Family ties reflect lung cancer risk.

Family ties reflect lung cancer risk

Researchers have yet to unravel the complicated tangle of factors leading to lung cancer. But two reports in the Aug. 1 JOURNAL OF THE NATIONAL CANCER INSTITUTE suggest that a still-unidentified gene influences the risk of lung cancer.

Thomas A. Sellers at the University of Minnesota in Minneapolis and his colleagues tailored a mathematical model to study 337 lung cancer patients and their families. After controlling for lung cancer risk factors such as smoking, the researchers discovered a pattern of lung cancer incidence suggesting that certain family members inherited a gene that raised their chances of developing the disease. In their model, nonsmokdrs who inherit the mysterious gene from both parents have a lung cnacer risk more than 2,200 times greater than that of nonsmokers lacking the gene, the team reports.

In separate work, a team led by Neil E. Caporaso of the National Cancer Institute found a heightened risk of lung cancer in people who inherit from one or both parents a gene that helps the body metabolize certain chemicals in cigarette smoke. Caporasohs study of 96 lung cancer patients and 92 controls, including some with other respiratory diseases or cancers, links lung cancer to the gene coding for an enzyme called CYP2D6. Caporaso says it remains unclear whether this is the same gene implicated by Sellers' model, and he notes that a variety of genes may influence the risk of lung cancer. But he emphasizes that cigarette smoking remains the most important factor contributing to the development of the disease.