Dec. 15, 2011 -- A test that looks for the virus that causes most cases of cervical cancer may be the best way to screen women over age 30 for the disease, a new study shows.
The study followed 45,000 women ages 29 to 56 in the Netherlands who were split into two groups. The first group got a traditional Pap test to look for cervical cancer. The second group got a Pap test along with a newer test for human papillomavirus (HPV). Studies have shown that HPV causes more than 90% of all cervical cancers.
Five years after they were first screened, all women were rescreened using both Pap and HPV tests.
In the first round of testing, HPV tests detected significantly more precancerous changes to cervical cells than Pap testing alone.
Because doctors caught and treated those changes sooner, women who initially got HPV tests were less likely to have full-blown cervical cancer when they were tested again five years later compared to women who got Pap tests alone.
The study found that women who got an initial HPV test had about a 27% reduced risk of having advanced precancerous lesions five years later compared to women who had a Pap test alone.
They were also less likely to have cervical cancer. There were 14 cases of cancer found in the group that only got a Pap test at the start of the study compared to four cases in the women who also got an HPV test.
What's more, the numbers of high-grade precancerous lesions found over time in the study didn't significantly differ between the two groups. Experts say that suggests that adding HPV testing didn't pick up infections that would have likely cleared on their own. That should eliminate any worry that HPV testing would lead to overtreatment, they contend.
The study, which is published in The Lancet, suggests that starting HPV testing at age 30 may benefit women along with routine Pap testing for cervical cancer.
Some experts project that HPV testing could one day replace Pap tests as the primary way doctors look for cervical cancer.
“I think for screening purposes, you can test by HPV alone,” says researcher Chris J.L.M. Meijer, MD, PhD, a pathologist at VU University Medical Center in Amsterdam, Netherlands.
The U.S. Preventive Services Task Force recommends that women get Pap tests every three years between ages 21 and 65. The task force says more evidence is needed before HPV screening alone or in combination with Pap testing is widely adopted for women 30 and older.
But experts who are updating those recommendations say they may reconsider both the testing interval and the value of HPV screening based on the results of this study.
“I don’t take care of that many women who are anxious to have their Pap smear,” says Michael LeFevre, MD, MSPH, who is co-vice-chair of the U.S. Preventive Services Task Force panel that is scheduled to issue final cervical cancer screening guidelines in 2012.
“If you can accomplish the same outcome with a much lower burden of testing to the individual woman, then you have to view that as positive,” says LeFevre, who is also a professor of family medicine at the University of Missouri in Columbia.