Future Doctors Could Sniff Out Cancer

Charles Q. Choi

Date: 05 September 2008 Time: 06:15 AM ET

The scent of skin cancer has been sniffed out for the first time.

Doctors in the future could rapidly and accurately detect the disease — the most common form of cancer in the United States — simply by waving a wand-like scanner over patients, researchers claim.

"We're the first to identify and quantify the compounds involved in skin cancer odors," said researcher Michelle Gallagher, an analytical chemist at specialty materials company Rohm and Haas in Spring House, Pa.

Skin cancer is on the rise in this country. The disease is currently diagnosed by taking a tissue sample of suspicious moles or lesions on the skin, which can be a slow and painful process. In cases where there are no outward signs of skin cancer, the disease can be extremely difficult to detect, leading to a delayed or missed diagnosis.

Recently, scientists found that dogs can actually be trained to sniff out skin tumors. This suggests the disease leads to changes within ill cells that release telltale chemicals. Medical tools that could detect these differences could give doctors a critical lead in fighting skin cancer.

"Knowledge of a link between odor and disease goes back to ancient Greece and ancient Rome," researcher George Preti, an analytical organic chemist with Monell Chemical Senses Center in Philadelphia, told LiveScience. For instance, sweet-smelling breath was a telltale sign of diabetes, while a foul odor from a wound indicated infection.

The researchers detailed their findings Aug. 20 at the national meeting of the American Chemical Society in Philadelphia. They were funded in part by the National Institutes of Health.

Gallagher, Preti and their colleagues sampled and analyzed the air directly above tumors in 11 patients with basal cell carcinoma, the most common type of skin cancer, with more than 1 million new U.S. cases annually. The mix of chemicals they detected was then compared with that from 11 people without cancer.

"We found a different profile of chemicals above tumor sites relative to healthy skin," Gallagher said. "The same chemicals are present, but at skin cancer sites some chemicals are increased, while others are decreased compared to healthy individuals."

Gallagher declined to give specific details as to what chemicals they discovered. The researchers have applied for a patent on their technique.

The scientists plan to identify the scents linked with the two other most common types of skin cancer, including squamous cell cancer and melanoma, the deadliest form. If they succeed, they hope to combine their findings with emerging "electronic nose" technology designed to identify odors. Gallagher envisions a wand-like device that can get waved across the skin and give off an alarm or beep when cancer is detected, similar to the fictional medical "tricorder" from "Star Trek."