The control of lung cancer relating to quitting active smoking and secondary smoking: a case-control study of lung cancer in Taiyuan

Background and purpose: Taiyuan City of Shanxi Province is one of the cities in China with serious air pollution. This study aimed to understand the risk factors of various types of lung cancer in order to take effective preventive measures. Methods: From March 2005 to September 2007, 396 lung cancer patients from Taiyuan Cancer Hospital and 465 healthy control persons were included in this study. The lung cancer cases diagnosed by pathology in Taiyuan Cancer Hospital were matched randomly selected population-based controls to carry out case-control investigation and environmental monitoring. During the analysis, the risk factors other than case-control risk factors were excluded and balanced, and the trend test was carried out at the same time; multivariate unconditional logistic regression analysis was used to analyze various risk factors, including odds ratio (OR) and 95% confidence interval (95% CI). Results: The results showed smoking was closely related to lung cancer. The risk of lung cancer in smokers was significantly higher than that in non-smokers (OR=3.75, 95% CI: 2.39-5.89), especially in lung squamous cell carcinoma and small cell lung cancer (OR=5.01 and 5.06). There was a significant dose-effect relationship between lung cancer and smoking amount, smoking years and smoking depth. Passive smoking, or long-term use of solid fuel in kitchen for cooking and heating also played an important role in the occurrence and development of lung cancer. The research of PM2.5 has just begun, and no significant correlation between indoor particulate matter pollution and lung cancer has been found. Conclusion: Smoking is still an important risk factor for lung cancer in Taiyuan City. Passive smoking and solid fuel cooking should not be ignored.