Are Certain Breast Cancers Overtreated?

The number of breast cancer diagnoses has risen over the last 25 years, and now 1 in 8 women will be diagnosed in their lifetime. This increase is partly due to better screening technology, which is detecting more cases of breast cancer, and in earlier stages. While finding cancer at an early stage is beneficial, this also can lead to overdiagnosis. And overdiagnosis leads to overtreatment. 

We will explain what these concepts mean, and how to know if you are at risk of receiving treatment that you don’t need.

What is overtreatment, and how is it harmful?

To understand overtreatment, let’s first explain overdiagnosis. Overdiagnosis occurs when a test picks up something that is abnormal, but not true disease. A mammogram may find a group of cells that have the potential to become cancerous, but aren’t yet. Increased screening leads to discovering and diagnosing more of these “precancerous” abnormalities. For example, lobular carcinoma in situ (LCIS) is a precancerous condition that rarely progresses to become cancer. It does not require treatment itself, but rather suggests someone may be at slightly increased risk for other breast cancers in the future. 

One of the dangers of overdiagnosis is that it makes us want to address or act on the abnormality. And sometimes the treatment is more harmful than the abnormality itself. Experts define overtreatment as treatment that ultimately provides no benefit to the patient. Treatments such as chemotherapy, radiation, or surgery come with many side effects: fatigue, nausea, pain, bleeding, infection, just to name a few. So treatment in early cases can  lead to unnecessary harm. 

Another danger of overdiagnosis is that it can lead to unnecessary additional testing.  In turn, CT scans, PET scans, or other imaging tests can needlessly increase someone's exposure to radiation.  Additionally, excessive testing can cost a lot of time and money. But just as costly may be the mental and emotional toll of facing a possible cancer diagnosis. 

Are all types of breast cancer at risk of overtreatment?

Breast cancers that are in the earliest stages (or even precancerous) are at greater risk of overtreatment than those in a later stage.  

The earliest stage of breast cancer is stage 0. In this stage, the tumor is contained within the breast and has not spread to the surrounding areas. The most common type of stage 0 breast cancer is ductal carcinoma in situ (DCIS). This type of cancer makes up roughly 20% to 25% of all diagnosed breast cancers. 

Treatment for early stage DCIS typically involves a combination of surgery, radiation, and hormonal therapy. But this is controversial as it is common for these cancers to never progress beyond stage 0. Only about 20% to 30% of women with early stage DCIS will go on to develop invasive breast cancer. 

Some people choose to monitor the cancer rather than jumping to aggressive treatments. People who are older and who have other medical conditions often consider this option. in particular when, because of other medical conditions or older age,  they may not tolerate treatment as well.  This approach is called active surveillance, and involves more frequent, routine screening to track any progression of the cancer. 

Less is known on whether more aggressive tumors are at higher risk of overtreatment. 

When should I start screening for breast cancer?

Evidence shows that early screenings create a higher risk of overdiagnosis and unneeded biopsies. To address this, expert health organizations have adjusted screening recommendations.

The American Cancer Society (ACS) is one group that changed its guidelines in 2015. For women with average breast cancer risk, the ACS now recommends:

• Annual screening mammograms should start at age 45 (instead of 40). 

• After the age of 55, women can space out their mammograms to once every 2 years. 

• Women and their providers should no longer perform breast exams. These exams are more likely to detect harmless lumps than breast cancer.

Other organizations encourage women to have a personal discussion with their providers to weigh the benefits of breast cancer screening with the risk of overdiagnosis:

• The U.S. Preventive Services Task Force recommends that breast cancer screening with mammography begin for women at the age of 50. For women who personally prefer earlier screening, they recommend a mammogram every 2 years between the ages of 40 and 49. 

• The American College of Obstetricians and Gynecologists (ACOG) does not provide any strict screening guidelines. They recommend  that women be counseled on the risk of overdiagnosis when choosing to be screened for breast cancer.

How can I be sure I am not overtreated?

When it comes to cancer, the language can be confusing and overwhelming. The word “cancer” alone makes us immediately assume the worst outcome, even when the prognosis is good. And so it is natural to then want to do everything in our power to treat the cancer.

Choosing Wisely, an initiative of the American Board of Internal Medicine, asks providers to be more discerning in treatment decisions.  The questioning of tests and treatments for cancer could help avoid the potential harms of overtreatment. 

The medical system, though, can be slow in enacting these changes. So it is important for people with breast cancer to talk to their providers about their different treatment options. They then can be  their own advocates and advocates for those in the breast cancer community. 

Why trust our experts?

Written by:

Cherilyn Davis, MD

Cherilyn Davis, MD, is a board-certified pediatrician in New York City. She has held local and national roles at the American Medical Women’s Association including board member of the physician division and physician chair of social media.

Edited by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

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