Laser Device May Improve Accuracy of Melanoma Tests

An advance in laser technology may improve the diagnosis of melanoma. Researchers who tested a new device say it could reduce the number of "false alarms" for skin cancer that arise when doctors use a microscope to assess suspicious moles.

The device, which beams lasers onto a tissue sample, provides researchers with a picture of the chemical composition of the suspected cancer. The study results showed that melanomas tend to have more of a brown-black skin pigment called eumelanin than benign moles do.

Currently, pathologists use a microscope to examine biopsied samples of moles to check for skin cancer . But in some cases, the pathologist cannot tell if a mole is cancerous. This can lead to additional biopsies, and even surgery.

A recent study published in the Journal of American Academy of Dermatology found that doctors disagreed in 14 percent of cases over whether the sample was cancerous, the researchers said.

Even if the new tool is only 50-percent more accurate than current biopsies, it would prevent about 100,000 false-positive melanoma diagnoses, said study researcher Warren S. Warren, director of the Center for Molecular and Biomolecular Imaging at Duke University.

With this device, "We're getting additional information that the doctors have never had," Warren said.

The traditional method of examining skin under a microscope could be thought of as providing a black-and-white picture, but with this device, "we're able to create a full-color picture that just has additional information in it," Warren told MyHealthNewsDaily.

The device still needs to be tested on more skin samples, but it could potentially save millions of dollars in unnecessary skin cancer tests, researchers said.

In the short term, Warren sees this device as being useful for cases in which pathologists cannot decide whether a tissue sample is cancerous.

Probing moles

Melanoma is the deadliest form of skin cancer, killing about 8,700 people in the United States each year, according to the National Cancer Institute. While overall cancer death rates declined by 19 percent in men and 11 percent in women between 1991 and 2005, the death rate for melanoma increased by 5 percent.

To test the accuracy of their device, the researchers examined 42 skin samples, 11 of which contained melanomas.

The device uses lasers to pump energy, less than that of a laser pointer, into the samples.

The researchers measured the amount of eumelanin present in the moles and used it to correctly identify all the melanoma samples.

The device would cost about $100,000 to put into practice. But the researchers said this high price would be made up for by the money saved by reducing false positive diagnoses, each of which might cost thousands of dollars.

More research needed

The new technology still depends on biopsied tissue. It would be of greater value if it could evaluate moles on people, said Dr. David Leffell, a professor of dermatology and surgery at Yale School of Medicine.'

"What they have shown is an important first step," said Leffell, who was not involved with the study. "The really promising aspect of this research is not in improving diagnosis under microscope, but rather in using this device to potentially screen patients for melanoma ... [to] help decide which ones should be biopsied and which ones don't need to be biopsied.

"A lot more work needs to be done to determine what its daily applicability is, in terms of taking care of patients," Leffell told MyHealthNewsDaily.

The study is published today (Feb. 23) in the journal Science and Translational Medicine.

Pass it on: A new laser device can identify melanoma in biopsied tissue samples. The device might one day save some patients from needing to undergo a biopsy for skin cancer.

Follow MyHealthNewsDaily staff writer Rachael Rettner on Twitter @RachaelRettner.

Rachael Rettner

Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.