October 13, 2008

Researchers Discover More Genes Linked To Skin Cancer

People of European descent have two genetic variations that appear to increase the risk of the most common skin cancer, researchers from Iceland's Decode Genetics said on Sunday.

Scientists said the variations play no role in skin color but people with both of them are nearly three times more likely to develop basal cell carcinoma compared with people without the changes.

Traditionally, darker skin is thought to be an important protection against skin cancer.

"Here we have two variants that have no impact on pigmentation and only affect the risk of basal cell carcinoma," said Kari Stefansson, Decode's chief executive, who led the study. "We don't know why that is."

According to the American Academy of Dermatology, basal cell carcinoma is the most common form of cancer worldwide, and in the vast majority of cases is caused by exposure to ultraviolet rays of the sun.

When detected early, most cases are easy to treat, but in rare instances the cancer is resistant to treatment, causing damage to skin and sometimes invading bone and cartilage.

The researchers at Decode, a biotech company hunting for new drugs using Iceland's unique gene pool dating back to the Vikings, analyzed genes of more than 30,000 people to identify the impact of the genetic variations located on chromosome 1.

Researchers said the variations differed from past genetic changes linked to basal cell carcinoma in that unlike the others they were not associated with fair skin or pigmentation.

The risk of developing basal cell carcinoma was 12 times higher for people with these new variations along with the three other genetic changes already linked to the cancer, according to the study.

Stefansson said exposure to the sun has no direct impact on the genes, which add to the total risk of basal cell carcinoma.


Image Caption: This is a histologic photograph of a nodular basal cell carcinoma taken by John Hendrix, MD. (Wikipedia)


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