April 3, 2003 -- Long-term use of birth control pills appears to
increase the risk of developing cervical
cancer in women who have HPV, but experts say the risk is eliminated with
Cervical cancer risk in women who used birth control pills for a
decade or more was double that of women who had never taken oral contraceptives in a review of 28
studies. But researchers say the findings do not mean that birth control pill
users should consider changing their birth control method,
especially if they have regular Pap tests or a newly approved test detecting
dangerous forms of human papillomavirus.
Human papillomavirus (HPV) is the most common cause of sexually
transmitted diseases and is the main risk factor for cervical cancer. Women
with persistent infection are considered to be at high risk for cervical
"Women who undergo careful screening should not base their
choice of contraceptive on this concern," cervical cancer researcher March
Schiffman, MD, of the National Cancer Institute, tells WebMD. "This is one
cancer that is highly preventable with a little vigilance."
In the newly published analysis, researchers from England's
Oxford University and France's International Agency for Research on Cancer
reviewed studies involving roughly 12,500 cervical cancer patients.
The increase in risk was 10%, 60%, and 100%, respectively, for
all women who took the pill for less than five years, five to nine years, and
10 or more years compared with women who never took oral contraceptives. Almost
double the risk for cervical cancer was seen in women taking birth control
pills who were also had HPV.
But lead investigator Amy Berrington, PhD, says it is not known
whether the risk persists in women who have stopped taking the pill. She and
her research team are now analyzing data on individual patients in an effort to
answer this question.
"We won't be able to tell how big a risk factor oral
contraceptive use is until we know whether the risk persists throughout a
woman's lifetime," she tells WebMD. "Only a few studies have looked at this,
and they suggest the risk decreases once a woman stops taking hormonal
Schiffman says the link between oral contraceptive use and
cervical cancer in the studies reviewed by Berrington and colleagues may be
explained by less than optimal screening. He found no such link in a study of
23,000 women in Portland, Ore., who were screened regularly to detect the
cellular changes that can lead to cervical cancer.
"We saw no elevated risk of cervical cancer in women using oral
contraceptives, even among those known to be infected with HPV," Schiffman
tells WebMD. "Smoking was a big risk factor, though." He added that smoking
appears to double the cervical cancer risk for women with persistent HPV
Just days ago, the FDA approved a new test that specifically
detects the 13 HPV viruses that have been linked to cervical cancer. Primarily
intended for use in women who have had an abnormal Pap smear, Schiffman says
the test will help doctors better identify women who need treatment to prevent
"There are a lot of risks that women can do little about, but
this is one that they can take charge of," he says. "This is a preventable