Can the Number of Moles on the Arm Indicate the Risk of the Skin Cancer Known as Malignant Melanoma?

According to a study published in the British Journal of Dermatology, the number of moles on the right arm parallels the total number of moles on the body in terms of melanoma skin cancer risk and provides an indication of melanoma risk.

Melanoma is a type of skin cancer that begins in cells called melanocytes, which give the skin its color. Although it accounts for approximately 5% of skin cancers, it causes the most deaths among skin cancer types. When melanoma is detected at an early stage, surgical removal of the affected skin region can achieve treatment success above 90%; however, 5-year survival rates in advanced melanoma remain unsatisfactory despite all advances in surgical and medical treatments. Early diagnosis of melanoma is therefore extremely important.

Approximately half of all melanomas develop from pre-existing nevi, commonly known as “moles.” Each additional mole is estimated to increase melanoma skin cancer risk by 2-4%. Monitoring existing moles is therefore important for early melanoma diagnosis. Melanomas developing from moles present as changes in the color, shape or size of a mole. However, these changes usually go unnoticed unless evaluated by a physician and monitored by the individual. Counting moles over the entire body to assess melanoma risk is not very practical either, both because individuals may not pay attention and because it is time-consuming for physicians. According to a study published in the British Journal of Dermatology, the number of moles on the right arm parallels the total body mole count and provides an indication of melanoma skin cancer risk.

The study conducted among twins evaluated a total of 3694 women. When the relationship between total body moles and moles in 17 separate body regions was assessed, moles on the right arm showed a strong parallel with the total number on the body. Having 11 or more moles on the right arm was found to indicate a 5-fold higher risk of melanoma.

It should also be noted that melanoma most often starts on the trunk in men and on the legs in women; these results therefore do not mean that only the arms should be examined. It is extremely important for everyone with moles on their body, especially those with many moles, to check them occasionally without becoming obsessive and consult their physician if changes in size, shape or color occur.