The Lung Cancer Debate
TL;DR:Too Long; Didn't Read
All cancer is bad. There is not one cancer that is better than the other. We know that children can get cancer. And we know that non-smokers can get lung cancer. Having said that, we emphasize lung cancer on this website because it's the deadliest cancer among both men and women, and almost all cases are preventable. On January 11, 1964, the landmark United States Surgeon General's report was released. Since then, the connection between lung cancer and smoking tobacco has been well-established (U.S. Department of Health and Human Services, 2014). But that hasn't always been the case.
To better understand why that connection was difficult to accept, we can compare two different environmental carcinogens that have similar properties — chimney soot and tar from tobacco smoke. Child labor was the norm in 18th-century England (Mukherjee, 2010, p. 239). Orphans were often apprenticed as chimney sweeps, and sent up the chimneys to remove ash (Mukherjee, 2010, p. 237). Soot would accumulate under their skin, and in some cases develop into cancer of the scrotum (scrotal cancer) (Mukherjee, 2010, p. 238).
In 1775, Percivall Pott, a surgeon at St. Bartholomew's Hospital in London, was inundated with scrotal cancer cases in his clinic (Mukherjee, 2010, p. 237). The condition was exclusive to the nether-regions of young men, so it was often taken as a sexually transmitted disease. However, when standard emollient drugs failed, Pott pursued another explanation (Mukherjee, 2010, p. 238). He discovered the link between the disease (scrotal cancer) and one occupation (chimney sweeps) because both were uncommon enough to stand out when associated with each other (Mukherjee, 2010, p. 241).
The health consequences of smoking, on the other hand, were not associated with the habit, because the habit was so common. During the 18th, 19th and 20th centuries, tobacco use escalated. It became an international addiction. Thus, the link between smoking and lung cancer became invisible, and was often dismissed as nonsense (Mukherjee, 2010, pp. 240-245). Tobacco smoke, then, was not considered a carcinogen because, unlike chimney soot, it did not appear to cause cancer.
In 1947, however, British statisticians noticed an exponential increase in lung cancer rates — an illumination that triggered massive research. In London, Austin Bradford Hill and Richard Doll developed a case-control study that established a statistical link between smoking cigarettes and lung cancer. In the United States, Evarts Graham and Ernst Wynder achieved similar results (Mukherjee, 2010, pp. 243-249).
However, both of these studies were retrospective; that is, past results were used to reach conclusions. Doll and Hill, then, developed a prospective study (in real time) that was used to calculate relative risk among non-smokers and smokers (Mukherjee, 2010, pp. 243-249). Autopsies, clinical studies, independent prospective trials, interviews, opinions and testimonies, would soon follow. In conclusion, there is a strong and indisputable connection between lung cancer and smoking tobacco (Mukherjee, 2010, pp. 260-262).
This section contains a list of references for the information that's used on The Lung Cancer Debate. Some references include a link that can be used to open the original source in a separate browser window.