Smoking status, occupational asbestos exposure and bronchial location of lung cancer

The objective of this study was to determine the factors associated with central airway versus peripheral bronchial location of lung cancer. All patients diagnosed with lung cancer from 1997 through 2000 in the Respiratory Disease Department of Rouen University Hospital were prospectively interviewed about their smoking and occupational history using a standardized questionnaire. All patients underwent white-light bronchial endoscopy using a 4.5 mm flexible endoscope. Tumors were classified as central when they were accessible and visible using this technique. Out of 217 cases of lung cancer included in this study, 155 (71%) were central. Histological type of lung cancer was strongly associated with bronchial location as central location was observed in 48, 82 and 92% of Adenocarcinoma (AC), Squamous Cell (SqC), and Small Cell Carcinoma (SCC), respectively (P<0.0001). Among non asbestos-exposed patients, location varied little with smoking status, with central location frequency ranging from 74 to 80%. In contrast, lung cancer was recorded central in 41% of long-term (> or =10 years) ex-smokers, 67% of short-term (<10 years) ex-smokers and 75% of current smokers (P=0.04) among patients exposed to asbestos, suggesting an interaction between duration of smoking cessation and occupational asbestos exposure with respect to lung cancer location. These findings were confirmed after adjustment for sex, age and histologic type in multivariate analysis. These results suggest that individually-tailored multimodality screening strategies relying on various combinations of low-dose CT scan, sputum analysis and fluorescence endoscopy according to each patient's profile may be more effective than standard strategies based on a single approach for all patients.