Last week, the American Cancer Society (ACS) changed its position on breast cancer screening to recommend less mammograms and no clinical breast exams for women of average risk. As I read news articles and social media posts on the topic, my immediate reaction was WTF??? The ACS has traditionally recommended more screening, not less. Why the change? I decided to get it straight from the horse’s mouth, so I read the actual guidelines published in the Journal of the American Medical Association. It wasn’t light reading, but I’m glad I read the full article.
As usually happens, some information is lost when people collapse complex messages into sound bites and headlines. While the ACS does propose less aggressive screening, their new recommendations contain a lot of gray areas that allow for individualized decision-making. They provide two types of recommendations:
Strong recommendations – Those that most people would want to follow, yet a small number of individuals might not; and
Qualified recommendations – Those that most people would follow, yet many individuals may choose not to based on their preferences.
Below are the American Cancer Society’s new recommendations and their associated qualifications. They apply to women of average risk, which the ACS defines as those without a personal history of breast cancer, a confirmed or suspected genetic mutation known to increase risk of breast cancer (eg, BRCA), or a history of previous radiotherapy to the chest at a young age.
Women with an average risk of breast cancer should undergo regular screening mammography starting at age 45 years. (Strong Recommendation)
Recommendation 1a: Women aged 45 to 54 years should be screened annually. (Qualified Recommendation)
Recommendation 1b: Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually. (Qualified Recommendation)
Recommendation 1c: Women should have the opportunity to begin annual screening between the ages of 40 and 44 years. (Qualified Recommendation)
Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer. (Qualified Recommendation)
The ACS does not recommend clinical breast examination for breast cancer screening among average-risk women at any age. (Qualified Recommendation)
Why Did the American Cancer Society Change Its Guidelines?
The rationale behind these new recommendations is that we should try to balance the benefits and the risks of breast cancer screening while taking into account patient preferences. The benefit of screening would be catching breast cancer early enough to treat it. The risks include false positives and treating slow growing cancers that may not have been harmful to the individual. Patient preferences vary along these two dimensions. Some women with average risk would rather avoid the burden of screening because their likelihood of having cancer is low, while other women would rather screen more to gain some peace of mind.
The ACS now recommends mammograms beginning at age 45 because it has been established that mammograms do a poor job of detecting cancer in younger breast tissue, which is dense.
I can vouch for this. My 2 cm lump was not visible on the mammogram image.
Dense tissue and cancer both show up white on a mammogram, making it difficult to distinguish between the two. This can lead to undetected cancer or to a false positive. False positives can then lead to unnecessary biopsies and stress.
But in recommendation 1C, the ACS states that women should still have the option of starting mammograms between the ages of 40 and 44. It appears that the ACS is providing some guidelines but ultimately leaving the mammogram decision up to each woman and her physician.
What about clinical breast exams? Why are they no longer recommended? The ACS didn’t find any evidence that they improve patient outcomes.
Again, I can vouch for this. My ob/gyn totally missed my lump during my breast exam.
However, I also believe that some physicians don’t conduct thorough breast exams. You lie on your back while they feel around the most prominent parts of your breast, but maybe they should also examine your breasts while you lie on your sides. Perhaps there’s room to improve the method for clinical breast exams, and then they might yield evidence of improved outcomes. In any case, I thought the ACS would at least recommend breast self exams, but they didn’t. At this time, there isn’t sufficient evidence to support self exams even though most women find their lumps themselves.
With their new recommendations, the ACS is basically saying, “Here’s what we suggest, but you and your doctor should go figure out what’s best for you.”
This ambiguity underscores the need for better breast cancer screening tools, especially for younger women. Existing tools are imprecise, so you need to balance the benefit of early detection with the emotional and physical burden of potential false positives. This is similar to determining your risk tolerance before investing your money. How much breast cancer risk are you willing to tolerate in order to avoid the burdens of imprecise screening? Indeed, this is a personal decision, but we could make better decisions if we had screening tools that offered better information.
The new recommendations also underscore the need for you to be informed about your breast health. These recommendations apply to women with average risk for breast cancer. What if you are high risk, but don’t know it? For example, I didn’t know that getting my period at age 11 put me at slightly higher risk for breast cancer. I didn’t learn this until I was actually diagnosed with breast cancer at 35.
You should also consider that the current definition of average risk is limited by our understanding of what causes breast cancer, and sadly, we don’t its causes very well. Breast cancer is a complex disease with many nuances and variations that researchers are still trying to figure out. We don’t know how to prevent breast cancer because we don’t know exactly what causes it. This means there must be risk factors we don’t know about yet. Maybe some women categorized as average risk are actually at higher risk, but we don’t have enough information to know this.
For these reasons, I still believe that you should check your breasts regularly. Knowing what your breasts normally feel like will help you detect anything unusual. Also, I encourage you to be well-informed about breast health. I really like this guide from the Young Survival Coalition. It provides essential information about breast health in a format that is easy to read and understand.
Remember, the ACS guidelines are recommendations, not hard and fast rules. Be informed. Talk to your health care providers, and make decisions that are best for you.