Vaccine May Prevent HPV-Related Anal Cancer
A new study shows that vaccination against the human papillomavirus may prevent the development of anal cancer.
The study, which was published in The New England Journal of Medicine, involved 602 men, ages 16–26 years, who have sex with men. The men got a placebo or the three-shot injection of the HPV vaccine known as Gardasil. Participants were then followed for three years after their last shot.
Gardasil is designed to protect against several “types” of HPV, including HPV types 16 and 18, which are commonly associated with anal cancer. In the study, Gardasil proved effective against these viral types by preventing people from being infected with them. Those vaccinated with Gardasil also had a 75 percent reduction in the number of precancerous lesions. For those in the study who were already exposed to one or more of the HPV cancer causing viral types the vaccine reduced the incidence of the precancerous lesions by 54 percent.
“Almost 6,000 people every year in this country are diagnosed with anal cancer, and more than 700 people die from the disease,” said Joel Palefsky, M.D., who directed the clinic that led study. “What this trial showed is that those cancers and deaths could be prevented.”
“A vaccine that can help prevent HPV types 16 and 18 related anal cancers, which account for approximately 80 percent of anal cancer cases, is an important tool to help prevent this disease,” added Richard M. Haupt, M.D., of Merck Research Laboratories. “These study data add to the large body of clinical trial data that support use of Gardasil in both females and males to help prevent certain HPV-related cancers and disease.”
Human papilloma virus is one of the most commonly sexually transmitted viruses. It is generally contracted when teenagers become sexually active. The virus can cause anal cancer, as well as other cancers, including cervical cancer in women. Two vaccines, including Gardasil, are already being given to young women to prevent these cancers.
An unintended consequence of more people having oral sex has been an increase in the number of throat and head cancers. A 2007 NEJM study showed that having had oral sex with more than six different partners increased the risk of developing throat cancer by 3.4 percent. Performing oral sex with 26 or more partners further tripled that risk. That’s because having more sexual partners increases the chance of being exposed to HPV 16 and 18—the specific viral types associated with HPV cancers. Fortunately the new vaccines protect against these viral types.
Another study, published in the Journal of Clinical Oncology, shows that oral sex may increase the risk of developing throat cancer more than smoking. The study also shows that if trends continue, by 2020, HPV-related throat cancer may be more common than HPV-related cervical cancer. Happily, these cancer trends should change for the better if the HPV vaccines become widely adminstered. —Healthy Living News