And in the longer term, researchers could determine which biological molecules the dogs are picking up in the cancer patients and create screening tests based on those compounds.
Dogs have smell receptors that are 10,000 times more accurate than humans, making them highly sensitive to odours that humans could never perceive. "A highly sensitive test could save thousands of lives, early detection offers the best hope of survival" explains Heather Junqueira. Then there's the 2011 study involving a black lab named Marine who was 97 percent accurate in detecting colon cancer among loose stool samples, which made her success rate even higher than the tests doctors do.
Mrs Junqueira, who leads the team at US-based firm BioScentDx, trained the beagle's using a form of clicker training to teach them to distinguish between normal blood and samples from lung cancer patients.
"Although there is now no cure for cancer, early detection offers the best hope of survival", said Heather Junqueira, who is lead researcher at BioScentDx and performed the study.
However, the other three dogs did take part.
The results will be presented at the American Society for Biochemistry and Molecular Biology annual meeting in Florida.
Malaria: In October, researchers reported that two Labrador-Golden Retriever cross, Lexi and Labrador, Sally were able to correctly identify 70 per cent of the malaria-infected samples and 90 per cent of the samples without malaria parasites.
BioScentDx, the lab where the study was performed, are now testing whether the dogs can smell cancer in the breath of breast cancer patients.
"This study paves the way for a larger scale research project created to explore the use of canine scent detection as a tool for detecting cancer biomarkers, ultimately leading to their identification", reads the yet-to-be-published study abstract.
And cancer isn't the only disease that dogs can assist in detecting.