You may have heard conflicting recommendations regarding when and how often to get regular mammograms to screen for breast cancer. The vast majority of authoritative U.S. health care organizations, including the American Medical Association, the American College of Obstetricians and Gynecologists, the American College of Radiology, the American Cancer Society, the American College of Family Physicians, and the National Cancer Institute, recommend annual mammography after a woman’s 40th birthday. When making decisions about your own personal health care, however, always talk to your regular health care provider, who can offer you informed advice while taking into consideration your individual needs, values, and medical history.
The U.S. Preventive Services Task Force (USPSTF), a volunteer panel of experts in preventive medicine that makes regular recommendations to Congress, made news in November of 2009 by challenging the established recommendations for screening mammography. The research they cited indicated that the reduction in breast cancer mortality achieved through screening mammograms was less and that the rate of false positive results was greater for women aged 40-49 than for women 50-74. Consequently, the group recommended that the decision for annual mammography for women aged 40-49 should be an individual one rather than standard practice. After age 50, the organization recommended screenings every two years rather than every year, as other authorities advise. You can read the entire recommendation statement released by the USPSTF here.
Why the Difference?
According to Susan G. Komen, there are three main factors that make mammography less beneficial for women aged 40-49 than those over 50.
- Younger women have denser breast tissue, making abnormalities more difficult to spot in a mammogram. This causes mammography to be a less effective screening tool for younger women.
- Breast cancers tend to grow more quickly in younger women. As a result, annual or biannual screenings are less likely to catch cancers at an early stage and less effective at reducing breast cancer mortality in women under 50.
- Women aged 40-49 have a lower risk of breast cancer and a higher rate of false positive results from mammography. The American College of Radiology reports that women aged 40-49 who receive annual mammograms have a 30% chance of getting a false positive result within that decade. False positive results cause harm in the form of unnecessary stress and follow-up procedures. The USPSTF concluded that these harms could outweigh the benefit of mammography for women under 50.
Factors to Consider
The USPSTF’s recommendations sparked a great deal of controversy. The primary argument is that if followed, their guidelines would cause many breast cancers to be diagnosed at a later stage, resulting in higher rates of mastectomy and mortality and reducing the percentage of women who become cancer-free after detection. Critics further argue that the USPSTF’s recommendations were based on analysis of film, not digital, mammography, and they did not take into account developments in treatment that lead to steadily improving survival rates.
Although research shows that the benefits of annual screening mammograms are greatest for women 50-74, a 2010 study cited by the American Cancer Society found that women in their 40s who were screened every 18-24 months had a breast cancer mortality rate that was 29% lower than women in the same age group who did not receive mammograms. For many women, this is reason enough to begin regular mammography at age 40.
Although the recommendations of the USPSTF can often influence what preventive measures health insurance companies carry, most insurance providers cover screening mammography for women over 40. In fact, the Affordable Care Act mandates that all Marketplace health plans cover mammography once every 1-2 years for women over 40 without charging a copayment, and Iowa law requires that private insurance plans cover biannual mammography for women 40-49 and annual screenings for women over 50.
For the following reasons, Iowa Radiology holds to the recommendations of American Medical Association, the American College of Obstetricians and Gynecologists, the American College of Radiology, the American Cancer Society, the American College of Family Physicians, and the National Cancer Institute supporting annual mammograms for women beginning at age 40:
- Mammography is a simple, noninvasive screening test that helps save lives. Of all the models, the greatest mortality reduction was with annual mammograms starting at age 40.
- Since 1990, the breast cancer death rate in the US, which had been unchanged for the preceding 50 years, has been decreased by 30%, primarily due to screening mammography.
- 17% of women diagnosed in their 40s will die of breast cancer. 22% of women diagnosed in their 50s will die of breast cancer. 75% of breast cancer is diagnosed in women who have no risk family history. Earlier diagnosis saves lives. Changing the established guidelines could impact thousands of women in the Des Moines area.
- The USPSTF’s recommendation is based on a compilation of old data, which did not include digital mammography and breast MRI.
- Mammography, like any test, has its limitations. However, it is the best tool we have available for detecting breast cancers at earlier stages in a large population. These substantial benefits outweigh the costs.
Always consult with your health care providers when deciding whether and when to obtain medical testing such as mammography. They can help you to understand the risks and benefits of any procedure and give recommendations that are specific to you.