By:  James P. Siepmann, MD

Yes, it is true, smoking does not cause lung cancer.  It is only one of many risk factors for lung cancer. I initially was going to write an article on how the professional literature and publications misuse the language by saying "smoking causes lung cancer"^1,2, but the more that I looked into how biased the literature, professional organizations, and the media are, I modified this article to one on trying to put the relationship between smoking and cancer into perspective. (No, I did not get paid off by the tobacco companies, or anything else like that.)

When the tobacco executives testified to Congress that they did not believe that smoking caused cancer, there answers were probably truthful and I agree with that statement. Now if they were asked if smoking increases the risk of getting lung cancer, then the answer based upon current evidence should be "yes."  But even so, the risk of a smoker getting lung cancer is much less than anyone would suspect.   Based upon what the media and anti-tobacco organizations say, one would think that if you smoke, you get lung cancer (a 100% correlation).  You would at least expect a 50+% occurrence before someone used the word "cause." 

Would you believe that the real number is < 10% (see Appendix A)? Yes, a US white male (USWM) cigarette smoker has an 8% lifetime chance of dying from lung cancer but the USWM nonsmoker also has a 1% chance of dying from lung cancer (see Appendix A).  In fact, the data used is biased in the way they are collected and the actual risk for a smoker is probably less.  I personally would not smoke cigarettes and take that risk, nor recommend cigarette smoking to others but the numbers were less than I had been led to believe.  I only did the data on white males because they account for the largest number of lung cancers in the US, but a similar analysis can be done for other groups using the CDC data.

You don't see this type of information being reported, and we hear things like, "if you smoke you will die" but when we actually look at the data, lung cancer accounts for only 2% of the annual deaths worldwide and only 3% in the US.**

When we look at the data over a longer period of time, such as 50 years as we did here, the lifetime relative risk is only 8 (see Appendix A).  That means that even using the biased data that is out there, a USWM smoker has only an 8x more risk of dying from lung cancer than a nonsmoker.  It surprised me too because I had always heard numbers like 20-40 times more risk. Statistics that are understandable and make sense... it may be a new avenue of scientific inquiry.

The process of developing cancer is complex and multifactorial.  It involves genetics, the immune system, cellular irritation, DNA alteration, dose and duration of exposure, and much more. Some of the known risk factors include genetics^4,5,6, asbestos exposure⁷, sex⁸, HIV status⁹, vitamin deficiency¹⁰, diet^11,12,13, pollution¹⁴ , shipbuilding¹⁵ and even just plain old being lazy.¹⁶ When some of these factors are combined they can have a synergistic effect¹⁷, but none of these risk factors are directly and independently responsible for "causing" lung cancer!

Take a look in any dictionary and you will find something like, "anything producing an effect or result."¹⁸ At what level of occurrence would you feel comfortable saying that X "causes" Y. For myself and most scientists, we would require Y to occur at least 50% of the time. Yet the media would have you believe that X causes Y when it actually occurs less than 10% of the time.

As ludicrous as that is, the medical and lay press is littered with such pabulum and gobbley-guk. Even as web literate physician, it took me over 50 hours of internet time to find enough raw data to write this article.  I went through thousands of abstracts and numerous articles, to only find two articles that even questioned the degree of correlation between smoking and lung cancer (British lung cancer rates do not correlating to smoking rates)^19,20 and another two articles which  questioned the link between second hand smoke (passive smoking) and lung cancer.^21,22 Everywhere I looked the information was hidden in terms like "odds ratio," "relative risk," or "annualized mortality rate," of which most doctors probably could not accurately define and interpret them all let along someone outside the medical profession. The public relies on the media to interpret this morass of data but instead they given politically correct and biased views.

If they would say that smoking increases the incidence of lung cancer or that smoking is a risk factor in the development of lung cancer, then I would agree. The purpose of this article is to emphasize the need for using language appropriately in the medical and scientific literature (the media as a whole may be a lost cause).

Everything in life has risk; just going to work each day has risk. Are we supposed to live our lives in bed, hiding under the blanket in case a tornado should come into our bedroom? We in science, have a duty to give the public accurate information and then let them decide for themselves what risk is appropriate. To do otherwise is to subtly impose our biases on the populace.

We must embrace Theoretics as a discipline as it strives to bring objectivity and logic back into science. Every article/study has some bias in it, the goal is to minimize such biases and present the facts in a comprehensible and logical manner. Unfortunately, most scientists have never taken a course in logic and I'm sure that English class was not their favorite. Theoretics is a field of science which focuses on the use of logic and appropriate language in order to develop scientifically credible theories and ideas which will then have experimental implications. As someone whom I respect says, "Words mean things."  Let us use language and logic appropriately in our research and the way that we communicate information.

