Sun Not Only Factor Leading to Melanoma in Fair-Skinned People

--by Jenara Nerenberg

The Gist

Fair-skinned red-heads and blondes—particularly those with freckles—are known to be at an increased risk for developing the skin cancer melanoma, but it turns out that their skin pigment itself may be part of the problem, according to new research appearing in an upcoming online issue of Nature. Whereas researchers have always put blame on the effects of the sun—and indeed, sunblock continues to be an important cancer-prevention measure—now scientists at Massachusetts General Hospital (MGH) are taking a closer look at the skin pigment found in these fair-skinned individuals.

"We've known for a long time that people with red hair and fair skin have the highest melanoma risk of any skin type. These new findings do not increase that risk, but identify a new mechanism to help explain it," says senior author David Fisher, MD, PhD. And as such, he continues, better sunscreens should be developed for those individuals who are at high risk.

The relevant pigment is called phenomelanin, and it is far from ideal for protecting against UV damage from the sun. 

The Expert Take

"Right now we're excited to have a new clue to help better understand the mystery behind melanoma, which we have always hoped could be a preventable disease," says Fisher. 

Fisher goes on to say that sunscreen remains an essential preventive measure for protecting against melanoma and other skin cancers, but that research should continue to look at what else is contributing to the problem. "The risk for people with this skin type has not changed, but now we know that blocking UV radiation—which continues to be essential—may not be enough."

Additional research will be necessary, including efforts to explore skin cancer risk factors for fair-skinned individuals who have dark hair. 

The Takeaway

Even though new findings indicate there are additional causes of melanoma, that should not stop people from using sunscreen, staying in the shade, and avoiding peak sun hours, which are generally between 10AM and 4PM, depending on location. Sunscreen is essential for protecting against skin cancers, such as melanoma, and light-haired, fair-skinned people should be vigilant about protecting themselves from the sun and always checking with the doctor if they detect skin changes on their bodies.

"About six out of seven melanomas will be cured if they are found early, so we need to heighten awareness and caution," adds Fisher.

Source and Method

Researchers at Massachusetts General Hospital looked at two groups of mice—one with the gene that produces light pigment in humans and one with the gene that produces dark pigment in humans. When the team discovered that the "light" group developed significantly more cases of melanoma, even though both groups were exposed to a melanoma-activating procedure in their cells, it became clear that the pigment itself was playing a role. The researchers followed up their work by removing the red-pigment genetic pathway from the mice and found that their rates of melanoma dramatically decreased.  

Other Research

A good overview of melanoma and its various causes and risk factors can be found in a 2000 study in Clinical and Experimental Epidemiology, which explains the role of skin color and sunburn. A 1998 study in Melanoma Research indicates that melanin found in red-heads can also help predict who is at risk for melanoma. A 2000 study in the American Journal of Human Genetics takes an even closer look at how hair color correlates with melanoma risk.

And while it is well known that artificial tanning beds put people at risk of melanoma and other skin cancers, this 2003 study from Oxford's Journal of the National Cancer Institute ties together the way hair color, sun exposure, and sunburn contribute to cancer. Sunburn that occurs in early childhood is a notable risk factor for adult skin cancer.