The level of evidence is downgraded by study quality. There was a lack of histopathological confirmation of BCC or cSCC in a significant percentage of cases. Amongst other sources of bias, it was not clear whether the study authors had assessed any interaction effects between the sunscreen and beta-carotene interventions.
A Cochrane review [Abstract] 1 included 1 study with a total of 1621 subjects. This study compared the daily application of sunscreen compared with discretionary use of sunscreen, with or without beta-carotene administration, in the general population. The study was undertaken in Australia; 55.2% of participants had fair skin, and they were monitored for 4.5 years for new cases of BCC or cSCC assessed by histopathology.
No difference was found in terms of the number of participants developing BCC (n = 1621; RR 1.03, 95% CI 0.74 to 1.43) or cSCC (n = 1621; RR 0.88, 95% CI 0.50 to 1.54) when comparing daily application of sunscreen with discretionary use, even when analyses were restricted to groups without beta-carotene supplementation. Adverse events included skin irritation or contact allergy.
No studies were found evaluating other sun protection measures, such as the use of sun-protective clothing, sunglasses, or hats, or seeking the shade when outdoors.
Date of latest search: 2016-5-10
Primary/Secondary Keywords