Allan Conney and colleagues at Rutgers University in New Jersey said they tested four common skin creams on gene-altered hairless mice exposed to heavy doses of cancer-causing UV light.
The results showed the skin creams caused a type of skin cancer called squamous cell carcinoma, which are slow growing and highly treatable and only fatal if patients fail to have them removed. Also, rates of non-melanoma skin cancers increased between 24 and 95 percent compared to control mice not treated with creams, the study found.
When the scientists repeated the experiments with special creams that did not have suspect ingredients including mineral oil and sodium lauryl sulfate, the cancer rates dropped sharply.
Researchers also cleared the fact that cancer in the mice was not caused by the use of moisturizers but from their early-life radiation exposure. However the creams did make skin cancers grow faster and more readily.
Researchers cautioned that rodent skin is more sensitive than human skin and further studies were needed to test the impact of topical creams on people. Moisturizers are classified as cosmetics by the U.S. Food and Drug Administration, which does not require that they undergo the same safety and efficacy tests required for drugs.
The four creams analyzed were: Dermabase, manufactured by Paddock Laboratories in Minneapolis, MN; Dermovan, made by Healthpoint Ltd. in Fort Worth, TX; Eucerin Original Moisturizing Cream, made by Beiersdorf Inc. in Wilton, CN; and Vanicream, made by Pharmaceutical Specialities, Inc. in Rochester, MN.
