Health knowledge made personal
Join this community!
› Share page:
Search posts:

The Case of the Woman Who Refused Her Mammogram

Posted Jul 15 2009 8:11pm 1 Comment

Recently a colleague of mine expressed frustration about a 52-year old woman who refused mammography. Given my interest in preventive health, he came to me to ask how he should go about convincing the patient to get her mammogram. He was surprised by my response: as long as the patient understands the risks and benefits, then it’s reasonable for her to refuse.

On one level, this response is downright shocking. Mammograms are proven to save lives; we must convince the patient to do what is best! On other hand, my response is straightforward. Patients have the right to refuse medical services — in the most cynical view my response was a medical-legal one (document understanding of risk and benefits in case she later develops breast cancer and sues).  In a way then, this becomes the classic paternalistic versus patient autonomy debate. But, in truth, my response was a reflection of neither viewpoint. It was based on a basic fact — it is as reasonable to undergo mammography as it is to forgo it. Mammograms are no panacea and have significant limitations that for certain women make the test not worth the risks.

Let’s begin by reviewing the the benefits and risks of mammography:

- Benefits:

Reduced death from breast cancer. Mammograms sometimes lead to the detection of cancer earlier than it would be found otherwise; sometimes earlier detection leads to earlier treatment that reduces morbidity and mortality. (Note that just because mammography finds breast cancer earlier does not mean it leads to improved outcomes.) For women ages 50 to 69 mammography has been shown to reduce deaths from breast cancer by 33 percent. This percentage though is a relative risk reduction; absolute risk reduction is much smaller. A less cited statistic is that in order to prevent one death from breast cancer 1000 women ages 50 to 69 need to be screened (that is, the number needed to screen is 1000).

- Risks:

1) False negatives - Sometimes mammograms fail to detect breast cancers and thus give a false negative result. It is estimated that 1 in 5 breast cancers present at the time of screening are missed. False negatives cause harm by delaying diagnosis and treatment and creating a false sense of security.

2) False positives - Sometimes mammograms suggest breast cancer is present when it is not there. This leads to unnecessary testing including biopsies, which are anxiety-provoking, expensive, and potentially disfiguring.

3) Overdiagnosis - Much less talked about is the risk of overdiagnosis. Overdiagnosis refers to cancers that will never cause harm if untreated. As I discussed in a recent blog entry ( ), cancer often solicits a knee-jerk, “get this thing out of me!” response. But the truth is that many cancers, if left untreated, would never cause harm to us during our lifetimes. Sometimes this is because the cancer is dormant or regresses; other times it is because we die of other causes before the cancer becomes clinically relevant. The trouble is that with the current state of technology, doctors cannot tell which cancers will cause harm and which ones will not, and as a result treat all cancers aggressively. The net result is that we risk the chance that women will undergo treatment for breast cancer including surgery and radiation without any health benefits. A recent study suggested 1 in 3 breast cancers detected in population-based screening programs are overdiagnoses (see reference below).

A editorial in the British Medical Journal published just last week presented an excellent framework for translating these risks and benefits in a way that patients can use to make informed decisions. The following table is taken directly from this editorial with the reference provided below. It shows the credits (benefits) and debits (harms) of screening one-thousand 50-year old women with mammography every year for 10 years. For example, it shows that for every 1000 women screened, 10 to 15 women will be diagnosed with breast cancer earlier than they would be otherwise but without any improvement in prognosis (or outcome).













In the editorial, the authors suggest that more data is needed to calculate more precise estimates of the credits and debits. They note that for many women the critical threshold for being in favor of or against mammography may be within the wide ranges of these estimates.

In my view, given the risks and benefits of mammography it is reasonable that my colleague’s patient, or any woman for that matter, refuse mammography. The question for health care providers is not “How can I get my patient to get her mammogram?”, but rather “How can I make sure my patient understands the benefits and risks of mammography and makes the right decision for herself?” Instead of focusing on getting 100% of our patients to meet the guidelines (as quality improvement agencies and pay-per-performance would have us do) what we should be focusing on is making sure that 100% of our patients are making informed healthcare decisions based on a solid understanding of the best available evidence. Getting mammograms are not an obvious choice for all women, so we need to step up our efforts at full consent and make sure we are not over-selling the benefits and under-appreciating the risks of mammography.

- Shantanu Nundy, M.D.

To access the article on overscreening visit Citation BMJ 2009;339:b2587 .

To access the editorial visit Citation BMJ 2009;339:b1425.

To learn more about breast cancer visit, National Cancer Institute webpage on breast cancer.

Comments (1)
Sort by: Newest first | Oldest first

I have made an informed decision not to have mammograms.

It concerns me that women get a one-sided promotion of screening tests with no risk information and no respect for the legal requirement of informed consent.

Thankfully the Nordic Cochrane Institute have produced an unbiased account of the risks and benefits of mammograms available at their website - this group criticised the information that is currently released to women.

Cervical screening is an even bigger gamble, unlike breast cancer, cervical cancer is rare/uncommon and this test was never properly evaluated before it's release, this cancer was also in steady decline before screening started - women get no risk information and are routinely pressured and coerced into testing (and often over-testing and inappropriate testing) - this test is unreliable and lots of women get false positives and face painful and potentially damaging & invasive biopsies and treatments. LEEP and cone biopsies can leave women with damage to the cervix which can lead to infertility, problems during pregnancy, miscarriages, premature babies, more c-sections and psych issues. 

When 99.35% of women derive no benefit from smears and 95% of women who have annual screening are referred at some stage for colposcopy and usually some sort of biopsy, that is massive over-diagnosis and over-treatment - and all with no informed consent. (the 99.35% includes the 0.35% of women who get false negatives)

The practice in the States and Canada of denying women birth control until they agree to screening amounts to coercion and is highly unethical. The demands also include routine pelvic exams which are of poor clinical value in a symptom-free woman and expose the woman to risk (more harmful investigation even surgery) and routine breast exams - no evidence they bring down the death rate, but they cause biopsies and some believe biopsies are a risk factor for cancer - some Dr's even demand rectal exams - too ridiculous for words!

Cancer screening has nothing to do with birth control.  

Every woman should do her reading and make her own informed decisions - saying NO to screening is perfectly reasonable.

I have never participated in cervical screening (as a low risk woman) and have recently decided on turning 50, not to have breast screening. (I've never permitted breast exams) 

Thankfully our doctors don't recommend routine gyn exams at any age; I wouldn't permit them anyway.

If I had been higher risk for cervical cancer, I might have opted for the Finnish program - 5 yearly from age 30, 5 - 7 tests in total - they have the lowest rates of cc in the world and just as importantly, send the fewest women for colposcopy/biopsy (fewer false positives - 30%-55% lifetime risk)

Two yearly is over-screening (Australia) - that carries a 77% lifetime risk.

Three yearly (UK) - 65%

Screening under 25 (some say 30) is of no benefit but causes massive and harmful over-treatment from false positives.

Anyone interested in the facts should go to Dr Joel Sherman's medical privacy blog and under women's privacy issues you'll find all the facts. See research by Dr Raffle, Richard DeMay and others. 



Post a comment
Write a comment:

Related Searches