SOME LUNG CANCER RISKS INDEPENDENT OF CIGARETTE SMOKING

The epidemiologic literature reports many risk factors for lung cancer that are independent of cigarette smoking. In other words, they are independent lung cancer risks for smokers and nonsmokers alike. Hence, epidemiologic studies of the association of lung cancer with active smoking or  with environmental tobacco smoke must investigate and measure the interference of any and all independent risk factors. These factors carry the appropriate technical designation of confounders, and it is an illegal technical and professional procedure to draw conclusions from a study without a meticulous accounting of such confounders.

Active cigarette smoking. Obviously it is not possible to draw conclusions about the magnitude of cigarette smoking risk for lung cancer without a reasonably accurate account of the possible influence of confounders. Yet, none of the studies of cigarette smoking and lung cancer reported by the U.S. Surgeon General (USSG, 1979) have taken into account any of the confounders here listed. The likely reason is that most of those studies were performed in the ‘50s and ‘60s, when the confounding risk factor here listed had yet to be reported.

Thus, it if it were possible to account for the inevitable interferences of confounders,  the magnitude of the relative risk and the numbers of lung cancers now attributed to smoking would have to be corrected downward, and likely substantially so. Sir Richard Doll, the dean of antismoking epidemiologists, aknowledged the discrepancy as he wrote: “...[active] smoking seems to act synergistically with other aetiologic agents such as consump­tion of alcohol; various aspects of the diet; levels of blood pressure, blood lipids, or other cardiovascular risk factors; or exposure to asbestos, radon, or possibly some infective factors. The quantitative effect of smoking will, therefore, vary with varia­tion in the prevalence of these other factors.” (Doll et al., 1994). Although Doll did not mention all the risk factors here listed, his admission is tantamount to stating that the magnitude of the risk and the number of lung cancer cases that could be attributed to cigarette smoking remain unknown.

 

Environmental tobacco smoke (ETS). Even if one were to use the illegal statistical and epidemiologic distortions introduced by the U.S. Environmental Protection Agency to dream up a conclusion about the lung cancer risk of ETS (USEPA, 1992), the currently available studies on this topic could not conjure up a relative risk greater than 1.05, namely an incongruous 5% elevation (Gori and Luik, 1999). Assuming for sake of argument that such an assessment were technically correct, it would be 20 to 300 times smaller as compared respectively to the lowest and highest risk factors here listed. It is undeniable, therefore, that even a slight confounding by any or many of the confounders here listed could have a much greater inpact in any study of ETS and lung cancer than the possible impact of ETS itself. Yet, the ETS and lung cancer studies so far published have accounted erratically for no more than a handful of the confounders here listed, thus making absolutely moot any interpretation of the possible association of ETS exposure and lung cancer.

 

How to read the following table. The first column describes the nature of the risk factors investigated. The second column gives the name of the first author of each study that has reported separately on the risk factor listed on the first column to the left. The complete bibliography of each study can be found alphabetically by author in the list of references. The third column lists the most likely and best estimate of the highest risk reported by each study. The risks are given as relative risks, namely relative to the risk of people not exposed to the risk factor under study. The fourth and last column gives the 95% confidence interval for each risk listed. The interval is a measure of the statistical uncertainty of the risk values listed in the third column, and indicates that the true value of the risk may be anywhere between the low and high figures in the fourth column, with a 1 in 20 probability of error.

