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El virus se ligó al cáncer cervical culpado en aumento en cánceres de la boca y de la garganta

por Brendon Nafziger, DOTmed News Associate Editor | April 01, 2010
The British Medical
Journal
An editorial in a recent issue of the British Medical Journal suggests the human papillomavirus (HPV) could be linked to a nearly one-quarter increase in mouth and throat cancers in the U.S., and that it could justify the cost of vaccinating boys against the disease before they reach sexual maturity.

HPV is a virus transmitted through skin contact and causes the majority of cases of cervical and anal cancer. It is also linked to genital warts and gruesome but rare cancers, such as ones of the penis, vulva and vagina.

Now, doctors fear it might be causing an upswing in potentially deadly malignancies of the head and neck, known as oropharyngeal squamous cell carcinoma.

The occurrence of these cancers, scaly growths that affect the back-third of the tongue and the throat, has climbed slightly in the United States. According to recent studies, rates have gone up about 22 percent over the last ten years, from around 1.53 per 100,000 people in 1999 to 1.87 per 100,000 people in 2006.

While the uptick in absolute numbers might be modest, it comes after a nearly 25-year period where rates of the cancer remained flat, from 1975 to 1999.

What's more, around the same time doctors have found a rise in HPV infection in biopsied samples of the cancers. A Swedish study of oropharangyeal cancer biopsies in Stockholm found the rate of HPV presence grew from 23 percent of samples in 1970 to more than 93 percent in 2006 and 2007.

And a recent U.S. study found that now 60-80 percent of cancer biopsy samples showed HPV infection, compared with only 40 percent from a decade ago.

"The increase in incidence of oropharyngeal squamous cell carcinoma seems to be accounted for by a rise in human papillomavirus (HPV) related oropharyngeal carcinoma," wrote Hisham Mehanna, head author of the British Medical Journal paper and director of a head and neck study center at the Universal Hospital in Coventry, England, and his fellow authors.

Changing vaccine economics

In the U.S., health experts recommend vaccinating girls before they become sexually active, at around ages 11 or 12, to prevent HPV infection and thereby dramatically cut their risk for cervical cancer.

But previously, most health authorities have been wary of recommending the vaccine for boys.

Although the FDA approved marketing Gardasil, by Merck, in October to prevent genital warts in males, the Centers for Disease Control doesn't currently include HPV vaccines in its immunization schedule for boys and men, citing lack of evidence.

"When more information is available, this vaccine may be...recommended for boys/men as well," notes the CDC on its website.