Review: Sunscreens lag behind protective measures in minimizing skin cancer risks

Zurich, Switzerland - Compared with using sunscreens, limiting of exposure to the sun and wearing sun-protective clothes are the most effective ways to reduce skin-cancer risks, reports Medscape in covering a review by a Swiss team published recently in the online issue of The Lancet.

The review authors, from Triemli Hospital, here, searched for articles in English, French and German published by Medline from 1990 to August 2006 with the keywords “sunscreen,” “photoprotection” and “sun protection,” with focus on work published over the past three years. The team also searched articles through Scopus from 1998 to the present and without language restriction, using the term “sunprotection,” and searched several review articles and book chapters.

The review’s results showed that preventive strategies in decreasing order of effectiveness and lifestyle disruption are: completely avoiding sun exposure; seeking shade at times when the sun’s rays are relatively intense; wearing clothes that protect against UV radiation; and using topical sunscreens.

“Sun exposure is the main cause of photocarcinogenesis, photoaging and photosensitivity; thus, photoprotection is an important issue,” the researchers write in their review. “In a skin cancer prevention strategy, behavioural measures - wearing sun-protective clothes and a hat, and reducing sun exposure to a minimum - should be preferred to sunscreens. Often this solution is deemed to be unacceptable in our global, outdoor society, and sunscreens could become the predominant mode of sun protection for various societal reasons.”

The authors note that adverse reactions from sunscreen ingredients - including allergic and irritant contact dermatitis, phototoxic and photoallergic reactions, contact urticaria and occasional severe anaphylactic reactions - appear to be on the rise: According to a recent Australian study, the authors write, these reactions occur in nearly 20 percent of individuals.

“To anticipate that newer formulations of sunscreens will lead to a benefit as a protective agent against melanoma is reasonable, although such a benefit might not be seen for several decades,” the authors conclude. “However, their use in practice could be difficult, time-consuming and expensive, and they can, in general, be used only in addition to the more reliable measures of clothing protection and reduction of ultraviolet exposure during peak hours of solar radiation.”