LUNG CANCER RISKS - LITERATURE

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• Alavanja M: Saturated Fat Intake and Lung Cancer Risk Among Nonsmoking Women in Missouri. J. Nat. Cancer Inst., 85(23):1906-16 (1993).
• Albanes D: Physical Activity and the Risk of Cancer in the NHANES I Population. Am. J. Pub. Health, 79:744‑50 (1989).
• Agudo A, et al.: Vegetable and Fruit Intake and the Risk of Lung Cancer in Women in Barcelona, Spain. Eur. J. Cancer, 33:1256‑61 (1997).
• Axelsson G, et al.: Dietary Factors and Lung Cancer Among Men in West Sweden. Int. J. Epidemiol., 25:32-39 (1996).
• Brown S, et al.: The Association of Economic Status With the Occurrence of Lung Cancer. Cancer, 36:1903‑11 (1975).
• Byers T, et al.: Diet and Lung Cancer Risk: Findings from the Western New York Diet Study. Am. J. Epidemiol., 125:351-63 (1987).
• Brownson R, et al.: Family History of Cancer and Risk of Lung Cancer in Lifetime Non-Smokers and Long-Term ExSmokers. Int. J. Epidemiol., 26(2):256-63 (1997).
• Candelora E, et al.: Dietary Intake and Risk of Lung Cancer in Women Who Never Smoked. Nutr. Cancer, 17(3):26370 (1992).
• Dement J, et al.: Follow‑Up Study of Chrisotyle Asbestos Textile Workers: Cohort Mortality and Case‑Control Analyses. Am. J. ‑Tnd. Med., 26:431‑47 (1994).
• Doll R, et al. (1994): Mortality in relation to smoking: 40 years’ observations in male British doctors. Br Med J, 309:901‑911.
• De Stefani E, et al.: Fatty Foods and the Risk of Lung Cancer: A Case-Control Study From Uruguay. Int. J. Cancer, 71:760-66 (1997).
• Edlin C, et al.: Radon in Homes-A Possible Cause of Lung Cancer. Scand. J. Work Environ. Health, 10:25-34 (1984).
• Gao Y, et al.: Lung Cancer Among Chinese Women. Int. J. Cancer, 40:604-09 (1987).
• Geng G, et al.: On the Relationship Between Smoking and Female Lung Cancer. In: Smoking and Health 1987 (Aoki M,et al., eds.), Elsevier Science Publishers, Amsterdam, Netherlands, pp. 483-86 (1988).
• Goodman M, et al.: The Effect of Dietary Cholesterol and Fat on the Risk of Lung Cancer in Hawaii. Am. J. Epidemiol., 128:1241-55 (1988).
• Gori GB, Luik JC : Passive smoke: The EPA’s betrayal of science and policy. The Fraser Institute, Vancouver (1999).
• Gustavsson P, et al.: Lung Cancer and Exposure to Diesel Exhaust Among Bus Garage Workers. Scand. J. Work Environ. Health, 16:334‑54 (1990).
• Hayes R, et al.: Lung Cancer in Motor Exhaust-Related Occupations. Am. J. Ind. Med., 16:685-95 (1989).
• Hinds M, et al.: Tuberculosis and Lung Cancer Risk in Non-Smoking Women. Am. Rev. Respir. Dis., 125:776-78 (1982).
• Horwitz R, et al.: An Ecogenetic Hypothesis for Lung Cancer in Women. Arch. Intern. Med., 148:2609-12 (1988).
• Jain M, et al.: Dietary Factors and Risk of Lung Cancer: Results from a Case-Control Study, Toronto, 1981-85. Int. J. Cancer, 45:287-93 (1990).
• Knekt P, et al.: Elevated Lung Cancer Risk Among Persons With Depressed Mood. Am. J. Epidemiol., 144:1096‑103 (1996).
• Ko Y-C, et al.: Risk Factors for Primary Lung Cancer Among Non-Smoking Women in Taiwan. Int. J. Epidemiol., 26:24-31 (1997).
• Koo L: Dietary Habits and Lung Cancer Risk Among Chinese Females in Hong Kong Who Never Smoked. Nutr. Cancer, 11:155-72 (1988).
• Kvale G, et al.: Occupational Exposure and Lung Cancer Risk. Int. J. Cancer, 37:185‑93 (1986).
• Kulessa C, et al.: Psychosocial Personality Traits and Cigarette Smoking Among Bronchial Carcinoma Patients. Stress Med., 5:37‑46 (1989).
• Lange P, et al.: Ventilatory Function and Chronic Mucus Hypersecretion as Predictors of Death from Lung Cancer. Am. Rev. Respir. Dis., 141:613‑17 (1990).
• Lee I, Paffenbarger R: Physical Activity and Its Relation to Cancer Risk.  Med. Sci. Sport Exerc., 26:831‑37 (1994).
• Lees R, et al.: A Case-Control Study of Lung Cancer Relative to Domestic Radon Exposure. Int. J. Epidemiol., 16:7-12 (1987).
• Le Marchand L, et al.: Vegetable Consumption and Lung Cancer Risk: A Population-Based Case-Control Study in Hawaii. J. Nat. Cancer Inst., 81:1158-64 (1989).
• Mettlin C: Milk Drinking, Other Beverage Habits, and Lung Cancer Risk. Int. J. Cancer, 43:608-12 (1989).
• Mumford J, et al.: Lung Cancer and Indoor Air Pollution in Xuan Wei, China. Science, 235:217-20 (1987).
• Oksa P, et al.: Cancer Incidence and Mortality Among Finnish Asbestos Sprayers and in Asbestosis and Silicosis Patients. Am. J. Ind. Med., 31:693‑98 (1997).
• Ooi W, et al.: Increased Familial Risk for Lung Cancer. J. Nat. Cancer Inst., 76:217-22 (1986).
• Pollack E, et al.: Prospective Study of Alcohol Consumption and Cancer. N. Engl. J. Med., 310:617-21 (1984).
• Pastorino U, et al.: Vitamin A and Female Lung Cancer: A Case-Control Study on Plasma and Diet. Nutr. Cancer, 10: 17179 (1987).
• Potter J, et al. , Alcohol, Beer and Lung Cancer in Post­menopausal Women: The Iowa Women Health Study. Ann. Epi­demiol., 2:587‑95 (1992).
• Raffin E, et al.: Incidence of Lung Cancer by Histological Type Among Asbestos Cement Workers in Denmark. Br. J. Ind. Med., 50:85‑89 (1993).
• Rylander R: Lung Cancer, Smoking and Diet Among Swedish Men.  Lung Cancer, 14(Supp. 1):S75-83 (1996).
• Sakurai R, et al.: Prognosis of Female Patients With Pulmonary Tuberculosis. Japan J. Med., 28:471-77 (1989).
• Samet J, et al.: Personal and Family History of Respiratory Disease and Lung Cancer Risk. Am. Rev. Respi-r. Dis., 134:466-70 (1986).
• Sankaranarayanan R, et al.: A Case-Control Study of Diet and Lung Cancer in Kerala, South India.  Int. J. Med., 58:644-49 (1994).
• Severson R, et al.: A Prospective Analysis of Physical Activity and Cancer. Am. J. Epidemiol., 130:522‑29 (1989).
• Severson R, et al.: A Prospective Analysis of Physical Activity and Cancer. Am. J. Epidemiol., 130:522‑29 (1989).
• Shy C: Air Pollution and Lung Cancer. In: Lung Cancer: Causes and Prevention. (Mizell M, Correa P, eds.), Verlag Chemie International, Berlin/Heidelberg, Germany, pp. 65‑72 (1984).
• Sobue T, et al.: Association of Indoor Air Pollution and Passive Smoking With Lung Cancer in Osaka, Japan. Japan J. Cancer Clin., 36:329-33 (1990).
• Tenkanen L, et al.: Smoking and Cardiac Symptoms as Pre­dictors of Lung Cancer.  J. Chronic Dis., 40:1121‑28 (1987).
• Thune I, Lund E: The Influence of Physical Activity on Lung Cancer Risk: A Prospective Study of 81,516 Men and Women. Int. J. Cancer, 70:57‑62 (1997).
• Tsuda T, et al.: Ingested Arsenic and Internal Cancer: A Historical Cohort Followed for 33 Years.  Am. J. Epi­demiol., 141:198‑209 (1995).

