LMD-17. Neoplastic meningitis in lung cancer: retrospective review of clinical features, diagnosis and outcome in adult patients

Abstract Background Neoplastic Meningitis (NM) is a lethal complication of cancer. Its incidence is rising and in 10% of the cases NM is the first manifestation of the disease. Diagnosis relies on the clinical manifestations, neuroimages, and finding of malignant cells in cerebrospinal fluid (CSF). Diagnosis is often challenging due to the low sensitivity of the different diagnostic modalities. The aim of this study is to identify the clinical features, diagnosis, treatment and outcome of lung cancer patients with NM. Methods Clinical records from patients with diagnosis of lung cancer and NM between 2011–2021 were retrospectively reviewed at a tertiary neurological center in Buenos Aires, Argentina. Results Twenty-seven patients were included. Median age was 58 years (IQR 52–64). 17 (65%) were female. Twenty-four patients had non-small cell lung cancer (91% adenocarcinoma), two had neuroendocrine lung cancer and one small cell lung cancer. In 19 (70%), meningeal involvement was a result of progressive disease from previously diagnosed cancer. In 12 (44%) patients meningeal disease developed posterior to parenchymal brain metastases surgical approach, 5 (41%) with posterior fossa craniotomy. Headache was the most frequent symptom (53%). CSF analysis was abnormal in 13 (48%) patients, with positive cytology in 10 (37%). Meningeal enhancement was detected with magnetic resonance imaging of brain or spine in 24 (92%) patients. Twenty-one (77%) patients received oncological treatment, 14 (51%) with chemotherapy (8 systemic, 3 intrathecal and 3 intrathecal plus systemic). Thirteen (48%) patients underwent treatment with either immunotherapy or target-therapy. 11 patients underwent whole brain radiotherapy. Median overall survival was 7 months (CI 95%: 3.5–10.4). Conclusion Headache was the most frequent symptom. Ninety-two percent of patients had meningeal pathological enhancement in high-quality MRI with gadolinium contrast of brain and spine. Despite median survival was poor (7 months), small subsets of these patients (22%) survived more than 2 years.