Relationship between Serum Bilirubin Level and the Prevalence of Lung Cancer in Smokers

Abstract Background The correlation between serum bilirubin level and multiple respiratory system diseases including lung cancer has been reported. We aimed to explore the relationship between serum bilirubin level and the prevalence of lung cancer among smokers in China. Methods We designed a retrospective case-control study and enrolled 266 lung cancer patients and 266 matched controls from The Third Xiangya Hospital of Central South University from February 2011 to May 2017. Data including diagnosis, serum bilirubin levels and smoking history were collected, which consistently showed significant differential in cases and controls. Results Lower total and indirect bilirubin level is correlated with smoking but they can be recuperating after cessation. The average bilirubin level in lung cancer patients was lower than matched controls. Low indirect bilirubin level within normal range is the risk factor of lung cancer in smokers (OR = 2.710). Of note, smokers whose serum bilirubin lower than 7.88 µmol / L has a higher risk of lung cancer in Chinese adults. Conclusions Serum indirect bilirubin level would be a screening predictor to identify higher risk smokers of lung cancer.