A meta-analysis of 18 studies that explored the association between melanoma risk and previous sunscreen use illustrates widely differing study qualities and suggests little or no association. A systematic review of the association between sunscreen use and the development of melanocytic nevi in children reported similar issues with study quality and heterogeneity, hindering conclusive assessments; however, of 15 studies meeting inclusion criteria, 12 found either an increased incidence or no association. Thus, the current evidence indicates that sunscreen application as practiced in the general population shows no clear association with reduced risk of melanocytic nevi or melanoma.
Behavioral Interventions to Change Sun-Protective Practices
As noted previously, direct evidence that interventions, such as sunscreen or protection from UV light exposure, decrease the risk of skin cancer is sparse. However, given the association between UV light exposure and subsequent risk of skin cancer, counseling interventions aimed at increasing sun-protective behaviors have been examined. The U.S. Preventive Services Task Force (USPSTF) commissioned a systematic review of this evidence. Although the USPSTF review found no randomized trials directly linking counseling strategies to skin cancer reduction, it found 11 trials, rated as fair in quality, that tested the effect of interventions on sun-protective behaviors. Several trials of behavioral interventions in adults, sometimes as part of an intervention addressing multiple health-related behaviors, such as smoking and nutrition, showed a short-term increase in self-reported sun-protective behaviors. However, the effect sizes were small to modest, without clear evidence that the differences were clinically meaningful.[33,34,35,36,37] Likewise, appearance-based behavioral interventions in young women have had a favorable impact on self-reported indoor tanning behavior, but no long-term follow-up or health outcomes were reported.[38,39,40] A randomized, primary care office-based counseling intervention in adolescents showed an increase in self-reported midday sun avoidance and sunscreen use in the intervention group for up to 24 months. A randomized trial of a provider-based sun protection promotion counseling program for parents for their infant children showed a small increase in sun-protective actions, of questionable clinical importance according to the researchers.