High Expression of TGF-β1 Predicting Tumor Progression in Skull Base Chordomas

OBJECTIVE: To investigate the expression characteristics and prognostic value of transforming growth factor beta 1 (TGF-beta 1) in primary skull base chordomas (SBCs). METHODS: The mRNA expression levels of TGF-beta 1 were measured in 57 frozen samples from patients with primary SBCs. Clinical data collection, follow-up, correlations, and survival analyses were performed. RESULTS: In the series of 57 patients (29 men and 28 women) with primary SBCs, the mean value of TGF-beta 1 mRNA was 1.713 with a median of 0.904. Twenty-four SBCs were soft type and 33 were hard type. The Mann-Whitney U test revealed that the expression level of TGF-beta 1 mRNA in hard type SBCs was significantly higher than the expression level found in the soft type (P = 0.03). The independent-samples median test suggested that the expression level of TGF-beta 1 mRNA in female patients' SBCs was significantly higher than that in male patients' SBCs (P = 0.01). Expression differences of TGF-beta 1 were not seen among different pathological subtypes, tumor blood supply, or degree of resection. The Spearman rank correlation coefficient clarified that TGF-beta 1 mRNA levels were not correlated with tumor diameter, preoperative Karnofsky Performance Status (KPS), postoperative KPS, follow-up KPS, age, or intraoperative blood loss. The multivariate Cox analysis revealed that pathological subtype (P = 0.008), expression level of TGF-beta 1 mRNA (P = 0.01), and tumor texture (P = 0.03) were all independent prognostic factors for tumor progression. CONCLUSIONS: SBCs in female patients and SBCs with hard texture were prone to have high TGF-beta 1 mRNA expression. High expression of TGF-beta 1, hard tumor texture, and conventional subtype were all independent risk factors for tumor progression.