Albino mice in a Rutgers University laboratory that were pre-treated with ultraviolet (UV) light to simulate the lifelong effect of a human’s sun exposure developed skin cancer when a number of common moisturizing creams were applied to their skins.  The creams were meant to be the vehicle by which caffeine would be administered to the mice in an effort to prove the theory that caffeine might prevent skin cancer.  The finding that the creams themselves caused cancer was a surprise to the research team.

Allan Conney and his research team at the New Jersey university suspect the mineral oil and the sodium laurel sulphate in the widely available moisturizing creams they originally used for their study.  Once the suspect ingredients were identified, the research team turned to Johnson & Johnson to develop a cream that does not contain these two ingredients.  The university and the manufacturer have received a joint patent on the cream they developed but it is not known at this time if the product will be marketed commercially.

The mice developed squamous cell carcinoma, a slow-growing form of skin cancer that is easily treated.  The discomfort of the procedure to remove such a skin tumor has been compared to that of getting a tooth filled.  The mice did not develop melanoma, the most dangerous form of skin cancer that can become fatal if not treated aggressively.

Critics of the study say the results are artificial since the mice are bred to be susceptible to skin cancer in the first place and because they were treated with substantial amounts of UV light, another factor that triggers skin cancer.

Other experts from around the world reiterate the nature of squamous cell carcinoma, saying it is very common, almost entirely curable, and should not be considered a major health concern.

Conney acknowledges his study was done on mice although they were the same breed of mice commonly used for skin cancer research and that the outcome may be entirely different when the creams are used on human skin.  He welcomes future studies that will help clarify that issue.

The Journal of Investigative Dermatology has published the findings of the Conney skin cancer study.