Background: In order to evaluate the efficacy of sputum cytology in lung cancer screening, we re-analyzed the data obtained in our previous case-control study.
Materials and methods: The source population was defined as the previous screenees for reducing self-selection bias. Matching conditions were: gender, year of birth, municipality and smoking history.
Results: Smoking adjusted odds ratio (SAOR) of dying from lung cancer for those screened by chest roentgenogram (CXp) only vs. not screened was 0.47, and that for those screened by sputum cytology (SpC) & CXp vs. not screened was 0.36, which was approximately three-fourths of the former. In another analysis, SAOR for those screened by SpC & CXp vs. those screened by CXp only was 0.63.
Conclusion: Although statistical significance was not obtained, there might be some possibility that the risk of lung cancer death in smokers would decrease by additional SpC, compared with CXp only.