Cancer diagnosis is frightening, invasive, time-consuming, and expensive. And more than 1.6 million people get that cancer diagnosis every year in the United States. That’s a lot of biopsies and a lot of looking at cells under highly sensitive microscopes.
. But what if detecting cancer in those samples was as simple as taking a whiff?
We know some animals, like dogs and mice, have very sensitive noses that can sniff out disease. Inspired by those studies, French scientists decided to explore whether much smaller creatures that are known for their olfactory prowess could do the same: ants.
“Using olfaction to detect diseases is not a novel idea,” says Baptiste Piqueret, PhD, a researcher at Sorbonne Paris Nord University and lead author of the study. “Knowing how well ants can learn and how they use olfaction, we tested the abilities of ants to learn and detect diseases.”
While this is still far away from real-life clinical use, it could one day lead to a cheaper, more accessible alternative for detecting cancer. What would this new diagnostic method look like?
Cancer cells make volatile organic compounds (VOCs) – organic chemicals that smell and can serve as biomarkers for diagnosis.
To train the ants to target VOCs, the researchers placed breast cancer cells and healthy cells in a petri dish — but the cancer cells included a sugary treat.
“We associated a reward to the smell of cancer,” Piqueret says.
It’s a technique scientists call classical, or Pavlovian, conditioning. A neutral stimulus (cancer smell) is associated with a second stimulus (food) that prompts a behavior. After doing this a few times, the ant learns that the first stimulus predicts the second, and it will seek out the odor hoping to find food.
Once the training was complete, the researchers presented the ant with