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Mammogram uproar

Posted by medconsumers on November 18, 2009

Ten years ago I opened my driver’s license renewal notice and out dropped a pink slip reminding me to have an annual mammogram. While it was touching to know that the New York State Department of Motor Vehicles cared about my breast health, I saw the pink slip as yet another example of over-the-top mammography promotion. (My husband has yet to receive any health instructions from the DMV.) When a test’s lifesaving benefit has been oversold to the public for over three decades—and the harms downplayed—any cutback in recommendations will be met with a firestorm of anger.

That’s exactly what happened yesterday when a highly respected organization recently broke ranks with others that issue screening guidelines and advised women at average risk for breast cancer to begin having regular mammograms at age 50, not age 40. The U.S. Preventive Services Task Force also changed two longstanding recommendations: women age 50 to 74 should have a mammogram every two years rather than annually (cuts down on the biopsies without altering the number of lives saved), and doctors should stop teaching women how to do breast self-examination (no benefit, more biopsies). Shock, horror, and condemnations followed the announcement in the media on Monday. Not a surprising reaction considering the advice to the public preceded the science.

The recommendation to start mammography screening at age 40 was premature to begin with, dating back to the early 1970s. Incredibly, it was based on one clinical trial conducted in the 1960s that found a 30% reduction in breast cancer deaths in the women over age 50 but no benefit for women in their forties. That clinical trial, known as the Health Insurance Plan of Greater New York study, had followed the participants for three to five years. Not unreasonably, public health officials at the time thought that the younger women in this study would eventually show a reduction in breast cancer mortality with longer followup. They didn’t bother to wait and the aggressive promotion of mammography took off after President Nixon declared the “war on cancer.” Thus began a nationwide campaign, sponsored by the American Cancer Society and the National Cancer Institute, urging women over the age of 35 to seek yearly mammograms complete with the overly optimistic message that early detection will save their lives.

Radiation exposure was the only acknowledged harm in this era, and it was usually dismissed as unimportant in comparison to the benefit of finding breast cancer early. By the 1980s, mammographic techniques had improved and the radiation exposure greatly reduced. A modest reduction in breast cancer deaths in younger women was found in some, but not all, clinical trials done in other countries. The largest trial intended to answer the question of mammography’s value to women in their forties found no lifesaving benefit. Basing its estimate on the trials that did find a benefit, the U.S Preventive Services Task Force concluded that one in every 1,900 women who undergo an annual mammography over a ten-year period will avoid a breast cancer death.

In 2001 the Lancet published the first evidence indicating that mammography screening leads to overtreatment without reducing mortality. The authors, both researchers at the Nordic Cochrane Centre, did an in-depth assessment of the data generated by all the randomized mammography screening trials. To this day the Cochrane researchers continue to reassess the research (read a 2009 update of their findings). What they have found is entirely counterintuitive and not confined to women in the forties. Mammograms can detect tiny cancers, but not all of them would become deadly or even produce symptoms if left untreated. Yet virtually all are treated aggressively because no test can accurately sort out the potentially lethal cancers from those that do not progress. Overdiagnosis and overtreatment are the terms for this problem, which was quantified in a study published recently in the British Medical Journal, showing that one in three cancers found on a mammogram would not become life-threatening. This should have been the major reason for the change in recommendations, but the media coverage frequently presented mammography’s major harm as the anxiety from false alarms and breast biopsies. As for the other major harm—radiation exposure—the USPSTF cites this estimate, “annual mammography of 100,000 women for 10 consecutive years would result in up to 8 radiation-induced breast cancer deaths.”

The USPSTF based its revised recommendations on the findings of a panel of experts made up of research physicians and most crucially, biostatisticians who quantified some of the harms as well as the benefit. Their task was to assess the evidence generated by the world’s gold standard trials, as well as observational studies. While we all hope that our physicians are familiar with the evidence supporting their advice, the sad reality is that many are not. Most simply follow the advice of organizations like the American Cancer Society and the American College of Obstetricians and Gynecologists. What’s more, it’s as hard for them to change their thinking as it is for us. Here’s just one example. From the professional advice given my daughter and her friends, I know that the long-discredited American Cancer Society recommendation for women to have a baseline mammogram in their late thirties continues to live on. (The ACS quietly withdrew this recommendation in 1992, but it takes time for the word to get out.)

