Many women at low risk for breast cancer annually undergo mammograms. Most are unaware of the extent to which annual irradiation of the breasts of asymptomatic women in search of cancer remains an experiment. This is the first in a series of posts examining the reasons this common practice has been controversial since its inception in the 1970s.

Mammography’s Shadows, I: The Mammogram

Crab ImageIf recent habits persist, this year roughly two-thirds of all women over 40, and even more women over 50, will appear in radiology departments around this country for their annual screening mammograms.  They will have been persuaded by the American Cancer Society (ACS) and the American College of Radiology (ACR), and most likely their own physicians, that having an annual screening mammogram may save them from dying of breast cancer.   The typical radiology waiting room and some physicians’ offices are well supplied with brochures, produced by the ACS and ACR, proclaiming the life-saving and putatively non-invasive merits of the mammography screening.

Most of these women will not be at high risk for breast cancer which, at its peak in 1970, took the lives of 509 out of every 100,000 women, or one-half of one percent, over the age of 45 each year.  (In 1970 over 12,250 women per 100,000 over 45—12%– died of heart disease.)  By 2010 the breast cancer death rate for women over 45 had been reduced by only 10%, with most of that reduction attributable to improvements in breast cancer treatment. [1]   Nonetheless, most states since the early 1990s have promoted insurance coverage for screening mammography.  Thanks to well-publicized anecdotal evidence from numerous individual cases, and effective lobbying by the American Cancer Society, the federal government since 1990 has ensured its availability to low-income women through state grants, as well as to Medicare recipients.  Thus thousands of radiology facilities and breast care centers across the country are heavily vested in screening mammography.

The American Cancer Society, now the eighth largest charity in the U.S., was founded in 1913 as the American Society for the Control of Cancer by a group of surgeons who believed that cancer could be cured by surgical removal.[2]  The organization was renamed the American Cancer Society in 1944.  Four years later it began to promote breast self-examination, and the notion that early detection saves lives.[3]  As innocently self-evident as this appeal was and remains, its implications are more complicated.

By directly linking the early detection of breast cancer to mortality, the slogan invites the prospective patient to believe that the only thing standing between her and a premature death from breast cancer is the annual irradiation of her breasts.[4]  This expectation often seems confirmed by the personal experiences of some women who also happen to be well-known breast cancer “survivors.”  But unless she has been reading the best press reporting such as that provided by Gina Kolata and Michael Moss in the New York Times, a woman at low risk for cancer who appears for a screening mammography may not appreciate the extent to which the wisdom of X-ray screening of the breast for cancer has been challenged from within the medical research community.

Once in the mammography room, each of her breasts will be placed—in horizontal and then vertical positions—on a plastic surface and compressed with a ‘paddle’ to a pressure of 25 pounds until a breast thickness of approximately 4.5 centimeters is achieved.  Then each of her breasts will receive an unknown (by her) amount of ionizing radiation for about 3 seconds for each of four images.

Unlike the dentist’s office, where patients receive a lead-lined throat and chest bib to protect them from X-ray scatter when having their teeth X-rayed, here she will not be provided a protective lead shield during her mammogram. If she has any questions about the radiation dose she will receive, the technician will assure her that the dose is trivial.  Indeed, because the X-ray is referred to as a “mammogram” or “mammography,” she may not question how the images of her breasts are obtained until she stands at the machine, if then.

If the radiologist reviewing the technician’s work is unable to interpret confidently the original four images, she will be summoned back for more images, more painful compression, and more x-radiation.  If there is a seemingly abnormal white spot or ‘suspicious’ area on her images, she will be encouraged to have a biopsy, which will involve more x-rays of greater strength and duration.  An unknown number of the cells in her breast will be damaged not only by the additional radiation, but by the core needle or scalpel used for her biopsy.

Women must assume that the formidable equipment acting on their breasts functions correctly and that radiologists reading their images have the training and experience to do so reliably.  But even after the Food and Drug Administration (FDA) began regulating mammography in 1992, that assumption was not entirely well-founded.[5]  Meanwhile, ACR and ACS brochures typically refer to a ‘small’ radiation risk, following such a reference with the reassurance: “the benefits are worth the risk.” [6]   This, of course, is a judgement that only a fully informed individual can make for herself.

Thus was a generation of American women, beginning in the late 1960s, encouraged to have their breasts irradiated to identify possible patients for further diagnostic and therapeutic treatments for breast cancer, in the belief that early detection would save lives.  Malignant tumors, however, can appear in all parts of the body, such as lungs, lymphatic system, brain, liver, testicles, and prostate glands.

And yet only women’s breasts are subjected to annual screening x-rays, reimbursable by health insurance companies and the federal government.  X-ray screeening for tuberculosis and lung cancer, which afflict both sexes, have been abandoned as not demonstrably saving lives. No other segment of our population, asymptomatic for cancer, is subject to annual screening x-rays of any sort in order to “save lives.”

