Contraceptive Pill: Cancer Protection
Strong Protection From Ovarian Cancer Gives the Pill Overall Anticancer Effect
WebMD News Archive
Jan 24, 2008 -- Oral contraceptives cut women's risk of ovarian
cancer for more than 30 years after they stop taking them -- giving the
pill a net anticancer effect.
Each five-year interval of oral contraceptive use cuts a woman's
ovarian cancer risk by up to 29%. The longer a woman uses the
pill, the lower her risk of ovarian cancer, find Valerie Beral, MD, director of
the Cancer Research Epidemiology Unit at Oxford University, England, and
"We can say the longer women take it, the longer the protection, which
lasts 30 years after they stop," Beral tells WebMD. "This does outweigh
any other cancer risk from taking the pill. So the net effect is to reduce
cancer overall. Women on the pill do not need to worry they are putting
themselves at long-term risk of cancer."
It's been known for a long time that oral contraceptives cut a woman's
lifetime risk of ovarian cancer. It's also known that the drug increases a
woman's risk of breast and cervical cancer while she's on the pill. Now Beral and
colleagues have been able to put numbers on these risks.
"In breast and cervical cancer there is increased risk, but these
effects disappear and are not persistent after a woman discontinues oral
contraceptives," Beral says. "Whereas ovarian cancer protection lasts
for decades -- into the ages when this cancer becomes more common for a
Pill's Anticancer Effect 'Definitive'
An astonishing amount of data went into the study. Beral and colleagues
combined data from 45 high-quality studies that included detailed data on
23,257 women with ovarian cancer and on 87,303 women without ovarian
They calculate that over the 50 years oral contraceptives have been on the
market, the drugs have prevented at least
200,000 ovarian cancers and prevented 100,000 deaths. Because use of the pill
is increasing, they predict that the pill will prevent at least 30,000 cases of
ovarian cancer each year for the next several decades.
It's an "unequivocal protective effect," says Eduardo Franco, DrPH,
director of the division of cancer epidemiology at Montreal's McGill
University. Franco's editorial accompanies the Beral paper in the Jan. 26 issue
of The Lancet.
"This study decides once and for all there is a real protective effect
against ovarian cancer that is strong and cuts across all demographic
groups," Franco tells WebMD.
Over-the-Counter Birth Control Pills?
Another editorial, by the editors of The Lancet, argues that the time
has come for "more widespread over-the-counter access to an agent that can
not only prevent cancers but also demonstrably save the lives of tens of
thousands of women."
Beral says the call for over-the-counter availability of oral contraceptives
stems from the high rate of teen pregnancy in the U.K. She does not endorse taking birth
control pills solely to prevent ovarian cancer.
"People should take the pill for other reasons than cancer
prevention," she says. "But there is a bonus when they do use the pill
for these reasons: They will be at reduced risk of cancer."
Franco, too, says it would be unwise for women to take birth control pills just for
Franco opposes over-the-counter availability of oral contraceptives.
"There are harmful effects from oral contraceptives as well as good
ones. It is a balancing act between risks and benefits," he says. "That
is why it is a prescription medication. Women who take oral contraceptives
should be monitored, and there is advice that goes with prescribing them. It is
not a simple matter, so a doctor has to be part of the equation."