Cancer-preventive effects of sunscreens are uncertain.

Provocative findings have been published suggesting that the use of sunscreens may promote skin cancer. A recent meeting of international experts on the use of sunscreens and skin cancer was held at the International Agency for Research on Cancer in Lyon. The workshop concluded that the topical use of sunscreens reduces the risk of sunburn and that sunscreens probably prevent squamous-cell carcinoma of the skin when used mainly during unintentional sun exposure. No conclusion could be drawn about the cancer-preventive activity of topical sunscreens against basal-cell carcinoma and cutaneous melanoma. The use of sunscreens can extend the duration of intentional sun exposure, such as sunbathing. Such an extension may increase the risk for cutaneous melanoma. The workshop warned against relying solely on sunscreens for protection from ultraviolet radiation.