THURSDAY, July 8 (HealthDay News) -- The ubiquitous virus linked to cervical, vaginal and throat cancers may also raise the risk of developing squamous cell carcinoma, the second most common form of skin cancer, a new study suggests.

The risk from human papillomavirus (HPV) seen in a new study was even higher if people are taking drugs such as glucocorticoids to suppress the immune system, according to new research by an international team led by Dr. Margaret Karagas of Dartmouth Medical School in Lebanon, N.H.

But all of this does not necessarily mean that HPV causes squamous cell carcinoma, one expert said.

"That's a fairly big leap to me," said Dr. Stephen Mandy, a member of the American Society for Dermatologic Surgery and clinical professor of dermatology at the University of Miami Miller School of Medicine. "It's perfectly possible that people with high titers [blood levels] of HPV antibodies also have skin cancer for other reasons."

There are vaccines already in use (such as Gardasil) that protect against the HPV strains that cause cervical cancer. But experts said that, given that there are more than 100 types of HPV, vaccines' protective ability is unlikely to translate to another disease.

"Does this mean if patients got the [HPV] vaccine they would be immune to squamous cell carcinoma? Probably not," Mandy said. "I think it's a great curiosity but it's hard to define."

Experts have already unearthed a link between HPV and skin cancer in patients who have had organ transplants (and are thus taking immunosuppressive drugs) and people with a rare genetic skin condition called epidermodysplasia verruciformis, who seem to be unusually susceptible to infection with HPV.

The new study expands the search, looking to see if such a risk extends to the general population. The team compared HPV antibody levels in 663 adults with squamous cell carcinoma, 898 people with basal cell carcinoma (the most common type of skin cancer) and 805 healthy controls.

Testing positive for two or three types of HPV conferred a 44 percent higher risk for squamous cell carcinoma, the team reported, while having four to eight types conferred a 51 percent higher risk, and having more than eight types boosted the odds by 71 percent.

People who had taken immunosuppressant drugs for a long time had triple the risk.

The findings were published online Friday in BMJ.

The study authors pointed out that the participants in this study were all white, making it unclear whether the findings could be generalized to others.

There are, in all, more than 100 different known types of HPV, with different types attracted to different parts of the body, explained Dr. Doris Day, a dermatologist with Lenox Hill Hospital in New York City.

In this study, HPV was linked with squamous cell carcinoma but not its more prevalent sister, basal cell carcinoma.

Experts stress that most cases of skin cancer come from one source: too much sun exposure. As always, protecting yourself from the sun is the best way to reduce the risk for skin cancer.

As for HPV, said Day, "a lot of it is [whether or not you have] natural immunity."

Avoiding contact with HPV is nearly impossible, as it is so omnipresent.

The main thing, Day said, "is to keep healthy, keep your skin healthy and minimize anything that compromises your immune system, so minimize excess sun exposure or [certain] drugs if you can, and take care of your skin inside and out. Eat a healthy diet, get adequate sleep, manage stress."

Also, try to avoid having open wounds or openings on your skin as this is the way for HPV and other pathogens to penetrate the body.

More information

There's more on squamous cell carcinoma at the American Academy of Dermatology.