Gorham Edward D, Mohr Sharif B, Garland Cedric F, Chaplin George, Garland Frank C
Department of Family and Preventive Medicine, University of California San Diego, 9500 Gilman Drive 0613C, La Jolla, CA 92093-0631, USA.
Ann Epidemiol. 2007 Dec;17(12):956-63. doi: 10.1016/j.annepidem.2007.06.008.
Sunscreens may allow overexposure to ultraviolet A (UVA) in fair-skinned persons and prevent symptoms of sunburn, but their benefits for the prevention of melanoma are uncertain.
A PubMed search was performed that identified all known studies of the association of sunscreen use with melanoma risk during 1966-2007. A total of 18 studies were identified, of which 17 met criteria for inclusion in the analysis. Of these, 10 were conducted at latitudes >40 degrees from the equator and 7 at <or=40 degrees . Data were pooled for all latitudes combined and also according to these latitude strata. The association of skin pigmentation and latitude with odds ratios was estimated using linear regression.
Overall, there was no statistically significant effect of use of sunscreens on risk of melanoma (odds ratio 1.2, 95% confidence interval [95% CI] 0.9-1.6; p for heterogeneity < 0.0001). However, there was an interaction with latitude. At >40 degrees from the equator, the odds ratio was 1.6 (95% C.I. 1.3-1.9; p for heterogeneity = 0.006), whereas it was 0.7 at <or=40 degrees (95% C.I. 0.4-1.0; p for heterogeneity = 0.0002).
Use of common sunscreen formulations that absorb UVB almost completely, but transmit large quantities of UVA, may contribute to risk of melanoma in populations at latitudes >40 degrees.
防晒霜可能会使皮肤白皙的人过度暴露于紫外线A（UVA）下，并预防晒伤症状，但其对预防黑色素瘤的益处尚不确定。
进行了一项PubMed检索，确定了1966年至2007年期间所有关于使用防晒霜与黑色素瘤风险关联的已知研究。共识别出18项研究，其中17项符合纳入分析的标准。其中，10项研究在距离赤道>40度的纬度进行，7项在≤40度的纬度进行。对所有纬度的数据进行合并，并根据这些纬度分层进行分析。使用线性回归估计皮肤色素沉着和纬度与比值比的关联。
总体而言，使用防晒霜对黑色素瘤风险没有统计学上的显著影响（比值比为1.2，95%置信区间[95%CI]为0.9 - 1.6；异质性p<0.0001）。然而，存在与纬度的交互作用。在距离赤道>40度处，比值比为1.6（95%CI为1.3 - 1.9；异质性p = 0.006），而在≤40度处为0.7（95%CI为0.4 - 1.0；异质性p = 0.0002）。
使用几乎能完全吸收UVB但能透射大量UVA的普通防晒霜配方，可能会增加纬度>40度人群患黑色素瘤的风险。
