Intrathecal chemotherapy as a treatment for leptomeningeal metastasis of non-small cell lung cancer: A pooled analysis

Leptomeningeal metastasis (LM) is increasingly common in patients with non-small cell lung cancer (NSCLC) due to improved treatment, and ultimately, prolonged patient survival. The current study is a pooled analysis that evaluated intrathecal chemotherapy (ITC) as a treatment for NSCLC patients with LM. The PUBMED, OVID, EBSCO and Cochrane Library databases were searched for published studies involving ITC in NSCLC patients with LM. The primary outcomes of interest included response (symptomatic, radiographic and cytological) and survival. Overall, 4 prospective studies and 5 retrospective studies were included. In total, 37 patients received ITC only, and 552 patients received multiple interventions (ITC, whole-brain radiotherapy, epidermal growth factor receptor tyrosine kinase inhibitors, systemic chemotherapy and support care). In patients with available individual information, the reevaluated cytological, clinical and radiographic rates of response to ITC were 55% (53-60%; n=49), 64% (53-79%; n=58), and 53% (n=32), respectively, and the reevaluated median survival time (from the onset of treatment, n=50) was 6.0 months (95% CI, 5.2-6.8). In patients without available individual information, the reported cytological and clinical rates of response to ITC are 14-52% and 13-50%, respectively, and the reported median survival time (from the diagnosis of LM) was 3.0-4.3 months. The clinical response rates of patients only receiving ITC varied from 71 to 79% (100% if including stable disease). The median survival time of patients who only received ITC (7.5 months) was much longer than that of patients who received multiple interventions (3.0-5.0 months). Accordingly, in NSCLC patients with LM, ITC may offer a promising response rate and survival benefits under a suitable regimen. In addition, a suitable combination strategy of multidisciplinary therapy is extremely important for these particular patients.