Retrospective analysis of screening results of lung cancer cases among occupational population at high risk of lung cancer

Abstract

Lung cancer has become the leading cause of the cancer death in China. Population-based lung cancer screening is still in controversy. The objective of this study is to analyze the effect of annual chest radiography and sputum cytological screening conducted in high lung cancer risk population who were exposed to work related carcinogens. A retrospective analysis was conducted to evaluate the screening results of the lung cancer cases diagnosed from 1992 to 2001 in the miners of Yunnan tin mine. A total of 9317 miners had been screened annually from 1992 to 1999. A total of 46 779 chest radiography and 45 672 sputum cytological examinations had been conducted, and 793 cohort subjects had at least one positive result. The annual positive detection rate ranged from 1214.1/100 000 to 3482.7/100 000. By December 31, 2001, 433 lung cancer cases had been confirmed, 371 cases out of them had cytological/pathological evidence, and 55.0% were squamous cell carcinoma followed by adenocarcinoma and small cell carcinoma. Stage I or II accounted for 24%. 62.1% of the cases had at least one positive screening result, while 165 cases were detected by chest radiography alone, 56 were detected by sputum cytology, and 48 were detected by both screening modalities. 64.2% of X-ray detected cases were squamous/adenous carcinomas and 75.0% of cytological detected cases were squamous carcinoma. 80.8% of early stage cases had at least one previous positive finding from screening. Annual lung cancer screening with combination of chest radiography and sputum cytology play some extent role in early detection of lung cancer in high risk population. The results may provide some primary data for lung cancer screening in special population who are at high risk of lung cancer in China.