Moisturizers Up Skin Cancer in Mice

Moisturizers Up Skin Cancer in Mice

4 Commonly Used Moisturizing Creams Promote Tumors in UV-Exposed Mice
By Daniel J. DeNoon /  WebMD Health News

Reviewed by Louise Chang, MD

Aug. 14, 2008 — Four commonly used moisturizers promoted skin cancers in mouse studies.

Mice are not men. But the unexpected finding suggests that these — and
perhaps other products — may not be as safe as they’re thought to be.

The moisturizers tested in the study were Dermabase, Dermovan (a wholesale-only product discontinued in 2006), Eucerin Original Moisturizing Cream, and Vanicream.

In a mouse model of sun-related skin
, frequent application of each product resulted in more skin tumors
and faster tumor growth, says study leader Allan H. Conney, PhD, director of
the Susan Lehman Cullman Laboratory for Cancer Research and professor in the
school of pharmacy at Rutgers University in Piscataway, N.J.

"This was unexpected. We really did not expect to see the
tumor-promoting activity of these creams," Conney tells WebMD.

In fact, Conney and colleagues were getting ready to use one of these
moisturizers — Dermabase — in human clinical trials of topical caffeine, which prevents skin cancer in animal

"We thought it would be prudent to test Dermabase by itself to see if it
had tumor-promoting activity," Conney says. "We did not think it would.
But lo and behold, to our surprise we got an increased rate of skin

This led to new tests of Dermabase and the three other moisturizers, which
the Conney team hoped to use in their human study. For these new animal
studies, the researchers used hairless mice irradiated with ultraviolet light
twice a week for 20 weeks. With no further irradiation, such mice eventually
develop skin cancer — very much like humans overexposed to sunlight early in

Five days a week, for 17 weeks, the researchers rubbed moisturizer into the
animals’ skin. The result:

  • Dermabase increased the total number of tumors by 69%.
  • Dermovan increased the total number of tumors by 95%.
  • Eucerin increased the total number of tumors by 24%.
  • Vanicream increased the total number of tumors by 58%.

"The multimillion-dollar question is, what about humans?" Conney
asks. "The answer is, we don’t know. Our study raises a red flag and points
out the need for epidemiologists to take a look at people who use moisturizing
creams. And the companies that market these products should take a look at
animal models and see if their products promote tumors."

Testing Moisturizers for Safety

Dermatologist Keyvan Nouri, MD, director of dermatologic surgery at the
University of Miami Miller School of Medicine and author of the best-selling
book Skin Cancer, agrees that companies that make moisturizers should
test their products.

"This study could definitely be a warning to alert these companies to
consider testing moisturizing creams with some sort of assay," Nouri tells
WebMD. "These creams need to be tested first before they come to

Moisturizers are classified as cosmetics by the FDA, which does not require
that they undergo the same safety and efficacy tests required for drugs

The moisturizers did not cause cancer in the mice. That came from their
early-life radiation exposure. But the creams did make skin cancers grow faster
and more readily.

Nouri notes that the radiation damaged the skin of the mice before the
moisturizing creams were applied. That, he says, might account for the
moisturizers’ unusual tumor-promoting effect.

However, he notes that the skin cancers are becoming much more common in

"There are over a million cases a year," he says. "It is by far
the most common cancer we deal with. Skin cancers account for more than half of
all cancers combined. But most skin cancers are totally curable."

What is it about the moisturizers that might promote cancer?

The Conney team asked Johnson & Johnson to make them a "custom
blend" moisturizer without two ingredients previously linked to skin
irritation (sodium lauryl sulfate) and tumor promotion (mineral oil). The
custom blend (on which Rutgers University and Johnson & Johnson hold a
patent) did not promote skin cancer.

But not all of the products tested use these ingredients, so exactly what —
if anything — might be linked to cancer isn’t known. And it’s certainly clear
that mouse and human skin are very different.

Moisturizers Still Necessary

Nouri warns consumers not to stop using moisturizers.

"As we get older, our skin gets drier," he says. "We need to
moisturize, otherwise our skin gets dry and we get eczema, dermatitis, rashes, and so on. It is too soon to say from this
study people should stop moisturizing."

Eucerin is made by Beiersdorf Inc.

"We have just learned about this study and are currently reviewing it to
understand the findings," Beiersdorf says in a statement to WebMD.
"Eucerin Original Creme has been on the market for more than 100 years and
is a highly respected, dermatologist-recommended brand. It has been widely used
by both individuals with normal skin and those with diseased skin under the
care of physicians, and no incidents of this nature have ever been

Vanicream is made by Pharmaceutical Specialties Inc. In a statement to
WebMD, PSI President Conrad O. Thompson, RPh, says there is nothing in the
Conney study to indicate any need for change in current recommendations for use
of Vanicream.

"Treatment with Vanicream Skin Cream clearly did not increase the
proportion of animals that developed tumors," Thompson notes.

Dermovan, a wholesale-only product
used as a base to which other ingredients are added by compounding pharmacists,
was made by Healthpoint Ltd. until the product was discontinued in

"The product has been around
for 50 years, and has no safety issues related to it," Healthpoint
spokesman Mark Mitchell tells WebMD.

Dermabase maker Paddock
Laboratories Inc. did not respond to WebMD’s request for comment.

The Conney study appears in the Aug. 14 advance online issue of the
Journal of Investigative Dermatology

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