Only about one in 10 smokers gets lung cancer, and scientists are close to figuring out why.
Two substances found in tobacco smoke have been detected by recent research, Reuters reports. Scientists say the findings may help explain why some smokers get cancer while others do not.
"Smoking leads to lung cancer, but there are about 60 possible carcinogens in tobacco smoke, and the more accurately we can identify the culprit, the better we will become at predicting risk," said Jian-Min Yuan of the University of Minnesota, who presented the findings at the American Association for Cancer Research in Denver.
Research shows that people with high concentrations in their urine of a nicotine byproduct called NNAL and another nicotine byproduct had more than eight times the risk of developing lung cancer than smokers with lower urine concentrations.
Currently, lung cancer is the top cause of cancer death in the world, killing 1.2 million people annually.