Other sources of information:
If you want to make an informed decision about mammography, go directly to the scientific evidence instead of your doctor. Here’s a timeline for the key studies and previous failed attempts to raise the starting age for mammography which was published recently in the New York Times. This is a “summary of the evidence” from the randomized trials and observational or population studies (i.e., mammography done in the real world), which formed the basis for the USPSTF’s revised recommendations. And this is the National Cancer Institute’s summary of pretty much the same clinical trials (note that the first trial that justified the advice to start mammography at age 40 is described as being of “poor quality”), as well as population studies. The NCI summary is difficult to read, but this sentence from the summary is easy to understand, “Screening for breast cancer does not affect overall mortality, and the absolute benefit for breast cancer mortality appears to be small.” This applies to women who start mammgraphy at age 50 as well as those who started at 40.

Using the same data, researchers at the Nordic Cochrane Centre have produced a more understandable summary for women that is available on the Web (see link within this article). To increase your chances of having a mammography performed skillfully, read How to Select a Mammography Facility . And to reduce your chances of an inaccurate diagnosis, read “When to get a 2nd pathology opinion.”

Maryann Napoli, Center for Medical Consumers(c)

Two days after the USPSTF issued its recommendations, HHS Secretary Kathleen Sebelius issued a statement distancing the Obama Administration from the new guidelines. In short, she told women to ignore them and claimed disingenuously that more research is needed. This is very disappointing to those of us who had high hopes that health care reform would mean that medical treatment and screening decisions, as well as cost-cutting measures, would be evidence-based. Once again, mammography’s evidence is clouded by politics. This time around, however, the politics make sense. No doubt, Secretary Sebelius did not want to derail the current health care reform efforts.

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17 Responses to “Mammogram uproar”

  1. Bonnie Spanier said

    Your analysis, as usual, Maryann Napoli, is excellent. But I may have found an inadvertent error in your answer to comment #6 below. Your link to the USPSTF “summary of evidence” is for the 2002 report, not the current 2009 one. You quote “Even in the best screening settings, most deaths from breast cancer are not currently prevented.” I cannot yet determine whether the 2009 Summary includes that statement, but your link is to 2002, not 2009.
    Your ability to write so clearly about such a complex issue and its many studies and interpretations is just awesome! Much appreciated.

  2. Laurel Robertson said

    I do appreciate your amazing work so much!

    But, please. To expect normal women, even educated ones, to navigate this roiling mix seems seriously unrealistic. Most of us practice the best health care we can, but few of us have training in statistics. Please give us your own concise ten-line recommendation list — if possible! I don’t want you to get sued or something. Each point could link to more info, as above.

    Please consider that isn’t just that we don’t want to DIE of it. We have been conditioned to loathe and fear the demon breast cancer, and to live in horror of being maimed because of having been diagnosed & treated late. It is not overstatement to say that “Breast Cancer Awareness” makes it scarier not to risk being over-tested than it is to hold off — at least, until you get one of those false positives.

    I haven’t had a mammogram because I have followed this discussion for so long, and because it hurts me to see the repeated rounds of incapacitating anxiety my friends have suffered from multiple needle biopsies, for nothing. Nothing but their costs in money and time, and, maybe, injury.

    How I wish we could seriously address known causes (at least) and curb this grotesquely profitable industry of breast “health care”! Well, you have done a lot on that score, and bravo.

    Thank you.

