January 25, 2011 — Melanoma in adults might be preventable with the regular use of sunscreen — that is, with the daily application to the head, neck, arms, and hands, according to Australian researchers who conducted a rare randomized controlled trial of sunscreen use.
The study randomized 1621 adults to regular sunscreen use or to discretionary use, which included no use at all.
The regular application of sunscreen with a sun protection factor of 15 or more during a 5-year treatment period reduced the incidence of new primary melanomas during a subsequent 10-year follow-up period, report the study authors, led by Adele Green, MB BS, PhD, from the University of Queensland in Brisbane.
"Our findings provide reassurance . . . about sunscreen's ability to prevent melanoma," write Dr. Green and her colleagues in the January 20 issue of the Journal of Clinical Oncology.
Two editorialists, who wrote an essay that accompanies the study, mostly endorse the findings.
"The question of its efficacy with respect to melanoma prevention should no longer deter scientists or clinicians from recommending sunscreen use," write Phyllis Gimotty, PhD, and Karen Glanz, PhD, MPH, from the University of Pennsylvania School of Medicine in Philadelphia.
However, Dr. Gimotty and Dr. Glanz, who are cancer epidemiologists, quibble about the study statistics, saying that the study's P values "could be considered of borderline significance."
But these experts in statistical methods ultimately yield to the study authors' conclusions. "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," the pair write.
The new findings come from the Nambour Skin Cancer Prevention Trial, which was conducted in Queensland, Australia — a region with "the highest rate of skin cancer in the world," the editorialists point out.