February 6, 2002
Mammography Is Dangerous Besides
Ineffective, Warns Samuel S. Epstein, M.D.
The following was released by Samuel S. Epstein, M.D., Chairman of the
Cancer Prevention Coalition and Professor Emeritus of Environmental and
Occupational Medicine, University of Illinois School of Public Health,
Recent confirmation by Danish researchers of longstanding evidence on the
ineffectiveness of screening mammography has been greeted by extensive
nationwide headlines. Entirely missing from this coverage, however, has been
any reference to the well-documented dangers of mammography.
-- Screening mammography poses significant and cumulative risks of breast
cancer for premenopausal women. The routine practice of taking four films of
each breast annually results in approximately 1 rad (radiation absorbed
dose) exposure, about 1,000 times greater than that from a chest x-ray. The
premenopausal breast is highly sensitive to radiation, each 1 rad exposure
increasing breast cancer risk by about 1 percent, with a cumulative 10
percent increased risk for each breast over a decade's screening. These
risks are even greater for younger women subject to "baseline screening."
-- Radiation risks are some four-fold greater for the 1 to 2 percent of
women who are silent carriers of the A-T (ataxia-telangiectasia) gene; by
some estimates this accounts for up to 20 percent of all breast cancers
-- Since 1928, physicians have been warned to handle "cancerous breasts with
care -- for fear of accidentally disseminating cells" and spreading the
cancer. Nevertheless, mammography entails tight and often painful breast
compression, particularly in premenopausal women, which could lead to
distant and lethal spread of malignant cells by rupturing small blood
vessels in or around small undetected breast cancers.
-- Missed cancers are common in premenopausal women owing to their dense
breasts, and also in postmenopausal women on estrogen replacement therapy.
-- Mistakenly diagnosed cancers are common. For women with multiple risk
factors including a strong family history and early menarche -- just those
strongly urged to have annual mammograms -- the cumulative risks of false
positives can reach as high as 100 percent over a decade's screening.
-- The widespread acceptance of screening has lead to overdiagnosis of
pre-invasive cancer (ductal carcinoma in situ), sometimes treated radically
by mastectomy and radiation, and even chemotherapy.
-- As increasing numbers of premenopausal women are responding to
aggressively promoted screening, imaging centers are becoming flooded.
Resultingly, patients referred for diagnostic mammography are now
experiencing potentially dangerous delays, up to several months, before they
can be examined.
-- The dangers and unreliability of screening are compounded by its growing
and inflationary costs. Screening all premenopausal women would cost $2.5
billion annually, about 14 percent of estimated Medicare spending on
prescription drugs. These costs would be increased some fourfold if the
highly profitable industry, enthusiastically supported by radiologists,
succeeds in replacing film machines, costing about $100,000 each, with the
latest high-tech digital machines recently approved by the FDA, costing
about $400,000 each, for which there is no evidence of improved
The ineffectiveness and dangers of mammography pose an agonizing dilemma for
the millions of women anxious for reassurance of early detection of breast
cancer. However, the dilemma is more apparent than real. As proven by a
September 2000 publication, based on a unique large-scale screening study by
University of Toronto epidemiologists, monthly breast self-examination (BSE)
following brief training, coupled with annual clinical breast examination (CBE)
by a trained health care professional, is at least as effective as
mammography in detecting early tumors, and also safe. National networks of
BSE and CBE clinics staffed by trained nurses should be established to
replace screening mammography. Apart from their minimal costs, such clinics
would empower women and free them from increasing dependence on
industrialized medicine and its complicit medical institutions.