The following major review article will appear June 2 in the Web edition of Chemical Research in Toxicology, a peer-reviewed journal published by the American Chemical Society, the world's largest scientific society.
First comprehensive review in a decade provides new insights on mechanisms of cancer induction by nitrosamines in tobacco products
A series of chemical compounds--known as nitrosamines--found in unburned tobacco and tobacco smoke have been strongly linked to lung cancer formation, says Stephen S. Hecht, Ph.D., of the University of Minnesota Cancer Center in Minneapolis. In the first comprehensive review in over a decade, Hecht summarizes all the peer-reviewed studies of the biochemistry, biology, and carcinogenicity of these tobacco- specific nitrosamines.
The tobacco specificity of these carcinogens is important, Hecht says, because they provide a link between nicotine addiction and cancer that can be attributed only to tobacco. This is in contrast to other smoke carcinogens such as polyaromatic hydrocarbons, which occur in the diet and the general environment. Other than nicotine chewing gum, Hecht says that there is no published evidence that these tobacco-specific nitrosamines are found in any other products except tobacco products. For example, the detection of a nitrosamine metabolite in the urine of non-smokers exposed to environmental tobacco smoke specifically implicates tobacco as the source of this carcinogenic exposure, according to Hecht. He maintains that this finding strengthens the argument that passive smoking causes lung cancer.
By developing the ways in which cancer is formed by cancer-specific nitrosamines in animal models, their fate in humans can be more fully determined, Hecht believes. This is the focus of his own research, to elucidate the factors which influence cancer development upon exposure to carcinogens.