NEW YORK, April 23 (UPI) -- Have you ever been informed after your routine visit to your doctor that some of the cells from the Pap smear turned out to look a little abnormal, and that you tested positive for a strain of virus called the human papillomavirus?
If so, you're one of many. And if you are a young woman in your 20s, chances are very likely that you will test positive. This does not, however, automatically translate to a high risk for cancer.
In most otherwise healthy women, the changes seen in the cells revert back to normal in a few months to a year, and the virus is eliminated.
HPV is spread through sexual contact, and besides causing genital warts, it has been clearly linked to cervical cancer. Cervical cancer is projected to kill 3,670 women in 2007 and is one of the leading causes of death in women in developing countries.
There are certain strains of this virus that are linked to genital warts, such as types 6 and 11. Types 16 and 18 are high-risk strains associated with cancer of the cervix. But not all strains picked up after a Pap smear carry a high risk for cancer. There are many other strains that can indicate infection with the virus but carry no risk.
Is the Pap smear on the road to becoming obsolete? Even though there is general agreement among doctors that it doesn't work very well -- a single Pap misses half of women with lesions -- it is still the best screening tool available to detect those women who do show abnormalities before cancer gets to an advanced stage.
The problem is, for every woman in whom late-stage cancer can be spared, many other women have to undergo unnecessary invasive procedures following misleading test results -- not to mention the anxiety suffered from a faulty false-positive diagnosis.
A better approach would be to stop infection with the virus in the first place -- a much more foolproof way of preventing cancer at its initial stage. This is what the new HPV vaccine, Gardasil -- which has garnered so much buzz lately -- sets out to do.
The vaccine gives better protection than screening with Pap smears every few years. It does this by preventing you from getting infected with four strains of the virus (types 6, 11, 16 and 18) if you have not come into contact with them already.
The vaccine teaches the immune system to learn the viruses' distinguishing features. Dead parts of virus particles are injected as part of the vaccine and are then recognized by specific immune cells that create a memory, making them ready to ward off infection if ever faced with the real live virus.
Ideally, this vaccine is most effective when given to teenagers prior to the onset of sexual activity, but any woman stands to benefit if she hasn't yet come in contact with these strains.
Even if infection exists with one of these high-risk types, a vaccination later in life may still offer protection against another type. It is important to realize that even once vaccinated, getting Pap smears to screen for cervical cancer should not be ruled out -- especially since the vaccine only protects against 70 percent of cervical-cancer cases.
What most people and even many internists don't know is the Pap smear test is not meant to screen for actual full-blown cancer, but is a screening method used to detect precursor cells that may develop into cancer 10 years in the future. With the peak incidence of cervical cancer in a woman's 40s, screening women in their early 20s or even before age 30 simply has no rationale. For instance, in most European countries Pap smears aren't routinely done before 30.
At a recent meeting on adolescent and young-adult gynecology in New York, key opinion leaders said screening for HPV should clearly be taken off the table in 20- to 29-year-olds, and new guidelines are coming out in a few months to reflect this new thinking.
If you are a woman over 30, and you have never had a Pap smear, it would be advisable to see your gynecologist and get yourself checked out as a precautionary measure.
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For more information:
4woman.gov/faq/pap.htm
nlm.nih.gov/medlineplus/ency/article/003911.htm
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Karen Dente is a physician-writer based in New York, whose online bylines have also appeared in Reuters Health, HealthDay News and Medscape of WebMD.
The medical information provided in this column is for informational purposes only, and is not a substitute for professional medical advice, diagnosis or treatment. If you have any questions regarding a medical condition, always seek the advice of a medical doctor or other qualified health provider.
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(e-mail: [email protected])
