Skip to content

    Breast Cancer Health Center

    Font Size
    A
    A
    A

    Annual Mammograms May Have More False-Positives

    Screening Mammograms Every Two Years Cut the Chances of False Alarm, Study Shows
    By Rita Rubin
    WebMD Health News
    Reviewed by Laura J. Martin, MD

    Oct. 17, 2011 -- Getting screening mammograms every two years instead of annually reduces the chance of a false alarm, a new study shows.

    The frequency of screening mammograms -- and the appropriate age to begin them -- has been debated since the U.S. Preventive Services Task Force in 2009 recommended that women routinely get screening mammograms every other year starting at age 50.

    The task force says the decision to start regular, biennial mammograms before age 50 should be an individual choice based on each patient's situation. Meanwhile, the American Cancer Society continues to recommend that women get mammograms every year beginning at age 40.

    Researchers analyzed data from nearly 170,000 women who had their first screening mammogram at age 40 to 59 years and almost 4,500 women with invasive breast cancer. Information about the women and their mammograms came from the Breast Cancer Surveillance Consortium, funded by the National Cancer Institute.

    False-Positives Are Common

    After 10 years of annual screening, more than half of women will be called back at least once for another mammogram. And 7% to 9% will be told they should have a biopsy because of something suspicious that turns out not to be cancer, the researchers concluded.

    Those false-positives may cause inconvenience and anxiety, and biopsies can cause pain and scarring, the researchers note.

    They found a small but not significant increase in the chance that women diagnosed with breast cancer had a more advanced case if they underwent screening every other year instead of every year.

    The study wasn't really designed to answer the question of which screening regimen is best, study researcher Rebecca Hubbard, PhD, says. Its main message, Hubbard says, is that call-backs (or recalls) for false-positive results are common, so women shouldn't panic when they occur.

    "In most cases, a recall doesn't mean you have cancer," says Hubbard, a biostatistician at the Group Health Research Institute in Seattle. "Hopefully, there will be less anxiety about getting a recall."

    Women can halve their risk of a call-back for a false-positive if the interpreting radiologist has previous mammograms for comparison, the researchers found.

    Ideally, Hubbard says, primary care doctors should talk to women about what to expect from annual and biennial screening before they get their first mammogram.

    Today on WebMD

    Breast Cancer Overview
    From mammograms to living after treatment.
    Dealing with breast cancer
    Get answers to your questions.
     
    woman having mammogram
    The 3 latest tips to know.
    woman undergoing breast cancer test
    Most abnormalities aren’t breast cancer.
     
    Resolved To Quit Smoking
    VIDEO
    Breast Cancer Treatments Improving
    Article
     
    Woman getting mammogram
    Article
    Screening Tests for Women
    Article
     
    serious woman
    Article
    Pink badge on woman chest to support breat cancer
    QUIZ
     
    what is your cancer risk
    Article
    breast cancer survivors
    Article