A team of researchers believe their latest study results provide evidence that lung cancer among never-smokers can differ on a fundamental level from lung cancer in smokers.

A team of researchers from the National Institutes of Health’s National Cancer Institute (NCI), in partnership with colleagues from several other countries, conducted the largest genome-wide association studies (GWAS) in female never-smokers to date. They identified three genetic regions that predispose Asian women who have never smoked to lung cancer.

“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 co-author Nathaniel Rothman, MD, MPH, MHS, of NCI. “These variants may also increase lung cancer risk associated with environmental factors, such as environmental tobacco smoke.”

For the study, the scientists combined data from 14 studies from mainland China, South Korea, Japan, Singapore, Taiwan, and Hong Kong that involved a total of about 14,000 Asian women (6,600 with lung cancer and 7,500 without the disease).

They discovered that variations at three locations in the genome—two on chromosome 6 and another on chromosome 10—were associated with lung cancer in Asian females who had never smoked. According to the team, the discovery on chromosome 10 was particularly noteworthy, since it has not been identified in any previous GWAS of lung cancer.

The researchers did not detect an association with variations at a location on chromosome 15, which have been linked to lung cancer risk in many previous GWAS of lung cancer that were conducted primarily in smokers.

The team did, however, find evidence that Asian women with one of the newly identified genetic variants may be more susceptible to the effects of environmental tobacco smoke. They note the need for more research to prove the connection.