Passive smoking more risky for women with a missing geneBMJ 1999; 319 doi: https://doi.org/10.1136/bmj.319.7224.1522b (Published 11 December 1999) Cite this as: BMJ 1999;319:1522
The combination of environmental tobacco smoke and a missing gene may make some women up to six times more likely to develop lung cancer if they are exposed to second hand smoke, according to the results of a new study.
The lead author, DrWilliam P Bennett of the National Cancer Institute in Bethesda, Maryland, and colleagues set out to determine if common genetic polymorphisms associated with the activation or detoxification of carcinogenic agents found in environmental tobacco smoke were associated with an increased vulnerability to lung cancer.
They tested for the genetic alterations in the archived tissue samples of 106 white Missouri women, mostly rural housewives, who had never smoked but had nevertheless been given a diagnosis of lung cancer Researchers found that those women lacking a specific gene were more likely to develop lung cancer as a result of second hand smoke and that they showed a rising trend in their risk of developing lung cancer with increasing smoke exposure (Journal of the National Cancer Institute 1999;91:2009-14).
The researchers identified a significant interaction of gene and environment among the women, in which a specific genetic alteration seemed to make women more susceptible to the carcinogenic effects of environmental tobacco smoke. The alteration caused a deficiency in a compound called glutathione-S-transferase M1 that, under normal circumstances, is used by the body to detoxify certain carcinogens commonly found in tobacco smoke.
As the exposure to environmental tobacco smoke increased, so did the risk of lung cancer for women with the gene deletion, reaching a more than sixfold increase in risk in women exposed to the highest levels of environmental smoke.