The diagnostic and prognostic relevance of human telomerase reverse transcriptase mRNA expression detected in situ in patients with nonsmall cell lung carcinoma

BACKGROUND. The objectives of this study were to evaluate the diagnostic and prognostic relevance of human telomerase reverse transcriptase (hTERT) detected in situ in patients with nonsmall cell lung carcinoma (NSCLC) and to investigate the possible correlations between hTERT mRNA in NSCLC and the patients' clinicopathologic features, including survival. METHODS. hTERT mRNA was detected by in situ hybridization in 146 samples from patients with NSCLC. The signal intensity of hTERT mRNA expression was evaluated by two independent observers. The expression level was defined subjectively as strong, moderate, or weak. RESULTS. hTERT mRNA was detected mainly in the cytoplasm of tumor cells. It was detected in the cytoplasm of 100% of samples from patients with NSCLC but was not detected in normal lung tissue, except in activated lymphocytes. There was a significant correlation between hTERT mRNA expression and pathologic tumor status, pathologic disease stage (pStage), and Ki-67 labeling index. There was no significant correlation between hTERT mRNA expression and age, gender, pathologic lymph node status (pN), histology, or tumor differentiation. The 5-year survival rates for patients with strong and moderate hTERT mRNA expression levels were 46.9% and 77.9%, respectively; the difference was statistically significant (P = 0.0001). A multivariate analysis of survival using a stepwise procedure revealed that hTERT mRNA expression, pN status, pStage, and age were statistically significant prognostic factors (P = 0.0029, P 0.0012, P = 0.0237, and P = 0.0496, respectively). CONCLUSIONS. The findings suggested that hTERT mRNA expression may be useful for the diagnosis of NSCLC and also may be an independent prognostic factor for patients with NSCLC. (C) 2003 American Cancer Society.