Risk Factors

Risk Factors

In the US, the incidence of melanoma is rising more rapidly than any other cancer. According to the American Cancer Society, about 59,580 new melanomas were to be diagnosed in the United States in 2005, with 7,700 people will dying from it.

Survival rates have been improving, however, and the increase in melanomas has occurred principally with thin, less aggressive forms of the disease. Some experts believe this is due to the increased awareness from effective public programs and earlier diagnosis.

While exposure to sunlight is the number one preventable cause of melanoma, it is not the only cause. Genetic factors and immune system deficiencies can also cause melanoma. People at high risk include those with multiple moles, large moles or atypical moles.

Age and Gender

Melanoma in Adults. Melanoma is most common in people over 40, and the incidence increases significantly as people get older. Before age 40, melanomas are slightly more common in women than men, but after age 40 men are more often affected. Men are also more likely to have invasive and fatal melanoma than are women, although some research suggests that the higher rates are only because men fail to seek a diagnosis of suspicious skin changes before they become dangerous. The rate in women levels off somewhat between age 45 and 60; researchers speculate that menopause could have some sort of protective effect during those years.

Melanoma in Children. Melanoma is rare in children under age 10. Among children ages 10 to 14 the incidence is only 0.3 per 100,000. Between ages 14 and 19, it is still very rare, 1.3 per 100,000. Parents, then, should not be unduly alarmed by every minor skin imperfection in their children. Nevertheless, melanoma is as serious in children as in adults and early detection is still critical.

Intense Exposure to Sunlight and Ultraviolet Radiation

Ethnic Groups and Complexion. People with light skin, blue, gray, or green eyes, red or blond hair, and lots of freckles are at highest risk than people with other skin types for developing melanoma. The risk increases for those who are easily sunburned and rarely tan, particularly if they live close to the equator where sunlight is most intense. Darker ethnic groups or those with swarthy complexions are not immune, however.

Experts have devised a classification system for skin phototypes (SPTs) based on the sensitivity to sunlight. It ranges from SPT I (lightest skin plus other factors) to IV (darkest skin). Tanning and Sunburn Risk People with skin types I and II are at highest risk for photoaging skin diseases, including cancer. It should be noted, however, that premature aging from sunlight can affect people of all skin shades.