Sunscreens as a preventative measure in melanoma: an evidence-based approach or the precautionary principle?

BACKGROUND: Meta-analyses of observational case-control studies have demonstrated no association between sunscreen use and the development of malignant melanoma.
OBJECTIVES: To postulate whether modern sunscreens are likely to be effective as a preventative agent in melanoma and, if so, how many cases might be avoided by their use.
METHODS: The potential number of melanomas prevented by encouraging the use of modern, high SPF, broad spectrum sunscreens during recreational summer exposure was estimated by combining the prevalence of their use with the relative risk of melanoma in nonusers compared with those people who regularly use these products.
RESULTS: Notwithstanding the inherent uncertainties and assumptions that this approach involves, it is shown that significant numbers of melanomas might be avoided by regular sunscreen use during recreational summer sun exposure, and with them appreciable financial, social and emotional costs, even for very modest estimates of the benefit of broad-spectrum sunscreens.
CONCLUSIONS: Despite the lack of evidence demonstrating the efficacy of modern sunscreens in preventing melanoma, it is argued that it would be irresponsible not to encourage their use, along with other sun protection strategies, as a means of combating the year-on-year rise in melanoma incidence.