Sunlight may help treat skin cancer, new studies show; reports overturn outdated beliefs on skin cancer

• The theory has been around for decades, fueled in part by statistics showing that people in sunnier climates are less likely to die from cancer than those in gloomier areas.
• One study, led by researchers at the Karolinska Institutet in Sweden, found that people who got lots of sun exposure through sunbathing or vacations in sunny places were less likely to develop lymphoma than people who stayed out of the sun.
• The other, led by researchers at the University of New Mexico, Albuquerque, found that people with melanoma were less likely to die from the disease if they had had lots of sun exposure.
• The findings were somewhat surprising because ultraviolet (UV) radiation from sun exposure is known to raise the risk of developing melanoma, and is also thought to play a role in the development of lymphoma.
• Both groups of researchers say sunlight's influence on vitamin D may provide one possible explanation for the results.
• Sunlight is another source; the UV rays stimulate the skin to produce it.
• We all need vitamin D to keep our bones healthy and strong.
• But it also seems to have an effect on the immune system and on how cells grow and change -- and that action may influence the development of some types of cancer.
• "Vitamin D is what everyone's really interested in right now," said Marianne Berwick, PhD, MPH, head of Epidemiology and Cancer Prevention at the UNM Cancer Research and Treatment Center and first author of the melanoma study.
• Sun exposure was thought to raise lymphoma risk because people who have had some types of skin cancer are also more likely to get lymphoma.
• Until more is known, it's important to keep protecting yourself from too much sun.