Smoking and Lung Cancer

Abstract

Several months ago I received by telephone, from a representative of one of the major broadcasting systems, an invitation to participate in a televised discussion of the question of smoking and health. I replied immediately that I had previously received such invitations but had always refused, explaining that I did not think such complicated scientific problems were clarified by debates on television. I was assured that this particular program was to be on a high plane, that it was my duty to inform the public of my view, that eminent scientists who were named, including the Surgeon General of the United States Public Health Service, were to participate. I gave way, mostly because of the participation of the Surgeon General, but only on certain conditions. One was that I have the opportunity to write out some questions and my answers as a basis for the televised interview. All my conditions were agreed to. I mentioned the matter of time. I was told that I would have all the time I needed. So, I quickly wrote out a series of questions and answers, sent it to the representative of the broadcasting system and received prompt assurance that it was very satisfactory as the basis of the interview. A few days later I had a telephone conversation about arranging the details of the interview. During this conversation, I again brought up the question of time. It was then that I learned what was meant by my having as much time as needed. This, it was revealed, referred to the taped interview. Then the broadcasting people would select the parts actually to be presented. I will not repeat here the terms in which I rescinded my acceptance of the invitation to appear on the program. That is how I came to have on my hands an unused television interview. I hate to waste it. So, instead of presenting a formal paper I shall read it to you, pretty much as I wrote it out except for some amplifications to make my meaning clearer and to allow me to introduce some illustrations that I did not include in my planned presentation. Q: Dr. Berkson, we have all heard it said that some statistical studies have shown fairly conclusively that smoking is the chief cause of lung cancer. You have expressed doubt about this. Can you briefly explain why? A: The way you have put the question reflects a widespread misunderstanding regarding the facts. You have heard the adage that the most misleading sort of untruth is a half truth. If it is said that these studies showed smokers to have a higher death rate from lung cancer than nonsmokers, this is about a 15 per cent truth. What these studies disclosed is that, in the populations under investigation, the smokers have a higher death rate from all causes together-lung cancer, other cancers including for instance cancer of the pancreas, of the bladder and of the prostate, heart disease, and diseases other than any of thesein short, all classes of disease. Lung cancer constituted only about 10 to 15 per cent of the total excess deaths. The problem. presented by these findings has been put as well as need be by Cuyler Hammond, the senior author of the American Cancer Society's reports, from whom I quote [22]: my opinion, the most important finding in all these studies is that overall death rate increases with the amount of smoking. I want to emphasize that I said 'overall death rate,' not 'lung cancer.' The relationship between smoking and lung cancer should be viewed in the light of this broader picture. The problem at hand is to discover the scientific explanation of these extraordinary findings. In figures 1, 2 and 3 are shown statistics from the American Cancer Society study by Hammond and Horn and from the study by Dorn on United States Veterans, illustrating *the association of smoking and death rate found in these studies. It is seen that the association affects all classes of disease and that the number of excess deaths from lung cancer is only 12 to 15 per cent of the total; some 85 per cent of the excess deaths are from causes other than lung cancer. Q: Well, if these studies show the death rate among smokers to be higher from all classes of other disease, as well as from lung cancer, doesn't this indict cigarette smoking even more? A: We are not concerned with indicting or exonerating smoking-I am myself a non-cigarette smoker-but to try to find the scientific explanation of these statistical results. The idea that cigarette smoking causes all these many deaths from all these many causes does indeed seem seriously questionable. There is not any scientifically known pharmacologic or physical explanation for so widespread and multifarious an effect. If we extrapolate the results to the general population, we must believe that