Scientists in the US have found that skin cancer has a distinctive smell that can be detected by sensitive laboratory equipment and they hope the discovery opens the door to developing a new non-invasive way to diagnose basal cell carcinoma and other cancers of the skin using “odor profiles”.

The research was led by scientists at the Monell Chemical Senses Center, a nonprofit basic research institute based in Philadelphia, Pennsylvania. The findings were presented on Tuesday 20 August at the 236th meeting of the American Chemical Society in Philadelphia.

Human skin, like other body organs, emits a variety of volatile organic compounds (VOCs), many of which have a smell.

Last month, one of the researchers, Dr Michelle Gallagher, who is now with Rohm and Haas, Spring House, Pennsylvania, and colleagues wrote a paper in the British Journal of Dermatology reporting the results of a study where they identified nearly 100 VOCs, some of which varied with age, from the upper back and forearm skin of 25 healthy male and female subjects aged from 19 to 79.

From that study Gallagher and colleagues produced a normative profile of VOCs, showing how the chemical concentrations of the 100 or so compounds varied with age in healthy subjects, and how they differed between the two skin sites. They found that the types of VOCs did not vary with age, but their relative concentrations did.

For this latest research, they sampled air above basal cell tumors on the upper back and forearms of 11 people with skin cancer and found a different profile of VOCs compared to those taken from similar sites in another 11 healthy controls.

VOC samples from both the skin cancer and the healthy group showed the same chemical compounds were present, but in different concentrations. By comparing the findings of this study with the normative profile of VOCs they developed in the earlier study, Gallagher and colleagues concluded that it should be possible to characterize the basal cell carcinoma form of skin cancer from its “odor profile”.

Gallagher said:

“Our findings may someday allow doctors to screen for and diagnose skin cancers at very early stages.”

The scientists are now planning to produce skin odor profiles for other forms of skin cancer, including squamous cell carcinoma and melanoma, the most serious form of skin cancer.

The two studies may help to push forward research into new ways of analyzing skin to check for illness, as Dr George Preti, an analytical organic chemist based at Monell and in whose lab the research was carried out, explained:

“Chemical biomarkers may eventually serve as objective clinical markers of disease if effective sensor technology can be developed.”

Here are the details of the first study:

“Analyses of volatile organic compounds from human skin.”
M. Gallagher, C.J. Wysocki, J.J. Leyden, A.I. Spielman, X. Sun, G. Preti.
British Journal of Dermatology, Early View, published online 14 July 2008.
DOI: 10.1111/j.1365-2133.2008.08748.x

Click here for Abstract.

Source: ACS, Monell Chemical Senses Center.

Written by: Catharine Paddock, PhD