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Brendon Nafziger, DOTmed News Associate Editor | July 09, 2010
Although no relationship was found between HPV and basal cell carcinoma, infection appeared to up the risk for squamous cell carcinoma.
And the more strains of beta HPV they were infected with, the less merry: Patients with skin cancer were about 1.4 times more likely to test positive for antibodies to two or three strains of HPV, but they were 1.7 times more likely to test positive to more than eight types of the virus, the authors said.
Other trends emerged, too. Long-term users of glucocorticoids, which weaken the immune system, who had HPV antibodies were more than three times more likely to have skin cancer than nonusers, the authors said, although this finding had little statistical power because of the small numbers of patients in the study who were on the medications.
Patients with cancer and HPV were also nearly twice as likely to have sensitive skin and have endured a severe, blistering sunburn, although a weaker relationship was found with the number of lifetime sunburns.
The sunburn connection is expected, as squamous cell carcinoma has a known relationship with ultraviolet light exposure. The researchers also suggest a protein in the virus might prevent the body from killing off cells damaged by UV rays.
Still, because of the study design, the researchers couldn't tell what the patients got first: HPV or the cancer. To control for that, the researchers tested blood samples from a separate group of patients who were part of a cancer trial before and after diagnosis of skin cancer. They didn't find that HPV infection rates jumped up after cancer diagnosis, as would be found if the cancer somehow made the infections more likely, and not vice versa.
"On the whole, it thus seems unlikely that our observations were due simply to higher antibody titres resulting from disease onset," the authors said.
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