Telomerase activity in endoscopically visible lung cancer

To examine the correlation between telomerase activity and clinical features in patients with lung cancer, we examined 86 patients with endoscopically visible lung cancer including 61 with non-small cell lung cancer (NSCLC) and 25 with small cell lung cancer (SCLC). Telomerase activity was detected by using Telomerase ELISA Kit (Böhringer Manheim, Germany). The median and interquartile ranges of telomerase activity in normal lung, NSCLC and SCLC were 65 and 51-75, 106 and 58-349 and 285 and 117-2214, respectively. Normal lung, NSCLC and SCLC had significantly different telomerase activity (p < or = 0.0001). Between NSCLC and SCLC, SCLC exhibited higher telomerase activity than did NSCLC (p=0.0029). A cut-off level of absorbance [A450nm-A690nm] of 86 derived from 90% specificity in normal lung was used; sensitivity for overall lung cancer, NSCLC and SCLC was 62.8%, 54.1% and 84.0%, respectively. There was no significant difference in telomerase activity between each stage in NSCLC (p=0.9243). In SCLC, however, the median and interquartile range of telomerase activity in extensive disease (2128 and 292-2681) was significantly higher than those in limited disease (207 and 97-252) (p=0.0285).