Cervarix, one of the human papillomavirus (HPV) vaccines used in innoculations against cervical cancer in girls, also appears to protect against the HPV infection responsible for most anal cancers. In a study just published in The Lancet Oncology, researchers from the National Cancer Institute and the National Institutes of Health assessed the efficacy of the bivalent HPV vaccine s reduction of the two most prevalent type of HPV strains, HPV 16 and HPV 18.
In their randomized, controlled study of over 4,200 healthy women (aged 18 to 25) in Costa Rica, the researchers found that the vaccine had 62 percent efficacy against HPV anal infection in the general population, regardless of previous exposure to HPV; in women who did not have previous exposure to HPV infection, the vaccine prevented anal infection in nearly 84 percent similar to its 89 percent efficacy against cervical HPV infection.
The results of the study are all the more reason for girls and young women to be vaccinated for HPV: Published evidence exists for vaccine efficacy against HPV 16 and HPV 18 infections at the cervix, vagina, vulva, and now anus, the authors write. This is good news, since cervical cancer is one of the most prevalent cancers in the developed world and, while anal cancer is much rarer, rates have doubled in recent decades and women are at twice the risk compared to men.
"While the evidence proving a reduction in anal cancer among vaccinated women is not yet in" says ACSH's Dr. Gilbert Ross, "we now have an even stronger reason to expect that ongoing studies will confirm this important benefit."