Gene Explains Men's Increased Skin Cancer Risk

Main Category: Melanoma / Skin Cancer
Article Date: 29 Nov 2003 - 0:00 PDT

email to a friend   printer friendly   opinions  

The discovery of a gene associated with an increased skin cancer risk could help explain why men are more likely to develop malignant melanoma than women.

While most people associate melanoma with overexposure to ultraviolet light from sunbathing, genetic factors also play a role.

Researchers from University Hospital Tuebingen in Germany set out to investigate these genetic factors and found one of particular significance to men.

Deadly disease

Malignant melanoma is the leading cause of death from skin disease.

The condition involves cells that grow without limit in a disorganized fashion, disrupting and replacing normal tissues and their functions.

As with other skin cancers, melanoma can be treated easily if tumors are caught in their early stages. If not, cancer cells can spread to the lymph nodes and other organs, after which melanoma is much more difficult to treat.

While the disease strikes both men and women, men have a one in 58 chance of developing it while women have a one in 82 chance.

In the males

To investigate genetic contributions to the disease, Tuebingen researchers took blood samples from 450 healthy people and 500 people with malignant melanoma.

They then studied DNA samples extracted from both groups for genetic differences and identified a gene called BRAF that contains several sites of natural variation.

Some variants were more common in people with melanoma.

Upon further analysis, the researchers found that these variants only conferred a higher risk of melanoma on men.

They conclude that BRAF may partly explain why males have a higher lifetime incidence of melanoma than females.

Top contributor

Previously, the best-known risk factor for melanoma was a mutation in the gene CDKN2A.

The Tuebingen researchers say that the risk associated with BRAF is more significant.

'We estimate that BRAF could account for an attributable risk of developing melanoma of approximately four percent in the German population,' they report. 'This risk estimate is much higher than that attributed to CDKN2A.'

More moles

The BRAF gene encodes a protein that activates cell growth and multiplication.

Mutations in BRAF, studies have shown, cause the protein to become more active.

The variants identified by the German researchers, however, do not affect the protein's activity.

The researchers think that they might instead predispose people to developing moles, and that this might explain the increased risk.

'Moles are a major risk factor for the development of malignant melanoma,' says researcher Claus Garbe. 'BRAF mutations occur in the majority of melanomas but also in moles.'

The study is reported in the Journal of Carcinogenesis (read abstract).

• Additional
• References
• Citations