Gene mutation the trigger for deadly melanoma

Apr 13 2009

According to British researchers as many as 70% of melanoma skin cancers may be triggered by a gene mutation.

Scientists at the Institute of Cancer Research have discovered that the BRAF gene mutation is often the first event in a cascade of genetic changes - this causes cells to become cancerous after excessive exposure to the sun, leading to melanoma, the most deadly form of skin cancer.

Scientists were already aware that the BRAF gene was frequently damaged in patients with melanoma but until now it was unclear if this was a cause or effect of the cancer and the new revelation could lead to better treatments for the deadly disease.

Lead researcher Professor Richard Marais says the study shows that the genetic damage of BRAF is the first step in skin cancer development and understanding this process will help them develop more effective treatments for the disease.

Scientists are optimistic that once the genetics behind skin cancer are clear it will lead to the development of targeted drugs that can fix the faulty genetic machinery.

Although the study was carried out in mice, the researchers said that melanomas which develop in the animals closely resemble those that develop in humans.

Though melanoma accounts for only a small percentage of skin cancers, it is the root cause of most skin cancer deaths.

Melanomas occur when pigment-producing skin cells called melanocytes proliferate in an uncontrolled manner and over-exposure to sunlight is the cause of at least two-thirds of cases when DNA in sun burnt skin cells becomes damaged, leading to the genetic mutations.

Melanoma is the most deadly and serious form of skin cancer and sun exposure is the main -and most preventable risk factor - other melanomas develop as a rule from normal moles.

Warning signs to look for include - two halves of a mole do not look the same - edges of a mole which are irregular, blurred or jagged, a mole with uneven colour, with more than one shade and a mole wider than 6mm.

The risk of developing melanoma can be reduced by staying out of the sun between 1100 and 1500, never getting burnt, wearing a t-shirt, hat and sunglasses and using factor 15+ sunscreen - extra care must be exercised with children and sun exposure.

The research is published in the journal Cancer Cell.