Stanton Glantz has a website called Tobacco Scam that should be appropriately called anti-tobacco scam. One of their ads makes the claim that second hand smoke doubles a woman’s chance of getting breast cancer. Not even his cronies at ACS buy this one.
“The issue of whether secondhand smoke causes breast cancer, as well as numerous other diseases, is difficult to study,” says Dr. Michael Thun, vice president of epidemiology and surveillance research at ACS.
Active smoking is not proven to increase breast cancer risk, he said, so explaining why much lower doses of smoke would do so is very complicated. Furthermore, in Western countries, most women in the age range where breast cancer becomes common have been exposed to substantial amounts of secondhand smoke, so it is difficult to find an unexposed comparison group.
Background: Several studies have reported positive associations between environmental tobacco smoke (ETS) and increased risk of breast cancer. However, studies of active smoking and risk of breast cancer are equivocal and in general do not support a positive association. To try to resolve this paradox, we examined the association between breast cancer mortality and potential ETS exposure from spousal smoking in an American Cancer Society prospective study of U.S. adult women. Methods: We assessed breast cancer death rates in a cohort of 146 488 never-smoking, single-marriage women who were cancer free at enrollment in 1982. Breast cancer death rates among women whose husbands smoked were compared with those among women married to men who had never smoked. Cox proportional hazards modeling was used to control for potential risk factors other than ETS exposure. Results: After 12 years of follow-up, 669 cases of fatal breast cancer were observed in the cohort. Overall, we saw no association between exposure to ETS and death from breast cancer (rate ratio [RR]= 1.0; 95% confidence interval [CI]= 0.8–1.2). We did, however, find a small, not statistically significant increased risk of breast cancer mortality among women who were married before age 20 years to smokers (RR = 1.2; 95% CI = 0.8–1.8). Conclusions: In contrast to the results of previous studies, this study found no association between exposure to ETS and female breast cancer mortality. The results of our study are particularly compelling because of its prospective design as compared with most earlier studies, the relatively large number of exposed women with breast cancer deaths, and the reporting of exposure by the spouse rather than by proxy.