- ultraviolet (UV) light: excessive, long-term exposure to sunlight or tanning lamps has been clearly linked to many types of skin cancer, including melanoma (although some melanomas are not UV-light related).
- sunburn: a history of three or more blistering sunburns before age 20 greatly increases risk
- moles: most moles (technically called "nevi") will never cause any problems, but a person who has a single large, irregularly-shaped ("dysplastic") nevus is associated with a 2-fold increased risk, while 10 or more nevi indicate a 12-fold increased risk of developing melanoma
- fair skin, freckling, and light hair: caucasians with blond or red hair and freckles have the highest risk (although people of all races and skin colors can develop melanoma)
- family history of melanoma: about 10% of all people with melanoma have a family history of the disease
- personal history of melanoma: about 5% to 10% of people with melanoma will develop a second one at some point
- compromised immune system: due to medicines that suppress the immune system, such as those taken by organ transplant patients, or diseases such as AIDS or lymphoma
- age: although melanoma is one of the most common cancers in people younger than 30, it is still more likely to occur in older people
- gender: men have a higher rate of melanoma than women
- certain genetic disorders such as xeroderma pigmentosum, a rare condition resulting from a defect in an enzyme that normally repairs DNA damage due to sun exposure
Research published in 2009 confirmed these risks, and added several more. Dermatologist Darrell S. Rigel, M.D., and colleagues at New York University Medical Center analyzed 600 people (300 melanoma patients and 300 who did not have melanoma) to try to determine what factors varied between the two groups and were most often linked to melanoma. They found six factors that independently predicted melanoma risk:
- History of blistering sunburns as a teenager
- Red or blonde hair
- Marked freckling of the upper back, a sign of excessive sun exposure and that a person is susceptible to it
- Family history of melanoma
- History of actinic keratoses, considered the earliest stage in the development of skin cancer
- Outdoor summer jobs for three or more years as a teenager
However, it is important to remember that having a risk factor, or even several risk factors, does not mean that you will get melanoma. And many people who get the disease may not have had any known risk factors. Nevertheless, melanoma can be cured if detected early, unlike many cancers. So knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and healthcare choices. If you have any of the above risk factors, it is important that you perform regular self examinations of your skin, see a dermatologist for regular examinations, and protect yourself from the sun.
"What are the Risk Factors for Melanoma?" American Cancer Society. 27 February 2009.
"Who is most at risk for melanoma?" American Academy of Dermatology. 27 February 2009.
"Melanoma Risk Factors and Prevention." ASCO. 27 February 2009.
"New Research Finds Six Factors Predictive of Melanoma Risk." American Academy of Dermatology. 5 March 2009.