Meanwhile, men, who also have breasts containing lobules and ducts, also get breast cancer—though the rate of diagnosed breast cancer in men is only about 2% of the rate for women.  While that is a small percent, for the over 5,700 men over 50 diagnosed with breast cancer in 2010, that percent is significant.

For men, the probability of survival 5 years from diagnosis, 1975 to 2006, averaged between 82% and 84%.   For women, the proportion of those diagnosed with breast cancer who could expect to survive  5 years from diagnosis, during  the same period, averaged between 75% and 92%, improving steadily from 1981 (77%) onwards.[7]

Without the presumed benefit of X-ray screening for breast cancer, then, male 5-year survival rates must be attributed to alternate diagnosis methods,[8] improved cancer treatment, and/or spontaneous regression[9]—which can occur in female breast cancer patients as well.   To the extent that screening mammography improves the probability of survival 5 years from diagnosis for women as compared to men, that improvement is on average about 10%.

That percent does indeed represent additional lives saved, and for the survivors and their loved ones, those additional lives are precious.  But it is unlikely that advantage can be attributed to mammography.  That is because of the greater longevity of women aged 50 and over compared to men of the same age group.  For whatever reasons, longevity for white women 50 years and over exceeds that of white men in the same age group by over 10%.[10]

šStatements that mammography “saves lives” are based on comparisons of the aggregate number of women receiving screening mammographies and the aggregate mortality from breast cancer over a given period.  Since mortality from any cause can be influenced by an individual’s overall health, linking a single diagnostic procedure to a single cause of death in a total population of women must treat their combined health status as a constant.

Data on breast cancer deaths among an aggregate population of men over a given period likewise treats variations in individual health status as a constant.  If females are generally healthier (represented by greater longevity) than men, one would expect that male mortality from diseases that occur in both sexes would be correspondingly higher than female mortality from the same disease, e.g. breast cancer. But even though breast cancer in men is not routinely diagnosed with mammography, their mortality from the disease does not exceed their higher mortality in general, compared to women.

Healthy women appearing for screening mammographies on the recommendation of their physicians or such organizations as the American Cancer Society can not ordinarily be expected to know this information.  And yet it is critical to making an “informed choice” whether or not to have their breasts x-rayed in search of breast cancer.

Only after a woman who has appeared for a screening mammography has disrobed from her waist up, albeit lightly covered with a flimsy cotton or paper hospital garment that opens readily in the front, will she be handed a clipboard with two documents.  There may be other similarly disrobed women awaiting their turn in the X-ray room.   Thus exposed and thereby vulnerable to social embarrassment, she will be expected to proceed as instructed by filling out a personal medical history and signing a consent form.

The consent form will contain a legally crafted disclaimer on behalf of the facility that mammography is not a certain diagnostic practice; there might be false positives, or false negatives.  There’s likely to be a brief reference to a small radiation risk, without any specificity, such as the absorbed glandular dose of radiation she is about to receive for each image taken.[11]   The assumption behind the consent form will be that if the woman had any questions or doubts about the procedure, she discussed them with her doctor.  If she does have such questions now, it is too late to retreat without fear of social reproach.

Her physician may have not told her that ionizing radiation (e.g., x-rays) is carcinogenic.  (See my subsequent post, “Mammography’s Shadows, IV: Cells and Rays.”) He  (or she) may not have warned her that, should the radiologist(s) examining her images recommend a biopsy, the process of tissue extraction—whether excision, incision (such as core biopsy) or aspiration—may itself stimulate the spread of any potentially cancerous cells.[12]  It is unlikely that he (or she) mentioned that what we can see with an x-ray cannot tell us anything about the nature of any shadow we may find, and that it is the metastasis of cancerous tissue that kills.[13]

A cancerous growth starts small, and by itself it can remain small and insignificant, or “indolent” during the normal lifespan of any given person. If, however, the membranes that contain a cluster of cancerous cells are broken, the cells are more likely to travel throughout the body, or to metastasize.  As they do, they can overwhelm the immune system’s efforts to prevent them from damaging the body’s vital organs.  That is when cancer may become fatal.

If the screening mammography this woman is about to receive is part of a federally funded medical research trial, she would be legally entitled to this information as a result of “informed consent” policies adopted by the National Institutes of Health in 1966 and all federal agencies by 1974.  In point of fact, all women who undergo screening mammographies are participating as human research subjects in a medical experiment.

Screening mammography is one of the longest, inconclusive and unresolved medical research enterprises of modern times.  Begun in the 1960s and continuing to this day, the claims for screening mammography of women both before and after 50 years of age have never been confirmed to the extent necessary to earn a consensus endorsement from those competent to offer one.

