Researchers with the Genetic Epidemiology of Lung Cancer Consortium (GELCC) have found that individuals with a certain type of genetic susceptibility to lung cancer face an increased risk for the disease with even a small exposure to cigarette smoke. Family members carrying the genetic variant show a risk of lung cancer similar to light and heavy smokers.
The study, published in Cancer Research, also found that even non-smokers who are exposed to second-hand cigarette smoke and have a family history of lung cancer should be monitored for early detection.
“The study shows a strong gene-environment interaction between a region of chromosome 6q and smoking,” says Marshall Anderson, PhD, a professor at the University of Cincinnati (UC) and principal investigator. “People with this susceptibility locus can develop lung cancer even with a very little bit of smoking.”
To study the chromosome region’s effect on lung cancer risk, the researchers identified a haplotype associated with the disease. They then collected data from several recruitment sites and divided smoking exposures into never smokers, light smokers, moderate smokers, and heavy smokers.
The risk of family members without this genetic variant developing the disease tracked closely with their level of smoking—in other words, heavy smokers had a significantly greater risk of developing lung cancer than moderate smokers. But in family members with the genetic risk haplotype, even light smoking resulted in a greatly increased risk for developing lung cancer.
“If you carried the inherited risk and then smoked, it didn’t matter if you were a light smoker or a heavy smoker—you were significantly more likely to develop lung cancer,” says Susan Pinney, PhD, an associate professor in the department of environmental health at UC and co-investigator on the study.