The skin gives off organic chemicals, many of which have a distinctive odor. Gallagher and colleagues sampled the air above patients' skin tumor sites and compared it to the air above similar skin sites from healthy people.
The chemicals were the same, but tumors gave off different amounts than normal skin.
"We're the first to identify and quantify the compounds involved in skin cancer odors," Gallagher says in a news release.
The researchers hope their findings will allow them to use an electronic nose -- a nanosensor that can detect tiny quantities of volatile compounds -- to detect skin cancers. Gallagher says the device would work like the fictional "tricorder" in the Star Trek TV series, which would beep when waved over skin cancer.
So far, the researchers have developed an odor profile only for basal cell carcinoma. They're working on profiles for the more serious squamous cell cancer and for melanoma, the deadliest form of skin cancer.
It would be a big advance. Currently, diagnosis of skin cancer requires an often-painful biopsy. And there's no way to detect these tumors until physical signs appear.
Gallagher, now a senior scientist at Rohm and Haas in Philadelphia, reported the findings at the 236th annual meeting of the American Chemical Society, held Aug. 17-21 in Philadelphia.