Does Suncreen Increase Risk of Skin Cancer?
Media reports that common sunscreen ingredients may lead to increased cancer risk have been widespread and both concern and confuse patients. A recent article in Cutis sought to address these concerns with a critical analysis of the available evidence-based data.
Sunscreens on the market today contain either organic or inorganic UV filters or a combination of both. The author states that organic UV filters are controversial due to reports of possible hormone disruptive effects. One of the most commonly manufactured and controversial agents is oxybenzone. One study demonstrated that nearly 300 years of daily sunscreen application would be needed to reach similar exposure levels of oxybenzone used in prior animal studies. Additionally, the binding affinity of oxybenzone for estrogen receptors has been shown to be much weaker and near insignificant compared to estrogen and estradiol.
Titanium dioxide and zinc oxide are the most common inorganic UV filters. Safety concerns focus on the nanoparticle formulations which have cosmetic benefit but spark worry that the metal oxides penetrate the skin and cause local and systemic toxicities. Several recent scientific studies have shown no percutaneous permeation of these particles in normal adult human skin and reported no cell damage. Some reports have also called into question the risk of inhaling titanium dioxide when using spray or powder products. Several studies investigating increased health risks, specifically lung cancer, in factory workers who were subjected to inhalation and concluded that exposure was unlikely to pose substantial health risks or toxicity.
The authors states that it appears that the current weight of scientific evidence suggests that sunscreens poses no or negligible potential risks to human health. Patients should be made aware that using broadband sunscreens that absorb and/or block UV radiation results in reduced damage to the skin’s DNA. This fact should be considered when taking into account the risks and benefits of sunscreen use. If a patient is still concerned about the active ingredients of UV filters, even given the high probability of safety, there are products available on the market that do not include organic filters or nanoparticles.
Adapted from the original article.
Byline: Martha L. Sikes, MS, RPh, PA-C
[image by Joe Shlabotnik]