Alternative lengthening of telomeres as a prognostic factor in malignant fibrous histiocytomas of bone.

BACKGROUND Malignant fibrous histiocytoma (MFH) of bone is a rare primary malignant neoplasm. Recent studies indicate a positive correlation between the telomere maintenance mechanism and tumour aggressiveness in sarcomas. This study was undertaken to analyse the clinical significance of telomere factors in primary tumour samples from patients with MFHs of bone. MATERIALS AND METHODS Telomerase activity was measured in ten bone MFH specimens using a PCR-based TRAP assay. Telomere length was assessed using gel hybridisation. Quantitative detection of human telomerase reverse transcriptase (hTERT) was performed by real-time PCR. RESULTS Telomerase activity and hTERT expression were detectable in 100% of tumour samples and 50% of tumour samples had evidence of engagement of the alternative lengthening of telomere (ALT) mechanisms. ALT was a significant prognostic risk factor (p = 0.0316). CONCLUSION This study suggests that the presence of ALT telomere maintenance mechanisms indicates a poor prognosis for bone MFH patients.