THURSDAY, Nov. 3 (HealthDay News) -- Home-based tests using
self-collected vaginal samples could serve as an alternative to the
traditional Pap smear tests designed to detect the virus that
causes cervical cancer, new study findings show.
While laboratories have confirmed the accuracy of vaginal tests
for human papillomavirus (HPV), it's been unclear if they would be
as effective as medical office-based Pap smears when women used
them at home.
Poor women around the world are especially unlikely to get Pap
smears, which require a visit to a medical office, according to the
authors of the new study, published online Nov. 2 in
The Lancet.
In the study, researchers randomly assigned poor Mexican women
aged 25 to 65 to get either a traditional Pap smear or take the
vaginal HPV test at home. More than 20,000 women took part in the
study.
The HPV test detected four times as many cases of cancer as the
Pap smear -- a rate of 30 per 10,000 women versus seven per 10,000,
the investigators found. However, the HPV test had a much higher
rate of false positives -- tests that inaccurately detected
cancer.
Despite the higher false-positive rate, the study authors noted,
the home-based tests may be preferable to Pap smears in poor
regions because of the challenges of getting Pap smears in these
areas.
Commenting on the study, Dr. Alan G. Waxman, professor of
obstetrics and gynecology at the University of New Mexico, pointed
out that in the United States, about 50 percent of the 12,000 women
who are diagnosed with cervical cancer each year have never had a
Pap smear.
Many of the women who develop the disease are minorities, he
said, "and a proportion are also immigrant women who may come from
a country where regular screening is not part of the culture."
Waxman said home-based tests are "the way to go" in poor
countries. As for costs, he said the tests wouldn't require office
visits.
And while Waxman acknowledged that the home-based tests produce
many false-positive results, he added that they are also more
sensitive to signs of cancer than Pap smears.
So why not replace Pap smears with HPV tests in the United
States? "In the United States, we don't do just one test. Women
have multiple Pap tests," Waxman said. Cervical cancer "is a
slow-growing process, so you make up for that difference by doing
multiple tests over time."
The
Lancet study was led by Eduardo Lazcano-Ponce of the Centre
of Investigation in Population Health at the National Institute of
Public Health in Morelos, Mexico, and Attila Lorincz of the Centre
for Cancer Prevention at Wolfson Institute of Preventive Medicine,
Barts and the London School of Medicine, Queen Mary University of
London.
More information
For more about
cervical cancer, see the U.S. National Library of Medicine.