The Great Mammogram Debate

The U.S. Preventative Services Task Force (USPSTF) recently posted the draft of their most recent recommendations for screening mammograms suggesting that screening mammograms do not need to be performed as frequently or as early as is currently practiced by most healthcare providers.

In its draft, the USPSTF recommends the following:

  • Mammogram screening in women ages 50-74 every two years (B recommendation)
  • Individualized decision making weighing harms and benefits of screening mammography in women aged 40-49 (C recommendation)
  • The USPSTF states that there is insufficient evidence to recommend for or against mammogram screening in women 75 years or older as well as insufficient evidence for using 3D mammography (tomosynthesis) for detecting breast cancer or alternative screening modalities in addition to mammography in women with dense breasts (I recommendations)
  • The draft did not alter prior recommendations of benefits and risks of breast MRI or on recommendations against breast self-examination by women or their physicians (D recommendation)
  • The USPSTF recommendations are meant for average risk women. Women at higher risk for breast cancer such as those with a family history of breast cancer, a genetic mutation increasing their risk for breast cancer such as a BRCA gene mutation, or other risk factors that would increase their risk for breast cancer may need to begin mammograms earlier or get them more frequently.

See this link for more information on the grading definitions for the USPSTF recommendations.

Currently, most women begin annual screening mammograms at age 40 and repeat every year unless they have other risk factors – such as a family history of breast cancer – which may lead to them beginning their mammograms earlier than age 40.

The USPSTF, comprised of an independent panel of experts in prevention and primary care that are appointed by the federal Department of Health and Human Services, is recommending that mammograms for women not be performed until age 50 and repeated every 2 years up until age 74, unless there are other breast cancer risk factors that would indicate earlier and more frequent screening. These recommendations are not new – the task force had very similar recommendations in 2009, however, not all professional organizations agreed with their recommendations and they were not widely adopted.

If there is this much confusion amongst health care providers, how is the average gal supposed to decide what to do!? Let’s take a look at why the USPSTF is making the recommendations they are and what other groups who disagree with them are saying:

USPSTF Recommendations

The USPSTF cites potential risks and lack of evidence of benefits from mammogram screening in certain age groups as the reasons not to support routine screening mammograms in women ages 40-49 years of age.  

  • Women under the age of 50 have a much lower risk of breast cancer than those over age 50, therefore when a young woman has a positive mammography screen it is much more likely to be a false positive (a positive screen that turns out NOT to be a breast cancer diagnosis) than a true positive diagnosis of breast cancer.
  • This can lead to potential harms from medical procedures that might follow to find out if there is a breast cancer diagnosis such as a breast biopsy as well as anxiety from the false alarm.  
  • Women may be found on screening mammogram to have ductal carcinoma in situ (DCIS) or small invasive breast cancers that may never have caused a problem or shortened their lives at all had it never been found by mammogram in the first place. The USPSTF refers to this as overdiagnosis.
  • Ductal carcinoma in situ (DCIS) is a non-invasive cancer. Although some DCIS cases, left untreated, would become invasive over time, others will never become an invasive breast cancer or a serious threat to a woman’s health. Doctors do not have a way to determine which cases of DCIS have the potential to become invasive and need to be treated and which do not and so most women with  DCIS end up being treated with some combination of surgery (lumpectomy or mastectomy), radiation, and other treatments such as hormone therapy. The USPSTF argues that mammograms lead to the finding of many cases of DCIS that would not need any treatment and that women may very well suffer harms from treatments that they don’t need. They refer to this as overtreatment.
  • The USPSTF cites risk of radiation exposure with mammograms and that risk for a radiation-induced cancer increases with the amount of exposure through more mammograms, although they admit that this risk is likely quite small.
  • The USPSTF cites lack of evidence that mammography offers as much benefit to younger women versus women over age 50.
  • This could be due to several factors including the likelihood for younger women to have false positives on screening mammography, the fact that younger women tend to have denser breasts where cancers may not necessarily be detected on screening mammograms, and the fact that breast cancers, when they occur in younger women, tend to be more aggressive and faster growing with poorer outcomes and so finding them earlier on screening mammograms does not tend to have the same survival and outcome benefits as seen with cancers detected on screening mammograms for older women.
  • The USPSTF also cites a lack of evidence for 3D mammograms (also called tomosynthesis) as well as adjuvant screening in women with dense breasts using other screening modalities such as ultrasound, 3D mammography, MRI, or other methods if they have had a normal mammogram.

Controversy and Concerns about the USPSTF Draft Recommendations

What’s Right for You?

So now that you have the facts, what’s the right decision for you? For women aged 50-74, the benefits of mammography are clear and you should absolutely get a screening mammogram every 1-2 years. For women aged 40-49, while your risk of breast cancer is lower and it is true that screening does not come without potential harms, those potential harms have to be balanced with the potential benefits which in some cases will be life saving. The potential for overdiagnosis, overtreatment, and false positives are a reality for any screening test and must be balanced with the potential benefits and information that can be gained from the screening test. The chance of breast cancer increases over the age of 50 and thus the chance of detecting a breast cancer by mammography increases after age 50. While screening mammograms are going to catch many breast cancers in women under age 50, the ratio of breast cancers detected compared to the amount of normal screens is much lower. So from a standpoint of balancing benefits vs. risks as well as cost-effectiveness (which is a big factor when looking at any screening test), the recommendation of waiting to begin mammograms until after age 50 make sense, from a public health standpoint, but not necessarily from an individual/personal health standpoint. The USPSTF states that they are not recommending against mammograms in women of this age group, rather they say that are recommending that this be an individualized discussion and shared decision between a woman and her provider based on an informed decision considering potential risks and benefits. However, there is a concern that a C level recommendation could lead to insurers dropping coverage for mammograms for women in this age group taking away their choice of screening mammography should they and their providers come to that informed decision that they do indeed want screening.

For women aged 40-49 or for those over age 74, talk to your healthcare provider about screening mammograms. Together you can discuss your personal and family history risk factors, the potential benefits and risks of screening mammograms, and decide what’s best for you.

For more information on the mammogram debate and breast cancer screening recommendations for women at average and high risk, check out Komen’s article here

For a great breakdown on media articles that discuss the USPSTF draft recommendations check out this HealthNewsReview link