NBCC Conference Notes: Hard Data

No, I’m not an expert.

My last post was just published on the news/blog aggregate site, Opposing Views, and received this comment:

“To opine that early detection does not matter when she benefited from it herself in order to make a separate point about MBC is a desperate attempt to sound like an ‘expert’ which obviously she is far from.

There is no cure for MBC, but she [meaning me] is living proof that her cancer was contained and small enough giving her every reason to expect to live a long life. It is quite the specious jump to compare a case of DCIS to MBC to gain attention. What’s worse, is in the same breath she says mammography does not find early cancer but her early cancer was found by mammography is misleading and irresponsible.”

Far from making me angry, it pointed up to me how hard it is to summarize complex information in the space of a blog post. I try to provide links to the references and resources I use to write my posts, and then attempt to summarize their findings. But I know that everyone does not have the time or inclination to click on every link to find out whether I’m just full of hot air or whether I can back up what I say. And sometimes, no matter what I say or how I say it, I just don’t manage to get my point across or my words and intent are misunderstood.

So, in this post, I’m going to provide some data. It’s unlikely to make anyone happy, but perhaps it will help to underscore some of the points I was attempting to make in my last post, which are:

  1. Screening mammography is different from diagnostic mammography.
  2. Screening mammography overall has been associated with only a small reduction in breast cancer mortality.
  3. Mammography in general is an imperfect tool for detecting breast cancer, particularly for younger women with dense breast tissue.
  4. Currently, mammography is one of the few tools we have, and we need better tools.
  5. Despite the increase in screening mammography, the mortality rate from metastatic breast cancer has remained virtually unchanged over the past twenty years, and the incidence of invasive breast cancer in women has, in fact, risen from 1 in 11 to 1 in 8 since 1975.
  6. Current treatment can sometimes slow or stabilize metastatic breast cancer, but we have no treatment at present that can stop it.

As for the rest of the commenter’s remarks, the inclusion of DCIS in my last post was obviously misunderstood and the context for it was apparently missed. To restate the issue, DCIS is an interesting and illustrative subject in the realm of the entire discussion of breast cancer because:

  1. Perhaps the one unqualified ‘success’ that may be ascribed to screening mammography is that it has helped to find far more incidences of DCIS over the years.
  2. Previous studies indicate that 14 to 53% of DCIS incidences may develop into invasive breast cancer.
  3. We do not yet know how to tell which types of DCIS may become invasive. So, despite the fact that some of them may not, we have to treat all of them as if they will.
  4. We also do not know yet how to predict with certainty whether any woman with any type of breast cancer will develop metastatic disease.
  5. All breast cancer treatment, including that for in-situ ductal and lobular carcinomas, is aimed at preventing the development of metastatic breast cancer.

Number crunching.

It’s not like I make this stuff up. First of all, here’s a link to the lengthy report, with research references, published by the National Breast Cancer Coalition, from which, along with what I learned at their recent conference, I have gleaned my information.

Ending Breast Cancer: A Baseline Status Report

It’s a downloadable PDF and I encourage everyone to browse through it. From the report:

“A great deal of attention and resources have focused on the area of early detection. A mantra that has been drummed into our consciousness over the past forty years is that early detection saves lives. The reality is otherwise. About 70% of women in this country over age 40 have had a mammogram in the last two years.[5] Unfortunately, randomized controlled trials for mammography have shown, at best, a marginal benefit.[6,7] Breast self-exam (BSE) has also long been a key women’s health mantra. But research has demonstrated that routine BSE does not lead to a decrease in mortality from breast cancer nor does it find breast cancer at an earlier stage.[8,9]”

While I am the first one to recommend that research findings be viewed with some healthy skepticism, study results that admit to ‘bad news,’ that do not appear to benefit the researchers or the tools, treatments or medications they report on, are hard to refute. The NIH has made hundred of research citations and results available on the subject of breast cancer. Here is a link to a PDF of the studies on the efficacy of screening mammography in reducing breast cancer mortality. From the data synthesis:

