Scientists unravel crucial skin cancer switch

Cancer Research UK

Up to 70 per cent of melanoma skin cancers could be triggered by a particular genetic mutation, according to a Cancer Research UK funded study published in Cancer Cell* today (Monday).

Scientists at The Institute of Cancer Research (ICR) had previously found that the BRAF gene is damaged or mutated in up to 70 per cent of human melanomas, but they did not know whether this was a cause or result of the cancer.

Now, the same group of researchers has discovered that acquiring the BRAF mutation can be the first event in the cascade of genetic changes that eventually leads to melanoma - the most deadly form of skin cancer.

This research confirms that BRAF is a driving force behind the disease and could be the trigger that leads to skin cancer.

Lead author Professor Richard Marais from the ICR, said: "We know that excessive sun exposure is the main cause of skin cancer, but not much is known about the genetics behind it.

"Our study shows that the genetic damage of BRAF is the first step in skin cancer development.

"Understanding this process will help us develop more effective treatments for the disease."

There are around 9,500 new cases of malignant melanoma and more than 2,300 deaths from the disease each year in the UK.

Over-exposure to sunlight causes at least two thirds of all malignant melanomas and up to nine out of ten of all non-melanoma skin cancers. This excessive exposure damages DNA and causes genetic mutations.

Dr Lesley Walker, director of cancer information at Cancer Research UK, said: "Skin cancer is the seventh most common cancer in the UK, but relatively little is known about the genetics behind the disease.

"This week, Cancer Research UK launches our SunSmart campaign to help raise awareness of the risks and causes of skin cancer.

"There's lots of exciting research focussed on developing new therapies that will block the function of mutant BRAF.

"A better understanding of the genetics of skin cancer can help scientists develop more targeted drugs with fewer side effects to treat the disease."

ENDS

For media enquiries please contact the Cancer Research UK press office on 020 7061 8300 or, out-of-hours, the duty press officer on 07050 264 059.

Notes to Editor

* Oncogenic BRAF induces melanocyte senescence and melanoma in mice. Dhomen et al. Monday 6 April 2009. Cancer Cell.

About skin cancer

There are two main types of skin cancer, melanoma and non-melanoma skin cancer. Melanoma is the most serious form of skin cancer.

Excessive sun exposure is the main cause of skin cancer. Ultraviolet radiation from the sun or sunbeds can prematurely age your skin and damage its DNA, causing sunburn and, eventually, skin cancer.

The earlier melanoma is detected, the better the chance that it can be successfully treated . If you notice any of the following signs, then see your doctor without delay.

A symmetry - The two halves of your mole do not look the same.

B order - The edges of your mole are irregular, blurred or jagged.

C olour - The colour of your mole is uneven, with more than one shade.

D iameter - Your mole is wider than 6mm in diameter (the size of a pencil eraser).

Also watch out for:

  • a new growth or sore that won't heal
  • a spot, mole or sore that itches or hurts
  • a mole or growth that bleeds, crusts or scabs

Remember the SunSmart messages

  • S pend time in the shade between 11 and 3
  • M ake sure you never burn
  • A im to cover up with a t-shirt, hat and sunglasses
  • R emember to take extra care with children
  • T hen use factor 15+ sunscreen

Also report mole changes or unusual skin growths promptly to your doctor.

SunSmart is the UK's national skin cancer awareness campaign commissioned by the UK Health Departments and run by Cancer Research UK. Find out more here.