The Downside of Mammograms
Mammography has been the medical industry’s “gold standard” breast cancer screening tool for nearly four decades, and the procedure has been pushed on women with great zeal by physicians, public health programs, and cancer organizations. However, mounting scientific evidence indicates that mammography may not only be far less effective than we have been led to believe, but that it also has numerous drawbacks that are affecting women on a massive scale. Read on to learn about the major drawbacks of mammography, what the research recommends for breast cancer screening, and about promising breast cancer detection alternatives.
A Brief History of Mammography
Mammography screening for breast cancer was first introduced in the late 1970s, and by the early 1980s, it had been widely incorporated into clinical practice. Prior to the widespread use of mammography, breast cancer detection tests were primarily based on breast self-exams and clinical breast exams performed by physicians. In the very early days of mammography, this test was used only in women at high risk for breast cancer; this included women who had a previous history of breast cancer, had a mother or sisters with breast cancer, or were over 50 years of age.
Fast-forward to the present day, and it is quite apparent that the use of mammography has increased dramatically. According to recent data, 66.8 percent of women over the age of 40 have had a mammogram within the past two years, an average of 15 million physician office visits have taken place per year in which a mammogram was either ordered or performed, and an additional 3 million outpatient visits have ordered or performed mammograms (1).
Despite this massive increase in the use of mammography, there is a substantial body of research indicating that the widespread, overenthusiastic practice of mammography over the past few decades has had little to no effect on breast cancer mortality rates (2). In fact, the research indicates that mammography screening may do more harm than good. Mammography has demonstrated a number of adverse effects, including breast cancer overdiagnosis, unnecessary breast cancer treatment, undue psychological stress, excessive radiation exposure, and a serious risk of tumor rupture and spread of cancerous cells (3, 4).
Could mammography screening do more harm than good? #breastcancer
Mammography Screening Leads to Breast Cancer Overdiagnosis and Overtreatment
A 17-year study conducted in Denmark from 1980 to 2010 measured the incidence of advanced (> 20 mm in size) and nonadvanced (≤ 20 mm in size) breast cancer tumors in women ages 35 to 84 who either had received regular breast cancer screening over the years or had not received screening. If mammography was effective at reducing rates of advanced breast cancers, a reduction in the incidence of advanced tumors in the women who received the screening should have been observed. However, no difference was found in the incidence of advanced tumors between the screened and unscreened groups. In addition, significant overdiagnosis of breast cancer was found in the screened group—approximately one out of every three invasive tumors and cases of ductal carcinoma in situ (DCIS) was found to represent breast cancer overdiagnosis. This meant that, due to screening mammography, healthy women were diagnosed with breast cancers. These women subsequently had to deal with the severe psychological distress of a cancer diagnosis, as well as the numerous physical harms of cancer treatment, when in fact their tumors were not cancers that necessitated treatment at all (5).
A systematic review published several years prior found very similar results; in the United Kingdom, Canada, Australia, Sweden, and Norway, the overdiagnosis rate in organized breast screening programs was 52 percent, meaning one in three cancers in the screened population was overdiagnosed (6).
Further research has found that mammography screening has led to an increased detection of small tumors, but only a modest decrease in the incidence of advanced tumors. Many of the small tumors being detected by mammography represent breast cancer overdiagnoses. These small tumors are growths that, if left alone, would never progress to an advanced stage. However, mammography is diagnosing them as cancer, which is in turn causing countless women to be convinced to undergo cancer treatment, with all its harm and side effects, and without any benefit. In regards to the modest reduction in large breast tumors noted above, this reduction has been attributed to improved breast cancer treatment, not to screening mammography (7).
Mammography Selectively Detects More Favorable Tumors
Mammography has a tendency to selectively identify tumors with favorable molecular features, which are features that make breast cancer treatment easier, offering a better prognosis. This is due to the fact that tumors with favorable characteristics tend to grow more slowly, so there is a larger window of time in which they can be detected by screening mammography. When screening mammography is used, these favorable tumors tend to be diagnosed long before they would begin to cause symptoms. This phenomenon is called length-bias sampling and refers to a statistical distortion of results that occurs when screening identifies disease cases before the onset of symptoms, making it appear as though survival time is increased for the particular disease due to screening. However, favorable tumors typically respond to treatment equally effectively at clinical presentation (when symptoms appear) as they do when diagnosed via mammography, so earlier detection through screening mammography does not translate into a reduction in breast cancer mortality (8).
