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Despite the long-standing claims, the evidence
that routine mammography
screening allows early detection and treatment of breast cancer,
thereby reducing
mortality, is at best highly questionable. In fact, “the overwhelming
majority of
breast cancers are unaffected by early detection, either because
they are aggressive
or slow growing" (21). There is supportive evidence that the
major variable
predicting survival is "biological determinism— a combination
of the virulence of
the individual tumor plus the host's immune response," rather
than just early
detection (22).
Claims for the benefit of screening mammography
in reducing breast cancer
mortality are based on eight international controlled trials involving
about 500,000
women (23). However, recent meta-analysis of these trials revealed
that only
two, based on 66,000 postmenopausal women, were adequately randomized
to
allow statistically valid conclusions (23). Based on these two
trials, the authors
concluded that "there is no reliable evidence that screening
decreases breast cancer
mortality— not even a tendency towards an effect." Accordingly,
the authors
concluded that there is no longer any justification for screening
mammography;
further evidence for this conclusion will be detailed at the May
6, 2001, annual
meeting of the National Breast Cancer Coalition in Washington, D.
C., and pub-lished
in the July report of the Nordic Cochrane Centre.
Even assuming that high quality screening of
a population of women between
the ages of 50 and 69 would reduce breast cancer mortality by
up to 25 percent,
yielding a reduced relative risk of 0.75, the chances of any
individual woman benefiting are remote (18). For women in this
age group, about
4 per-cent
are likely to develop breast cancer annually, about one in four
of whom,
or 1 percent overall, will die from this disease. Thus, the 0.75
relative risk
applies to this 1 percent, so 99.75 percent of the women screened
are unlikely
to benefit.
THE UNITED STATES VERSUS OTHER NATIONS
No nation other than the United States routinely screens premenopausal
women by
mammography. In this context, it may be noted that the January
1997 National
Institutes of Health Consensus Conference recommended against
premenopausal screening (24), a decision that the NCI, but
not the ACS, accepted
(4). However,
under pressure from Congress and the ACS, the NCI reversed
its decision some
three months later in favor of premenopausal screening.
The U. S. overkill extends to the standard practice
of taking two or more
mammograms per breast annually in postmenopausal women. This
contrasts with
the more restrained European practice of a single view every
two to three years (4).
COSTS OF SCREENING
The dangers and unreliability of mammography screening are
compounded by its
growing and inflationary costs; Medicare and insurance
average costs are $70 and
$125, respectively. Inadequate Medicare reimbursement rates
are now prompting
fewer hospitals and clinics to offer mammograms, and deterring
young doctors
from becoming radiologists. Accordingly, Senators Charles
Schumer (D-NY) and
Tom Harkin (D-IA) are introducing legislation to raise
Medicare reimbursement
to $100 (42).
If all U. S. premenopausal women, about 20 million
according to the Census
Bureau, submitted to annual mammograms, minimal annual
costs would be
$2.5 billion (4). These costs would be increased to $10
billion, about 5 percent
of
the $200 billion 2001 Medicare budget, if all postmenopausal women
were also screened annually, or about 14 percent of the
estimated
Medicare
spending on
prescription drugs. Such costs will further increase some fourfold
if the industry, enthusiastically supported by radiologists,
succeeds
in its efforts
to replace
film
machines, costing about $100,000, with the latest high-tech digital
machines,
approved by the FDA in November 2000, costing about $400,000.
Screening mammography thus poses major threats to the
financially strained
Medicare
system. Inflationary costs apart, there is no evidence of the greater
effectiveness of
digital than film mammography (43), as confirmed by a study reported
at the November 2000 annual meeting of the Radiological
Society of North
America
(44). In fact, digital mammography is likely to result in the increased
diagnosis of ductal carcinoma-in-sutu (DCIS).
The comparative cost of CBE and mammography
in the 1992 Canadian Breast Cancer Screening Study was reported
to be 1 to 3 (45).
However, this ratio
ignores the high costs of capital items including buildings,
equipment, and mobile vans,
let alone the much greater hidden costs of unnecessary biopsies,
specialized staff
training, and programs for quality control and professional accreditation
(46). This
ratio could be even more favorable for CBE and BSE instruction
if both were conducted by trained nurses. The excessive costs of
mammography
screening
should be diverted away from industry to breast cancer prevention
and other
women's health programs.
