Researchers at Kyushu University exposed C. elegans, millimeter-long worms with a strong sense of smell, to urine samples from cancer patients and healthy people, then recorded which direction the worms moved.
Across 242 urine samples, the worms moved toward cancer-patient urine and away from healthy urine with 95.8 percent sensitivity and 95.0 percent specificity, detecting cancers at their earliest stages more reliably than many existing tumor-marker blood tests, and worms with their sense of smell disabled lost the preference entirely.
The worms respond to an odor difference in urine, not a specific molecular marker, so the test currently cannot say what type of cancer is present, only that something is likely there. The approach has since been developed into a commercial screening test in Japan, though it is meant to prompt further diagnostic testing rather than replace it.
Read the original study
Hirotsu et al., PLoS ONE, 2015 · doi.org/10.1371/journal.pone.0118699
A worm's nose outperformed some of medicine's blood tests.
Source
- Hirotsu, T., Sonoda, H., Uozumi, T., Shinden, Y., Mimori, K., Maehara, Y., Ueda, N., & Hamakawa, M. (2015). A highly accurate inclusive cancer screening test using Caenorhabditis elegans scent detection. PLOS ONE, 10(3), e0118699. https://doi.org/10.1371/journal.pone.0118699