Researchers at Michigan State University recently discovered that honeybees, with their keen sense of smell, can sniff out lung cancer on a patient’s breath.
“Our world is visual. Insects’ world is all based on smell, so their sense of smell is very, very good,” says Debajit Saha, assistant professor of biomedical engineering at Michigan State University, who was part of a team that published research on the discovery last month.
“There is quite a bit of research that shows that when some cancer grows inside our body, our breath actually changes. Our research does show that honeybees can detect lung cancer and possibly other diseases based on the smell of those cells.”
Saha and his team harnessed the bees and attached electrodes to their brains. The insects were then exposed to synthetic compounds that mimicked the breath of a lung cancer patient. Ninety-three percent of the time, the bees could tell the difference between the cancer breath and the artificial breath of a healthy person. The bees could also distinguish between different types of lung cancer.
The discovery could have implications for early detection of many cancers, including lung, breast, head and neck, and colorectal cancers.
“We do think breath-based diagnostics of cancer can be a game changer,” Saha says. “The reason is, many times we detect the cancer late, when the tumor has already grown pretty big. But generally, when cancer starts growing in your body, the breath signature starts changing much earlier.”
He hopes to develop a portable system in which electrodes are implanted in a honeybee brain that a patient will be able to breathe into. This cyborg sensor, which is part-brain, part-engineered, would deliver test results in real time.
“Hopefully, within the next five years, we'll have something to show that humans can be diagnosed using these insect brain disc sensors,” Saha says.
Using animals to detect cancer isn’t a new concept. At the Penn Vet Working Dog Center at the University of Pennsylvania, researchers are training dogs to recognize certain cancer odors.
“A lot of other animals also have quite intense and capable senses of smell,” says Cindy Otto, executive director of the Penn Vet Working Dog Center. “But part of what makes dogs so good is that they cooperate with humans, and so, they communicate that information.”
The dogs are in a foster program where they live with families and are brought to “work” each day. Not all dogs can do the work, according to Clara Wilson, a postdoctoral researcher at the center.
“If the dog is not really interested in this type of work, we find out pretty quickly. And you can't make a dog want to do this, because they're not going to give you high-quality answers,” Wilson says. “They need to love it to be engaged. And so, it's a really fun game for them.”
Sniffing out cancer might be a game to the animals, but researchers are finding that the animals detect cancer better than machines. A dog’s sense of smell is 10,000 to 100,000 times more acute than that of humans.
“Why are we finding that these dogs are outperforming the computers?” says Amritha Mallikarjun, another postdoctoral researcher at the center. “Well, part of their success is because of this superior sensitivity to detect odor molecules as compared to anything we currently have on the market.”
The researchers hope to continue isolating characteristics of cancer odors to enhance technological development, eventually creating e-noses that duplicate a dog’s cancer sniffing abilities, enabling earlier detection of cancer.
“This may not be the endgame, but I think it's going to advance the overall approach to diagnosing not only cancer but many other diseases,” Otto says.
“You can look back in history to the Greeks and Romans. The physicians then used odor as part of their diagnostic tools, and I think as modern humans, we've kind of let go of that. I think we can really capitalize on that and advance the health of not only humans, but dogs and other species as well.”