Breast tissue density affects the ability of mammography to successfully detect tumors. Low-density breast tissue makes it easier for mammography to visualize tumors than does higher-density breast tissue. In the fatty breast, mammography sensitivity is 98 percent; in the very dense breast, the sensitivity goes down to as low as 48 percent (9). This is a significant issue because in postmenopausal women (the subgroup of our population that undergoes regular mammography screening), high-density breast tissue is associated with an increased risk of breast cancer as well as with the presence of tumors with more aggressive characteristics, such as larger tumors and estrogen receptor-negative tumors. The relative ease with which mammography detects favorable tumors has led to an overestimation of the effect of screening mammography on breast cancer mortality (10).
Radiation from Mammography May Increase Risk of Breast Cancer
The cumulative effect of routine mammography screening may increase women’s risk of developing radiation-induced breast cancer (11). The current recommendations for mammography screening have led women to start screening at a younger age and also to receive more frequent screening; this has amplified the amount of radiation to which the breasts are being exposed, and the effects are not trivial. In addition, women who are exposed to radiation for other purposes or women who are carriers of the BRCA (breast cancer susceptibility) gene are at an even higher risk of experiencing adverse effects from mammography radiation (12).
While not a direct reflection of the impact of mammography on breast cancer risk, other studies examining the effect of diagnostic chest x-rays on breast cancer risk have found that medical radiation exposure increases breast cancer risk (13).
Mammography Can Rupture Tumors and Spread Malignant Cells
Mammography involves compressing the breasts between two plates in order to spread out the breast tissue for imaging. Today’s mammogram equipment applies 42 pounds of pressure to the breasts. Not surprisingly, this can cause significant pain. However, there is also a serious health risk associated with the compression applied to the breasts. Only 22 pounds of pressure is needed to rupture the encapsulation of a cancerous tumor (14). The amount of pressure involved in a mammography procedure therefore has the potential to rupture existing tumors and spread malignant cells into the bloodstream (15).
Conflicts of Interest and Mammography Recommendations
There is significant bias in the medical literature regarding mammography. This has led to significant breast cancer overdiagnosis and overtreatment, while also significantly influencing women’s perceptions about the purported effectiveness of mammography.
A literature review of 171 articles in the journal Evidence-Based Medicine found that a significant number of studies examining the effectiveness of mammography were published by interest groups and authors with vested interests in mammography screening. Scientific journal articles on breast cancer screening written by authors who have a vested interest in the practice of mammography tend to emphasize the potential benefits of mammography, while downplaying or outright rejecting the major harms such as overdiagnosis and overtreatment. Authors may have a vested interest in promoting mammography if they are receiving income from mammography screening programs or if they are contributing to scientific journals tied to political interest groups such as the American Cancer Society, which has financial ties with the makers of mammography equipment (16, 17).
Due to conflicts of interest, the research being used to develop recommendations for mammography screening protocols is biased and is not a true representation of the efficacy of mammography for reducing breast cancer mortality. This has had a large-scale impact on the development of mammography screening programs (18).
Perceptions of Mammography Benefits vs. Reality
In a survey of U.S. women’s perceptions of mammography, 717 of 1,003 women (71.5 percent) said they believed that mammography reduced the risk of breast cancer deaths by at least half, and 723 women (72.1 percent) thought that at least 80 deaths would be prevented per 1,000 women who were invited for screening. However, based on U.S. mortality statistics, screening mammography prevents approximately one death per 1,000 women screened. Due to the influence of mammography propaganda, women’s perceptions of the effectiveness of mammography are overly optimistic and not even remotely a reflection of the true efficacy of mammography for preventing breast cancer deaths (19).
Research also shows that women who are better informed about the risk of overdetection and overdiagnosis of breast cancer associated with mammography screening are less likely to participate in mammography screening (20).
