Melanoma and use of sunscreens: An EORTC case‐control study in germany, belgium and france

Abstract

Use of sunscreens is widely advocated as a preventive measure against sun-induced skin cancers. However, to date, no epidemiologic study has reported a decreased melanoma risk associated with sunscreen use. We have conducted a case-control study aimed at evaluating the influence of sunscreen use on the occurrence of cutaneous malignant melanoma. In 1991 and 1992, 418 melanoma cases and 438 healthy controls were interviewed in Germany, France and Belgium. The questionnaire used differentiated between regular sunscreens, psoralen sunscreen (prepared with 5-methoxypsoralen, a tanning activator and photocarcinogen), and self-tanning cosmetics (which produce a tan without ultraviolet radiation). After adjusting for age, sex, hair colour and holiday weeks spent each year in sunny resorts, the melanoma risk was of 1.50 (95% Cl:1.09-2.06) for regular sunscreens, and of 2.28 (95% Cl: 1.28-4.04) for psoralen sunscreens. No melanoma risk was associated with use of self-tanning cosmetics. Among subjects with a poor ability to tan, psoralen sunscreen users displayed a melanoma risk of 4.45 (95% Cl: 1.25-15.8) when compared with regular sunscreen users. There was a significant negative interaction between regular sunscreen use and sunburns experienced in adulthood. Use of sunscreens, especially psoralen sunscreen, was associated with higher density of pigmented lesions of the skin. Although we cannot exclude the presence of an unknown confounding factor, our results support the hypothesis that sunscreens do not protect against melanoma, probably because of their ability to delay or avoid sunburn episodes, which may allow prolonged exposure to unfiltered ultraviolet radiation. Serious doubts are raised regarding the safety of sunscreens containing psoralens.

Epidemiologic Evidence for Different Roles of Ultraviolet A and B Radiation in Melanoma Mortality Rates

“…Eight epidemiologic studies have reported that regular use of sunscreens is associated with significantly increased risk of melanoma (19,(47)(48)(49)(50)(51)(52)(53). The association persisted after controlling for the amount of time spent in the sun, skin type, and other predisposing factors, including history of sunburns.…”

“…The association persisted after controlling for the amount of time spent in the sun, skin type, and other predisposing factors, including history of sunburns. Five of these studies reported higher risk of melanoma associated with use of sunscreens in both sexes (19,49,50,52,53), while three reported the association in men (47,48,51). Another study reported a higher incidence of nevi, pigmented benign lesions of the epidermis that are associated with increased risk of melanoma, in children whose parents regularly applied sunscreens to the children's skin when outdoors in the sun (43).…”

“…Historically, it has been thought that the most important action spectrum for human melanoma is solely UVB (14,15), although a role for ultraviolet A (UVA) has been suspected (12,13,(16)(17)(18)(19)(20). The reported associations of sunscreen usage with melanoma and other skin cancers could not be explained by predisposing factors such as skin type.…”

Sunscreen enhancement of UV-induced reactive oxygen species in the skin

“…It is therefore an unsettling observation that increased sunscreen use has coincided with an increase in skin cancer. Most notably the incidence of melanoma has risen, although the relationship between the effects of sunscreens upon melanoma is hotly debated [1][2][3][4][5][6]. Complicating the traditional concept of photoprotection is our limited understanding of the photochemistry UV filters undergo in the skin.…”

Interventional study in 1,232 young German children to prevent the development of melanocytic nevi failed to change sun exposure and sun protective behavior

“…Numerous case-control studies focusing on the effect of sunscreen use and the risk of CM reported contradicting results reaching from a reduced risk, [5][6][7][8] an unchanged risk, 9 to an increased risk in persons using sunscreen. [10][11][12][13][14][15][16][17] Most of these case-control studies were hospitalbased, might not have been controlled comprehensively for exposure to sunlight and skin type and were most likely influenced by recall bias, as they involved melanoma patients. Meta-analyses of studies published recently on the relationship of sunscreen use and the risk of CM could not find any association.…”