    • medconsumers said

      You’re right. We have been conditioned to fear breast cancer. Fear-mongering is essential to the promotion of all cancer screening tests. I cannot explain why mammography is far more likely to harm than help women without symptoms any better than I did in my reply to comment #6 below. See the 2nd paragraph that describes the three different forms of breast cancer and click into the hyperlink to the Cochrane Review at the end of my reply. The latter indicates that mammography is ten times more likely to ruin your life than save your life. Mammography screening itself results in the “horror of being maimed” unnecessarily. This Cochrane review shows that ten healthy women are treated unnecessarily for every one woman who avoids a breast cancer death.

  3. Mary M said

    Thank you so much for explaining what is known about breast cancers (Medconsumers/comment posted Dec. 6) as it was information I had not seen previously, though I try to keep informed on this. As I understand this, all the early diagnosis on women with no symptoms does not affect mortality, meaning many treatments (often problematic in themselves)are futile in terms of saving lives. It’s not something we want to hear, which perhaps is why it’s so difficult to accept. I know research on cures is important, but why is there not more emphasis on causes? Better to prevent the cancer than try to treat it, although this might make many chemical companies unhappy.

    • medconsumers said

      Unfortunately, you misunderstood. Go back and read my description of the three types of breast cancer. Early detection of one form of breast cancer will definitely save lives, but this is a small category representing only about 15% of all deadly breast cancers. I agree with your last point about prevention.

  4. Roberta Pikser said

    One hears that African American women are at greater risk of developing breast cancer than Caucasian women. 1) Have any studies dealt with this? 2) If it is the case, what would recommendations for mammograms be for African American women.

    • medconsumers said

      African American women are slightly less likely to get breast cancer than white women but more likely to die of breast cancer, according to the American Cancer Society. African American women have been underrepresented in the mammography screening largely due to the fact that the majority were conducted in Sweden, U.K., and Canada. Perhaps that is why the U.S. Preventive Services Task Force did not single out African American women for more frequent mammograms.

  5. JaneM said

    I’m concerned that I’m not seeing much information about the possibility that 10 years of mammograms may be causing cases of cancer and that the mammogram itself, specifically the compression, may damage tissues and cause otherwise capsulated cancers to be spread. I don’t think women are getting the message that the cure may be as bad as the disease.

    • medconsumers said

      See the article above for the number of radiation-induced breast cancers expected after ten years of mammograms. I don’t know of any research about damage to breast tissue from breast compression, but you might want to read this about mammography’s role in surgery-induced damage to premenopausal women. This 2002 interview with two mammography researchers mentions the work of Dr. Michael Retsky at the Harvard Medical School, “Mammography: Should you have one?”

      • JaneM said

        It makes me so furious! I have been a good girl and had my yearly mammograms since I was 40. This year, at age 56, I declined to get one for the first time as I had never before heard of these issues. It is not right that women are not being fully informed of their risks. I have friends who have died from breast cancer, or rather, probably from the chemotherapy treatment for breast cancer. How many of them have died needlessly?

        Thank you for this wonderful site which I only recently have discovered. I can tell you for sure, though, I would certainly take advantage of the consultant biopsy services before I started radiation or chemotherapy.

  6. A Redoux said

    Is the statistic that 1/3 cancers found on mammogram would not become life-threatening supposed to be reassuring for skipping mammography? I’d prefer to risk having treatment if there was a 2/3 chance that it’s life-threatening. And I’d prefer creating 8 cancers in 100,000 women in the process of finding and treating 2 in every 27women (I calculate 2/27 from the breast cancer incidence of 1/9 and the 1in 3 not life-threatening).

    I’m puzzled with all this. Plenty die young from breast cancer. How can we catch any early if we throw out mammography AND self breast exam which was previously reported as no longer recommended. (Though last I’d heard most cancers are found by women doing self breast exam.)

