There was some recent discussion on EmpowHer (Never Been "Mammogrammed") regarding the automatic advice of medical community to routinely prescribe mammograms as a harmful practice. Surprised? There is much discussion and advocacy related to mammograms, that it seems as it is the norm and the risks are not discussed...or even mentioned.
Are there risks to routine mammography? A few people think so, and after my literature review, I wanted to share these risks openly so that you can feel you have all of the information to make an informed decision about your health.
As I mentioned, the EmpowHer discussion regarding mammography risk is not unfounded, as a research study (NEJM Ten-Year Risk of False Positive) found that up to one-third of women screened (mammogram) received abnormal test results that required additional evaluation, and no breast cancer was present. (Please note: this study was conducted 11 years ago, and technology has come a long way since this time...it is just still on women's minds.
So, what are the risks and benefits of mammograms?
RISKS
- False Negatives*
- False Positives^
- Overdiagnosis and overtreatment
- Pain and anxiety of screening
- Anxiety and stress after screening for results and follow-up
BENEFITS
- Detects breast cancers earlier than other methods (symptomatically, manually, clinically)
- Mammography-detected cancers tend to have better prognoses
- Increase in breast cancer survival
As with any medical screening, evaluation or treatment, it is important to know all the facts about the specific treatment...but also important is to learn about the facility, doctors, technicians and health professionals themselves.
Here are some statistics on mammograms (for the US):
- Mammograms have a false positive rate of about 10% (average)
- Mammograms have a false negative rate of about 20% (average)
Notice that these are averages...and you can actually increase your odds of receiving an accurate result with a little homework! According to an article last year in US News and World Report (Avoiding a False Positive on Your Mammogram, there are several proactive measures you can take to ensure your facility is a "top performer" (a "top performer" was listed as a facility with a false positive rate of only 8%):
1. The facility is dedicated only to breast screening
2. A breast imaging specialist is on staff
3. Radiologists don't perform "double readings"
4. Quality assurance audits (machines and staff) are conducted 2 or more time annually
Beyond this, what is most crucial to know: your personal health risks. Some lifestyle behaviors (such as being overweight or sedentary) can increase your risk. Family history of breast cancer is important, too. It is estimated that about 5%-10% of breast cancer is thought to be hereditary, and this risk is "higher among women whose close blood relatives have breast cancer". In fact, "having one first-degree relative (mother, sister, daughter) with breast cancer can double a woman's risk. Having 2 first-degree relatives increases her risk 5-fold." (Source: What are the risk factors for breast cancer?.
Other important information to know about mammography (Mayo Clinic):
- False positive: If you do receive a positive result: "...most abnormal findings are not cancer."
- False negative: "a cancer may be too small or in an area difficult to be viewed by mammography."
For information on breast cancer screening guidelines (Mayo Clinic) (click on orange hyperlink).
Definitions:
* False Negative: a result that shows negative or normal, but failed to find an abnormality that is present.
^ False Positive: a result that is shows positive for abnormalities, when there is no condition present; the test should read "normal".
What are your thoughts about mammography, after reading this information? Does a false positive (and the implication of receiving unwarranted medical treatment, along with its anxiety, pain and/or recovery) change your mind? Does a false negative create doubt in "going through the trouble" of getting this screening?
I wanted to create an open discussion about this topic, and I personally hope that the minuscule numbers of about 10% rate for any-type of false result will not be your "excuse" to opt-out of this potentially life-saving screening method! You can read about people who are "against" the medical establishment as a whole, and you can also read about women whose lives were saved from their early detection of breast cancer. You can decide what is best for your own health!
My last question for discussion: do most women know that medical screenings, tests, evaluations and treatments are not 100% guaranteed accurate? This is common sense, right? Why are we expecting anything different with a mammogram?
Sources:
http://www.nlm.nih.gov/medlineplus/mammography.html
http://content.nejm.org/cgi/content/abstract/338/16/1089
http://www.breastcancer.org/symptoms/testing/new_research/20070411b.jsp
http://www.cancer.org/docroot/NWS/content/NWS_1_1x_False-Positive_Mammogram_Results_Vary_Among_Radiologists.asp
http://jnci.oxfordjournals.org/cgi/content/abstract/97/16/1195
http://www.nlm.nih.gov/medlineplus/news/fullstory_86677.html