“Mammography screening reduces breast cancer mortality by 15% for women age 39-49 (relative risk [RR] 0.85; 95% credible interval [CrI], 0.75-0.96; 8 trials). Results are similar to those for women age 50-59 years (RR 0.86; 95% CrI, 0.75-0.99; 6 trials), but effects are less than for women age 60-69 years (RR 0.68; 95% CrI, 0.54-0.87; 2 trials). Data are lacking for women age 70 years and older. Radiation exposure from mammography is low. Patient adverse experiences are common and transient and do not affect screening practices. Estimates of overdiagnosis vary from 1-10%. Younger women have more false-positive mammography results and additional imaging but fewer biopsies than older women. Trials of CBE [Clinical Breast Exams] are ongoing; trials of BSE [Formal Breast Self-Exams] showed no reductions in mortality but increases in benign biopsy results.”

What this states is that, for women between the ages of 39 and 59, there is about a 15% reduction in breast cancer mortality associated with screening mammography. I’m glad to hear that it has done some good. And I have not ever said anywhere that I think women should stop having screening mammograms. But the crucial points here are:

  1. A 15% reduction in breast cancer mortality among women who have had screening mammograms means that for the other 85%, screening mammograms made no difference in reducing breast cancer mortality.
  2. There were no studies cited in this portion of the NIH report for women under the age of 39, a population for whom breast cancer is often more aggresive, and for whom mammography is often ineffective in detecting breast cancer due to breast tissue density.

As early as 2003, a review of much of the data on breast cancer screening, published in 2003 in the Journal of the American Board of Family Medicine, found errors in the studies then available showing that screening mammography was effective in reducing mortality. Some studies done by Canadian researchers showed no benefit at all. In one study, CBE, performed by a doctor during an office exam, found breast tumors that mammography had missed, and other studies showed that women found their own tumors, from 55% to 65% of the time, whether they were screened by mammography or not. The self-discovery of these tumors were found by both formal BSE and informal palpation, with no increase in detection demonstrated by BSE over informal palpation.

Finally, I just want to reiterate the explanation I included in a comment on my last post about the difference between screening and diagnostic mammography:

The basic technology is the same for both screening and diagnostic mammograms, but the specificity & number of images done are different. Screening mammograms are done for women who do not have any symptoms. They take only a few standard views of each breast. Diagnostic mammograms are for checking breasts that have symptoms or for women who have had breast cancer in the past. They take more views from various angles and usually zero in on any suspicious area. Often, the mamm tech will place small stick-on markers over the nipple or previous scars or any other area that needs to be highlighted.

Hard to swallow.

So, now you have some hard data. It still doesn’t make the conclusions easier to swallow. It doesn’t change the fact that we need better screening techniques. It doesn’t change the incidence of invasive breast cancer, which has, in fact, increased since 1975. And for women with metastatic breast cancer, it doesn’t change the odds.

I think we can all agree that what we want is real survival. Please don’t shoot the messenger.


Resource Links:
Breast Cancer Deadline 2020 — Why Now?
Metavivor Research and Support, Inc., for women and men with metastatic breast cancer.
Metastatic Breast Cancer Network
Advanced BC.org
Theories on Metastasis: An Advocacy Perspective, a presentation Musa Mayer made in a Leadership Training workshop at the recent NBCC Conference.


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This entry was written by Kathi, posted on Friday, May 06, 2011 at 11:05 am, filed under Attitude, Fighting the Pink Peril, Health & Healthcare, Nitty Gritty, Research and tagged , , , , , . Bookmark the permalink . Post a comment below or leave a trackback: Trackback URL.

21 Responses to “NBCC Conference Notes: Hard Data”

  1. Direct Quote from the NBCC: Ending Breast Cancer A Baseline Status Report (2011): “Yet many resources are devoted to giving the message of breast self-exam and mammography screening for younger and younger populations. Attempts to apply evidence to the message of early detection are often met with anger and derision, as evidences by the response to the revised screening guidelines issues by the U.S. Preventive Services Task Force in 2009. But these are matters of science. As our knowledge progresses, our beliefs must change to accommodate new information, no matter how much this challenges long-held beliefs and no matter how much we do not like the answer.”

