Lung Cancer And The British Royal College Of Physicians Report

In his speech Sir Charles tries to downplay the Royal College of Physicians' conclusion that cigarettes cause lung cancer, calling it an emotional reaction based on an incomplete examination of the data. He does, however, acknowledge that smoking causes bronchitis.

After reading the Report of the Royal College of Physicians and the debate in the House of Lords the dominant impression I received was that of people who had reached an emotional conclusion in which they believed passionately and sincerely. This report provided the occasion for statements of faith by people who seemed to find it necessary, however, to silence their own self-criticism by repeating phrases like, "conclusive proof beyond the shadow of doubt" [,] ... "devastating effect of the marshalling of cold scientific facts", and so on. Yet we who have been immersed in the subject for many years know that this report produced no new fact, produced no new arguments, indeed, except for the contribution of an emotional gloss, left the subject untouched. We know only too well that there are no conclusive proofs; that there are few, if any, cold scientific facts.

However, emotional conclusions cannot be disregarded. They may not be right, but they are not necessarily wrong. Emotional judgments are often the basis for national thinking, and since a national attitude to smoking may be building up it is essential for us to consider what are the components in this emotion.

The most important is the dread word "cancer". Most people cease to be able to reason once it is mentioned, and you will all be aware how difficult it is for doctors to overcome the reluctance of people to admit the possibility of having cancer and to present themselves for early examination. Lung cancer carries with it all of these associations, and also shares some of the aura of dread connected with tuberculosis. I can well remember how pneumoconiosis in the coal mines had much of this emotional background and was correspondingly difficult to deal with in a rational manner. Smoker's cough is a real phenomenon and obvious to everyone , and we should recognize that it is a factor in the emotional build-up [emphasis added]. {1102.01, pp. 3–4}

"Smoker's cough" is a symptom of lower airway irritation caused by cigarette smoke. "Bronchitis" is the clinical term that is implied by the phrase "smoker's cough." This irritation occurs as a result of smoke inhalation, which, in turn, is necessary for nicotine absorption from a cigarette (see chapter 3). Where there is a smoker's cough, there is some degree of bronchitis.

Sir Charles states that the evidence directly implicating cigarette smoking as a cause of lung cancer was epidemiological except for a single study by Blacklock (4). Blacklock had injected cigarette smoke con-

densates mixed with the adjuvant eucerin, a material to amplify the effects of smoke condensate, into the lungs of rats, guinea pigs, and rabbits. The animals lived out their natural lives and then were examined. Cancers were observed in six of seventy-two rats and in one rabbit.

In saying that Blacklock's work was the only biological study in the literature that addressed the question of smoking as a cause of lung cancer, Sir Charles is framing the issue very narrowly. A decade earlier, the young US physician Ernst Wynder had shown that cigarette smoke tar condensate caused cancer in a mouse skin model (5, 6). The test involved repeatedly painting smoke condensate onto the skin of mice and observing the animals over a long period of time to see whether cancers developed at the exposed site. Although Sir Charles does not mention the mouse skin–painting model as relevant to the question of whether smoking causes lung cancer, BAT was to use this very model in Project Janus (discussed below) as its gold standard for determining whether specific product modifications could reduce the dangers of smoking.