Effectiveness of low-dose CT scan for lung cancer screening in the community setting.

Abstract

1543 Background: Lung cancer is the leading cause of cancer death in the United States (US) and worldwide. Chest X-ray (CXR) is ineffective in reducing lung cancer mortality. National Lung Cancer Screening Trail (NLST) reported 20% reduction in mortality with the use of low-dose computed tomography (LDCT) scan to screen high risk individuals. Therefore, major organizations including US Preventive Services Task Force has adopted LDCT for lung cancer screening in high risk populations. However, The generalizability of this approach in community setting is yet to be confirmed. Our objective is to assess the ability of LDCT in detection of lung nodules and lung cancer in the community setting and compare the results to those reported in the NLST. Methods: Charts of subjects who underwent LDCT screening between 2013 and 2016 at SJHMC were retrospectively reviewed. Demographic data, the results of the LDCT scans, interventions performed, complications of procedures and pathology findings were collected. All cancer cases found by LDCT and the stage of cancers were documented. The results of our study were statistically compared to the results of both arms of the NLST (CT and CXR arms). Since CXR is ineffective for lung cancer screening, CXR arm serves equivalently to no screening. Results: The baseline characteristics of the subjects are significantly different between this study and NLST. LDCT in our study detected significantly higher positive findings. There are more cancers detected in this study compared to NLST CT and CXR arms, which could reflect higher incidence of cancer in this community or higher proportion of current smokers in our study. In this study, LDCT detected cancers at higher stages compared to that of the NLST CT arm but similar stages to NLST CXR arm. This may indicate that LDCT when performed in the community is less effective in detecting cancer at early stages. Conclusions: The community population have different characteristics compared those enrolled in clinical trials. This may limit the generalizability of the results. Population-based studies are needed to confirm the results of the NLST. [Table: see text]