2014 British Medical Journal Study Should Not Change Mammography Guidelines

Colin Begg, Chairman of the Department of Epidemiology and Biostatistics

Colin Begg, Chairman of the Department of Epidemiology and Biostatistics

A study published on Tuesday by the British Medical Journal questioning the benefit of yearly mammogram screenings has gained momentum in the media, while causing confusion among women and concern among experts in the field, including those here at Memorial Sloan Kettering.

The long-running Canadian study contends that annual screening in women aged 40 to 59 does not lower breast cancer death rates. But experts such as Larry Norton, Memorial Sloan Kettering’s Deputy Physician-in-Chief for Breast Cancer Programs, caution women not to be swayed by the headlines. They say the study has critical weaknesses that invalidate its conclusions and that regular mammography screening continues to be recommended for women in this age group.

“This is further follow-up of a flawed study,” Dr. Norton says. “There are no new data here, so it should not influence any changes in screening recommendations.”

The initial Canadian National Breast Screening Study (CNBSS), which began in 1980, was strongly criticized for two reasons. First, the mammograms performed were judged by outside experts to be of extremely poor quality, and the skills of the imaging technologists were deemed inadequate. Second, the subjects used for the study were not properly randomized into two groups of equal risk for comparison.

Colin Begg, who heads Memorial Sloan Kettering’s Department of Epidemiology & Biostatistics, says the Canadian study has always been an outlier. “It conflicts with all the other large randomized trials conducted a generation or more ago, which showed that mammograms lead to a notable reduction in breast cancer mortality,” he explains.

Study is ‘Flawed and Misleading’

Carol Lee, a diagnostic radiologist at Memorial Sloan Kettering who also chairs the Communications Committee of the Breast Imaging Commission of the American College of Radiology, says, “It is not surprising that the update didn’t show a benefit from screening, as the original report did not.”

The American College of Radiology and the Society of Breast Imaging also called the study “incredibly flawed and misleading.” The organizations released a joint statement saying, “The results of this BMJ study, and others resulting from the CNBSS trial, should not be used to create breast cancer screening policy, as this would place a great many women at increased risk of dying unnecessarily from breast cancer.”

The authors of the BMJ study suggest that annual screening mammograms can lead to “overdiagnosis” of breast cancer, causing women to receive treatments such as surgery for early-stage breast cancers that never would have progressed. But Memorial Sloan Kettering experts assert that it is impossible to determine whether a breast cancer will become dangerous and that fears of overdiagnosis are misplaced.

“Women contemplating screening for breast cancer are overwhelmingly concerned about dying from breast cancer, not the various side effects of screening,” Dr. Begg says.

So what should women do? Bottom line: Doctors at Memorial Sloan Kettering agree that annual mammograms starting at age 40 save lives and decrease the likelihood that women will die of breast cancer by at least 25 to 30 percent.


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Let me be the first to say, I am not one to throw the baby out with the bath water. There may be a role for the routine mammogram in certain populations of women in the US. However, for the vast majority of women, I believe it is only a matter of time before routine mammograms are no longer recommended. I cannot speak to the point about the mammographers being unskilled. Regarding the older studies, many experts have asserted that treatment for breast cancer has improved since these studies were completed and early diagnosis means less (in terms of mortality) given the better treatment. Dr. Begg's quote at the end encapsulates the screening conundrum very well. Unfortunately, there is far too much hysteria regarding breast cancer. Women should be able to make an informed decision before subjecting themselves to any cancer screening test. We are moving into an age of "personalized medicine." Yes, this term is indeed overused, but it is appropriate. Patients need to weigh the benefits, risks, and alternatives of screening with their individual provider before making any decision regarding their health. We are moving beyond this one-size fits all paradigm.

Regarding the concerns brought up by Dr. Tarone in his Cancer article -- his claims/suggestions were considered, but re-evaluation did not find them valid.

I realize it is only a quote, but the statement from Dr. Begg that “[w]omen contemplating screening for breast cancer are overwhelmingly concerned about dying from breast cancer, not the various side effects of screening,” seems incorrect to me. I am equally concerned about the side effects of screening and the possible risks overdiagnosis and burdens of overtreatment to which it may lead, out of the very same concern for my overall health that motivates me to seek screening.

Thanks so much for sharing your experience, Anne.

While I am grateful to have access to this well presented article, I am concerned about what may be overuse of available screening. The data on 3-D is minimal and I just had a 3-D with additional standard screening and Ultasound and have been asked to go for MRI. I understand that MRI will give a better indication, so I will do so. However, I have always had dense breast tissue. Perhaps I should only have the MRI. Will I continue to need all these tests every year? Also, would it be better if the same radiologist would evaluate the tests each year? My mother did have breast cancer in her 80's and I am now 75.

Judith, unfortuntately we are unable to answer specific medical questions such as this on our blog. You should discuss these types of medical decisions with your doctor. If you would like to make an appointment with a Memorial Sloan Kettering physician, please call our Physician Referral Service at 800-525-2225 or go to http://www.mskcc.org/cancer-care/appointment. Thanks for your comment.

my wife is 64 years old.
under OBACARE would it be best to just have theMRI for her yearly detection.
i would rather pay for one decisive exam than go for multiple pre-exams of lesser specificity

Thank you everyone for the information. Yes I am 42 and I refuse the recommendations by the American Cancer Society and go by the US Preventive Services Task Force. So I will start at 50, given that, fortunately, there is not a history of cancer in my family. I agree Julie, it is a matter of time before the change the guidelines. Although, my Gyn informed me of the risks of not having a mammogram at the age of 40, as if I was "wrong" and irresponsible. Oh well! After all any diagnostic test is easy money for providers, etc. It is sad that they are making money by scarring people.