    • medconsumers said

      No, the one-in-three stat was mentioned in the above article to show women their chances of being treated unnecessarily once breast cancer is detected by mammography (and it refers to all women, ages 40 to 70). It did not come from the new U. S. Preventive Services Task Force (USPSTF), which failed to quantify this important harm in its newly revised mammography recommendations. It came from other researchers who have been reviewing the data from much the same published mammography studies that formed the basis for the USPSTF recommendations. The USPSTF described “anxiety, discomfort and cost…false positives” as the “most frequently discussed adverse effects.” This in turn played out in the media as the most serious harm. Your 2 in 27 stat doesn’t hold up because that familiar 1 in 9 stat is just the lifetime estimate of a woman’s chance of being diagnosed with breast cancer if she lives to be 90. The 1 in 3 stat, on the other hand, refers to all mammography-detected breast cancers. It is based on findings from clinical trials and refers to a woman’s chances of being treated for a breast cancer she did not need to know about.

      Your puzzlement, no doubt, stems from the longstanding “early detection saves lives” message, which implies erroneously that early detection is synonymous with cure. Breast cancer is complicated, falling roughly into one of three distinct categories. One type is so rapidly fatal (within about two years) that early diagnosis makes no difference; another type is cured by early detection, but it is thought to include only 15% of all deadly breast cancers; and the third type—which is the largest category—grows so slowly that it doesn’t need to be detected early and as many as 25% of them would have remained dormant for a lifetime. This description of breast cancer has been around for well over 15 years…in medical journals. It is a paraphrase of an explanation given to The New York Times recently by a doctor who served on the USPSTF.

      You will not find such clarity in the USPTF recommendations, with these two exceptions: “Even in the best screening settings, most deaths from breast cancer are not currently prevented.” This sentence appears at the end of the “discussion” section in the USPSTF’s “summary of the evidence”. And just above that sentence is this, “We found no evidence that clinical breast examination [performed by a health professional] or breast self-examination reduces breast cancer mortality.”

      The USPSTF did not suggest that mammography should be thrown out. It simply recommended starting mammography at age 50 and having one every other year rather than annually. This will cut down on the anxiety-provoking biopsies without altering a fortysomething woman’s 1 in 1900 chance of avoiding a breast cancer death. Unfortunately the USPSTF did not make this critical point clear: for every woman whose life is saved, great harm is inflicted on many more. See this Cochrane review for another research team’s benefit/harm calculations for all women, not just those in their forties.

  7. jane doll said

    Heard you this am on Cspan. In 2006 I was diagnosed with DCIS papilliary cancer in left breast, approx 2cm with negative margins and lymph nodes. Followup was 35 sessions of radiation with tamoxifin for 5 years. I had poor reaction to medication, even with a change to femara. After 3 months I stopped all medication. In 2008 a mamogram indicated an area the radiologist thought benign but the surgeon insisted on a surgical biopsy which was benign. I have concluded I was being overtreated. However I’ve not heard of this until this am. How do I confirm my suspicions? Without the knowledge of research I sense that there is hysteria abounding re breast cancer. Of course if I was sick and maybe dying I might feel differently. I was never given a stage of the original cancer but was told not to worry. I too had a sister diagnosed at 49 with an agressive invasive breast cancer. Where does one turn?

    • medconsumers said

      You could consider paying for a second pathology opinion for your original diagnosis from one of the pathologists. Their respectives services are described in my recent article entitled “When to get a 2nd pathology opinion.”

  8. Pam Carpenter said

    I’m so thankful that I adhered to the advise of getting a mammogram starting at age 40. I was diagnosed with Breast cancer at the age of 49. I believe that the 8 mammograms prior to the one that diagnosed my cancer were well worth the small amount of radiation that I was exposed to. It gave me peace of mind more than anything else. See, my sister had cancer when I was in my earlier 40’s. I believe that it is each individual woman’s right to decide when she should start having mammograms along with the advice of her Doctor.

    • J Simha said

      Hi Pam,

      You are a high risk woman. Your sister’s diagnosis made you that. The recommendations do not apply to you. They also do not apply to anyone who has a lump and needs a diagnostic mammogram. It is important to read the recommendations, understand them and try very hard to take all the information in and make an informed decision whether or not to engage in screening mammography.

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