Terrified of your skin turning reptilian as you get older? Take heart:
people with very wrinkled faces seem less likely to get basal-cell carcinoma
(BCC), the most common form of skin cancer, new research suggests
"It seemed that people we were operating on for BCC had very few wrinkles," says Christopher Griffiths, a dermatologist at Hope Hospital in Manchester, UK, who noticed the contradictory trend in people coming to his skin clinic.
What connects wrinkles and BCC is not yet clear, although sunlight contributes to both. The tissue-repair mechanisms that keep some people smooth-skinned may put them at greater risk of BCC, the researchers suggest.
They hope to identify the molecular basis of the apparently protective effect of wrinkling and to determine whether it extends to other, more harmful skin cancers.
Griffiths' team assigned a 'wrinkle grade' - from 1 (least wrinkly) to 8 (most wrinkly) - to 239 white subjects - the ethnic group most susceptible to BCC - of around 70 years old.
After taking into account wrinkle-influencing factors such as age, sex, previous skin treatments and smoking history, the researchers found that people graded 5 or above were 90% less likely to have BCC than those with wrinkle grades 2 and 3.
The smooth-skinned people in the study - those most susceptible to BCC - had fair skin that does not tan well. Broken blood vessels on their skin suggested that they had been exposed to similar amounts of sunlight as wrinkled people.
Although it's "pure speculation" at this stage, these broken blood vessels (telangiectasia) may be a clue to their susceptibility to BCC, says Griffiths.
Ultraviolet rays destroy the skin's elastic collagen fibres. Wrinkles are thought to occur when the skin repairs itself without replacing collagen. But old smooth skin seems to replace lost collagen, possibly by producing transforming growth factor-beta (TGF-β).
TGF-β also stimulates blood-vessel growth and depresses the immune system. This would explain the telangiectasia, says Griffiths, and possibly the BCC: immune suppression and blood-vessel growth are also associated with cancer.
"If the TGF-β story holds up, it would be rather nice," says consultant dermatologist Charlotte Proby of the Imperial Cancer Research Fund in London, UK, because it would point to a molecular mechanism for BCC. "But it's too speculative at this point," she says.
"If, truly, people with wrinkles don't get BCC it would be very interesting," says Proby, as it contradicts the broadly accepted idea that wrinkling is an indicator of sunlight-induced damage and therefore of BCC risk.
But, she says, Griffiths will have to follow a large number of people with various skin types as they age to establish whether or not those who wrinkle really are protected from getting BCC.