"Lung cancer mortality rates in Xuan Wei are among the highest in China in both nonsmoking women and men who smoke, and are associated with exposure to indoor emissions from the burning of smoky coal," said Phouthone Keohavong, Ph.D., study author and associate professor, department of environmental and occupational health, University of Pittsburgh Graduate School of Public Health (GSPH). "In order to account for the high rates of disease within this region, we tested for mutations generally associated with lung cancer in people who had no evidence of disease. We found that a good number of these individuals had mutations that indicated they were at higher risk for developing lung cancer in the future."
The study analyzed sputum samples from the bronchial tract of 92 individuals who had no evidence of lung cancer and screened them for p53 and K-ras mutations. Damage to both p53, a tumor suppressor gene that prevents normal cells from turning into tumor cells, and K-ras, an oncogene, is fundamental to the development of a vast majority of cancers. Mutations to both p53 and K-ras are thought to be primarily caused by chemicals called polycyclic aromatic hydrocarbons that are emitted during the burning of smoky coal. The study found that 15 individuals, or 16.3 percent, tested positive for genetic mutations 13 individuals tested positive for p53 mutations, one tested positive for K-ras mutation and one tested positive for both p53 and K-ras mutations.
According to Dr. Keohavong, also a
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30-Sep-2004