Supratentorial high-grade astrocytoma with leptomeningeal spread to the fourth ventricle: a lethal dissemination with dismal prognosis.

Abstract

Leptomeningeal spread to the fourth ventricle (LSFV) from supratentorial high-grade astrocytoma (HGA) is rarely investigated. The incidence and prognostic merit of LSFV were analyzed in this study. A consecutive cohort of 175 patients with pathologically diagnosed HGA according to the 2016 WHO classification of brain tumors was enrolled. LSFV was defined as radiological occupation in the fourth ventricle at the moment of initial progression. Clinical, radiological, and pathological data were analyzed to explore the difference between HGA patients with and without LSFV. There were 18 of 175 (10.3%) HGAs confirmed with LSFV. The difference of survival rate between patients with LSFV or not was significant in both overall survival (OS) (14.5 vs. 24months, P = 0.0007) and post progression survival (PPS) (6.0 vs. 11.5months, P = 0.0004), while no significant difference was observed in time to progression (TTP) (8.5 months vs. 9.5months P = 0.6795). In the Cox multivariate analysis, LSFV was confirmed as an independent prognostic risk factor for OS (HR 2.06, P = 0.010). LSFV was correlated with younger age (P = 0.044), ventricle infringement of primary tumor (P < 0.001) and higher Ki-67 index (P = 0.013) in further analysis, and the latter two have been validated in the Logistic regression analysis (OR 18.16, P = 0.006; OR 4.04, P = 0.012, respectively). LSFV was indicative of end-stage for supratentorial HGA patients, which shortened patients' PPS and OS instead of TTP. It's never too cautious to alert this lethal event when tumor harbored ventricle infringement and higher Ki-67 index in routine clinical course.