When comparing socioeconomic status and neighborhood ultraviolet (UV) radiation levels, the researchers found that that affluence actually had a bigger impact on melanoma risk than UV exposure.
“That was a surprise to us,” said study co-researcher Christina Clarke, PhD, MPH, of Stanford University and the Cancer Prevention Institute of California. “We thought UV radiation exposure would be a more important predictor of melanoma risk than socioeconomic status, but that is not what we found.”
Melanoma is caused by sun exposure, and it has long been known that fair-skinned people have the highest risk. More than 90% of all skin cancers in the U.S. occur in non-Hispanic whites.
Rates of the skin cancer have more than doubled over the past three decades and continue to rise among white teenage girls and younger women. Meanwhile, rates among teenage boys and young men have remained static since 1980.
The study included 3,800 white women between the ages of 15 and 39 with melanomas detected between 1988 and 1992 and between 1998 and 2002. Most of the cancerous lesions were diagnosed and removed before they spread beyond the skin.
Researchers hope the findings will help public health officials direct screening and education efforts aimed at preventing melanomas and other skin cancers.
“California is a sunny state, but we found that risk was not just related to living in a sunny area,” Clarke said. “Women living in affluent, sunny areas may have different cultural norms or they may have more time to tan.”
The study will be published in the July issue of Archives of Dermatology.