A key immune cell could determine a person's likelihood of developing lung cancer.
Researchers at St Louis' Washington University School of Medicine used a mouse model to find evidence that natural killer cells have genetic diversity that contributes to the animal's likelihood of suffering from the condition.
Natural killer cells typically discover and destroy tumour cells and the research indicates that these may be better at eliminating developing lung cancer in some people than in others.
The study, which was published in Cancer Research, has led to investigations in human research subjects.
"Overall humans are genetically very similar, but their immune systems are incredibly diverse," explained Dr Alexander Krupnick, Siteman Cancer Center thoracic surgeon.
"Our findings add to the growing body of evidence suggesting that innate differences in immunity may determine not only a person's susceptibility to colds, but also to lung cancer," he added.
For the research, mice were exposed to a carcinogen that prompted one group to quickly develop lung cancer, while another appeared less likely to, with a third group demonstrating a moderate incidence of tumours.
Investigators then used an antibody to deplete natural killer cells, which resulted in the animals that were most resistant to lung cancer developing aggressive tumours.
They also used a bone marrow transplant to manipulate the immune systems of the mice that were susceptible to lung cancer, which appeared to significantly impact the progression of the ailment.
A new clinical study that could eventually impact countless international healthcare centres will see Dr Krupnick and his colleagues examining the blood of non-smokers and heavy smokers with or without lung cancer to investigate any differences between the groups.
He explained the scientists wish to determine if smokers without lung cancer could have natural killer cells that can destroy tumours, as well as if non-smokers who develop lung cancer have particularly weak natural killer cells.
Smoking is typically the cause of lung cancer and the illness can be treated through radiotherapy, chemotherapy and surgery.