A Cancer-Causing Virus—Should
You Be Tested?
For: Wellness Fact, February 2003
An abnormal result on a Pap test is never good news, but with proper follow-up it can save your life. Since Dr. G. N. Papanicolau’s test for cervical cancer went into wide use in the 1940s, the death rate from cervical cancer has been dramatically reduced—at least in countries where women undergo testing. And there has been other decisive progress on the cervical cancer front. Cervical cancer is one disease whose "necessary cause" (meaning that the disease will not develop unless this factor is present) can be pinpointed. It is a virus known as human papilloma virus, or HPV. Now there is a test—known as the Digene Capture II HPV test, recently approved by the FDA—to identify this virus.
HPV is a huge family of viruses, 77 types of which have been identified. They are very common and have an affinity for the skin and mucous membranes. Some cause warts on the fingers or the genitals. Out of the whole family, 13 are known to cause cancer. Without the presence of one of these 13, cervical cancer will almost never develop, no matter what other risk factors a woman may have. Though not a lot of fanfare has greeted this advance in scientific knowledge, cervical cancer is the only cancer so far to be so well understood. (It’s not the first time a virus has been implicated in cancer, of course. The hepatitis C virus increases the risk of liver cancer.)
But now, in addition to the Pap test, should all women take the test for HPV? Some experts have suggested making the test routine, but it’s too early to recommend this. No one yet knows how accurate the test will ultimately prove to be when used for thousands of women. Eventually, a home test kit could be im-portant for women with limited access to health care. But for now a woman can remain in good health without ever being tested for HPV, so long as she gets regular Pap tests.
What you need to know and do
• All women should begin having Pap tests at age 18, or earlier if sexually active before that age. (Cervical cancer occurs only rarely in women who never have sex, but it’s still important to guard against it.) The test is quick, painless, inexpensive, and usually covered by insurance, at least in part. Any health professional trained in the technique can take a cervical smear and send it to a lab for analysis.
• After the first Pap test, you should have three more tests at yearly intervals. If no abnormalities are found, you can drop back to a once-every-three-year schedule, unless you are a smoker or have multiple sex partners. Both these factors increase your risk. Cervical cancer is slow to develop; testing at regular intervals can find precancerous cells in time to prevent them from going further. Regular testing can also compensate for occasional errors in getting a good cervical sample or for mistakes at the lab. However, new technologies and new regulations have made Pap testing more accurate than ever, and women who get tested on schedule don’t need to worry.
• You should continue to be tested throughout your life, even if you have had a hysterectomy (so long as you have retained your cervix). Some doctors think a woman can discontinue testing after age 65. You should discuss this matter with your physician or nurse-practitioner. We think you should continue to be tested at three-year intervals after age 65, particularly if you are sexually active. Older women who have never been tested (now a declining percentage of the population) should get their first test.
What if the results are abnormal?
What the Pap test does so well is to detect precancerous cells at various stages, but it cannot detect HPV. But less than 10% of atypical cells will ever progress to cancer. Benign conditions such as hormonal changes, infections, or the effects of birth control pills or pregnancy can produce atypical cells. The cells most often return to normal by themselves. Usually, all you’ll need to do is have another Pap test in six months, or whenever your physician advises. If suspicious-looking cells are still present, or if you have had abnormal results at some earlier time, then an HPV test may be in order. It, too, is a simple and painless smear, and the cost, though somewhat higher than a Pap, is usually covered by insurance.
If cancer-causing viruses are present, this will serve as an alert that close follow-up is necessary. But don’t be unduly alarmed: HPV usually disappears by itself. And remember, the great majority of women infected with HPV don’t develop cervical cancer.
And keep in mind: If you have multiple sex partners, you are at increased risk for HPV infection. Condoms don’t offer full protection against HPV, since the virus is transmitted from skin to skin. But condoms are the only effective way to protect against other sexually transmitted diseases. To guard against cervical cancer, all women should get regular Pap tests, as outlined above.
UC Berkeley Wellness Letter, April 2000