Not only is that a waste of money, researchers say, it also means that women who test positive may be getting extra treatment that won't necessarily help them, but comes with a risk of complications and side effects.
Doctors use the HPV test in addition to Pap smears to screen women for signs of cervical cancer. But researchers say that in young women, a positive test gives doctors very little information, since HPV is common in women in their 20's and probably won't lead to cancer.
Still, "there's a much greater emphasis on avoiding a single cancer versus literally thousands of women being over-screened and over-treated," said Philip Castle, an HPV expert at the American Society for Clinical Pathology in Chicago, Illinois, who wrote a commentary on the new study in Obstetrics & Gynecology.
There are about 40 different kinds of sexually transmitted HPV, according to the Centers for Disease Control and Prevention -- and at least half of sexually active people will get HPV at some point. The virus can't be cured, but often goes away on its own without treatment.
Some types of HPV have been linked to cervical cancer in women, whereas other types cause genital warts.
HPV tests, which start at about $30 but can cost much more, look for HPV in cells taken from a swab of the cervix.
For the current study, Dr. Mona Saraiya of the CDC and her colleagues analyzed data from a national survey of doctors and clinics that used Pap tests. In total, 376 individual doctors and another 216 outpatient clinics responded to survey questions about whether and how they performed HPV testing.
Three-quarters of doctors and clinics had ordered an HPV test at least once. Of those, more than half said they used HPV testing regularly alongside Pap smears in women less than 30 years old -- a use not recommended by the American Cancer Society and other organizations.
The majority also reported using HPV tests as a follow-up to a questionable Pap smear when the tests may not have helped doctors with much more information.
Finally, almost one-third of doctors and clinics who did HPV testing used two different kinds of HPV tests, the so called "high-risk" and "low-risk" HPV tests, even though the low-risk test tells doctors nothing about cervical cancer, researchers said, because it screens for the types of HPV that don't cause cancer.
Doctors may be confused about which tests to order if they aren't keeping up with current evidence, Castle told Reuters Health. "The low-risk test really has no business being on the market at all," he added.
And with regard to testing in women less than 30, "cancer is really rare in that group," Castle said. Routine HPV testing at that age, he said, could lead to biopsies and cancer treatments that aren't really necessary -- along with a lot of stress and worry.
"There's a lot of HPV and very little disease" in women in their 20s, he said. "And the disease that's found there is generally about 10 to 15 years away from becoming invasive. There's no good justification for using" the HPV test routinely.
Castle said the findings are particularly troubling given how clear the guidelines are regarding use of the HPV test, and how united experts are about which instances call for the test and which don't.
"It's quite clear that HPV testing can be used in a very beneficial way," he said, including for routine cancer screening in older women and to clarify some types of "equivocal" Pap smears. "But misuses of it just have no place in medical practice," he said.
Saraiya said that women can do their homework -- including on the CDC website, http://www.cdc.gov/cancer -- and be aware of when they should or shouldn't get an HPV test and discuss that with their doctors.
"Doctors are all over the map right now in terms of the recommendations," she told Reuters Health.
Some questions women might want to consider and ask their physicians, Saraiya said, include: "What is the test they're going to be giving to me for screening? Is it a Pap test, an HPV test, or both?"
And for young women: "I've heard I do not need an HPV test for screening under age 30 -- why are you giving it to me?"
"The whole field of HPV and cervical cancer is a fast-changing field. For a clinician to be keeping up with the literature, especially outside of the OB/GYN field, is quite difficult," she said.
"A well informed patient does go a long way."
SOURCE: http://bit.ly/jPDFUi Obstetrics & Gynecology, online June 20, 2011.
Copyright 2011 Thomson Reuters