A tourist sunbathes at Illetas beach on the Balearic island of Mallorca June 4, 2008. (Dani Cardona/Reuters)

CHICAGO (Reuters) -
People who have had a normally
non-fatal form of skin cancer have double the risk of
developing other types of cancers, U.S. researchers said on
Tuesday.

They said the increased risk is especially pronounced in
younger people and suggests people who get these less serious
forms of skin cancer may be more cancer-prone in general.

“It seems like non-melanoma skin cancer, even though it is
a non-fatal disease, may be a warning sign for increased risk
of other, more serious cancers,” said Anthony Alberg, a
researcher at the Medical University of South Carolina in
Charleston, whose study appears in the Journal of the National
Cancer Institute.

Non-melanoma skin cancers, which include basal cell
carcinoma and squamous cell carcinoma, affect an estimated 1
million people each year in the United States, according to the
American Cancer Society.

“It is far and away the most common form of cancer,” Alberg
said in a telephone interview. But they are slow-growing and
cause no harm if they are removed.

Previous studies have found that people who get these types
of skin cancers are at higher risk of developing melanoma, the
deadly form of skin cancer.

Alberg said his research suggests that non-melanoma skin
cancer may be a risk factor for other cancers as well.

He and colleagues analyzed data from a 16-year study of
people in Washington County, Maryland, that compared cancer
risks among 769 people who had been diagnosed with non-melanoma
skin cancer and 18,405 people who had no history of skin
cancer.

INCREASED RISK

“People with a personal history of non-melanoma skin cancer
were two times more likely to develop a subsequent cancer
compared to people without a personal history of non-melanoma
skin cancer,” Alberg said.

That was true even after they adjusted for age, obesity,
history of smoking, level of education, skin type and sun
exposure. “The differences didn't go away,” Alberg said.

And people who developed skin cancer at a younger age,
those 25 to 44, had 2.6 times higher risk of developing another
cancer.

“The results were pretty clear in showing the earlier the
age of developing non-melanoma skin cancer, the higher the
increased risk for subsequent malignancies,” he said.

Alberg said the findings suggest some people may have a
genetic predisposition to skin cancer that may also be linked
to the development of other forms of cancer.

He suspects this may have something to do with a person's
ability to repair DNA in skin cells damaged by ultraviolet
radiation from the sun. “If they are less adept at that, their
risk for skin cancer increases,” Alberg said.

While more study is needed about individual risks, Alberg
said people who have had non-melanoma skin cancer would be wise
to mention it to their doctor.

“It seems to be a more important part of a personal health
history than we thought before,” he said.

(Editing by Maggie Fox and Cynthia Osterman)