Their study, reported in the October 15 issue of Cancer Research, is the first epidemiological study to show the association of lung cancer risk in African-Americans and efficiency of the critical "G2/M checkpoint." While the researchers report that this checkpoint was generally less effective in the group of African-American lung cancer patients they studied, they found this risk to be especially high in African-American women and nearly a five-fold increase in lung cancer risk in women with faulty G2-M checkpoint compared to women with efficient G2-M checkpoint. The study did not found any association of this checkpoint with lung cancer risk in whites.
"Although the study has limitations, our findings suggest one possible explanation for the higher incidence of lung cancer in African Americans, who as a group smoke less than whites, yet still develop more lung cancer at comparatively younger ages," said the study's lead author, Yun-Ling Zheng, M.D., Ph.D., an assistant professor in the Department of Oncology at the Lombardi Comprehensive Cancer Center.
"Epidemiologists have long known that cancers are expressed at varying rates in different racial groups, but we are only now able to use advanced research techniques to look at the molecular reasons for these disparities," Zheng said. "The value of such research is that it can provide new tools for risk calculation."
According to a 2002 report by the Surveillance, Epidemiology, and End Results (SEER), the incidence of lung cancer in African-American men was 42 percent higher compared with the incidence in white men, and the risk of lung cancer for African-American women was 13 percent higher.