Purpose: To explore the impact of intrathecal pemetrexed (IP) on the survival of lung adenocarcinoma (LUAC) patients with leptomeningeal metastasis (LM).
Methods: We analyzed patients with LUAC and LM who received systemic therapy after LM diagnosis at the Fujian Cancer Hospital between July 2018 and March 2022. Patients who underwent IP were assigned to the IP group; those without IP treatment were designated as the non-IP group. Propensity score matching (PSM) was performed between the two groups.
Results: 165 patients were enrolled: 83 and 82 in the IP and non-IP groups, respectively. After 1:1 PSM, we included 114 patients in the matched cohort. Median overall survival (OS) was 13.2 months (95% CI 10.8-15.6 months) in the IP group versus 10.1 months (95% CI 5.3-14.9 months) in the non-IP group (P = 0.488). Only Eastern Cooperative Oncology Group Performance Status (ECOG PS) was confirmed as an independent predictor for OS in the matched cohort (hazard ratio (HR) 2.03; P = 0.023). Multivariate competing-risks analysis showed that IP significantly correlated with central nervous system-related death (HR 0.31; P = 0.046). When stratified by ECOG PS, IP improved survival in patients with poor ECOG PS (PS = 2) (14.3 months vs. 1.6 months; P = 0.003).
Conclusions: Intrathecal pemetrexed did not enhance OS for the entire LUAC patient with LM compared to non-intrathecal chemotherapy. However, it exhibited the potential to reduce the risk of central nervous system-related mortality and improve survival in patients with poor ECOG PS.
Keywords: Intrathecal chemotherapy; Leptomeningeal metastasis; Lung adenocarcinoma; Pemetrexed; Propensity score matching.
© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.