You’ve heard about HPV, right? You probably know there’s a test for it and a vaccine to prevent it—but do you really know what it is and how it’s spread? Or that you’re likely to contract it at some point in your life?
Human papillomavirus (HPV) is an extremely common virus—as common as the common cold. By the time they reach age 50, 80% of American women will have been infected with genital HPV; worldwide, it’s the most common sexually transmitted infection.
“Nearly all sexually active people are going to get exposed to the virus sometime during their lives,” says Kevin Ault, MD, associate professor of obstetrics and gynecology at Emory University School of Medicine in Atlanta and a key researcher in the development of the HPV vaccine. “For most people, HPV causes no complications and goes away on its own.
However, in some cases, if left untreated, certain high-risk types of HPV can lead to cervical cancer,” he says.
Nearly 25 million American women ages 14 and 59 are infected with HPV. The annual cost of screening and treating cervical abnormalities is about $4 billion, according to the
Society of Gynecologic Oncologists.
There are more than 100 types of HPV. Some cause warts, and others produce no visible symptoms whatsoever. Collectively, there are 40 types known as genital HPV. Some of these are low-risk types that can cause genital warts in both men and women; others are high-risk types, putting women at risk for cervical cancer and men at risk for penile cancer. In fact, according to the National Cancer Institute, almost all cervical cancer starts with the cellular changes (or damage) caused by HPV infection.
HPV is prevalent because it’s easily transmitted from person to person. Compared with HIV or the hepatitis B virus, which are spread by contact with body fluids like blood or semen, genital HPV can be spread through any kind of sexual activity that involves skin-to-skin contact, including oral to genital contact.
This is why condoms don’t completely protect against HPV. In fact, short of abstinence from all sexual contact, the HPV vaccine Gardasil is the only prevention available, and even it doesn’t protect against all types of HPV, only the types that cause most cervical cancers and genital warts.. The more sexual partners you’ve had, or the more partners your partners have had, the higher your risk of exposure.
Am I at risk?
If HPV infection seems almost inescapable, or if you’ve been told you have HPV, you should know that, although there’s no cure for it, your immune system does a pretty good job of clearing it from your system—or at least causing the virus to become dormant.
You may already have had an HPV infection and not even know it, unless you saw genital warts or had abnormal cells on a Pap test.
Did you know that 90% of women who are newly infected with the types of HPV that can cause cervical cancer will clear the active infection and any damage to the cervix, all on their own without any treatment, within two years? So—when abnormal cells are first discovered on a Pap test, most healthcare providers will hold off on treating the damage to the cervix, preferring to repeat the Pap test at six and 12 months. More highly suspicious cells will be evaluated more closely and treated. Your age, health and medical history can also affect treatment decisions.
When it’s cancer
So who’s at risk for cervical cancer? To begin with, there’s the 10% of women who don’t clear the virus on their own and who continue to have abnormal cells. Because it’s hard to know who will clear their HPV and who will continue to show its effects, Pap tests are very important. If worrisome changes that could lead to cancer are seen to persist, they can be stopped in their tracks with treatment.
You can also be at increased risk for cervical cancer if your immune system is weak for any reason (from taking certain drugs, including anti-cancer drugs, for example) or if you have HIV or other diseases that compromise your immune system.
If you smoke, you double your risk of developing cervical cancer compared with women who don’t smoke.
Cervical cancer is most commonly diagnosed in women ages 40 to 59; women ages 60 and older account for 25% of new cases and 40% of deaths from cervical cancer. So, although most new cases of HPV infection are diagnosed in women in their teens and 20s, older women who develop cervical cancer do so not because of a new HPV exposure but because a prior HPV infection reactivates and progresses to cervical cancer.
This is an important reason why midlife and older women still need regular Pap tests. Even after menopause, or if you’re no longer sexually active, you can still be at risk. In one study of women belonging to an HMO, fewer than half of the women ages 60 and older who were newly diagnosed with cervical cancer had received a Pap test in the previous three years.
Should I get vaccinated?
There are currently two vaccines, Gardisil and Cervirix, approved to protect against the two types of HPV, types 16 and 18. These two HPV types cause 70% of all cervical cancer. Additionally, Gardisil is also approved to protect against the two types of HPV that are responsible for 90% of all cases of genital warts. Clinical trials demonstrated that the vaccine was close to 100% effective in protecting women from these HPV types.
So far, so good, but here’s the hitch: To get this almost perfect protection you can’t already have been exposed to the HPV types the vaccine prevents. If you have been exposed, the vaccine won’t provide any future protection against these types of the virus.
How can you know what these HPV types are? You can’t, because currently the tests that identify specific HPV types are only used in research settings and aren’t commercially available. That’s why experts think there’s value and possible protection in getting vaccinated.
Other vaccines that may protect against more types of HPV are in development. In the meantime, you still need regular Pap tests to check for cervical changes that could lead to cancer, even if you’ve been vaccinated.