P08.02 * IDENTIFICATION AND QUANTIFICATION OF CSF MALIGNANT CELLS BY THE CELLSEARCH(R) TECHNOLOGY IN PATIENTS WITH LUNG LEPTOMENINGEAL METASTASIS

Abstract

INTRODUCTION: Diagnosis of lung leptomeningeal metastasis (LM) remains difficult. The usual diagnostic methods of cytomorphological assessment of cerebro-spinal fluid (CSF) and gadolinium-enhanced MRI lack both specificity and sensitivity. The Veridex CellSearch® technology is validated in detection of circulating tumor cells (CTC) in blood and in the follow-up of breast, prostate and colorectal cancer. Our aim was to adapt this technology for detection and quatification of tumor cells in the CSF of lung cancer patients with LM. METHODS: Patients with suspected lung LM from a french neuro-oncological center (Nancy) were prospectively included. The CSF samples were collected on traditional cytology tubes (1mL) and on CellSave® Preservative tubes (4 mL). RESULTS: 12 patients with clinical symptoms and/or radiological criteria suggestive of lung LM (5 at diagnosis/7 at recurrence) underwent CSF analysis with conventional cytology and with Veridex Cellsearch® technology. Conventional CSF cytomorphological analysis was positive in 5 patients (with a median of 13 tumor cells/mm3; range 10 to 25 tumor cells/mm3) whereas the assessment with Veridex Cellsearch® technology was positive in 12 patients. Quantitative analysis with the Veridex CellSearch® technology showed a median of 203 tumor cells/5mL of CSF (range 1 to 1500 tumor cells per 5 mL of CSF). CONCLUSIONS: In contrast to the current gold standard cytomorphological analysis, this new approach seems more sensitive and allowed a quantification of CSF tumor cells in lung LM. This methodology could be useful for earlier diagnosis of lung LM and for follow-up. A large prospective study is required.