Download Breast Cancer Screening

Breast Cancer Screening
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Methods
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Mammography
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Digital Breast
Tomosynthesis
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Guidelines
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Preventive Services Task Force (USPSTF)
Guidelines
Screening for women aged 40-49 is not supported
Biennial (versus annual) screening supported for
women aged 50-74.
Kopans, 2010. Radiol Clin N Am. 48: 843-57.
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•
Age 40 was chosen in part because the breast tissue of women
younger than 40 is more susceptible to radiation damage.
•
Age 50 was chosen as a surrogate for menopause.
Deaths from breast cancer in women over age 40 have decreased 28% over the
last 30 years. “This reduction I mortality is probably due to some combination of
the effects of screening mammography and better treatment” (treatment
accounting for as little as 35% of the reduction to as much as 72%; the higher
number is closer to reality.)
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Bleyer and Welch, 2012. NEJM. 367;21: 1998-2005.
“Only 8 of 122
were destined to
progress to
advanced disease.”
9
Bleyer and Welch, 2012. NEJM. 367;21: 1998-2005.
“Despite substantial increases in the number of cases of early-stage breast
cancer detected, screening mammography has only marginally reduced the rate
at which women present with advanced cancer. Although it is not certain which
women have been affected, the imbalance suggests that there is substantial over
diagnosis, accounting for nearly a third of all newly diagnosed breast cancers,
and that screening is having, at best, only a small affect on the rate of death
from breast cancer.”
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Bleyer and Welch, 2012. NEJM. 367;21: 1998-2005.
What are the “harms” in over-diagnosing?
Are we over-diagnosing?
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• Although randomized clinical trials are difficult to do, several studies support the notion
that the decline in death rate from breast cancer since 1990 is predominantly a result of
mammography (not treatment).
• There is no data that screening of high-risk patients has any positive impact on lives
saved.
• “The task force admitted that their approach would result in unnecessary deaths that
could be prevented by screening, but the guidelines would reduce the false-positive
studies, which they decided was more important than saving lives.”
• USPSTF recommendations were determined using computer modeling that focused on
the “number of women needed to be screened to save one life.” (a surrogate for cost?)
• 40-49: 1900
• 50-59: 1300
• 60-74:
300
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Kopans, 2010. Radiol Clin N Am. 48: 843-57.
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Kopans, 2010. Radiol Clin N Am. 48: 843-57.