Breast Cancer Screening FAQ

Background

In November 2009, a federal advisory group, the U.S. Preventive Services Task Force, issued recommendations calling for a reduction in mammography screening for breast cancer. The new breast screening guidelines differed from the existing recommendations of such organizations as the American Cancer Society and American Medical Association, which created public controversy and confusion. 

In its report, published in the Annals of Internal Medicine, the panel recommended that women of average risk wait until age 50 for routine mammography screening, and then be screened every other year until age 74. It also advised against teaching breast self-exam. This compares with current standards that recommend annual breast screening mammography beginning at age 40, with no specified age limit.

Days after the panel's recommendations were released, the Secretary of the Department of Health and Human Services issued a statement explaining that the government's guidelines were not changing. Experts at the Moores Cancer Center believe that screening mammography continues to be the best available tool for early detection of breast cancer, and in fact, saves lives. The Cancer Center will continue to adhere to those currently established guidelines.

FAQ with Dr. Anne Wallace

Because of the ongoing questions surrounding breast mammography screening, breast surgeon Anne Wallace, MD, director of the Moores Cancer Center Breast Cancer Program, answered some commonly asked questions in an attempt to put the new guidelines in perspective.

Does mammography detect many breast cancers for women between ages 40-49?

Mammography will detect 15 percent of breast cancers for women in this age group that are not found by any other means. Mammography is not perfect and has a lower sensitivity in the young, dense breast than in those of older women. However, it does find some cancers that may otherwise elude detection for years.

Why did the task force make these recommendations?

As a medical community, physicians never want to order a test without sound evidence that the test's benefits outweigh the risks. In this study, the statistics showed that one life would be saved for every 1,900 women ages 40-49 screened for 10 years. However, of those 1,900 women, some will require biopsies that turn out to be benign, some will suffer anxiety and others may be inconvenienced by the whole process. It was the feeling of the task force that those survival benefits did not outweigh the potential risks.

What was not considered by the task force?

The studies included in this review were based on older film screen mammography – not digital mammography – which is now the standard in most centers. Digital mammography has been found to be more sensitive in younger women who have denser breasts. As a result, current screening may even be detecting more cancers than in “historical” reports. In addition, it has only been in the past few years that stage 0 breast cancer, or ductal carcinoma in situ (DCIS), with estrogen receptors, has been evaluated. DCIS seen in young women is often the estrogen receptor-negative type, which is an aggressive early cancer that could turn into an aggressive, invasive cancer later in life. Finding such cancers early may be tremendously beneficial to a woman in her 40s. The older data was unable to reflect this. 

Finally, it's now known that mammograms may detect “atypia,” or a cell abnormality, which can be a sign of future malignancy in this age group. The treatment for atypia is chemoprevention with tamoxifen. As a result, mammography may allow some groups of women to prevent future breast cancers. All these issues reflect that much more recent data collection is necessary.

What about high-risk women?

The task force did not make any changes in recommendations for women who have family history of breast cancer, carry the BRCA breast cancer gene or have other extreme risk factors.

Why did the task force recommend against self exams?

The task force did not find the benefits of breast self exam to be worth the potential increase in anxiety and unnecessary biopsies that may result from suspicious lumps. While some studies have shown a lack of evidence that self-exams reduce the rate of deaths from breast cancer, women who are comfortable examining their breasts should continue to do so and women should always know if something is new or has changed in their breasts.

Why did the task force recommend against mammography for women over 74?

While the task force said that there was not enough evidence to recommend that women 75 or older receive routine screening, we believe that if a woman is healthy and active at an advanced age, she should continue to discuss the benefits of mammography with her doctor. As women live longer, the data may not be reflecting the true benefit of screening in this age group. Certainly, if an older woman has serious or life threatening medical problems where screening mammography is a burden or will not change her likelihood of life expectancy, than she may consider forgoing mammography.

What should women in their 40s now do?

The recommendations by the task force are just that. At this time, women should have a discussion with their primary care doctor about the pros and cons of getting screened. Along with the American Cancer Society, the Moores Cancer Center Breast Cancer Program still supports screening in this age group after a balanced discussion regarding the risks and benefits.