More…
“Mammography’s Mixed Blessings”
Canadian
Research Study finds Failure of Mammography
REFERENCES
1. Gofman, J. W. Preventing Breast Cancer: The Story of a
Major Proven Preventable
Cause of this Disease. Committee for Nuclear Responsibility,
San Francisco, 1995.
2. Epstein, S. S., Steinman, D., and LeVert,
S. The Breast Cancer Prevention Program,
Ed. 2. Macmillan, New York, 1998.
3. Bertell, R. Breast cancer and mammography.
Mothering, Summer 1992, pp. 49– 52.
4. National Academy of Sciences– National
Research Council, Advisory Committee. Biological Effects
of Ionizing Radiation (BEIR). Washington,
D. C., 1972.
5. Swift, M. Ionizing radiation, breast cancer,
and ataxia-telangiectasia. J. Natl. Cancer
Inst. 86( 21): 1571– 1572, 1994.
6. Bridges, B. A., and Arlett,
C. F. Risk of breast cancer in ataxia-telangiectasia. N.
Engl. J. Med. 326( 20): 1357, 1992.
7. Quigley, D. T. Some neglected points in
the pathology of breast cancer, and treatment
of breast cancer. Radiology, May 1928, pp. 338– 346.
8. Watmough, D. J., and Quan, K. M. X-ray
mammography and breast compression.
Lancet 340: 122, 1992.
9. Martinez, B. Mammography centers shut down
as reimbursement feud rages on.
Wall Street Journal, October 30, 2000, p. A-1.
10. Vogel, V. G. Screening younger women at
risk for breast cancer. J. Natl. Cancer
Inst. Monogr. 16: 55– 60, 1994.
11. Baines, C. J., and Dayan, R. A tangled
web: Factors likely to affect the efficacy of
screening mammography. J. Natl. Cancer Inst. 91( 10): 833– 838,
1999.
12. Laya, M. B. Effect of estrogen replacement
therapy on the specificity
and sensitivity
of screening mammography. J. Natl. Cancer Inst. 88(10): 643– 649,
1996.
13. Spratt, J. S., and Spratt, S. W. Legal
perspectives on mammography
and self-referral.
Cancer 69( 2): 599– 600, 1992.
14. Skrabanek, P. Shadows over screening mammography. Clin.
Radiol.
40: 4– 5,
1989.
15. Davis, D. L., and Love, S. J. Mammography
screening. JAMA 271( 2): 152– 153,
1994.
16. Christiansen, C. L., et al. Predicting
the cumulative risk of false-positive mammograms. J. Natl.
Cancer Inst. 92( 20): 1657– 1666, 2000.
17. Napoli, M. Overdiagnosis and overtreatment:
The hidden pitfalls of cancer screening.
Am. J. Nurs., 2001, in press.
18. Baum, M. Epidemiology versus scaremongering:
The case for humane interpretation
of statistics and breast cancer. Breast J. 6( 5): 331– 334,
2000.
19. Miller, A. B., et al. Canadian National
Breast Screening Study-2:
13-year results of a
randomized trial in women aged 50– 59 years. J. Natl.
Cancer Inst. 92(18):
1490– 1499,
2000.
20. Black, W. C. Overdiagnosis: An underrecognized
cause of confusion and harm in
cancer screening. J. Natl. Cancer Inst. 92(16): 1280–1282,
2000.
21. Napoli, M. What do women want to know.
J. Natl. Cancer Inst. Monogr. 22: 11– 13,
1997.
22. Lerner, B. H. Public health then and now:
Great expectations: Historical perspectives
on genetic breast cancer testing. Am. J. Public Health 89( 6):
938– 944,
1999.
23. Gotzsche, P. C., and Olsen, O. Is screening
for breast cancer with mammography
justifiable? Lancet 355: 129– 134, 2000.
24. National Institutes of Health Consensus
Development Conference Statement. Breast
cancer screening for women ages 40– 49, January 21– 23,
1997. J. Natl. Cancer Inst. Monogr. 22: 7– 18, 1997.
Excerpted from “Dangers
and Unreliability of Mammography: Breast Examination is a Safe,
Effective and Practical Alternative”, by Samuel
S. Epstein, Rosalie Bertell, and Barbara Seaman, International
Journal
of Health Services, Volume 31, Number 3, 2001
CONTACT:
Samuel S. Epstein, M.D.
Chairman, Cancer Prevention Coalition
c/o University of Illinois at Chicago
School of Public Health, M/C 922
2121 W. Taylor Street
Chicago, IL 60612
epstein@uic.edu
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