastases (LM). The secondary objective was to explore the distribution of driver mutations in the primary tumor, plasma, cell free CSF (cfCSF), and isolated CTC from CSF in non-small cell lung cancer (NSCLC). METHODS: We tested the performance of the CTC assay vs CSF cytology in a prospective study in 81 patients with a clinical suspicion of LM but a nonconfirmatory MRI. In an NSCLC subcohort, we analyzed circulating tumor (ct)DNA of the selected driver mutations by digital droplet PCR (ddPCR). RESULTS: The sensitivity of the CTC assay was 94% (95% confidence interval [CI] 80-99) and the specificity was 100% (95% CI 91-100) at the optimal cutoff of 0.9 CTC/mL. The sensitivity of cytology was 76% (95% CI 58-89). Twelve of the 23 patients with NSCLC had mutated epidermal growth factor receptor (EGFR). All 5 tested patients with LM demonstrated the primary EGFR driver mutation in cfCSF. The driver mutation could also be detected in CTC isolated from CSF. CONCLUSION: CTC in CSF are detected with a high sensitivity for the diagnosis of LM. ddPCR can determine EGFR mutations in both cfCSF and isolated CTC from CSF of patients with EGFR-mutated NSCLC and LM. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that EpCAM-based immunoflow cytometry analysis of CSF accurately identifies patients with LM.

Breast cancer leptomeningeal metastasis: the results of combined treatment and the comparison of methotrexate and liposomal cytarabine as intra-cerebrospinal fluid chemotherapy.

BACKGROUND: This was a prospective observational study to assess the results of the treatment of patients with breast cancer leptomeningeal metastasis (LM) and to compare the efficacy of methotrexate and liposomal cytarabine in patients treated intrathecally by lumbar puncture. PATIENTS AND METHODS: In this prospective observational study, 149 consecutive patients with breast cancer and LM treated between the years 1999 and 2011 were assessed. Multimodality treatment methods were used: systemic therapy in 77 patients, radiotherapy in 92 patients, intrathecal methotrexate in 81 patients, and intrathecal liposomal cytarabine in 15 patients. RESULTS: The median survival of all patients was 4.2 months. The median survival of patients in whom systemic intravenous/oral treatment was used was 6 months, in those who did not have systemic treatment, the median survival was 2 months (P < .001). The median survival of patients treated with intrathecal methotrexate was 4.2 months; in patients treated with intrathecal liposomal cytarabine, the median survival was 4.6 months, and in patients who did not receive intrathecal treatment, the median survival was 3.7 months (P = .717). Median survival after whole-brain radiotherapy was 4.6 months and with no radiotherapy, it was 3.2 months (P = .028). Multivariate analysis revealed a Karnofsky performance status (KPS) of > 70. Systemic intravenous/oral treatment and bone as a site of metastasis were factors prolonging survival from LM. CONCLUSION: Among treatment methods, only systemic therapy prolonged survival in patients with LM. Neither radiotherapy nor lumbar intrathecal therapy influenced survival in those patients; however, both methods alleviated signs and symptoms of LM. No difference in survival was observed in patients treated intrathecally with methotrexate and those treated with liposomal cytarabine. Treatment with both drugs was comparable.