Mammogram
“A 25 year Canadian study just published in the British Medical Journal questions the value of mammography. Research suggesting that mammography may not be beneficial was covered by some of the nation’s most widely-read newspapers as well as on several medical websites.
“In a front-page story, the New York Times (2/12, Kolata) reports that research published in the BMJ, “one of the largest and most meticulous studies of mammography ever done, involving 90,000 women and lasting a quarter-century, has added powerful new doubts about the value of the screening test for women of any age.”
“The findings may “lead to an even deeper polarization between those who believe that regular mammography saves lives, including many breast cancer patients and advocates for them, and a growing number of researchers who say the evidence is lacking or, at the very least, murky.”
“The Los Angeles Times (2/12, Morin) reports that investigators “examined the medical records of 89,835 women in six Canadian provinces between the ages of 40 and 59. All of the trial participants received annual physical breast examinations, while half of them also had yearly mammogram screenings for five years, beginning in 1980.” During “the next 25 years, 3,250 of the 44,925 women in the mammography arm of the study were diagnosed with breast cancer, along with 3,133 of the 44,910 women in the control group.” Meanwhile, a nearly identical number of patients from each group died of breast cancer.
“In a separate story, the New York Times (2/12, Rabin) reports that the new findings will add to the controversy surrounding the value of mammograms. Further complicating the issue is the fact that different medical groups have different recommendations regarding mammography.
“USA Today (2/11, Szabo) reports that ‘Barbara Monsees, a radiologist with the American College of Radiology, says the…study is fundamentally flawed and useless for drawing conclusions.’ “
Blogfinger Medical Commentary by Paul Goldfinger MD, FACC:
If you walk on Main Avenue in Ocean Grove, if the snow has been cleared, you will see remnants of a pink stripe that was put down during a one month breast cancer fundraiser in October. The pink symbols were everywhere, and the theme was to promote mammograms for women who hadn’t had them. I thought that the pervasive drumbeat was overdone, given that it was all about pushing mammograms. I couldn’t recall another comparable fundraiser that focused on a diagnostic test rather than basic or clinical research into prevention and cures, so this month- long effort seemed to me to be out of proportion.
In 2009, the US Preventive Services Task Force recommended cutting back on mammograms for all women, and especially avoiding them altogether for those in their 40’s. They suggested that women age 50-74 have the test every other year. The American Cancer Society disagreed and suggested mammograms yearly from age 40 and up.
A controversy ensued which is still simmering and has now been exacerbated by this massive Canadian trial on nearly 90,000 women over 25 years. The study concluded that annual screening mammograms do not reduce death rates when compared to skilled manual examinations by specially trained nurses. They say that too many mammograms are being done and that mammograms can cause “harm.”
Last week, on NPR.org radio, there was a one hour discussion with Diane Rehm interviewing two of the world’s experts in mammography as they debated the results of the Canadian trial. They had practically opposite opinions and they were attacking each other over facts and even issues such as conflicts of interest and flawed conclusions.
So there is no way that I can do this subject justice except to summarize the facts and the issues, especially as put forth by the Canadian trial. I suggest that women do some reading on their own to avoid being swayed by experts with agendas:
1. Mammography is an imperfect test for the diagnosis of breast cancer and is over-rated as a life-saving procedure. The idea that early detection saves lives is being seriously questioned.
It is true that in recent years, the survival rates of breast cancer have improved significantly, especially in the 40-49 year old group, but the benefit seems to be due to newer treatment options, such as the drug tamoxifen, and not due to screening mammograms.
2. This huge Canadian trial is being criticized by some, such as a leading professor of radiology from Harvard, on the grounds that the study design was flawed, the quality of the mammograms was awful, and too many small tumors were missed due to antiquated machines. He also had other highly technical criticisms as well.
3. Even current mammography machines sometimes miss small cancers. The test also often raises questions about abnormalities that are not cancer (i.e. false positive results.) 30% of the time patients are brought back for more films causing great stress and extra radiation. In addition, the test may detect cancers that either are too small and slow growing to cause harm or are pre-cancerous conditions which will not endanger lives. One in five cancers found by mammography are the kind that pose no lethal threat, so those patients currently get unnecessary treatment.
4. The problem with such “over diagnosis” is that some women get subjected to harmful aggressive approaches including biopsies, drugs and mastectomies which are not necessary. The harms include drug toxicity, surgical mutilation and risks, and mental distress. The researchers in Canada say that sometimes mammograms cause more harm than good.
The clinical challenge is to decide which cancers can be left alone or just treated medically. The ability of oncologists to make these differentiations are currently inadequate.
5. Some fund raising organizations have been accused of over stressing the importance of mammography and distorting the statistics of success attributed to the test. (see the Time article below).
