Lung Cancer That Is Not Attributable to Smoking

The report by the Centers for Disease Control on mortality attributable to cigarette smoking has led the researchers to look further at respiratory cancers to see how much of these diseases might not be attributable to smoking.

Abstract

To the Editor. — The report by the Centers for Disease Control, Atlanta, Ga, on mortality attributable to cigarette smoking1has led us to look further at respiratory cancers to see how much of these diseases might not be attributable to smoking. The smoking-attributable fraction for bronchogenic cancer can be developed from published data2on the proportion of active smokers, the proportion of quit smokers, and the amounts smoked. From the data of Dorn and Hammond,3the relative risk for smokers is roughly given by 1 plus half the number of cigarettes smoked per day. Assuming that the average quit smoker is at one third the excess risks of a continuing smoker, we find the following smoking-attributable fractions for lung cancer based on 1965 smoking patterns: These smoking-attributable fractions imply that for recent lung cancer mortality4(1984 data, allowing for roughly a 20-year latent period), the