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More Than 11 Moles on a Person's Arm Could Indicate Higher Risk for Melanoma, Study Finds

More than 11 moles on a person's arm could indicate a higher risk for melanoma, according to a new study by British researchers.

Females 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, researchers at King's College London found.

The 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, researchers said. It would help general practitioners better determine who may be at risk.

This, June 24, 2014, file photo shows people swimming on a sunny day at Mission Beach in San Diego. Avoid sunbathing and using indoor tanning beds, the U.S. surgeon general warned in a report that cited an alarming 200 percent jump in deadly melanoma cases since 1973. (AP Photo/Gregory Bull, File)

Melanoma is not the most common type of skin cancer, but it causes the most deaths, said Dr. Hooman Khorasani, MD, assistant professor of dermatology for the Icahn School of Medicine at Mount Sinai.

However, if melanoma is recognized and treated early, it is highly curable. If neglected, the cancer can spread to other parts of the body, where it can be fatal, Khorasani said.

"Melanoma is an issue that people should be mindful of year-round. Ultraviolet (UV) radiation from the sun causes damage to DNA, which leads to skin cancer and melanoma," Khorasani said. "Protection from UV radiation is important year-round and not just during the summer months or when at the beach. UV radiation from the sun can cause damage to your skin even on a cloudy day. UV radiation can reflect off of water, sand, and even snow."

It is important to implement sun protective measures year-round, Khorasani said.

"It is important to wear sunscreen with a sun protection factor (SPF) of 30 or higher, that offers both UVA and UVB protection," he said. "It is imperative to reapply the sunscreen every two hours and after swimming or sweating as the sunscreen will wash off."

"I recommend staying in the shade if possible during the midday hours when the sun is the strongest. Wear a hat with a wide brim to protect your face, scalp, ears, and neck. Also wear clothing that covers your arms and legs if possible. Wear sunglasses that block both UVA and UVB," Khorasani explained.

Each year in the United States, nearly 5 million people are treated for all skin cancers combined, with an estimated annual cost of $8.1 billion, the U.S. Surgeon General's Office said. Melanoma is responsible for the most deaths of all skin cancers, with nearly 9,000 people dying from it each year.

King's College researchers studied data from 3,594 female Caucasian twins between January 1995 and December 2003 as part of the TwinsUK study protocol. The study was published in the British Journal of Dermatology.

"It is of utmost importance to see your dermatologist whenever you see a mole or spot on your skin that is changing, as often the first sign of melanoma is a change in the shape, color, or size of an existing mole. I recommend seeing your dermatologist once a year for a total body skin exam, especially if you have a family or personal history of skin cancer," Khorasani added.