Medical researchers at the University of Cincinnati have discovered a genetic indicator that might improve screening for lung cancer. The indicator shows up in those who have a higher than normal risk of developing the cancer. The researchers' report says it's an inherited genetic trait that can make it harder for people's bodies to stop tumor growth. People with it can be more susceptible to harm from smoking. They also could pass the trait on to their children. Researchers worked with 52 families who have multiple cases of lung cancer. The National Cancer Institute paid almost six (M) million dollars for the five-year project. The full study has been posted on the Web site of the American Journal of Human Genetics and will be published in the journal's September edition.