Is there a relationship between the presence of lung mucosa preinvasive lesions and lung cancer incidence? Influence of tobacco consumption

Although studied for years, the nature of the relationships between tobacco consumption, bronchial preinvasive lesions and lung cancer are still not completely elucidated. Objectives were to determine the relationship between tobacco consumption and lung mucosa preinvasive and invasive lesions and to describe patients' evolution according to baseline characteristics.

Methods: Bronchial biopsy specimens were taken at six predetermined sites in 156 males, current smokers, aged above 18 years. Relationships between smoking characteristics and preinvasive lesions indexes and between baseline characteristics and lung cancer occurrence during a prospective follow-up were examined.

Results: Maximum grade was hyperplasia for 16.7% of patients, metaplasia 33.3%, dysplasia 25.0%, and carcinoma in situ 1.3%. For 23.7% of patients, all biopsies were considered normal. Preinvasive lesion indexes were related to smoking intensity (cigarettes/day). Lung cancer incidence during the follow-up was 19.9%. No association between severity of mucosa lesions at baseline and incidence of cancer during the follow-up period was observed.

Conclusion: The majority of smokers had mucosa lesions, but a relatively small number of them would have a cancer, and there was a poor correlation between severity of mucosalesions and incidence of cancer. Even if an evolution from preinvasive lesions to an invasive cancer is plausible and coherent with current concepts, this link does not appear strong enough to recommend the use of systematic classic endoscopy for targeting of a sub-group of higher risk smokers who would require a closer follow up.