Telomerase activity is responsible for telomere maintenance and is believed to be crucial in most immortal cells and cancer cells; however, its clinicopathological significance in gastric cancer remains to be clarified. The aim of the present study was to assess whether malignant progression of gastric adenocarcinoma correlates with telomerase activity. We also investigated the correlation between telomerase activity and histopathological findings. We examined telomerase activity in tumor specimens and adjacent normal tissues from 43 patients with gastric adenocarcinoma. Telomerase activity was measured quantitatively by the TRAPEZE Gel Based Telomerase Detection Kit. Approximately 98% of the tumor tissues were telomerase positive, but telomerase activity was detected not only in tumor tissues but also in normal gastric mucosa. Although telomerase activity was found to be higher in tumor samples than normal tissue for each subject, we could not find a general cut-off level for telomerase activity in gastric adenocarcinoma. In addition, telomerase activity was not correlated with tumor invasion, lymph node involvement and histological stage. Our results support the idea that telomerase reactivation is a common event in gastric adenocarcinoma and it is not related to histopathological parameters. Since it is difficult to set a cut-off level for this type of cancer, we suggest that the prognostic utility of telomerase assay has not yet reached the clinic in terms of predicting outcome for patients with gastric adenocarcinoma. For the assessment of gastric carcinoma, telomerase activity should be evaluated in both tumor and normal tissues, because normal gastric mucosa samples show appreciable telomerase activity.
Key words: Telomerase activity, Gastric adenocarcinoma, Tumor progression.