Prognostic significance of telomeric repeat length alterations in pathological stage I-IIIA non-small cell lung cancer

This study was performed to evaluate the prognostic significance of alteration in telomere length in pathological stage (p-stage) I-IIIA non-small cell lung cancer (NSCLC). Paired cancer and normal lung tissues were obtained from 72 patients with histologically confirmed p-stage I-IIIA NSCLC. Terminal restriction fragment (TRF) length, which indicates telomere length, was measured by Southern blot analysis. Tumor telomerase activity was also assayed by non-radioactive PCR-ELISA in 55 patients. TRF length (mean ± SD) in normal tissue was 6.2 ± 1.1 Kb. Therefore, upper and lower limits of normal range in TRF length was set at 8.4 (mean + 2SD) Kb and 4.0 (mean - 2SD) Kb, respectively. A tumor showing TRF length over normal range was defined as positive for the alteration. In 72 patients, 25 (34.7%) with alteration in TRF length had significantly shorter survival durations than those of the others. Telomerase activity did not correlate with survival duration. In multivariate analysis, alteration in TRF length (P = 0.0033) was Second to p-stage (P = 0.0004) in importance among the various parameters.