Common Virus That Causes Deadly Cancer in Women Linked to Penile Cancer in Men
by Brendon Nafziger
, DOTmed News Associate Editor | August 27, 2009
The human papillomavirus (HPV),
known to cause cervical cancer,
is now linked to a rare cancer in men
The human papillomavirus (HPV) - which causes cervical cancer in women - might be linked to cancer of the penis in men, according to a paper in the Journal of Clinical Pathology released on Tuesday.
While reviewing all the major studies on penile cancer published in the last 20 years, doctors from Spain and Paraguay discovered that HPV was present in nearly half of the 1,466 cases of penile cancer recorded by the studies. A particularly aggressive strain of the virus known as HPV-16 accounted for more than 60 percent of all HPV-linked cancer cases.
How HPV causes cancer is not well understood. "We know that HPV interacts with the human cell cycle and produces aberrations in the normal function of cells," Dr. Silvia de Sanjose, one of the authors of the study, and a researcher in cancer epidemiology in Barcelona, tells DOTmed Business News. Dr. Sanjose believes that repeated interactions between the virus and human cells trigger "genomic instability," which then could lead to cancer.
The virus spreads through skin-to-skin contact, and is known to cause cervical cancer in women, which kills over 4,000 Americans each year.
"Anywhere between 50 to 80 percent of women who have ever been sexually active have been exposed to the HPV virus at some point," says Dr. Debbie Saslow, director of breast and gynecologic cancer at the American Cancer Society, although she adds that most HPV infections never lead to cancer.
Rates of HPV infection in men are not well known, Dr. Saslow notes, because it's hard to get reliable samples from the penis. "I've read some of these studies, and it's like, how do you test for it? With women you can do a scraping of a cervix, the same way you do a Pap test." However, she adds that some doctors have now started to rub "really fine sandpaper" against the penis in their quest to collect samples.
In addition to penile and cervical caner, Dr. Saslow says there is evidence that HPV might be linked to anal and oral cancers. Certain strains are also known to cause genital warts.
While penile cancer, if left untreated, can mean the loss of the penis or even death, it is rare in North America. According to the American Cancer Society, it afflicts about one out of 100,000 men in the United States, accounting for only 0.2 percent of all cancers in men and 0.1 percent of all cancer deaths in men. However, in Africa and South America it accounts for almost one in ten male cancers.
Merck & Co., Inc., the makers of the Gardasil, a vaccine approved for women to help prevent infection by HPV strains including the cancer-causing HPV-16, will meet with the Food and Drug Administration next month to discuss using Gardasil in males. Merck says they have already conducted preliminary trials showing the vaccine could prevent 85 percent of relevant HPV infections in men.
But Dr. Saslow cautions that the shots, at over $300 for a series, are among the most expensive on the market, and right now are mainly being considered for use in men to prevent genital warts. Yet, if the links between HPV and a variety of cancers, not just penile, hold true, she admits the vaccine could have some promise: "At some point there will be a difference between recommending a vaccine for one very rare cancer, as opposed to several not all that common cancers."
So what should a worried man do in the meantime? The American Cancer Society recommends men follow some basic preventive steps, such as practicing safe sex, quitting smoking and keeping their private parts clean - poor hygiene, especially dirt under the foreskin of uncircumcised men, might be a big risk factor for penile cancer.
SOURCES: Journal of Clinical Pathology, American Cancer Society, Merck & Co., Inc.