• USEPA : United States Environmental Protection Agency. Respiratory health effects of passive smoking. Lung cancer and other disorders. December 1992. Office of Research and Development, Washington, DC, (1992).

• USSG (1984): The health consequences of smoking: Chronic obstructive lung diseases. A report of the Surgeon General. US Department of Health and Human Services, Washington DC.

• Van Loon A, et al.: Socioeconomic Status and Lung Cancer Incidence in Men in the Netherlands: Is There a Role for Occupational Exposure?  J. Epidemiol. Comm. Health, 51:24‑29 (1997.
• Wu A, et al.: Smoking and Other Risk Factors for Lung Cancer in Women.  J. Nat. Cancer Inst., 74(4):747-51 (1985).
• Wu A, et al.: Personal and Family History of Lung Disease as Risk Factors for Adenocarcinoma of the Lung.  Cancer Res., 48:7279-84 (1988).
• Wynder E, et al.: Association of Dietary Fat and Lung Cancer.  J. Nat. Cancer Inst., 79:631-37 (1987).
• Yong L, et al.: Intake of Vitamins E, C, and A and Risk of Lung Cancer: The NHANES‑I Epidemiologic Followup Study, First National Health and Nutrition Examination Survey.  Am. J. Epidemiol., 146:321‑43 (1997).
• Ziegler R, et al.: Carotenoid Intake, Vegetables, and the Risk of Lung Cancer Among White Men in New Jersey.  Am. J. Epidemiol., 123:1080-93 (1986).
• Zhu H, Wang Z: Study of Occupational Lung Cancer in Asbestos Factories in China.  J. Ind. Med. 50:1039‑42 (1993).