Clinical significance of telomerase activity in the non-cancerous epithelial region of oesophageal squamous cell carcinoma

Background The aim of this study was to examine telomerase activity in affected and adjacent tissue in patients with oesophageal squamous cell carcinoma (SCC). Methods Telomerase activity was measured in oesophageal SCC cells, normal oesophageal culture cells, primary cancer tissues and adjacent normal tissues from patients with oesophageal SCC using a polymerase chain reaction-based assay. Results All oesophageal SCC cells had telomerase activity, whereas normal cultured cells showed no activity. All 57 cancer tissues showed telomerase activity compared with only five (10 per cent) of 50 normal tissues. Cancer cells infiltrating the vessels of mucosal or submucosal tissues in non-cancerous regions were detected in four of five telomerase-positive normal tissues, whereas such infiltration was detected in only three of 45 telomerase-negative normal tissues. Conclusion In patients with oesophageal SCC, measurement of telomerase activity in normal epithelium is a highly sensitive method of detecting the microinvasion of cancer cells.