Researchers identify cancer-causing agent in cigarette smoke

BETHESDA, Md. Researchers at the University of California, Davis, have discovered that, while tobacco smoke contains more than 4,000 chemical compounds, it is the hydrogen peroxide that actually causes healthy lung tissue to turn cancerous.

This is good news, both for the oncology profession and the cigarette industry. Scientists may be able to use the information to develop new treatments for smoking-related lung cancer and tobacco companies may be able to start producing “safe” cigarettes.

“With the five-year survival rate for people with lung cancer at a dismally low 15.5 percent, we hope this study will provide better insight into the identification of new therapeutic targets,” senior author Tzipora Goldkorn stated.

The results of the study were published by the Federation of American Societies for Experimental Biology in its March journal. In the study, different sets of human lung tissue were exposed to cigarette smoke or hydrogen peroxide and then compared to each other and to unexposed tissue. The researchers found the same molecular signatures of cancer development on both sets of exposed cells, but none on the unexposed airway tissue.

The Centers for Disease Control and Prevention reports that more than 400,000 deaths per year in the United States can be traced to smoking, which causes 90 percent of male lung cancer deaths and 80 percent of those for women. In theory, aside from the medical benefits, the tobacco industry may even be able to market a hydrogen peroxide-free formulation that could eventually significantly decrease the CDC’s numbers.

“Guns kill, bombs kill and cigarettes kill,” stated Gerald Weissmann, editor-in-chief of the FASEB Journal. “While biologists can’t do much about the first two, studies like this will help in the fight against tobacco-related death and disease. These experiments not only pinpoint new molecular targets for cancer treatment, but also identify culprits in cigarette smoke that eventually will do the smoker in.”