Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Breast Cancer Health Center

Font Size

Mammography Cuts Breast Cancer Deaths by 28%: Study

But experts say women still need risks, benefits spelled out


They evaluated more than 15 million person-years of observation, finding breast cancer deaths occurred in 1,175 of the women invited for a mammogram, and nearly 9,000 of those who weren't invited for screening. "Person-years" is a method used by researchers to take into account the number of people in a study and the amount of time each was in it.

The 28 percent reduction in breast cancer deaths they found means that for every 10,000 women invited to get a mammogram, about 27 deaths from breast cancer could be avoided.

The researchers then estimated the effect of the invitation to get a mammogram among women who actually got one, figuring that about three-quarters followed through. They estimated a 37 percent reduction in breast cancer deaths among women who actually got the exam.

Besides evaluating the effect of the mammograms on breast cancer deaths, "a second aim was to find out how many women need to be invited to mammography screening to prevent one breast cancer death," Vatten said. "And we found that 368 women need to be invited to prevent one death."

Furthermore, 280 women would need to be screened to prevent one breast cancer death, they estimated.

The benefits found in the Norwegian study reflect the findings of other studies, said Robert Smith, director of cancer screening for the American Cancer Society.

Smith, who wasn't involved in the study, said he, too, would describe the benefits found as substantial.

"This provides strong support for the value of a screening program for breast cancer," Smith said. However, the study wasn't designed to assess when mammograms should begin or how often they should be repeated.

1 | 2

Today on WebMD

Breast Cancer Overview
From self-exams and biopsies to reconstruction, we’ve got you covered.
Dealing with breast cancer
Get answers to your questions.
woman having mammogram
Experts don’t agree on all fronts, but you can be your own advocate.
woman undergoing breast cancer test
Many women worry. But the truth? Most abnormalities aren’t breast cancer.
Breast Cancer Treatments Improving
Resolved To Quit Smoking
Woman getting mammogram
Screening Tests for Women
ovarian cancer overview slideshow
serious woman
what is your cancer risk
10 Ways to Revitalize Slideshow