Preliminary reports of lung cancer screening with low-dose computed tomography: a nationwide performance on the Korean population in 2019-2020.

Background: Korea introduced its National Lung Cancer Screening Program (NLCSP) with low-dose computed tomography (LDCT) in 2019. However, there are few published results of lung cancer screening at national level. We investigated the performance of LDCT for lung cancer screening and suggested recommendations for improving a nationwide population-based program.

Materials And Methods: This study was a nationwide, population-based cross-sectional study. We analyzed the Korean National Health Insurance Big Data Base, which included lung cancer-related screening information between 2019 and 2020, was analyzed. Performance indicators were the number of examinations, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), overexposure, and suspected lung cancer (LCA). The performance indicators were stratified according to screening year, sex, age group, and region.

Results: A total of 149,936 examinations were done in 2019-2020. Most participants were men (98.3%) or were aged 54-59 or 60-64 (35.2% and 38.2%). The sensitivity, specificity, PPV, NPV, overexposure, and suspected LCA were 82.9%, 91.9%, 6.4%, 99.9%, 2.7%, and 4.0%, respectively. Women showed lower sensitivity than men. In 2020, there was a substantial increase in PPV (11.0%), and a substantial decrease in overexposure (47.7%) and suspected LCA (16.9%) compared to 2019. At regional level, there was a large variance in sensitivity, PPV, overexposure, and suspected LCA.

Conclusions: Korea's NLCSP successfully demonstrated validity and reliability at national level. Sexual, and regional differences should be addressed to improve NLCSP.

Key Points: Question How has biennial low-dose CT (LDCT) lung cancer screening performed in Korea for individuals aged 54-74 years with a smoking history of ≥ 30 pack-years? Findings The sensitivity, specificity, and positive predictive value were 82.9%, 91.9%, and 6.4%. Clinical relevance Korea's program demonstrated a similar level of validity and reliability of previous lung cancer screening studies at national level. It facilitated early diagnosis of lung cancer for all the relevant Korean population and laid the foundation for long-term cancer screening.