Cigarette smoking and lung cancer cell types.

The role of tobacco smoke in the development of lung cancer is well known for squamous and small cell types, somewhat less so for adenocarcinoma, and not specifically assessed for large cell carcinoma. In the current analysis, based on 851 men and 507 women with lung cancer and their matched controls (888 men and 608 women), smoking was associated with each lung cancer cell type, and differences in smoking habits by cell types were small. However, the increase of lung cancer risk according to number of cigarettes per day was stronger for small cell and oat cell carcinoma than for adenocarcinoma. There was no increase for large cell carcinoma. For squamous cell carcinoma, this dose response was weak among men and strong among women. The strength of the association between smoking and lung cancer cell types may be related to cancer location, with more peripheral lung cancer types (such as adenocarcinoma and large cell carcinoma) showing weaker associations than more central tumors (such as squamous or small cell and oat cell carcinoma).