Background Information/Resources
Stan Glantz, P.hD., Professor of Medicine and Director, Center for Tobacco Control Research and Education at the University of California at San Francisco. is also director of the UCSF Center for Tobacco Control Research and Education, co-author of The Cigarette Papers and Tobacco War, and founder of Smoke Free Movies, a campaign to get smoking out of movies.
Dr. Glantz is internationally known for his tobacco control research, his work on the health effects of secondhand tobacco smoke, as well as his basic research in cardiovascular function and applied biostatistics. He has not only been extremely active in the studies of the health effects of involuntary smoking, but also in the politics of health, science, and tobacco industry practices. Dr. Glantz has been both a leading tobacco control scholar and advocate of nonsmoker's rights for more than 20 years. In 1983, he helped the successful defense of the San Francisco Workplace Smoking Ordinance against a tobacco industry attempt to repeal it by referendum, which represented the first electoral defeat of the tobacco industry and is now viewed as a major turning point in the battle for controlling where cigarettes can be smoked. In 2003, the American Public Health Association (APHA) Alcohol and Tobacco section selected Dr. Glantz to receive its 2003 Lifetime Achievement Award for his tobacco control research and advocacy work to reduce tobacco use.
Dr. Glantz is the author of three books and more than 150 scientific papers, including the first major review that identified involuntary smoking as a cause of heart disease, and the landmark July 19, 1995 issue of JAMA that showed the tobacco industry knew 30 years earlier that nicotine was addictive and smoking caused cancer. His recent work has focused on the relationship between secondhand tobacco smoke and breast cancer, which he will discuss on this call.
This call was moderated by Michael Lerner, President of Commonweal and Co-coordinator of the CHE Cancer Working Group.
Call Notes
Participants: Mary Bachran, Nanna Borchard, Theo Colborn, Nancy Evans, Marian Feinberg, Stanton Glantz, Alexander Goreman, Michael Lerner, Karen Miller, Leo Petrilli, Brenda Salgado, Laurel Standley, Catherine Thomsen, Julia Varshavsky
Dr. Glantz introduced the new CalEPA Report (http://www.oehha.ca.gov/air/environmental_tobacco/2005etsfinal.html), which he was a reviewer of, that shows there is causal evidence that secondhand smoke (SHS) causes breast cancer in younger, primarily premenopausal women. This is an important finding, a breakthrough, because there is no clear evidence of risk in older, postmenopausal women, so the risk appears to be concentrated in premenopausal women, with a 1.7 risk (70% elevation) – the biggest risk ever associated with SHS. Lung cancer has a relative risk of about 1.2, and heart disease about 1.3.
Note: Researchers used the term “younger, primarily premenopausal” because they are not sure if the risk has to do with age or estrogen. For example, women who have a genetic susceptibility get cancer fairly young, so they show up in the premenopausal group because they are younger, not necessarily having anything to do with being premenospausal (Slides 2 & 3).
Dr. Glantz also discussed the biological evidence linking breast cancer to SHS: various known mammary carcinogens are present in cigarettes - why would benzene coming out of an automobile tailpipe cause breast cancer, whereas benzene coming out of a cigarette would not (Slide 4)? Also, Carcinogen metabolites have been found to damage DNA in the breast (Slide 5), damage to the p53 tumor suppression gene has been shown, etc. (Slide 6). The epidemiological evidence is also very compelling: Out of 14 studies, 13 showed an increased risk in premenopausal women, which is very unlikely due to chance (Slide 7).
The Surgeon General report (http://www.surgeongeneral.gov/library/secondhandsmoke/report/), in comparison, did not show this much of an increase in risk, due to exposure misclassification. Instead of comparing smokers with non-smokers, they were comparing active smokers with passive smokers (people exposed to environmental tobacco smoke, ETS), and therefore not seeing that much of a difference in risk between the exposed and control groups. Only when active smokers are compared with true non-smokers (people not exposed to ETS), does the high relative risk appear (Slides 8-15).
Dr. Glantz commented that the evidence of SHS and breast cancer is stronger now than the evidence linking cigarettes to lung cancer in 1986, when the Surgeon General declared the connection (Slide 16). The occupational groups most heavily exposed to SHS are waitresses and bartenders, and women working in these industries tend to become exposed at what might possibly be the most vulnerable time period for them (between puberty and first full-term birth). In closing, Dr. Glantz mentioned some of the campaign work that he does to get smoking out of restaurants and movies (http://www.tobaccoscam.ucsf.edu).
Discussion / Q&A
• We discussed the possibility that mainstream cancer groups are so hesitant to accept that SHS causes breast cancer because they do not want to open the door to the role of environmental contaminants in cancer in general, which would negate the prior idea that only 5% of cancer may be caused by environmental factors.
• We discussed the idea of smoking organic cigarettes that do not contain many chemicals, but Dr. Glantz commented that the combustion of dry organic material creates chemicals in itself.
• We discussed the possibility that fetal exposure to SHS may increase the risk of cancer in later life. Dr. Glantz commented that a study came out recently linking the probability that offspring of a smoker may be more likely to become smokers themselves, due to changes in the brain that take place during gestation, which would increase the risk of getting cancer in their lifetimes.
• We discussed the complexity of estimating risk when dealing with a multitude of environmental contaminants. Dr. Glantz commented that sometimes the whole can have a greater impact than the sum of its parts.
• We discussed the presense of mycotoxin in cigarettes, and Dr. Glantz commented that although people used to think that mycotoxins burn off when a cigarette is smoked, this is not actually true. He also commented that the longer a cigarette burns, the more toxic the smoke gets.
