Breast Cancer Screening Recommendations for Women at Average Risk

Mammography is the most effective breast cancer screening tool we have today. Its benefits, however, seem to vary by age. The benefits of mammography in women ages 40-49 ; 50-69; and 70 and older are discussed below.

Figure 3.1 shows the screening recommendations for women at average risk of breast cancer from several major health organizations.

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Breast self-exam is a tool that can be used to increase awareness of breast cancer and to learn about the changes that should be reported to your health care provider. Learn more about breast self-exam.

Mammography for women ages 50-69

There is little debate about the life-saving importance of mammography for women ages 50 to 69. All women ages 50 to 69 should have regular mammograms (Komen recommends every year). This guideline is based on scientific evidence from randomized controlled trials done in the United States, Canada and Europe. A 2006 study that combined the data from seven randomized trials found that women aged 50 and older who had regular mammography had a 23 percent lower risk of dying from breast cancer than their peers who did not [15].

Trends in screening mammography among women ages 50 to 69

Between 2000 and 2006, screening mammography rates declined among U.S. women ages 50 to 59 (from 82.0 to 80.5 percent) [13]. Although the reasons behind this decline are unclear at this time, there is concern that lower screening rates may lead to an increase in breast cancer mortality in the future.

Learn about race and ethnicity and mammography rates.

Mammography for women ages 40-49

Mammography in women ages 40 to 49 saves lives, but the benefit for these younger women is less than in older women. A meta-analysis that combined data from randomized controlled trials found that women 40 to 49 who had regular mammograms had a 15 percent lower risk of dying from breast cancer [16]. However, other studies did not find a benefit for women in this age group [15,17].

Benefits and risks of mammography for women ages 40-49

There are a few reasons why mammography might be less beneficial in younger women. One reason is that the dense breast tissue of younger women can make abnormalities hard to see with current mammography techniques [18]. Also, breast cancers in younger women often grow faster than breast cancers in older women [18]. This means that regular mammograms every one to two years in younger women may be less likely to find cancers early, when they are most treatable.

Compared to older women, women ages 40 to 49 have a lower risk of breast cancer. Because of this, there are fewer benefits of screening mammography and some drawbacks. There is a high rate of false positive results in this age group. A false positive result occurs when the screening test shows that there is cancer when in fact, cancer is not present. Because so few breast cancers occur in young women, younger women who are screened with mammography are more likely than older women to have a false positive result. This means they will be told that they have an abnormality and will undergo follow-up tests (such as additional mammograms, ultrasounds or even biopsies) only to find that they do not have breast cancer. Learn more about follow-up of an abnormal mammogram. 

Why are there differences in screening recommendations for women ages 40 to 49?

Most major organizations, including Susan G. Komen for the Cure®, the American Cancer Society and the National Cancer Institute, feel that the modest survival benefits of mammography in women ages 40 to 49 outweigh the risks of false positive results. They all recommend regular mammograms for all women aged 40 to 49.

The U.S. Preventive Services Task Force no longer recommends routine mammography for women ages 40 to 49 [76]. (It now recommends that mammography screening begin at age 50.) Rather than routine mammography, the Task Force encourages women ages 40 to 49 to make informed decisions about when to start mammography screening [76]. Likewise, the American College of Physicians recommends that women ages 40 to 49 and their health care providers together make decisions about mammography [19]. Decisions should be guided by a woman's breast cancer risk profile as well as her own preferences based on the potential benefits and harms of screening mammography [19].

Learn more about these recommendations.

Trends in screening mammography among women ages 40 to 49

Although screening mammography rates among women ages 40 and older remained fairly stable between 2000 and 2006 (from 76.5% to 76.1%), rates among women 40 to 49 declined slightly (from 71.0% to 69.2%) [13].

Learn about race and ethnicity and mammography rates.

Mammography for women ages 70 and older

There are few studies on the benefits of mammography in women age 70 and older, and none of these have been randomized controlled trials. The U.S. Preventive Task Force no longer recommends routine mammography screening in women ages 75 and older [76]. However, most major health organizations, including Susan G. Komen for the Cure®, recommend that healthy women ages 70 and older get regular mammograms [20-22]. Breast cancer risk increases with age, and there does not appear to be a biological reason why mammography might be less effective for women 70 and older.

One reason women ages 70 and older stop routine screening is poor health. Women who have a serious health problem may not benefit enough from having breast cancer found early to justify screening. However, women who are in good health and would benefit from treatment (if breast cancer were found) should continue to get mammograms. If there is any question about whether you should continue getting screened, talk to your health care provider.

Learn about race and ethnicity and mammography rates.

Weighing the benefits and risks of mammography

Although regular mammography saves lives, it does have some drawbacks. Understanding your chances of having a false positive result can help you know what to expect from regular screening. This may help lessen the anxiety over an abnormal finding on a mammogram.

The table below shows the chances of selected screening outcomes over a 10-year period for women who get annual mammograms. In 10 years, about 2-6 out of 1,000 women will have their lives saved by mammography; a third to a half will have at least one false positive mammogram; and about a fifth will go on to have a biopsy (only a small percentage of these women will have cancer) [23].

For more on weighing the risks and benefits of screening mammography, visit Making Sense of the Mammography Debate.

Updated 11/19/09

Breast Self-Exam

Breast Cancer Screening Recommendations for Women at Higher Risk