High expression of TGF-β1 predicting tumor progression in skull base chordomas

Abstract Objective To investigate the expression characteristics and prognostic value of TGF-β1 in primary skull base chordomas (SBCs). Methods The mRNA expression levels of TGF-β1 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 males and 28 females) with primary SBCs, the mean value of TGF-β1 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-β1 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-β1 mRNA in female patients’ SBCs was significantly higher than that in male patients’ SBCs (P=0.01). Expression differences of TGF-β1 were not seen among different pathological subtypes, tumor blood supply, or degree of resection. The Spearman rank correlation coefficient clarified that TGF-β1 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-β1 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-β1 mRNA expression. High expression of TGF-β1, hard tumor texture and conventional subtype were all independent risk factors for tumor progression.