British researchers have come up with a simple way to quickly determine a person’s skin cancer risk by simply counting the number of moles on the arm.

In a new study of female twins, medical investigators with King's College London found those with more than 11 moles on their right arms were at much higher risks of developing life-threatening melanoma skin cancer, Medical Xpress reports.

For the study, researchers used data from 3594 female twins between January 1995 and December 2003 who underwent a skin examination 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. Women with more than seven moles on their right arm had nine times the risk of having more than 50 on the whole body and 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 a melanoma.

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

"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 researcher Simone Ribero.

"The findings could have a significant impact for primary care, allowing GPs to more accurately estimate the total number of moles in a patient extremely quickly via an easily accessible body part. This would mean that more patients at risk of melanoma can be identified and monitored."