Altered expression or activity of human telomerase reverse transcriptase (hTERT) has been associated with human carcinogenesis. This study detected hTERT expression in spinal chordoma tissues and associated the level of hTERT expression with clinicopathological data and patient survival. Tissue samples from 54 patients and 20 controls were subjected to immunohistochemical analysis of hTERT protein levels. hTERT expression levels were then analyzed for associations with patient survival rates and clinicopathological parameters (such as age, gender, tumor size, location, tumor grade, tumor stage, muscle invasion, recurrence or not, type of resection, tumor hemorrhage, tumor necrosis, levels of tumor-infiltrating lymphocytes (TILs) and Ki-67 expression). hTERT expression was detected in all 54 spinal chordomas. Expression levels were weak in 7, moderate in 17 and strong in 30 spinal chordoma tissue samples. In contrast, hTERT was rarely expressed in nucleus pulposus tissues (20 samples). hTERT expression was significantly associated with the Ki-67-staining index (t = -6.616, p < 0.001), TIL levels (F = 5.27, p = 0.008) and tumor invasion of the surrounding muscle tissue (t = -4.49, p < 0.001). Kaplan-Meier curves indicated that high hTERT expression was significantly associated with poor local recurrence-free survival of patients (χ(2) = 19.07, p < 0.001 via the log-rank test), but not associated with overall patient survival. Multivariate analysis of local recurrence-free survival demonstrated that hTERT expression was an independent prognostic factor among spinal chordoma patients (HR = 1.013, 95% CI: 1.002-1.024, p = 0.016). High hTERT expression was associated with spinal chordoma growth, invasion and poor patient prognosis. Future studies will investigate the use of hTERT as a biomarker to predict patient prognosis and disease progression or as a potential spinal chordoma therapy target.
Keywords: Chordoma; biomarker; human telomerase reverse transcriptase (hTERT); prognosis.