|The HPV Test - Is It For You?|
By Laura Dolson
The message is finally getting out: HPV (the human papillomavirus) causes cancer. As I have discussed in other articles, there are co-factors (most HPV infections don't become cancer), but it is now readily apparent that HPV plays an important role in getting a lot of epithelial cancers started, particularly those of the uterine cervix, as well as the vagina, vulva, anus, and penis.
The next question is: once a person has become infected with HPV, what do we do with this information? When is it important to know whether a person is infected with HPV, or what types they are infected with? These are especially important questions knowing that 1) at this point in history, most people are infected with HPV at some time in their lives and 2) the vast majority of those infections will be asymptomatic.
What is the HPV test? The Digene Hybrid Capture® HPV test checks for so-called "high risk", or oncogenic types of HPV. So far, about 120 types of HPV have been isolated. About 30 can infect the genital tract, and nine have been found to be related to cancer, although 85% of cervical cancers are related to only four types of HPV (16, 18, 31, and 45).
How is the test performed? At the time a Pap test is done, some of the material can be saved to be tested for HPV if theThinPrep® type of Pap test is used. Otherwise, a separate collection has to be done for the HPV test, which is a similar procedure to that of a Pap test. The name of the test is the Digene HPV Test.
Does insurance cover the HPV test? Almost all insurance in the U.S. now covers an HPV test ordered by a doctor. Also, many insurance plans in Canada will cover the test. (See link in side bar.)
Should everyone be screened? No, definitely not. When a virus is endemic in the population, and usually causes no problems, it is probably not helpful to test everyone. With regards to sexual activity, is is best to assume that everyone is infected. This is especially true because there is not yet any good HPV screening test for males.
Should women with cancer be tested? One might think that it would be a good idea to find out whether HPV is present in cancers that are already established. Sometimes women with cervical, vaginal, or vulvar cancers wonder whether HPV contributed to their getting cancer. But in fact, there's no real medical reason to test for HPV at that point, as it would not change the treatment choices or prognosis.
So, somewhere along the path from asymptomatic infection to cancer, it is helpful to test for HPV. When and why would this be? The answer lies with our friend, the Pap test. Every woman who is sexually active, and every woman over the age of 18 in any case, should get an annual Pap test. (There may be a few exceptions to this rule.) To understand the possible abnormal results from a Pap test, see Dysplasia 101. Now we will look at which of these may be cues to do HPV testing.
ASCUS Pap Results - The main indication for HPV testing is the ASCUS Pap result. ASCUS stands for "Atypical Squamous Cells of Undetermined Significance", and the National Cancer Institute issued a statement earlier this year recommending that all ASCUS Pap results be followed up with an HPV test. The reason is that ASCUS results often leave physicians in a quandary. This result can be caused in a lot of different ways, many of which are normal or return to normal on their own. So, one option is to do a retest again in a few months to see whether the Pap is still abnormal. On the other hand, some ASCUS Pap results are due to dysplasia which should ideally be evaluated more closely. When dysplasia is suspected, the next step is culposcopy and biopsy - but it is expensive and nerve-racking to put women through these procedures unnecessarily. Since only around half of ASCUS Paps test positive for HPV, this is a good way to narrow down who needs closer followup.
AGUS/AGCUS Pap Results - Due to the lower numbers of Paps in this category, it has not been studied as much. There is some evidence that there may be some value in HPV testing for this category, but since virtually all women with this result are evaluated further, there may be little value to the extra testing step. At this point, researchers are not making a specific recommendation regarding HPV testing for AGUS Paps.
LSIL or CIN1 Pap Results - At first glance, you might think that it would be a good idea to do HPV tests on Paps showing mild cellular changes, since most of the time mild dysplasia reverts to normal on its own after a few months. However, the vast majority of Paps in this category are already positive for HPV, so doing the test adds little information. There may be an exception for women over 35, as this group tends to have a lower percentage of active HPV, and the abnormal Pap is sometimes caused by physiological factors due to approaching menopause. Research is currently being done as to the value of the HPV test for LSIL Paps in women over 35.
HSIL Pap Results - HPV testing does not have value for this group, since almost all will test positive for HPV, and all will undergo further evaluation in any case.
Does a Positive HPV Test mean I am likely to get cancer? No, not at all. It means that your doctor will want to follow what is going on more closely, and perhaps treat the dysplasia. Most of the time, HPV is cleared from the body by the immune system. In any case, it is extremely rare for a woman under a doctor's care for HPV or dysplasia to get cancer. That is the wonderful thing about Pap tests and treatment for dysplasia.
Read about the new study about HPV Risks and Prevention, plus "How to Prevent HPV and Cancer"
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Copyright © 2001 by Laura Dolson. All rights reserved.
The material on this page and Web site is for informational and educational purposes only, and should not substitute for medical advice. Anyone having questions about the application of information appearing here to a specific person or situation should obtain advice from a qualified physician.