Informed Choice Is in Jeopardy
Surveys indicate that women want to have balanced information and share the decision with their physician when it comes to whether or not they choose to go through screening mammography. However, many women have reported that they were never provided with information on the drawbacks of mammography, such as the risks of overdiagnosis, unnecessary cancer treatment, excessive radiation exposure, and potential for causing tumor rupture. The lack of balanced information about mammography provided for women jeopardizes their ability to make their own decisions regarding healthcare (21).
Making Decisions Regarding Mammography
What is the best decision to make in regards to mammography? This is a question that many women are likely wondering as criticism of this diagnostic technique grows. The truth is that guidelines for the recommended frequency of mammography screening and the age at which screening should begin tend to vary from one organization or committee to another. The American Cancer Society states that women ages 40 to 44 should be given the choice to start annual breast cancer screening, women ages 45 to 54 should get mammograms every year, women 55 and older should switch to mammograms every two years, and screening should continue as long as a woman is in good health (22). The U.S. Preventive Services Task Force has more liberal recommendations and suggests that the decision to start mammography screening before 50 should be an “individual decision,” that women ages 50 to 74 years should receive mammograms every two years, and that there is insufficient evidence that women over 75 should even receive mammograms (23).
In light of all this information, it is important to emphasize that mammography screening is a highly personal decision that should be made with the assistance of an unbiased physician and with full knowledge of the potential drawbacks. Women should also be fully informed about alternative breast cancer screening tools. Some of these alternative tools may be helpful adjunct techniques to use with mammography, and others may actually be suitable replacements for mammography screening.
Alternative Screening Tools
Alternative screening tools to mammography include clinical breast exams, digital mammography, ultrasound, and thermography.
- Clinical breast exam (CBE) is a physical exam of the breasts done by a trained healthcare provider. Addition of mammography screening to clinical breast exam did not reduce the risk of mortality from breast cancer, indicating that CBE is a highly effective screening tool (24). However, CBE is typically still combined with at least one additional type of screening tool, such as thermography or ultrasound.
- Digital mammography allows for images of the breasts to be captured in a digital format rather than on film, as is done in traditional mammography. Studies show that digital mammography is at least as sensitive and specific, if not more sensitive and specific, than film mammography. In addition, digital mammography has advantages over film mammography in that the operator can access the images immediately, the images can be stored on computers, and the images can be enhanced and manipulated to allow for visualization of subtle changes in tissue structure in the breast (25). While digital mammography still involves compression of the breasts, it does use a lower dose of radiation than film mammography. Digital mammography may soon be the new stand-alone “gold standard” for breast cancer detection.
- Thermography uses infrared technology to detect inflammatory patterns in breast tissue. It is noninvasive, does not emit radiation, can be done during pregnancy, and has the ability to effectively visualize dense breast tissue, unlike mammography. Thermography screening has demonstrated a high sensitivity and specificity. A high rate of false positives has been recognized as one of the drawbacks of this tool. However, these false positives may in fact be abnormal thermal patterns that are foretelling a future cancer that has not yet begun to grow to a physically detectable size. This theory is supported by studies in which thermography detected abnormal heat patterns in breasts several years before a breast cancer diagnosis was made. Thermography may therefore be a valuable screening tool due to its ability to detect functional changes in breast tissue before the onset of structural changes that occur in a cancerous state (26, 27, 28).
- Ultrasound is a noninvasive diagnostic tool that does not emit radiation and is safe to use during pregnancy. Ultrasound has demonstrated the ability to detect breast cancer at rates comparable to mammography, while also being very economical and patient friendly. A potential drawback is that ultrasound may not be able to detect tumors less than 1 cm in size. In addition, ultrasound is a highly operator-dependent tool and requires the involvement of a skilled sonologist. Nonetheless, ultrasound is a very promising emerging tool for breast cancer screening and may one day be a viable stand-alone alternative to mammography (29).
This type of article does not help women at all, only brings even more doubts and does not give a plausible solution. If you do not have a more effective solution, it’s best to be quiet.
It really comes down to benefits vs. risks, doesn’t it?
BTW – All mammograms are digital, unless you’re at some small clinic in the sticks. Film has been out of use in radiology departments for 10 yrs. And ultrasound will not be used by itself, only in conjunction with a mammogram; a radiologist will not read it out otherwise.
