1532 Background: We hypothesized that telomere length in peripheral blood would have significant predictive value for risk of recurrence after curative resection in non-small cell lung cancer (NSCLC). Methods: This prospective study included 473 patients with histologically confirmed early stage NSCLC who underwent curative resection at MD Anderson Cancer Center between 1995 and 2008. Relative telomere length (RTL) of peripheral leukocytes was measured by real-time PCR. The risk of recurrence was estimated as hazard ratios (HRs) and 95% confidence intervals (CIs) using a multivariable Cox proportional hazard regression model. Results: Median duration of follow-up was 61 months and 151 patients (32%) had developed recurrence at time of analysis. Patients who developed recurrence had significantly longer mean RTL compared to those without recurrence (1.13 vs 1.07, P=0.046). A subgroup analysis indicates that women had longer RTL compared to males (1.12 vs 1.06, P=0.025), and the patients with adenocarcinoma demonstrated longer RTL compared to those with other histologic types (1.11 vs 1.05, P=0.042). To determine if longer RTL in women and adenocarcinoma subgroup would predict risk of recurrence, multivariate Cox analysis adjusting for age, gender, stage, pack year and treatment regimens was performed. Longer telomeres were significantly associated with higher risk of developing recurrence in female (HR=2.25; 95% CI, 1.02-4.96, P=0.044) and adenocarcinoma subgroups (HR=2.19; 95% CI, 1.05-4.55, P=0.036). The increased risk of recurrence due to long RTL was more apparent in females with adenocarcinoma (HR=2.67; 95% CI, 1.19-6.03, P=0.018). Conclusions: This is the first prospective study to suggest that long RTL is associated with recurrence in early stage NSCLC after curative resection. Women and adenocarcinoma appear to be special subgroups in which telomere biology may play an important role. (Supported by NCI CA 111646, CA 55769, and CA 70907.)