Genetic Tests Show How Sunlight Turns Moles into Melanoma

Source: NBC News, November 2015

Researchers have found a new way to tell if a suspicious-looking mole is about to turn malignant by looking at its genetic changes.

And they’ve confirmed that people who have moles should not let the sun get on them. Ultraviolet radiation from the sun directly causes the genetic mutations that finally tip a mole over into becoming melanoma, they report in the New England Journal of Medicine.

“Ultraviolet radiation turns moles into melanoma," said Dr. Boris Bastian of the University of California San Francisco, a pathologist who helped lead the study.

“Moles don’t belong in the sun."

Bastian and colleagues dove into a collection of moles that had turned malignant taken from 37 patients around the world. They sequenced the DNA in the tumors and compared it to DNA from healthy tissue that’s almost always taken from around the tumor to make sure all the cancer cells are removed.