May 9, 2013

expert reaction to new research into red hair and skin cancer risk

Research published in BioEssays claimed the synthesis of the pigment pheomelanin, which gives red hair its color, is carcinogenic. This stands apart from the widely held hypothesis that  it is poor protection from UV light which puts people with pale skin and red hair at greater risk of cancer. 

Prof Jonathan Rees, Grant Chair of Dermatology, University of Edinburgh, said:

“The authors state various things as new, but in reality much of what they say, others have described before.

“The idea that the risk of skin cancer with pheomelanin is not associated with UVR seems a little far-fetched. So:

“1. Skin cancer occurs on areas that get the most sun. You rarely get skin cancer on your bum! This is true in those with red hair, and those without red hair.

“2. Rates of skin cancer in red heads are higher than those without red hair, but rates in reds are highest where there is most sun. So, red heads in Australia show higher rates of skin cancer than those in the UK.

“3. The risk of cancer in red heads rises with sun exposure (just like in those without red hair, the rate rises with UVR).

“For ‘hair’ the ratio of pheomelanin to eumelanin is increased in red heads. However, the data shows that the skin of red heads contains less of both types of melanin, i.e. this is not just about pheomelanin, rather that red heads often have less of both types of melanin. The study mentioned was done in mice.  Mice are not great models for studying skin cancer in humans; for one thing mice are covered in hair.  Mice are not men!”

Dr Bruce Morland, Consultant Paediatric Oncologist, Birmingham Children’s Hospital, said:

“The link between red heads and cancer was postulated by this research group in an article published in Nature last year. This article postulates the mechanism behind the observation but as yet does not provide the scientific proof. Clearly further work is needed before we will fully understand if the hypothesis is indeed correct.”

‘How does pheomelanin synthesis contribute to melanomagenesis?’ by A Morgan et al. will be published in BioEssays on Thursday 9^th May.