Hi everyone. Today I want to talk about a recently published article with unintended findings that suggests that commonly used moisturizers may contribute to skin cancer formation. Patients often inquire about the safety of products and while products are extensively tested by the FDA prior to approval, there are things that do go undetected.
In this recently published study (in the respected Journal of Investigative Dermatology), researchers were looking to investigate the protective role of caffeine for skin cancer. In order to see what cream or vehicle might be best to get caffeine into the skin, they were looking at the effects of several commonly used moisturizers in order to determine which may be best to use with caffeine. The study was done with mice that were exposed to harmful ultraviolet radiation and then treated with several commonly used moisturizers. To the surprise of the researchers, these moisturizers led to increased numbers of squamous cell carcinomas that grew more rapidly with the use of the moisturizers. The four moisturizers tested were Dermabase, Dermovan, Eucerin, and Vanicream. All four creams led to increased numbers of discovered tumors, which was an unexpected finding.
So are moisturizers safe to use and do they lead to greater numbers of skin cancers? These are now pertinent questions which have never been contemplated because no data like this has ever been seen. The manufacturers of the creams dismiss this study because it is the first showing these results and it was a small study with mice and not people. These criticisms have some validity but clearly there is real reason to further investigate the safety of these products.
Mice and humans are remarkably similar both genetically and comparing skin samples. While it is always a big leap to go from treating mice to people, there is enough similarity that mice are commonly used research tools because in many ways, mouse and human biology are similar. For example, cancer treatments are often tested in mouse models before going to human testing. However, it is important to note that many medications that help cancer, for example, in mice do not end up having use in humans. Thus, it may be valid to say that these moisturizers may contribute to skin cancer in mice but not humans. Also, it is important to note that the moisturizers did not cause skin cancer as the tumors were caused by harmful ultraviolet light to which they were exposed prior to moisturizer application.
While this study is certainly provoking, our skin does need moisturizer and sunscreens that contain chemicals included in those moisturizers in the study. Dry and easily irritated skin is not healthy and can lead to itching and scratching, which can lead to superficial skin infections. Furthermore, many moisturizers contain sunscreen and we know the benefits of sunscreen on skin cancer prevention so we all should continue to use moisturizers and sunscreens with broad spectrum protection (against UVA and UVB). Hopefully, this study will lead to greater testing of these over-the-counter creams and lead to a greater understanding of what causes cancer so we can better prevent it. I do not think this article is cause for alarm, but it certainly sends a signal to manufacturers that more testing is needed to assure us that products we expect to help us are not actually hurting us.