Can skin cancer be sniffed out?

Odours from human skin cells can be used to identify melanoma, the deadliest form of skin cancer, a new research has found.
In addition to detecting a unique odour signature associated with melanoma cells, the researchers from the Monell Center in US and collaborating institutions, also demonstrated that a nanotechnology-based sensor could reliably differentiate melanoma cells from normal skin cells.
The findings suggest that non-invasive odour analysis may be a valuable technique in the detection and early diagnosis of human melanoma.
Current detection methods for melanoma most commonly rely on visual inspection of the skin, which is highly dependent on individual self-examination and clinical skill.

The current study took advantage of the fact that human skin produces numerous airborne chemical molecules known as volatile organic compounds, or VOCs, many of which are odorous.
"There is a potential wealth of information waiting to be extracted from examination of VOCs associated with various diseases, including cancers, genetic disorders, and viral or bacterial infections," said George Preti, an organic chemist at Monell, one of the paper's senior authors.

In the study, published in the Journal of Chromatography B, researchers used sophisticated sampling and analytical techniques to identify VOCs from melanoma cells at three stages of the disease as well as from normal melanocytes. All the cells were grown in culture.

The researchers used an absorbent device to collect chemical compounds from air in closed containers containing the various types of cells.
Then, gas chromatography-mass spectrometry techniques were used to analyse the compounds and identified different profiles of VOCs emitting from melanoma cells relative to normal cells.
Both the types and concentrations of chemicals were affected. Melanoma cells produced certain compounds not detected in VOCs from normal melanocytes and also more or less of other chemicals. Further, the different types of melanoma cells could be distinguished from one another.
Noting that translation of these results into the clinical diagnostic realm would require a reliable and portable sensor device, the researchers went on to examine VOCs from normal melanocytes and melanoma cells using a previously described nano-sensor.

Constructed of nano-sized carbon tubes coated with strands of DNA, the tiny sensors can be bioengineered to recognise a wide variety of targets, including specific odour molecules. The nano-sensor was able to distinguish differences in VOCs from normal and several different types of melanoma cells.