Ethnicity and Lung Cancer Risk

Lung cancer risk among Asian women who have never smoked may be linked to genes

(RxWiki News) While you may expect to see a high number of lung cancer cases among smokers, people who have never smoked also get the disease. Asian women, especially, seem to be at risk.

An international team has discovered that Asian women have certain genetic characteristics that make them more vulnerable to getting lung cancer

"Quit smoking, regardless of your genetic risk."

Nathaniel Rothman, MD, a senior investigator in the division of cancer epidemiology and genetics at the US National Cancer Institute (NCI), coauthored the research, which looked at data on about 14,000 Asian women.

The information was gathered from 14 studies, representing 6,600 women with cancer and 7,500 without the disease.

Dr. Rothman and fellow researchers from the National Cancer Institute partnered with researchers from several other countries to create the Female Lung Cancer Consortium in Asia. The consortium conducted one of the largest genome-wide association studies (GWAS) in female never-smokers to date.

A GWAS is a study of many common gene variations in different individuals to see if a variation is related to a trait or condition, such as lung cancer. These studies typically compare those who have disease with those who do not.

Historically, most lung cancer diagnosed among women in Eastern Asia has been among those who never smoked.

Investigators pinpointed three genetics variations associated with lung cancer in Asian women who never smoked.

Environmental factors, such as secondhand smoke or exhaust from indoor cooking likely account for some cases of lung cancer among Asian women who have never smoked, but they explain only a small proportion of the disease.

“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. Rothman.

Investigators noted that a common genetic variant that is linked to lung cancer in smokers was not found in cancer patients in this study. The absence of this variant in this review of nonsmokers lends further support that this variant may only be found in those who smoke.

Dr. Rothman and his colleagues also found limited evidence that secondhand smoke may play a role in causing cancer in these women, but noted that more research is needed to draw definite conclusions.

“We will continue to develop better, smarter applications of this technique [using genome-wide association studies]…to further our understanding of how inherited genetic factors modify risk from environmental exposures,” said Stephen J. Chanock, MD, acting co-director of NCI’s Center for Cancer Genomics and a co-author of the study.

The study was published online in November in Nature Genetics. This work was supported by NCI’s Division of Cancer Epidemiology and Genetics.

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Review Date: 
November 15, 2012