The potential role of lung cancer screening in lung cancer survivors.

7553 Background: The National Lung Screening Trial demonstrated improved overall survival (OS) and lung cancer specific survival (LCSS) in the 55-74-year-old age group, likely due to finding early-stage lung cancer. Patients with a past history of lung cancer were excluded from this trial. The purpose of investigation is to assess whether there is an increasing frequency of second lung cancers and whether the first primary reduces survival in a proposed screening population with Stage I (tumor size <4cm) NSCLC (survivor population, SP) as compared to similar patients presenting with their first lung cancer (new patients, NP). Methods: The SEER databases were used to investigate incidence (1973-2009) and OS/LCSS (1998-2009) of secondary lung cancer. Incidence was examined by frequency analysis and trend analysis. A SP was chosen who was originally treated definitively for Stage I-III NSCLC and survived at least four years after diagnosis (N=515). They were compared to NP who were presenting with their first lung cancer (N = 21,040). OS/LCSS in NP and SP with Stage I NSCLC were analyzed by Kaplan-Meier estimation, log-rank tests, and multivariate proportional hazards modeling. Results: The annual incidence rate/100,000 for secondary lung cancer has increased almost 5-fold in last 36 years (2.5 in 1973; 12 in 2009; p<0.001), more so in male patients. OS was not significantly different between NP and SP after accounting for treatment, tumor, and patient characteristics (male, HR=1.111, p=0.330; female, HR=0.840, p=0.118). Multivariate analyses show that LCSS was significantly better in SP females than for NP females (HR=0.849, p=0.025) but did not differ for males (HR=0.923, p=0.388). In the SP, OS decreased significantly with less aggressive treatment compared to lobectomy as the reference treatment (sub-lobar resection, HR=1.841, p=0.009; radiation, HR=2.351, p=0.002; observation, HR=2.145, p=0.016). Patient and tumor characteristics of the first lung cancer diagnosis were not significantly linked to OS. Conclusions: NP and SP diagnosed at Stage I had similar survival rates. The SP group also benefitted from increasingly aggressive treatment. Screening for lung cancer might be of benefit to lung cancer survivors.