Summary in seconds: the importance of early detection and treatment of malignant tumors, problems facing current cancer diagnostic methods, trained animals and detecting the smell of cancer, the ability of silk ants to successfully detect malignant tumors, and the need for further research.
According to the World Health Organization1, cancer is the leading cause of death in the world. In 2020, nearly 10 million people died from cancer, or nearly one in six deaths worldwide. Improving diagnostic methods to detect tumors early is known to improve patients’ chances to overcome this disease. Current available methods for early detection of cancer can be expensive and/or invasive, which limit the number of people that benefit from their use.
Tumor cells are known to emit volatile organic compounds (VOCs) that are linked to their altered cellular metabolism2. Certain animals can be trained to use their sense of smell to detect these VOCs. Trained dogs were able to detect cancer in samples of tumor cells and body odor3. Other animals, like trained mice, certain nematodes, and fruit flies were all found to have the ability to detect cancer cells4.
Insects, however, are more promising as early detection tools for cancer and can be easily trained in fewer trials. Insects are easy to handle, more abundant and do not need special breeding quarters or expensive accommodation facilities.
In a recent study4, researchers selected “silk ants” (Formica fusca) for their remarkable ability to learn and to retain what they have learned. They were trained to recognize the odors of human breast and ovarian cancers. The study demonstrated that trained silk ants were able to correctly distinguish between the two cancerous cell lines, breast and ovarian, and a healthy cell line.
Although the current study4 provides evidence that training ants can become an inexpensive, non-invasive, and reliable tool for early detection of human malignant tumors, more research is needed to study the ability of trained ants to distinguish between different tumor types taken directly from human patients.
References
1. World Health Organization, Cancer. Published on line February 8, 2022.
2. Hanahan D., Weinberg R.A., Hallmarks of Cancer: the next generation. Cell 144, 646-674 (2011).
3. Pirrone F., Albertini M., Olfactory detection of cancer by trained sniffer dogs: a systematic review of the literature. J. Vet. Behav. Clin. Appl. Res. 19, 105-117 (2017).
4. Baptiste Piqueret, Elodie Montaudon, Paul Devienne, et al., Ants act as olfactory bio-detectors of tumours in patient-derived xenograft mice. Proceedings of the Royal Society B,
Published: January, 25 2023
https://royalsocietypublishing.org/doi/10.1098/rspb.2022.1962