Yes, smoking is bad for you, but so are fast-food hamburgers, driving, and so on. We must weigh the risk and benefits of the behavior both as a society and as an individual based on unbiased information. Be warned though that a society without risk shall cease to exist. Let us be logical in our endeavors and true in our pursuit of knowledge. Instead of just waiting for lung cancer to get me (because the media and a lot of the medical literature told me that smoking causes lung cancer), I can enjoy my occasional cigar even more now...now that I know the whole story.

1. USWM smokers have a lifetime relative risk of dying from lung cancer of only 8 (not the 20 or more that is based on an annual death rate and therefore virtually useless).
2. No study has ever shown that casual cigar smoker (<5 cigars/wk, not inhaled) has an increased incidence of lung cancer.
3. Lung cancer is not in even in the top 5 causes of death, it is only #9.**
4. All cancers combined account for only 13% of all annual deaths and lung cancer only 2%.**
5. Occasional cigarette use (<1 pk/wk) has never been shown to be a risk factor in lung cancer.
6. Certain types of pollution are more dangerous than second hand smoke.³
7. Second hand smoke has never been shown to be a causative factor in lung cancer.
8. A WHO study did not show that passive (second hand) smoke statistically increased the risk of getting lung cancer.
9. No study has shown that second hand smoke exposure during childhood increases their risk of getting lung cancer.
10. In one study they couldn't even cause lung cancer in mice after exposing them to cigarette smoke for a long time.²³
11. If everyone in the world stopped smoking 50 years ago, the premature death rate would still be well over 80% of what it is today.¹ (But I thought that smoking was the major cause of preventable death...hmmm.)

**WHO data of member countries

Keywords:  lung cancer, mortality, tobacco, smoking, Theoretics, language, WHO, cigarette, cigar, logic.

References (I back up my statements with facts, will those who respond to me do the same?)

1. Articles:

Pisani P, Parkin DM, Bray F, Ferlay J, Estimates of the worldwide mortality from 25 cancers in 1990, Int J Cancer 1999 Sep 24;83(1):18-29 "Tobacco smoking and chewing are almost certainly the major preventable causes of cancer today."

American Thoracic Society, Cigarette smoking and health.. , Am J Respir Crit Care Med; 153(2):861-5 1996 "Cigarette smoking remains the primary cause of preventable death and morbidity in the United States."

Nordlund LA, Trends in smoking habits and lung cancer in Sweden, Eur J Cancer Prev 1998 Apr;7(2):109-16 "Tobacco smoking is the most important cause of lung cancer and accounts for about 80-90% of all cases of lung cancer among men and about 50-80% among women."

JAMA 1997;278:1505-1508 "The chief cause of death included lung cancer, esophageal cancer and liver cancer. The death rate was higher for those who started smoking before age 25. If current smoking patterns persist, tobacco will eventually cause more than two million deaths each year in China."

JAMA 1997;278:1500-1504 "We have demonstrated that smoking is a major cause of death in China...."

Hecht SS  hecht002@tc.umn.edu, Tobacco smoke carcinogens and lung cancer, J Natl Cancer Inst 1999 Jul 21;91(14):1194-210. "The complexity of tobacco smoke leads to some confusion about the mechanisms by which it causes lung cancer."

Sarna L, Prevention: Tobacco control and cancer nursing, Cancer Nurs 1999 Feb;22(1):21-8 "In the next century, tobacco will become the number-one cause of preventable death throughout the world, resulting in half a billion deaths."

Liu BQ, Peto R, Chen ZM, Boreham J, Wu YP, Li JY, Campbell TC, Chen JS, Emerging tobacco hazards in China: 1. Retrospective proportional mortality study of one million deaths, BMJ 1998 Nov 21;317(7170):1411-22 " If current smoking uptake rates persist in China (where about two thirds of men but few women become smokers) tobacco will kill about 100 million...."

Nordlund LA Trends in smoking habits and lung cancer in Sweden. Eur J Cancer Prev 1998 Apr;7(2):109-16 "Tobacco smoking is the most important cause of lung cancer and accounts for about 80-90% of all cases of lung cancer among men and about 50-80% among women."

Skurnik Y, Shoenfeld Y Health effects of cigarette smoking, Clin Dermatol 1998 Sep-Oct;16(5):545-56

"Cigarette smoking, the chief preventable cause of illness and death in the industrialized nations

2. Websites:

JAMA website: http://www.ama-assn.org/sci-pubs/sci-news/1996/snr0424.htm   "Yet huge obstacles remain in our path, and new roadblocks are being erected continuously," writes Ronald M. Davis, M.D., director of the Center for Health Promotion and Disease Prevention, Henry Ford Health System, Detroit, Mich., in urging a review of the effort against "the most important preventable cause of death in our society."

