Telomerase activity as a prognostic indicator in stage I non-small cell lung cancer

Patients with stage I non-small cell lung cancer (NSCLC) are typically treated with surgical resection alone. However, about one-third of such patients develop disease recurrence and die within 5 years after complete resection. The ability to predict recurrence could represent an important contribution to treatment planning. This study evaluates the presence of telomerase activity in tumor cells as a predictor of disease recurrence and cancer-related death after operation for stage I NSCLC patients. The activity of the telomerase enzyme was investigated by telomeric repeat amplification protocol (TRAP) in tumors and matching normal lung tissue samples obtained from 107 consecutive operable patients with pathological stage I NSCLC. Telomerase activity was detected in 66 (62%) of the 107 tumors examined and in none of the corresponding adjacent noncancerous lung tissue samples. Correlation with pathological parameters showed that telomerase activity was associated with histopathological grade (P = 0.0135) but not with tumor size or histological type. Univariate survival curves, estimated using the method of Kaplan and Meier, defined a significant association between telomerase activity and both disease-free survival (P = 0.0115) and overall survival (P = 0.0129). In multivariate analyses, performed by Cox's proportional hazards regression models, the presence of telomerase activity was the only strong predictor of disease-free survival (P = 0.0173) and overall survival (P = 0.0187). Our data indicate that telomerase activity can be an important prognostic factor that should be considered in future prospective trials of adjuvant therapy for high-risk stage I NSCLC patients.