Skin with few apparent freckles or blemishes may harbour sun-damaged DNA changes that might lead to cancer, according to a study conducted by scientists at the University of Queensland (UQ).

The study, published in the Science Advances journal, looked into the correlation between a person’s prior history of skin malignancies and the number of mutations discovered in “normal-looking’’ skin.

“We took skin samples from the forearms of 37 skin cancer patients who were frequently sun exposed,’’ said Ho Yi Wong, lead author of the study and UQ’s Ph.D candidate.

The researchers found that Australians had an average of four to five times more mutations in normal-looking skin compared to similar studies overseas, as the country had two to four times higher levels of ultraviolet light than Britain and Europe.

The study also matched people of the same age and sex who had a different number of skin cancers, with one group having many skin cancers and the other having few to none in the past five years.

“We found a 45 per cent difference between the groups, with a much larger number of mutations on the forearms of those with more skin cancers,’’ Wong noted.

The findings, according to the study’s senior author and UQ’s professor Kiarash Khosrotehrani, explain why persons who have already had one skin cancer have a much-increased risk of having other cases in the same body part later on.

“The findings also suggest that if we reduce mutation levels in normal-looking skin, then we could reduce the risk of new skin cancers,’’ said the professor.

The next step is to explore therapies that can reduce the load of skin mutations, Khosrotehrani added. (Xinhua/NAN)