15 NCCN Guidelines for Patients ® : Melanoma, 2018 1 Melanoma basics Risks and prevention Risks and prevention Exactly what causes melanoma is unknown. But, many risk factors for melanoma are known. A risk factor is anything that increases the chance of getting a disease. Some risk factors are passed down from parent to child through genes. Other risk factors are activities that people do. Having one or more risk factors doesn’t mean you’ll get melanoma. Likewise, melanoma occurs in some people who have no risk factors. Key melanoma risk factors are described next. Ultraviolet energy Melanoma often occurs on parts of the body exposed to UV energy. UV energy is an invisible light energy. The main source of UV energy or rays is sunlight. Tanning beds also expose the skin to UV rays and are known to cause skin cancer, including melanoma. Both UVA ( u ltra v iolet- A ) and UVB ( u ltra v iolet- B ) rays contribute to the development of melanoma and skin cancer. Too much exposure damages the skin and increases the risk for skin cancer. Whether sun exposure was too much depends on UV intensity, length of exposure, and how well the skin was protected. Severe sunburns with blisters, especially in youth, increase the risk for melanoma. Many or atypical moles Moles are made up of clusters of melanocytes. Babies usually don’t have moles at birth. They first appear during youth and continue to appear until about age 40. Most adults have moles. Most moles don’t turn into melanoma. But, having many moles, large moles, or atypical moles puts you at higher risk for melanoma. An atypical mole is a mole that has some features of melanoma listed in the “ABCDE rule” and looks different from a normal or common mole. Most atypical moles do not become cancer. Fair complexion Having a fair complexion raises your risk for developing melanoma. Examples of a fair complexion are red or blond hair, blue or green eyes, or skin that easily freckles or sunburns. Fair skin is less protective against UV energy because it has less melanin. Family history Although rare, melanoma can run in families. Thus, you have a higher risk of developing melanoma if a blood relative has had melanoma. The more family members with melanoma, the more you are at risk. Tell your doctor if any of your family members had melanoma, pancreatic cancer, astrocytoma (brain tumor), uveal melanoma (in the eye), or mesothelioma. Your doctor can help you understand your risk and if needed, refer you to a qualified cancer genetics counselor for possible testing for gene mutations. Xeroderma pigmentosum Xeroderma pigmentosum is a very rare medical condition in which the skin can’t repair itself from UV damage. It is passed down from parents to children. It causes an extreme skin reaction to UV energy because the skin can’t heal itself well. Xeroderma pigmentosum increases the risk for both melanoma and other types of skin cancer. Age Most people who develop melanoma do so after age 60. But, melanoma is one of the most common cancers in people younger than age 30, particularly in young women who tan frequently or use tanning beds. People with a strong family history of melanoma may also develop melanoma at a young age.