Leptomeningeal spread in high-grade gliomas: Is surgery or adjuvant therapy after leptomeningeal spread associated with survival benefit?

Purpose This study aimed to identify prognostic factors associated with survival in patients with high-grade glioma (HGG) after leptomeningeal spread (LMS) and to clarify the behavior and treatment response. Methods This retrospective study included 114 patients with HGGs diagnosed with LMS from August 1, 2014, to July 30, 2021, at our institution. Clinical, radiological, pathological, and outcome data were collected. Univariable and multivariable Cox regression were used for overall survival (OS) and post-LMS survival (PLS) analysis. Results The median OS was 17.0 months and the median PLS was 6.0 months. Gross total resection (GTR) after LMS diagnosis and pathology grade III were statistically significantly associated with longer OS in all patients. GTR after LMS diagnosis and nodular LMS were independent favorable prognostic factors on PLS. Non-adjuvant therapy after LMS diagnosis was associated with shorter OS and PLS. In glioblastoma (GBM) subgroup analysis, GTR after LMS diagnosis and secondary LMS were independent favorable prognostic factors on OS. Karnofsky Performance Status (KPS) of ≥80 at LMS diagnosis, chemotherapy after LMS and intrathecal methotrexate (MTX) treatment were statistically significantly associated with longer PLS. MRI type II was a predictor of shorter PLS. Conclusion The treatment of patients with glioma after LMS diagnosis is very challenging and limited. Safe GTR of tumor and subsequent adjuvant therapy after LMS remains a powerful weapon to improve survival for HGG patients with LMS. Chemotherapy and Intrathecal MTX treatment are feasible treatments after LMS. The extent of tumor dissemination may affect the survival after LMS.