6. This new trial of 90,000 will cause all doctors who treat breast cancer to re-evaluate their use of mammography and will result in a new assessment of the criteria for ordering screening mammograms. These new guidelines should be available in 2015, but as with the PSA controversy, different expert panels will offer different recommendations.
7. At this time, most women will probably plan to continue with the same yearly regimen from age 40-59 (which is the age range of the new study,) but they may be surprised to find a more nuanced individualized approach when they see their doctors. And they may discover that their doctor offers them an option of skipping mammography altogether.
One potential concern is whether the new Obamacare insurance policies will cover all mammograms that are requested. This Canadian study will likely provoke women’s advocacy groups to object strenuously because most American women have been sold on the life-saving benefits of early diagnosis with mammography.
8. There will be many women who have not had mammography or who have been skeptical of the test. They will use the controversy as a reason not to have mammograms. But if a woman makes that choice, she must do self examinations and have a manual exam by an expert examiner yearly. (The same is true also for women who do have mammograms.) She also should discuss her decision with a doctor, because some individuals have higher risks than others.
9. New imaging methods are in the works including 3-D mammography.
Time magazine article on Komen ad
10. Here’s a link to a NY Times article on self examination of breasts:
Paul, Your take on mammography seems to be well thought out. I understand some of the concerns, but can there be a study on anything spanning 25 years where there isn’t much room for contention?
Yes, tamoxifen is routinely used now and my mother was on it several years before she died on another issue and she died 20 years ago. So, that drug which is great has been around during both arms of the study.
Another issue is that most breast cancers are present long before they kill and most believe that they are around years before they are palpable. While no one knows the answer to this, I do not think it possible to have a better study over a 25 year period because in any 25 years period, diagnostics change , drugs change etc..
I believe self examination often and medical examination periodically is probably the better approach.
Also, when a woman has a nodule on x-ray in the US, it is often followed by a biopsy and days of anguish for the patient. I do not know the answer, but the costs eliminated prior to surgery would be substantial if that approach were not done.
Good blog.
(note: rk is a retired internist from New Jersey)
Thank you for posting Anna’s comment. It’s so important to know about other options. I agree about ultrasound. If a problem shows up on the mammo…they send you for an ultrasound. Why not skip the radiation and vise treatment? I use thermography and ultrasound.
BTW….”Dallas Buyers Club” was a very interesting (but rough) movie!
So much money is at stake from these findings like these. MD income, investments in imaging centers, the medical device manufacturers. Kudos to the researchers for presenting unbiased results.
I saw a discussion on PBS about the study. The researchers are not recommending an end to mammography. Only that mammography does not seem to provide any better screening than a physical exam. And that women should make an informed choice about mammography as a screening option. That would be more likely to happen if the providers did not have such a large financial stake in the status quo.
Anna: Thank you for your comment. This post is about mammography, and that is why other diagnostic procedures such as ultrasound were not mentioned.
Not a mention of ultrasound. An accurate, no harm done procedure. Ultrasound machines have come a long way too using 3 and 4 D imaging. Ultrasound is used second to a mammogram when the nurse finds something. And ultrasound is less expensive. Lets recap: less harmful, no radiation; less expensive, less painful/uncomfortable, more accurate. There is also a test, not covered by insurance, where a breast pump is used to induce fluid from the nipple, which is then sent to a lab for testing. This method can detect and predict cancer many years in advance. I have had all the above tests as precautionary testing. I have never had breast cancer, thank God. I do not go for yearly mammograms. I am more concerned with ovarian cancer which is much harder to detect. Good luck ladies in choosing the right modality and have insurance pay for it. Anna
I think there are different levels of conflicts of interest. The worst kind is when there is a money trail. In the case of the breast cancer screening war, the lead author of the Canadian paper, a professor at the Univ. of Toronto, has given 25 years of his life to this study. He receives no money from drug companies or device manufacturers. He receives his pay as a professor, and his work on the study is part of his job. I guess his only agenda is to protect his reputation as his study is being criticized by some other scientists.
But the Harvard professor who savaged the study on NPR is a professor of Radiology at Harvard Med who trains doctors to read breast films and he obtained a patent for a new mammography machine. He says that his hospital in Boston actually holds the patent, but do you think that he will not benefit financially if mammography remains an important test? I don’t know, but in assessing medical research, human nature is such that conflicts of interest must be discovered in order to be sure of the credibility of the study. Major medical journals will not publish scientific papers now without each author stating potential conflicts (such as owning stock in the company whose drug he is studying.)
If only there were such a thing as “an expert without an agenda”, who, pray tell, would that be? Who do YOU believe?
I saw the movie DALLAS BUYER CLUB which raised the same issues of competing groups fighting for themselves: drug companies, various Government Agencies, hospitals, physicians, ,healthcare corporations, publications, etc… rather than what MIGHT be best for the patients. It was not resolved (in the movie) until a foreign medical journal, The LANCET published some info.
Are we seeing a similar “script” re breast cancer?