NEW RESEARCH SUGGESTS that people who have more than 11 moles on one arm could have a higher than average risk of developing skin cancer or melanoma.

The study, carried out by the researchers at King’s College London, used data collected from 3,592 female twins in the UK over eight years.

It found that if a person has more than 100 moles on their body this indicates five times the normal risk of developing skin cancer.

About 20% to 40% of melanoma cases are thought to arise from pre-existing moles.

Each year, more than 700 cases of melanoma are diagnosed in Ireland, but the Irish Cancer Society says this number is likely to “greatly increase in future years“.

The study, funded by the Wellcome Trust, used female and male participants to identify the most useful ‘proxy’ site for a full body mole count as well as the cut-off number of moles that can be used to predict those at the highest risk of developing skin cancer.

Counting moles on the right arm was found to be a good indicator of total moles on the body, making it easier for GPs to identify those with an increased risk of developing cancer.

‘Significant impact’

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

Simone Ribero, of the Department of Twin Research & Genetic Epidemiology, was the study’s lead author.

“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,” she said.

The study was published in the British Journal of Dermatology.