This article is incomplete because it does not mention Breast MRI – which delivers the most detailed images. The current “standard of practice” is to do a mammo, then ultrasound, then MRI – in that order and as needed based on the results of the previous. It’s almost impossible to request only the MRI, because again, a radiologist will not agree to read it without the other relevant studies.
You also have to go throught the “steps” for insurance to cover.
Oh my, Chris. Have you waded into a hornet’s nest. You have done your usual thorough job at researching problems with mammography and restating these, but there could be a bit more balance and a few more solutions. As one of those “evil” physicians, as characterized above (who doesn’t herd her patients), I get dinged financially by my accountable care organization and insurance companies if I don’t refer patients per the current standard of care, or sued or have a patient with an agonizing death, if I miss a breast cancer. I do my best to help my patients make informed decisions as individuals. I wish to point out the following:
1) Unfortunately, the evidence that thermography and ultrasound are adequate screening tools and save lives is wanting. Anecdotally, I have also seen patients like the unfortunate postee above, who relied on thermography. There is NO perfect screening tool, and all screening recommendations sacrifice the well being of the individual for the well being of “populations.” Fortunately, genetic research is bringing back interest in the care of the individual in determining who is at higher risk and what environmental and lifestyle factors turn cancer promoter and suppressor genes off and on. But progress has been slow to change the guidelines.
2) Consider the toll on the woman who gets thermography and is told 10 years in advance of a treatable cancer that she has “a potentially pre-cancerous abnormality” on her thermogram (that mammography can’t “see” yet, and, pray tell, what am I do to with that information for this anxious patient?
3) Cancers large enough to rupture on mammography screening should be detectable on exam. Incidentally, the USPHTF does not recommend self breast exam. This nihilistic recommendation is so typical of this entity. This would be a difficult thing to study, so they don’t have the info to recommend it. Why wouldn’t you check yourself? I have seen patients whose very large tumors were not seen on mammography OR US, and were discovered by the most low-tech method of all: palpation. What happens to women who wait until they have a palpable tumor is not pretty. So maybe they don’t die from their cancer, but just wish they had. Their treatment is more aggressive and will include chemotherapy and radiation, potentially leaving them with neuropathy, cognitive problems and other issues. The research bias for later treatment, is that maybe these women don’t die with metastatic breast cancer, but from heart disease caused by their radiation or some other more subtle effect of necessarily more aggressive treatment of a larger cancer. There are devastating financial consequences of going through “triple therapy,” even for women who have insurance. Mammography’s claim to fame is picking up smaller tumors (we are not talking about DCIS, which is a whole other can of worms). So, in these uncertain times, we are balancing false positive mammography and unnecessary biopsies, against these very real, unpleasant and potentially life-threatening issues for women with cancer diagnoses.
4) Digital mammography is the standard of care, not an alternative screening tool at this point.
5) Beware of 3D mammograms for routine screening — some protocols involve less radiation and some involve more, depending on the number of views, so ask, if it matters to you. Perhaps the solution is to get it once if you have dense breasts, and if normal, skip a year, per USPHSTF recs. They are typically more expensive because insurance companies are not yet covering.
As a conscientious physician, who has breasts, this is what I do:
I do my best to risk stratify my patients using a Gail model risk predictor (you can find the risk calculator on line, folks), and consider other lifestyle factors known to increase risk: weight, exercise, other signs of estrogen dominance, HRT use. If a patient is lower risk, we jointly consider going to the USPHSTF recs for starting later and checking every other year. I also advise my patients to lower their risk with lifestyle measures. Get those insulin levels down with weight loss, exercise and diet. A recent piece of research shows a 30% lower incidence of breast cancer recurrence in patients who fast 13 hours nightly (one of Chris’s faves). If you are estrogen dominant, AFTER you have done what you can with these lifestyle recs, consider adding a DIM (di-indole methane) supplement, with or without calcium glucarate.
Thank you Laurie for your thoughtful comment. I agree that this is a complicated and thorny issue, in part because as clinicians we don’t treat populations, we treat individuals.
If a test leads to unnecessary and potentially risky treatment in nine people but saves one life, that would be viewed quite differently from the perspective of the person who’s life was saved and the nine people who underwent unnecessary treatment (though unfortunately they often never find out that it was unnecessary).
