Doctors have known for many years that the number of moles on your body is one of the key markers of risk for melanoma, the deadliest type of skin cancer. But counting every one on a patient's body can be time consuming and is rarely done by primary-care physicians unless there's already reason to worry. That means many cases are caught later than they should be.
British researchers seeking a more efficient way to gauge a patient's risk theorized that there may be a way to quickly estimate the number of moles on an entire body by counting in a smaller proxy area. The question was where.
The initial research involved 3,594 twins — all female and all white — who were part of the TwinsUK study group. Trained nurses counted their moles on 17 body sites and recorded their skin type, hair, eye color and freckles. The protocol was then repeated on a wider group of men and women.
The results were striking: The number of moles on your right right arm appeared to be highly predictive of the moles on the rest of the body. In fact, those with over seven moles on their right arm had nine times the risk of having more than 50 on their whole body. Those with over 11 on their right arm were more likely to have over 100.
Previous studies have shown that our risk increases 2 to 4 percent per mole on the body.
The study, one of the largest of its kind and published in the, also found a number of other areas that appeared to be predictive. For both genders, those are areas above the right elbow and on legs. In males only, the back area.
Simone Ribero of the Department of Twin Research & Genetic Epidemiology said that the findings could have significant impact in primary-care settings. "This would mean that more patients at risk of melanoma can be identified and monitored," Ribero said in a statement.
In a separate announcement last week, the Oregon Health & Science University released an iPhone app called Mole Mapper that gives users the ability to accurately measure and monitor moles, and contribute photos of how their potential trouble spots evolve over time. The app is part of Apple's ResearchKit, the open source framework that the company is using to connect researchers with the millions of people around the world who use its mobile devices.
