Real-time PCR hTERT mRNA pattern in tumor core, edge, resection margin, and lymph nodes in laryngeal tumors: Relation to proliferative index and impact on prognosis

Background: The immortalizing enzyme, telomerase, has been linked to carcinogenesis and is being targeted as a novel molecular marker. This study investigated the pattern of human telomerase reverse transcriptase (hTERT) mRNA by real-time polymerase chain reaction (PCR) in tumor core, edge, and safety margin of laryngeal tumors and related lymph nodes, as well as their relation to the proliferative index (PI) and their impact on prognosis. Material and methods: This prospective study included 35 patients with laryngeal carcinoma who were surgically treated by total or partial laryngectomy. Collected tissues from tumor core, edge, resection margin, and lymph nodes were examined by flow cytometry and real-time PCR quantification of hTERT mRNA. Results: The PI showed a statistically significant difference between the contrasted parts (P = 0.04). The highest median for PI was found in the tumor edge samples (31.3), followed by the tumor core (27.5), the resection margin (21.4), and finally the lymph nodes (10.3). There was no significant difference with regard to the ploidy patterns or the synthetic phase fraction (SPF) among the different tissue parts. Real-time PCR hTERT mRNA patterns showed that the highest median for hTERT mRNA level (copies/mu g RNA) was in the tumor core (70.5), followed by the tumor edge (36.5), the resection margin (17.3), and finally the lymph nodes (4A). There was a statistically significant difference with regard to the hTERT mRNA patterns among the different tissue parts (P = 0.04). Tumor differentiation, tumor edge ploidy, and tumor edge hTERT levels were significantly different between survivors and non-survivors, while tumor core S-phase fraction and tumor core PI significantly altered the disease-free survival rate. Conclusion: hTERT mRNA may potentially be used for molecular reevaluation of the safety margin for conservational laryngeal surgery, and as a prognostic factor for overall survival especially if determined in samples taken from the growing edge of tumors. (c) 2005 The Canadian Society of Clinical Chemists. All rights reserved.