Early Impact of Lung Cancer Screening in US population in the SEER Registries

Background: The Lung Cancer Screening Trial (NLST) demonstrated improved overall survival (OS) and lung cancer specific survival (LCSS), likely due to finding early-stage NSCLC. Our study investigates the impact of the NLST publication in 2011 on the lung cancer outcomes in the general US Population by assessing the incidence rates, ratio of early/late stage, and lung cancer mortality in the years immediately prior to and following this publication. Methods: Rate sessions from the SEER18 database were accessed during the years 2008-2015. We analyzed overall lung cancer incidence and mortality rates. The ratio of early/late stage was obtained by dividing the number of stage I and II cases by the number of stage III and IV diagnosed by year. We investigate changes in level and trend using interrupted time series in STATA12, considering 2011 as the intervention. In addition, we performed a T-test for averages ratios comparing the years 2007-2010 to the years 2012-2015 for the entire lung cancer population and for subgroups by median family, ethnicity, Sex, Age and SEER Registry. Results: Although the overall lung cancer rates remained stable during the study period, a significant increase in the ratio of early/late stage was observed following the release of NLST for the overall lung cancer population (p=0.006) and for the screening age group (p= 0.014). The effects of ratio of early/late stage as noted in the overall group persisted for all patient subgroups, except for patients associated with a median income Conclusions: Since the publication of the NLST in 2011, there has been no impact on lung cancer mortality or incidence of lung cancer in the general US population. However, favorable increase in the proportion of early stage lung cancers, depending upon median family income, race and location. We expected a greater impact of lung cancer screening after 2015 since CT-screening for lung cancer was adopted by CMS and other insurances during that year