HPV Viruses and Skin Cancer
A few years ago, Dr. Berman posted information on how the human papillomavirus infection (HPV) can sometimes cause skin cancer, specifically squamous cell carcinoma (SCC). A study, completed by Margaret R. Karagas, Ph.D. of Dartmouth Medical School, suggests a relationship to SCC and the number of HPV viruses a person contracts.
Cutaneous HPV viruses are those that affect the skin, and include common warts. Common warts normally appear on the hands and feet, although can also be found on the elbows and knees. These are more common in children, possibly because people develop immunity to these viruses. Throughout your life, you may be exposed to many different strains of HPV viruses. These were previously thought to be unrelated to skin cancer but may play a role.
Dr. Karagas' study showed that those with SCC were infected with more types of cutaneous HPV than those without cancer. According to the study, it was not necessarily the type of HPV infection, but the number of different infections which increased the risk of cancer. The study also showed that basal cell carcinoma was not impacted by the HPV virus.
This may have something to do with your immune system's ability to fight the HPV viruses. Karagas found that people on long-term steroid medications were more at risk for developing HPV associated skin cancer, possibly people these medications can suppress the immune system. When the immune system is not working properly, HPV viruses can turn into cancerous cells. This, however, was reported in the study but shown not to be conclusive.
In the study, men had a slightly higher rate of testing positive for HPV viruses (48% for men and 42% for women) but there was no difference in age, level of education, smoking status, skin sensitivity or painful sunburns.
Although the study did not conclusively link the HPV virus with SCC, Karagas believes that it points to HPV, previously thought to only cause cervical cancer, playing a part in SCC. She also is hopeful that learning more about HPV virus, including how to prevent and treat it, can help to reduce the incidence of this type of cancer. Dr. Karagas plans to continue her studies, checking additional strains of the HPV virus and studying whether these additional types are also associated with SCC and nonmelanoma type skin cancers.
"Genus human papillomaviruses and incidence of basal cell and squamous cell carcinomas of skin: population based case-control study," 2010, Margaret R. Karagas et al, BMJ Journal, 341: c2986
Human Papillomavirus Infection and Incidence of Squamous Cell and Basal Cell Carcinomas of the Skin," 2006, Margaret R. Karagas et al, Journal of the National Cancer Institute, Volume 98, Issue 6, pp. 389-395