    IF WE CHOOSE TO IGNORE THIS STATEMENT, THEN WE ARE CHOOSING TO IGNORE OUR CHANCES TO MOVE THE FIGHT TO BREAST CANCER ERADICATION/CURE FORWARD.

    KEEP SHOUTING KATHI, I’M RIGHT THERE WITH YOU SISTAH!

  2. I think you’ve touched on the problem; it doesn’t make easy reading. Many people can’t cope with this (for a whole range of reasons). The problem is that as a result, the real issue is all too often missed. The messengers will continue to be shot at, but we are experts in survival! So I’m with ccchronicals – keep shouting.
    E xx

  3. A follow up question I have to this post and that I believe would educate and help readers understand the big picture would be “What are the benefits of breast self exams and mammogram screening for women below the age of 39? Do they help at all?”

  4. Great question, Murray. And great to meet you at the NBCC Conference. Formal breast self-exams (the step by step kind) don’t work any better than the informal palpation women do in the shower or in other daily activities. Which means that women should still be aware of any changes in their breasts & not ignore them, but they don’t need to do that formal, monthly thing we all used to do. Here’s a link from my friend Gina’s site on her Before Forty Initiative. She is trying to get the baseline screening mammography age lowered down to 35 for all women & down to 30 for women in high-risk groups. And also to get insurance coverage for baseline breast MRI’s for younger women, the ones for whom mammography is most likely to miss something. If a woman younger than 40 finds something, she should probably be getting a diagnostic mamm, plus a breast MRI, plus other diagnostics, to get as much info as possible. I need to look up the studies done on women under 40 on mammography efficacy. We desperately need better diagnostic tools.

  5. The best any of us can do is not just read the NBBC report (which has its own bias to drive home their conclusions) or ACS report, or Komen report. There’s truly no unbiased source of information. The best we can do is read the data ourselves; or in lieu of that, ask questions outside of what is presented.

    We need to walk into all of our breast cancer treatment decisions with information and our feet on the ground. Metastatic disease needs attention. We get that. DCIS needs attention. Gary Schwitzer has done a good job of covering the coverage, on both the USPSTF guidlines and DCIS (http://www.healthnewsreview.org/blog/2010/07/excellent-story-by-new-york-times-on-dcis.html; http://www.healthnewsreview.org/blog/2010/01/why-dont-journalists-pay-more-attention-to-dcis.html; http://blog.lib.umn.edu/schwitz/healthnews/2009/10/dcis-dilemma-de.html). We really need a summit on DCIS as well as metastatic disease.

    And “matters of science” which NBBC alludes blithely? Matters of science are essential if we are to achieve Deadline 2020 or any slowing of progression in triple negative and inflammatory breast cancers. That’s where incidence of mortality will drop like a stone. Matters of science will keep these precious women alive long enough for their cancers to be studied.

    PS – did any of us ask whether or not OncoTypeDX was of any value for DCIS? I don’t know the answer to that.

    But I do know this: when we’re talking about cancer, I’m more than willing to wade through the information. Thank you, Kathi. I love it that you roll up your sleeves and dig in.

    Jody

  6. Love your articles Kathi! The information in the previous two is unpalatable but the hard evidence can’t be refuted.

    I am hugely ambivalent concerning the screening of women with low risk factors in their 40s. From age 45, I had yearly diagnostic mammograms and ultrasounds due to recurrent cysts. At the time I thought it was just regular screening but now I realise that it was diagnostic because each year, additional x-rays were taken and I nearly always had spot compression followed by ultrasound. Did the extra radiation contribute to my extensive, high grade, microinvasive DCIS just after I turned 50 which required a mastectomy? If mammography was truly efficient, it would have found the cancer when it was tiny and fully contained.

    So, yes, my cancer was picked up “early” and I am hugely grateful that I didn’t have to face the much harder journeys of those who have more advanced cancer but…it would have been nice to keep my breast.

