A five-center collaborative study that scanned the genomes of thousands of "never smokers" diagnosed with lung cancer as well as healthy never smokers has found a gene they say could be responsible for a significant number of those cancers.

In the March 22 online issue of Lancet Oncology, the researchers reported that about 30 percent of patients who never smoked and who developed lung cancer had the same uncommon variant, or allele, residing in a gene known as GPC5. The research was co-led by scientists at the Mayo Clinic campus in Minnesota, Harvard University, University of California at Los Angeles (UCLA), and MD Anderson Cancer Center. Researchers found in laboratory studies that this allele leads to greatly reduced GPC5 expression, compared to normal lung tissue. The finding suggests that the gene has an important tumor suppressor-like function and that insufficient function can promote lung cancer development.

"This is the first gene that has been found that is specifically associated with lung cancer in people who have never smoked," says the study's lead investigator, Ping Yang, M.D., Ph.D., Mayo Clinic genetic epidemiologist.

"What's more, our findings suggest GPC5 may be a critical gene in lung cancer development, and genetic variations of this gene may significantly contribute to increased risk of lung cancer," she says. "This is very exciting."

In this video, Dr. Yang discusses the study and its findings.