Lung cancer screening--comparison of computed tomography and X-ray.

Recent studies on lung cancer screening with CT disclosed a discrepancy between its efficiency in detecting early lung cancer and a lack of proof for decreasing mortality from lung cancer. The present study, in a city in Japan where an X-ray screening program is provided, bi-annual CT screening was performed for X-ray screening negative subjects for 4 years. Ten patients with lung cancer were detected among 22,720 person-year subjects (0.