Background: Lung cancer screening by chest X-rays and/or cytological tests of sputum has been practiced for many years. Nonetheless the number of deaths from lung cancer was kept increasing all this while. We wanted to find a way to decrease the mortality from lung cancer by investigating the screening methods or lifestyle to prevent the lung cancer.
Methods: I. The detection rate of lung cancer was investigated according to each method of screening-helical CT, chest X-rays or sputum tests, from 1998 to 2000.
II. Seventy-nine cases of lung cancer detected by the screening carried from 1995 to 2000 at our institute were compared with control cases matched with respect to age, sex and seasons of screening.
Results: I. The detection rate by helical CT in 1998, 1999, and 2000 was 0.29%, 0.24%, and 0.19%, respectively, while the detection rate by chest X-rays was 0.01%, 0.02% and 0.2%. There was no detection of lung cancer by sputum tests in those three years.
II. The ingestion of vegetables was the only one statistical difference between the lung cancer group and the control group. A lesser ingestion of vegetables increased the risk for lung cancer.
Conclusions: The detection rate of lung cancer by helical CT is remarkably higher than chest X-rays or cytological tests of sputum. People who eat a lot of vegetables have a lesser chance to suffer from lung cancer.