(Published May 7, 2015. The next post will examine the limits of numbers in evaluating medical protocols and devices—such as those involved in breast cancer screening.  It also investigates the original, and highly flawed, study that is often cited as proving that screening mammography saves lives.)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[1] Centers for Disease Control, National Center for Health Statistics, “Health, United States, 2010, With Special Feature on Death and Dying,” Hyattsville, MD (2011); Centers for Disease Control, National Center for Health Statistics, “Health, United States, 2010, With Special Feature on Prescription Drugs,” Hyattsville, MD (2013).

[2] Based on 2013 private support of $889million. (downloaded Oct. 21, 2014).

[3] Maureen Hogan Casamayou, The Politics of Breast Cancer (Georgetown University Press, 2001), Chapter, 3.

[4] Domenighetti G., D’Avanzo B., Egger M., et al. “Women’s Perceptions of the Benefits of Mammography Screening: Population Based Survey in Four Countries.”  International  Journal of Epidemiology, Vol. 32

[5] Michael Moss, “Spotting Breast Cancer: Doctors Are Weak Link,” New York Times (June 27, 2002).

[6] The great volume of books and articles, not to mention Internet articles and blog posts, on the subject of breast cancer, defies summary.  But excellent general treatments can be found in Maureen Hogan Casamayou, The Politics of Breast Cancer (Georgetown University Press, 2001); Barron H. Lerner, M.D., The Breast Cancer Wars: Fear, Hope, and the Pursuit of a Cure in Twentieth-Century America (Oxford University Press, 2001); Robert A. Aronowitz, Unnatural History: Breast Cancer and American Society (Cambridge University Press, 2007); and Handel Reynods, M.D. The Big Squeeze: A Social and Political History of the Controversial Mammogram (Cornell University Press, 2012).  All serious reading about cancer should include Siddartha Mukherjee’s The Emperor of All Maladies: A Biography of Cancer (Scribner, 2010).

[7] Age adjusted SEER incidence and 5-year survival rates, white and black women and men over 50 years, 1975-2006, 2011. National Cancer Institute, Surveillance, Epidemiology, and End Results Program, “Fast Stats.”  http://seer,  Downloaded August 22, 2014.  Longitudinal data for black males is insufficient for generalizations.  Both incidence and 5-year surval (from diagnosis) rates for black women lag those for white women, though the reverse is true for black men.

[8] Physical exam and history, clinical breast exam, ultrasound, magnetic resonance imaging, blood chemistry studies, and biopsy.

[9]  Thomas Jessy, “Immunity over Inability: The Spontaneous Regression of Cancer,” Journal of Natural Science, Biology and Medicine, (Jan-June, 20-11);  Jennifer Durgin, “Study Reveals Surprising Cancer Remission Rate,”  Dartmouth Medicine (Spring, 2009).

[10]  The comparable female longevity “advantage” over men among non-white persons exceeds 14%.Data for 2011. National Vital Statistics Reports,

[11] International Atomic Energy Agency, “Radiation Protection in Diagnostic and Interventional Radiology” [PPT slides],…/RPDIR-L01_Overview_WEB.ppt.  Downloaded December 14, 2014.

[12] Quigley, D.T., “Some Neglected Points in the Pathology of Breast Camcer and Treatment of Breast Cancer,” Radiology (May, 1928), pp. 338-346;J. W. Hendrick, M.D., “Aspiration Biopsy in Breast Cancer,” Journal of the American Medical Association, Vol. 166, No. 8 (February 22, 1958), p. 892; “Results of Treatment of Carcinoma of the Breast—Five to 18 Years,” Annals of Surgery, Vol. 146 (November, 1957), pp. 728-750; Shyamala, K., Girish, H.C., and Sanjay Murgod, “Risk of Tumor Cell Seeding Through Biopsy and Aspiration Cytology,” Journal of International Society of Preventive and Community Dentistry,”  (Jan-Apr.,, 2014, pp. 5-11;  Shalani Menon, Karen A. Beningo, “Cancer Cell Invasion is Enhanced by Applied Mechanical Stimulation,” Plos One (February 17, 2010,; Cornelia J. Baines, “Mammography Screening:  Are Women Really Giving Informed Consent?” Journal of the National Cancer Institute, Vol. 95, No. 20 (October 15, 2003).

[13] Siddhartha Mukherjee, The Emperor of All Maladies: A Biography of Cancer (Simon & Schuster, Inc., 2010).  NOOK edition, location 364; Johannes P. van Natten, Stephen A. Cann and James G. Hall, “Mammography Controversies: Time for Informed Consent?” Journal of the National Cancer Institute , Vol. 89 (August 6, 1997).

Post to Twitter Tweet This Post

No Comments

Leave a Reply

Your email is never shared.Required fields are marked *