In the past year, you've seen the headlines -- from "The Cancer Vaccine of the Future?" to "How to Kill a Cancer" -- that have been harbingers of big breakthroughs in cervical cancer. Indeed, there's been good news for women in this area of medicine: The potential for a vaccine, as well as new screening guidelines, means that doctors are closing in on better ways to manage, treat and even prevent this gynecologic disease, which strikes 13,000 American women and takes 4,100 lives annually.
One of the most important advances in recent years has been the discovery that 99.8 percent of cases of cervical cancer are caused by certain strains of the sexually transmitted infection (STI) known as the human papillomavirus, or HPV. This virus is so common that 75 percent of sexually active Americans get it at some time in their lives and 5.5 million new cases occur yearly. As a result of being infected, about 1 percent of people develop genital warts and 10 percent of women develop abnormal or precancerous lesions on their cervix, which are often found by a Pap test.
What do you need to know to protect yourself from cervical cancer? Here are some answers to the most frequently asked questions about the relationship between cervical cancer and HPV infection.
1. When will the cervical-cancer vaccine be available?
In five to 10 years, say experts. The good news is that a recent study published in The New England Journal of Medicine showed that a vaccine could offer 100 percent protection against HPV 16, the strain most commonly linked to cervical cancer. Merck Research Laboratories, which developed the vaccine used in the study, is currently working on another formulation that will protect against four types of HPV: 16 and 18, which contribute to 70 percent of cervical cancers, says study author Laura A. Koutsky, Ph.D., a University of Washington epidemiologist, and HPV 6 and 11, which cause 90 percent of genital warts.
But even when a vaccine becomes available, it's unlikely that you, an adult woman, will be first in line to receive it. "The best candidates will be 10- to 13-year-old girls and boys," Koutsky says. "We have to vaccinate people before they become sexually active and are exposed to the virus."
Several therapeutic vaccines -- which would be given after infection to speed up the immune response to the virus -- are also being studied, says Thomas C. Wright Jr., M.D., associate professor of pathology at Columbia University in New York City, but haven't been shown to be effective (yet).
2. Are some types of HPV more dangerous than others?
Yes. Of the more than 100 different strains of HPV that have been identified, several (such as HPV 6 and 11) are known to cause genital warts, which are benign and aren't associated with cervical cancer. Others, such as HPV 16 and 18, are more dangerous. The trouble is that although the currently available HPV test (see answer No. 6 for more information) can detect 13 types of HPV, it can't tell you which strain you have.
Thomas Cox, M.D., director of the Women's Clinic at the University of California, Santa Barbara, reports that new tests are being developed that will be capable of picking out individual types, but won't be available for another year or two. "These tests will be able to tell if you have a persistent high-risk HPV type, which increases your risk for cervical cancer, or an HPV type that may be transient [i.e., will go away on its own] or low-risk," he adds.
3. Is HPV curable?
That's debatable. Doctors don't have any way to fight the virus itself. They can, however, treat the cell changes and genital warts it can cause with medicines such as Aldara (imiquimod) and Condylox (podofilox) or by freezing, burning or cutting the warts off. Or they may advise just watching the conditions for further changes. In fact, 90 percent of infections -- whether they produce symptoms or not -- will spontaneously disappear within one to two years. But doctors don't know if this means you're actually cured of the virus or if your immune system has just overpowered it so it's lying dormant in your body the way the herpes virus does.
4. Should I get the newer "liquid Pap" test instead of a Pap smear?
There are some good reasons to get ThinPrep, as the liquid cytology test is called, Cox says. Both tests look for cell changes on the cervix that could lead to cancer, but ThinPrep produces better samples for analysis and is slightly more accurate than a Pap smear. In addition, the cells scraped from the cervix for ThinPrep can be analyzed for HPV and other STIs, so if an abnormality is found, you don't have to return to your doctor to give another sample. For these reasons, the liquid test is now the most commonly performed cervical-cancer screening test in the United States. (If you're not sure which test you're receiving, ask your doctor or nurse.)
5. Do I still need to get a Pap test every year?
New guidelines from the American Cancer Society say that if you opt for ThinPrep rather than a Pap smear, you only need to be tested every two years. If you're over 30 (after which your risk of HPV infection declines) and you've had three consecutive normal results, you can space out testing to every two or three years.
One caveat is that even if you skip annual Paps, gynecologists still recommend that you get a pelvic exam each year to make sure your ovaries are normal and, if you're not monogamous, to test for other STIs, such as chlamydia.
6. Now there's an HPV test. Do I need to get it?
Currently, it's absolutely appropriate if you have an abnormal Pap test result called ASCUS, which stands for Atypical Squamous Cells of Undetermined Significance (see answer No. 7 for more on that), because if the results are positive, it tells your doctor you need further testing or treatment. And if they're negative, you get assurance that you aren't at risk for cervical cancer.
But the HPV test is not appropriate as an annual screening test (either with a Pap test or alone), because it can pick up transient infections, leading to unnecessary additional testing and anxiety. However, the U.S. Food and Drug Administration (FDA) has just approved use of the test in combination with a Pap smear for women over the age of 30, and many doctors recommend you have the dual test every three years. "That interval would provide enough time to catch cervical precancers, which are slow to progress," Wright says, while not picking up temporary cases. (Of course, that's only if the results are normal. If they're abnormal, you'll need repeat or further testing.)
7. If I get an abnormal Pap test result, what other tests do I need?
If your Pap test is returned with an ASCUS result, recent guidelines show you have three equally accurate options for further diagnosis: You can have two repeat Pap tests spaced four to six months apart, an HPV test, or a colposcopy (an office procedure during which the doctor uses a lighted scope to examine potential precancers). Other more potentially serious abnormal results -- with acronyms such as AGUS, LSIL and HSIL -- should be followed up immediately with colposcopy, says the National Cancer Institute's Diane Solomon, M.D., who helped draft the latest guidelines on the subject.
8. If I have HPV, should my boyfriend or spouse be tested too?
No, there's little reason for that, says Cox, since you probably share the infection already and there's nothing that can be done to treat him if he doesn't have warts or HPV changes (known as lesions) on his genitals. What's more, there's currently no FDA-approved screening test for males.
As for transmission of HPV to new partners, studies suggest condom use may reduce the risk of HPV-related diseases, including genital warts and cervical cancer. But condoms seem to be only somewhat protective at best, because they don't cover all of the genital skin. "Abstinence is the only real way to prevent getting infected with HPV," Wright explains. When an HPV vaccine becomes available, however, men -- or more specifically pre-adolescent boys -- will be targeted for immunization along with girls of the same age.
For more information on HPV, contact:
- The American Social Health Association (800-783-9877, www.ashastd.org)
- The Centers for Disease Control and Prevention STD Hotline (800-227-8922, www.cdc.gov/std)