Lung cancer risk with cigar and pipe use

Abstract

Data from a large study of lung cancer (6,920 cases and 13,460 controls) conducted in Western Europe were analyzed to evaluate risks associated with cigar and pipe use among males. Relative to risks among nonsmokers, risks of lung cancer for cigar-only [relative risk (RR) = 2.9] and pipe-only (RR = 2.5) smokers were significantly elevated, but at levels below mixed cigarette and cigar (RR = 6.9) or pipe (RR = 8.1) users and cigarette-only (RR = 9.0) smokers. There were significant trends of increased risk of lung cancer with years of cigar and pipe use and with number of cigars and pipes smoked per day. The increases were seen most clearly among exclusive cigar or exclusive pipe users. Among cigar-only smokers risks increased with greater frequency and depth of inhalation and decreased with years since cessation of use, whereas among pipe-only and mixed smokers trends in risks were not seen with these variables. The histology of the lung cancers among cigar-only and pipe-only smokers closely paralleled the cell type distribution of cases smoking cigarettes only; about 75% were squamous or oat (small) cell carcinomas and less than 10% were adenocarcinomas, in contrast to the findings in nonsmokers, in whom 41% were classified as squamous or oat (small) cell carcinoma versus 37% adenocarcinoma. These results clearly demonstrate a link between cigar and/or pipe use and risk of lung cancer and suggest that differences in risk levels between cigar-only, pipe-only, mixed, and cigarette-only smokers are strongly related to inhalation practices.