Assessing the performance of chest x-ray screening in detecting early-stage lung cancer in the general population

Chest x-ray (CXR) is widely used for lung cancer screening in Japan. We evaluated the sensitivity and specificity of CXR in detecting early lung cancer and its histological types. We cross-referenced lung cancer municipality screening data with the regional cancer registry database. The results of individuals screened at least once from 2016 to 2018 were utilized to calculate CXR's sensitivity and specificity for lung cancer diagnosed within 1 year of screening (n = 161,251) by stage and its histological types. We stratified analyses based on sex, age, smoking status, first screening, and screening intervals. CXR's sensitivity and specificity for early-stage lung cancer were 73.6% (95% confidence interval [CI], 66.8-79.6) and 94.1% (95% CI, 94.0-94.2), respectively. No significant differences were found in sex or smoking status. The sensitivity for early-stage adenocarcinoma was 76.0% (95% CI, 68.3-82.7), which was higher than that for early-stage squamous cell carcinoma (70.4% [95% CI, 67.3-86.0]). However, no significant differences were observed (p = .532). No significant differences were found in sex or smoking status for early-stage adenocarcinoma or early-stage squamous cell carcinoma. Due to its moderate sensitivity and high specificity, CXR could be a useful tool for mass screening in the general population. However, because CXR failed to detect 26.4% of early-stage cases, practitioners should inform high-risk patients of other screening options.