The researchers found people who were encouraged to slather on sunscreen in the 1990s were 50% less likely to develop melanoma 15 years later, a finding that suggests sunscreen even benefits adults and that the benefits last for years.
The numbers were small – only 22 people were diagnosed with melanoma out of 1,600 – but should settle a debate over whether using sunscreen simply encourages people to stay out in the sun too long, the researchers said.
Adele Green of the University of Queensland and colleagues followed on a study of more than 1,600 Australians that started in 1992. They had been randomly assigned to either get standard advice to use sunscreen, or to be given sunscreen to use with careful instructions and supervision until 1996.
Ten years after the trial ended, 11 patients who had been supervised developed melanoma, compared to 22 who just got standard advice to use sunscreen and cover up.
This is a 50% reduction, and the risk of invasive melanoma was even lower, reduced by 73%, Green’s team reported in the Journal of Clinical Oncology.
Phyllis Gimotty and Karen Glanz of the University of Pennsylvania School of Medicine said Green’s study was not perfect but should answer many doubts.
“To our knowledge, the trial’s findings are the first to provide strong evidence for a reduction in the incidence of invasive melanoma after regular application of broad spectrum sunscreen in adults,” they wrote in a commentary in the journal.