Over 11 moles on arm can predict deadly skin cancer risk: Scientists

If you are a woman and have more than 11 moles on your right arm, check if you have over 100 such moles all over the body as the high mole presence can predict a higher risk of developing a deadly skin cancer.

Scientists found that the count of moles on the right arm was most predictive of the total number on the whole body.

Females with more than seven moles on their right arm had nine times the risk of having more than 50 on the whole body.

Those with more than 11 on their right arm were more likely to have over 100 on their body in total, meaning they were at a higher risk of developing melanoma, the researchers noted.

"This study follows on from previous work to identify the best proxy site for measuring the number of moles on the body as a whole," said lead author Simone Ribero from King's College London in a university statement.

The new method can be used by doctors to quickly determine the number of moles on the entire body by counting the number found on a smaller "proxy" body area such as an arm.

Naevus (mole) count is one of the most important markers of risk for skin cancer despite only 20 to 40 percent of melanoma arising from pre-existing moles.

The risk is thought to increase by two to four percent per additional mole on the body, but counting the total number on the entire body can be time consuming in a primary care setting.

The researchers used data from 3594 female Caucasian twins between January 1995 and December 2003.

Twins underwent a skin examination including recording skin type, hair and eye colour and freckles as well as mole count on 17 body sites performed by trained nurses.

Scientists found that the count of moles on the right arm was most predictive of the total number on the whole body. Scientists also found that the area above the right elbow was particularly predictive of the total body count of moles.

The legs were also strongly associated with the total count as well as the back area in males.

These findings could help general physicians to easily identify those at the highest risk of developing a melanoma.