Differences in Dural Penetration of Clival Chordomas Are Associated with Different Prognosis and Expression of Platelet-Derived Growth Factor Receptor-β.

Abstract

We sought to compare the prognosis of clival chordomas with different dural penetration and establish the relationship between dural penetration and platelet-derived growth factor receptor (PDGFR)-β signaling pathway. Tumors in Type I (33 cases) showed limited dural penetration, while those in Type II (34 cases) had more serious dural penetration. Cox multivariate regression analysis was used to analyze risk factors affecting survival. Kaplan-Meier analysis measured overall survival (OS) and progression-free survival (PFS). To determine the relationship between dural penetration and PDGFR-β signaling, expression of PDGFR-β, Akt, mammalian target of rapamycin (mTOR), and phosphatase and tensin homolog (PTEN) expression was compared using immunohistochemistry, quantitative reverse transcription polymerase chain reaction, and Western blotting. Total resection was achieved in 9 cases in Type I and 11 in Type II. There were significant correlations between OS and dural penetration (P = 0.032) and age (P = 0.034). PFS correlated significantly with dural penetration (P = 0.022), gender (P = 0.001), and degree of resection (P = 0.001). Mean OS in Type I was significantly longer than in Type II (P = 0.046). Patients aged <55 years had longer OS than those aged ≥55 years (P = 0.004). Total resection was correlated with longer PFS (P = 0.011). Among patients with tumors totally resected, mean PFS in Type I was significantly longer than in Type II (P = 0.007). Expression of PDGFR-β in Type II was higher than in Type I. Clival chordomas have different degrees of dural penetration. Patients with chordomas with serious dural penetration have poorer prognosis. Higher expression of PDGFR-β is related to more serious dural penetration of clival chordomas.