    I’m joining in the YELLING and SCREAMING for better technology! How wonderful it would be if cancer could be discovered when it was just a tiny cluster of contained cells…

  7. Jane, first of all, it’s nice to see you here, sistah!! This is SUCH a thorny & complex subject. One of the things that convinced me that I did the right thing by having half my breast removed for DCIS was that the apparent spread of it had widened from that seen on the original diagnostic images and the mamm that was done right before my surgery to perform the wire localization several weeks later. The radiologist who did the wire localization ended up have to insert two wires to bracket the spread so that the surgeon could find them all. The other thing that convinced me was the final pathology report after the surgery. The cells found in the tissue that was removed were Grade 2 and 3, meaning that they were growing moderately quickly, and some of them were growing very quickly. I had only had normal, quick, screening mamms all the years before, and there was nothing on the one I had the year before the last one that showed the DCIS. So, that tells me that my own DCIS might have turned ugly and invasive had it not been removed when it was.

    Someday, let’s hope that we have better tools for finding cancer, as well as better tests for evaluating biopsy tissue. I’m going to keep screaming until we do!!!

  8. Great post by the way. I believe you are doing a fantastic job of explaining complex issues and getting discussion going. I have many follow up questions. Lots of research to do.

  9. Kathi, I found my own breast cancer, 6 months after a birads1 mammogram at age 49. I got them annually. When I presented to my gyn, she blew it off, but I insisted on the diagnostic and it was a 1.6 cm IDC. All those years of annual screening, with dense breasts, and I found it while reaching to turn off a lamp.

    Yes, early stage breast cancer has a better prognosis and requires less treatment.

    But the need of over-simplification is clearly refuted by your data.

    You’re presenting uncomfortable facts–and I do appreciate your honest and well researched and well written posts.

  10. Kathi, I found my own breast cancer, 6 months after a birads1 mammogram at age 49. I got them annually. When I presented to my gyn, she blew it off, but I insisted on the diagnostic and it was a 1.6 cm IDC. All those years of annual screening, with dense breasts, and I found it while reaching to turn off a lamp.

    Yes, early stage breast cancer has a better prognosis and requires less treatment.

    But the need of over-simplification is clearly refuted by your data.

    You’re presenting uncomfortable facts–and I do appreciate your honest and well researched and well written posts.

  11. Thanks Judy & Jody.

    Those links were great, Jody. There is also this weird, insidious tendency in the US these days to ignore or dismiss scientific findings on all kinds of issues, often to bolster a political agenda. The global warming debate is a case in point. There are certainly valid reasons to be cautious about leaping to conclusions when reviewing any scientific research, because researchers themselves are often not immune to presenting results that support their own agenda. One of the most difficult posts I’ve written was about research spin [Hormones + Breast Cancer = Spin?].

    There’s a post about this at The Ethical Nag, called Experts: Why So Wrong, So Often? that mentions a book whose author found that, among other things, “About two-thirds of the findings published in leading medical journals are refuted within a few years.”

    But science is what we have. And no one with any sense would toss it out as useless or entirely suspect.

    Like everything else, we need to be smart consumers of information.

  12. Kathi,have you read the New Yorker article about inherent bias in research: it’s great, IMO
    It’s called : The Truth Wears Off
    http://www.newyorker.com/reporting/2010/12/13/101213fa_fact_lehrer

    It is all about inherent bias and inability to replicate research.

  13. Wow, Judy. Yet another salvo about the scientific method. One of the best speakers at the conference talked about how researchers need to be able to publish ‘negative’ research, i.e., studies that disprove whatever hypothesis they set out to study. He thinks this is just as, if not more, important as publishing ‘positive’ findings. And open source databases.

    Interesting. This is the study I cited in that previous post about research bias:
    Research Bias JAMA

  14. This is an excellent post, Kathi. Mammography screening has been the most widely studied screening tool, and the low 15% benefit is appalling. A more recent study found that the benefit attributed to screening may be only 10%. In either case, the vast majority of women are not living longer in the long run as a result of mammography screening (based on the current technology).

    Compare this to almost a 99% reduction in cervical cancer mortality from the pap smear when the tool is used regularly. WOW! Now that’s a screening tool that works.

    You’re absolutely right that we need a better screening tool. To keep going on with the message that screening leads to early detection, which ultimately saves lives…is preventing the public from seeing the forest AND the trees.

    Thanks for writing this.

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