Your case-by-case approach seems like a good strategy in a very murky area.
I’m pleased to see this. I had a baseline mammograph at age 40, under pressure from my mother, and have stayed away every since. The small piece of data – that people who see doctors are sicker than those who don’t – helps me feel better. I rely on a homeopath and an energy healer for my health care – you will probably think I must be crazy or stupid for this, but at 68 I’m vigorous and doing farm work. Of course I also take care of my nutrition, live in clean air and spend a lot of time outdoors.
I don’t have enough money to see a doctor or pay for Medicare Part B – I use that to pay for my good food and healthy lifestyle. So the mammogram issue has disappeared for me.
And you know that the American Cancer Society is primarily funded by companies that make cancer equipment (and toxic chemicals – look it up).
I have a feeling I am one of those who had a small tumor recognized as cancer and went through a very emotional roller coaster of a cancer diagnosis. I had 2 surgeries and then 33 rounds of radiation. I do feel they DO NOT inform you of the risks of mammograms! Not once has a physician explained that! I am really starting to advocate for myself! This makes me mad, sad, etc. that these mammograms are pushed so heavily and the conflicts! UGH!!! Everything seems profit driven not patient driven. I am so disappointed.
Thank you for posting this article and the many comments above. I have a terrific OB-GYN who usually brings up the mammogram. Because I have extremely tiny breasts, I always ask her to give me a good reason why I really need to have one – I can feel my ribs very easily under my breasts. She can’t give me one so I always skip the annual mammogram. I’ve had two mammograms, both in my 40’s. I’m now 54. One was a baseline and one when I found a couple tiny (smaller than a lentil) lumps that turned out to be cysts per the ultrasound. About five months ago, I had a chest x-ray for an illness and a spot was found on my lung. I don’t smoke and I’m very health conscious so this puzzled and really concerned me. Instead of recommending a pulmonary specialist or wait and to see a few months (based on my research on lung cancer and lung spots), my primary care clinic kept insisting I have a mammogram. They were very angry with me for even questioning their judgement. I refused because this made no sense and there was nothing abnormal in my breasts. Shortly after, they decided my spot was calcium. I never got the mammogram. I have no idea why they and the radiologist would recommend mammography for a lung spot. Since I barely have any breast tissue, I’m really concerned about where the radiation would go with an unnecessary mammogram. Be an advocate for your health, research a lot and don’t just take your doctor’s word without doing your homework. Also, don’t be afraid to express your concerns with your doctor and ultimately make your own decision, get a second opinion or a new doctor. Decide not from fear or intimidation but from as much research and education from quality sources as you possibly can.
J – When I asked the radiologist why he recommended an annual mammogram when the results were inconclusive (I have dense breasts) he also got very angry at me. I was just trying to be informed about my body! I did not go back for a mammogram this year. I am with you, be your own advocate, do your own research, be a “wise woman.” 🙂
I have extremely dense breasts and the last time I had a mammogram over ten years ago, it hurt so much it made me cry. In the end, the results of the exam were nonconclusive, since they couldn’t see anything through the fibrous tissue. I avoided mammograms after that until I was told to go to one this year. I reluctantly went, especially having read the Danish study and other reports that said mammograms may actually be increasing breast cancer rates, as well as the fact that dense breasted women have increased breast cancer rates. However, I had a lot of unexplained hormonal symptoms so I went ahead and listened to the doctor. They promised me it wouldn’t hurt and they also did an ultrasound. The results were the same: too dense to be able to see anything through the mammogram. But the ultrasound was fine. The doctor then muttered something that I couldn’t hear and told me to come back next year for another mammogram and ultrasound. When I asked him why I should get a mammogram if you can’t really determine anything from them, he called me an airhead! For not listening to him (or really, because I asked an intelligent question, I think.) I asked him to repeat what I apparently missed the first time around, and he said that it is still necessary for dense-breasted women to have mammograms because they can catch “groupings of microcalcifications,” which he said is THE only real way to catch cancer. Does anyone know anything about this?
