works: It can detect cancer. On that point, at least, most
past two decades, however, doctors and researchers have been
debating the details of the popular screening, including the
best age to start and whether the risks of false alarms
outweigh the benefits of catching cancer in its early stages.
or X-rays of the breast, are the best way to spot cancer
early, when itís easier to treat and before itís big
enough to be felt or cause symptoms. For women between the
ages of 50 and 74, thereís general agreement that mammograms
are a valuable screening tool. The American Cancer Society
recommends yearly mammograms, and the U.S. Preventive Services
Task Force recommends mammograms every two years.
women in their 40s, itís not so clear cut. Mammograms may
identify cancers that could turn lethal. But they can also
flag disease that would never have been a problem, triggering
a cascade of potentially unnecessary treatment and anxiety.
positives are no less of a problem for women older than 50.
But there is a comparatively smaller risk of breast cancer in
the 40s versus for those 50 and older, said Dr. Robert Smith,
a cancer epidemiologist and senior director of cancer control
for the American Cancer Society.
organizations, including the American Cancer Society and the
National Cancer Institute, recommend screenings begin at age
40. But in 2009 the U.S. Preventive Services Task Force, a
government-backed panel of preventive-medicine experts, shook
up the cancer world when it recommended the procedure every
two years, starting at age 50. Women between 40 and 49 can
benefit from screening, but they should make an individual
decision in conjunction with their doctor, the task force
research showed the new advice didnít change breast
screening rates: In 2010, women in their 40s continued to show
up for their mammograms. About 70 percent of women older than
40 reported having a recent mammogram. But should they?
two experts explain the rationale behind the differing
screening guidelines. Their responses have been edited.
Robert Smith, a cancer epidemiologist and senior director of
cancer control for the American Cancer Society:
mammograms starting at age 40 are a smart move.
mammograms can be thought of as a form of insurance, said
Smith, an adjunct professor of epidemiology at Emory
takes time and is a bit of a nuisance, but it protects you
against high enough odds ó but still unlikely ó that
something catastrophic will happen," he said.
average womanís risk of breast cancer was 1 in 12 in 1980;
today it is 1 in 8. Breast cancer risk rises with age.
of that risk is going to occur after 65; the odds of
developing it as a 40-something is less than 2 percent, about
1 in 60 women during the decade, Smith said.
it does happen, itís more likely to be treated if detected
by a mammogram before symptoms develop, Smith said.
agrees the high rate of false positives needs to be reduced,
though they canít be completely eliminated. Research shows
"that anxiety (related to a diagnosis) is short-lived and
doesnít affect whether you come back for a mammogram or
not," he said. "Women tell us they understand that
false positives are a fact of life and have a much higher
priority on finding it early than avoiding downsides of having
to go through the experience."
LeFevre, co-vice chair of the U.S. Preventive Services Task
Force and a professor and vice chair in family and community
medicine at the University of Missouri:
are important for some in their 40s; itís up to each woman
emotional, physical and financial toll related to false
positives needs to be considered, LeFevre said. For women who
have a suspicious mammogram, "thereís lingering anxiety
that hangs out there," LeFevre said. "We donít
think itís enough to discourage a mammogram, but women who
donít want the pain or anxiety might wait until age 50 to
start screening," he said. "Another woman, who can
live with false positives and unnecessary biopsies, might want
to maximize her chances. Then she can start screening at age
statistical terms, if 1,000 women, starting at age 40, are
followed until death, 30 will die of breast cancer if no
screening is done, LeFevre said. If they are screened every
other year between age 50 and 75, the number of deaths falls
from 30 to 23, dropping the death rate from 3 percent to 2.3
percent. If screening begins at 40 instead of 50, the number
of deaths can be lowered by one ó to 22 from 23 per 1,000.
But it also results in 5,000 additional mammograms and 500
false positives. That means 1 of 2 women screened in their 40s
get called back due to something on their mammogram that
requires further attention. Thirty-three of those get
biopsies, and one death will be averted, he said.
balance is favored toward mammography but only a small
amount," LeFevre said. "We judged that to be a small
benefit relative to the harms.
of most common risk factors for women in their 40s is family
history. They might decide starting earlier rather than later
because there is greater benefit. Women with no risk factors
might say Ďitís not worth it to me.í But they should be
able to make that decision rather than be told what to