The consortium found that variations at three locations in the genome - two on chromosome 6 and one on chromosome 10 - were associated with lung cancer in Asian female never-smokers. The discovery on chromosome 10 was particularly significant because it has not been found in any other GWAS of lung cancer in white or Asian populations.

"Our study provides strong evidence that common inherited genetic variants contribute to an increased risk of lung cancer among Asian women who have never smoked," said Dr Nathaniel Rothman, a senior investigator in NCI's Division of Cancer Epidemiology and Genetics and coauthor of the study. "These variants may also increase lung cancer risk associated with environmental factors, such as environmental tobacco smoke."

The researchers did not detect an association with variations at a location on chromosome 15 that has been associated with lung cancer risk in many previous GWAS of lung cancer in smokers. The absence of this association provides further support for the suggestion that the genetic variation on chromosome 15 may be smoking-related.

The researchers found some evidence that Asian women with one of the newly identified genetic variants may be more susceptible to the effects of environmental tobacco smoke. However, the authors note that more research is needed to draw definitive conclusions from this observation.

"This study is an example of how genome-wide association susceptibility studies can evaluate inherited genetic risk in populations with unique characteristics or environmental exposures," said Dr Stephen J Chanock, acting co-director of NCI's Center for Cancer Genomics and a co-author of the study. "We will continue to develop better, smarter applications of this technique and apply them to populations where we have detailed information on environmental factors to further our understanding of how inherited genetic factors modify risk from environmental exposures."