LPTO-07. CARCINOEMBRYONIC ANTIGEN OF CEREBROSPINAL FLUID PREDICT PROGNOSIS OF LEPTOMENINGEAL METASTASIS FROM NON-SMALL CELL LUNG CANCER

BACKGROUND: Leptomeningeal metastasis (LM) is a detrimental complication of patients with non-small cell lung cancer (NSCLC) and its incidence has increased due to recent improvements in survival. The aim of this study was to identify the clinicolpathological features and prognostic factors related to overall survival in NSCLC patients with LM. METHODS: Seventy-four consecutive patients diagnosed with LM from NSCLC between 2009 and 2018 in Guangdong Sanjiu Brain Hospital were retrospectively reviewed. RESULTS: Median KPS at diagnosis of LM were 60 (range, 20–90). Forty-seven (63.5%) patients harboring epidermal growth factor receptor (EGFR) or anaplasticlymphoma kinase (ALK) mutation while other twenty-seven patients (36.5%) were wild type or unknown status. Local treatment for LM consisted of whole-brain radiotherapy (WBRT) (52.7%), ventriculoperitoneal (VP) shunt (6.8%) and external drainage (6.8%). Systematic therapy for LM included EGFR or ALK tyrosine kinase inhibitors (TKI) (59.5%), chemotherapy (40.5%) and bevacizumab (8.1%). The median overall survival from diagnosis of LM to death was 8.1 months (95% confidence interval: 5.2 to 11.0). Patients with high Cerebrospinal Fluid (CSF) carcinoembryonic antigen (CEA) level (＞50ng/ml) had worse prognosis compared with those low CSF CEA level (≤50ng/ml) ones (p=0.02). However, there was no significant difference in survival between patients with high serum CEA and those with low serum CEA (p=0.645). EGFR/ALK mutation and EGFR/ALK TKI after LM were also identified as variables that had prognostic influence on survival, while KPS, concurrent brain metastasis, WBRT and chemotherapy had no prognostic value for survival. CONCLUSION: Median overall survival was higher than historical experience in this retrospective analysis. It is CSF CEA level, but not serum CEA level that correlated with prognosis for LM from NSCLC.