JAMA Website: http://www.ama-assn.org/sci-pubs/sci-news/1997/snr1203.htm#joc6d99 "According to the authors, tobacco use has been cited as the chief avoidable cause of death in the U.S., responsible for more than 420,000 deaths annually ...."

JAMA Website: http://jama.ama-assn.org/issues/v281n2/full/jwm80010-2.html "The researchers reported that of deaths caused by tobacco...."

3. The World Health Report 1999, chapter 5 and Statistical Annex (http://www.who.int/whr/1999/en/report.htm) and CDC data (http://www.cdc.gov/scientific.htm).

4.Mutat Res 1998 Feb 26;398(1-2):43-54 Association of the NAT1*10 genotype with increased chromosome aberrations and higher lung cancer risk in cigarette smokers. Abdel-Rahman SZ, El-Zein RA, Z

5. Schwartz AG, Rothrock M, Yang P, Swanson GM, "Increased cancer risk among relatives of nonsmoking lung cancer cases," Genet Epidemiol 1999;17(1):1-15

6. Amos CI, Xu W, Spitz MR, Is there a genetic basis for lung cancer susceptibility?, Recent Results Cancer Res 1999;151:3-12

7. Silica, asbestos, man-made mineral fibers, and cancer. Author Steenland K; Stayner L Cancer Causes Control, 8(3):491-503 1997 May

8. Lam S, leRiche JC, Zheng Y, Coldman A, MacAulay C, Hawk E, Kelloff G, Gazdar AF, Sex-related differences in bronchial epithelial changes associated with tobacco smoking, J Natl Cancer Inst 1999 Apr 21;91(8):691-6

9. Ignacio I. Wistuba, MD, Comparison of Molecular Changes in Lung Cancers in HIV-Positive and HIV-Indeterminate Subjects, JAMAVol. 279, pp. 1554-1559, May 20, 1998

10. Kumagai Y, Pi JB, Lee S, Sun GF, Yamanushi T, Sagai M, Shimojo N, Serum antioxidant vitamins and risk of lung and stomach cancers in Shenyang, Cancer Lett 1998 Jul 17;129(2):145-9 China.

11. Nyberg F, et al., Dietary factors and risk of lung cancer in never-smokers, Int J Cancer 1998 Nov 9;78(4):430-6

12. Sinha R, Kulldorff M, Curtin J, Brown CC, Alavanja MC, Swanson CA, "Fried, well-done red meat and risk of lung cancer in women." Cancer Causes Control 1998 Dec;9(6):621-30.

13. Young KJ, Lee PN, Statistics and Computing Ltd, Surrey, UK. Intervention studies on cancer, Eur J Cancer Prev 1999 Apr;8(2):91-103

14. Long-term inhalable particles and other air pollutants related to mortality in nonsmokers.
Am J Respir Crit Care Med. 1999 Feb;159(2):373-82.

15. Blot WJ, Fraumeni JF, Lung Cancer Mortality in the US: Shipyard Correlations Source, Ann N Y Acad Sci; 330:313-315 1979 UI: 80659437

16. Lee IM, Sesso HD, Paffenbarger RS Jr, Physical activity and risk of lung cancer. Int J Epidemiol 1999 Aug;28(4):620-5

17. Kamp DW, Greenberger MJ, Sbalchierro JS, Preusen SE, Weitzman SA, Cigarette smoke augments asbestos-induced alveolar epithelial cell injury: role of free radicals, Free Radic Biol Med 1998 Oct;25(6):728-39

18. The Complete Reference Collection, 1996-9, Compton's.

19. Lee PN, Forey BA, Trends in cigarette consumption cannot fully explain trends in British lung cancer rates, J Epidemiol Community Health; 52(2):82-92 1998

20. Pandey M, Mathew A, Nair MK, Global perspective of tobacco habits and lung cancer: a lesson for third world countries. Eur J Cancer Prev 1999 Aug;8(4):271-9

21. Jahn O, [Passive smoking, a risk factor for lung carcinoma?], Wien Klin Wochenschr; 108(18):570-3 1996

22. Nilsson R, Environmental tobacco smoke and lung cancer: a reappraisal, Ecotoxicol Environ Saf; 34(1):2-17 1996

23. Finch GL, Nikula KJ, Belinsky SA, Barr EB, Stoner GD, Lechner JF, Failure of cigarette smoke to induce or promote lung cancer in the A/J mouse, Cancer Lett; 99(2):161-7 1996

Appendix A:                                               US white male data³

As long as I'm being controversial by presenting both sides of the story, do I dare tell you that a woman is three times more likely to die from an abortion than from delivering a baby (WHO data).