Heather, I’m not a medical professional, so I have no idea if that doctor was telling the truth or not about microcalcifications. But given his behavior, I wouldn’t be surprised if he were using that phrase — a rather technical phrase, mind you — as a way to make you feel bewildered and to just start obeying him. Then again, I’m suspicious that way. In all seriousness, I can’t tell you whether to go back or not. But if he were to call me an airhead and then use a term like “groupings of microcalcifications,” I’d wonder if he were trying to make me feel like an airhead. Regardless of the meaning of the phrase, though, if he’s calling you names, you need to find a new doctor if you haven’t already. You deserve better treatment!
Jessica, thanks for your response. I most definitely did not go back to him! I just wanted to know about the micro calcifications as a matter of principle. I have not yet gone back for a mammogram (anywhere), nor do I intend to anytime soon, unless I hear more evidence as to how it can actually be beneficial.
I just went in for a screening ultrasound because I didn’t want to have a mammogram performed. My doctor had to order it, as you can not walk in like a mammogram and have it done. Find a good doctor that respects your choices and only do what you feel is right for your body.
I don’t believe in mammograms. There has been no history of breast cancer in my family ever. But since they started getting mammograms, half of the women in my family have gotten it. They say the radiation is very low-but if they find something suspicious, they nuke you to death to get pictures from every angle which in my opinion is increasing the likelihood. My mother had fibrocystic disease of the breast (benign cysts) never went back and died of a heart attack in her 70s. My sister and I both had mammograms at 40 and they told us both they found “something”, took like 20 pictures, did a needle biopsy to tell me it was benign. I wasn’t scared because I knew it was nothing. In fact I read somewhere that if you have benign breast disease you are LESS likely to get cancer. My sister made herself sick with worry all for nothing. When God decides my time is up, He will take me. If it isn’t time, he won’t. That is what I believe. If I am wrong, I would still rather live a normal 60 years, than an unhealthy, fearful 90 years all cut up waiting for it to come back.
Linda, I couldn’t agree with you more. I’ve never done routine screenings of any kind, including mammograms, because I don’t believe in them. I’m an active, healthy woman of 74, and I’ve never had cause to regret that decision.
I recently had a mammogram after a long hiatus. I am 66 and about 20 years ago I opted out of getting the test. I did it because the whole process around it was fraught with anxiety, uncertainty, and a general lack of compassion in the process of getting mammogram itself.
I have never been warned about drawbacks of mammography. t has always been “sold” to me as a way to catch cancers when they are too small for detection my hand. Sometime in the 80s I started getting nicely produced reminders to get my test. It began to feel like it was being marketed, so I did more research since i was already feeling pretty uncertain about the screening. I read an article in Atlantic, which spoke to my concerns about the case for mammogram screening. The upshot of the article was that there was no clear case to be made, statistically for an annual test.
When I had my very recent one, which i was encouraged to do in a recent checkup, they were unable to retrieve my older pictures, since id waited too long. (couldn’t they keep them longer?? maybe)
Anyway a similar routine occurred to my past mammograms. I received no result except by mail several days later–a note which said they would like to get additional views and would I call and make an appt. I did that but was told that they’d sent info to my Dr.to ask for a necessary order. I wondered why send the letter then….
The breast center called me back eventually and I went in for a nerve wracking add’l image which wasn’t enough then they also wanted to do an ultrasound. By that time I was getting very nervous and brought my husband in to wait with me. I’m sure many people can relate tho that part.
Finally the ultra sound person came back in after the test and said you’re okay and the radiologist WAS concerned about a small area but not VERY concerned–they would send the results to my dr along with their recommendation, which by the time i got home I realized I didn’t ask for. I had a migraine from the loss of sleep from worry, the waiting and the OMG the whole thing I guess. Their recommendation must be that i get screened next year–something I am not inclined to do after this last all too familiar experience. Perhaps I’ll be permitted to get an ultrasound done instead by the time someone tries to talk me into doing another test.
I can’t say that I have only scientific reasons for not wanting to get regular mammograms, but I do feel that there is enough uncertainty about the efficacy and overall benefit of mammograms, and feel that they are part of a “medical industrial system” I’ve grown very skeptical of.
I am not at all critical of anyone who gets mammograms or is helped by having one. These thoughts are about my feelings about mammograms, for me. Thanks