Effects of mammography screening under different screening schedules: model estimates of potential benefits and harms.
BACKGROUND
Despite trials of mammography and widespread use, optimal screening policy is controversial.


OBJECTIVE
To evaluate U.S. breast cancer screening strategies.


METHODS
6 models using common data elements.


METHODS
National data on age-specific incidence, competing mortality, mammography characteristics, and treatment effects.


METHODS
A contemporary population cohort.


METHODS
Lifetime.


CONCLUSIONS
Societal.


METHODS
20 screening strategies with varying initiation and cessation ages applied annually or biennially.


METHODS
Number of mammograms, reduction in deaths from breast cancer or life-years gained (vs. no screening), false-positive results, unnecessary biopsies, and overdiagnosis.


RESULTS
The 6 models produced consistent rankings of screening strategies. Screening biennially maintained an average of 81% (range across strategies and models, 67% to 99%) of the benefit of annual screening with almost half the number of false-positive results. Screening biennially from ages 50 to 69 years achieved a median 16.5% (range, 15% to 23%) reduction in breast cancer deaths versus no screening. Initiating biennial screening at age 40 years (vs. 50 years) reduced mortality by an additional 3% (range, 1% to 6%), consumed more resources, and yielded more false-positive results. Biennial screening after age 69 years yielded some additional mortality reduction in all models, but overdiagnosis increased most substantially at older ages.


RESULTS
Varying test sensitivity or treatment patterns did not change conclusions.


CONCLUSIONS
Results do not include morbidity from false-positive results, patient knowledge of earlier diagnosis, or unnecessary treatment.


CONCLUSIONS
Biennial screening achieves most of the benefit of annual screening with less harm. Decisions about the best strategy depend on program and individual objectives and the weight placed on benefits, harms, and resource considerations.


BACKGROUND
National Cancer Institute.
Mandelblatt
Jeanne S
JS
Georgetown University Medical Center and Lombardi Comprehensive Cancer Center, Washington, DC, USA. mandelbj@georgetown.edu
Cronin
Kathleen A
KA
Bailey
Stephanie
S
Berry
Donald A
DA
de Koning
Harry J
HJ
Draisma
Gerrit
G
Huang
Hui
H
Lee
Sandra J
SJ
Munsell
Mark
M
Plevritis
Sylvia K
SK
Ravdin
Peter
P
Schechter
Clyde B
CB
Sigal
Bronislava
B
Stoto
Michael A
MA
Stout
Natasha K
NK
van Ravesteyn
Nicolien T
NT
Venier
John
J
Zelen
Marvin
M
Feuer
Eric J
EJ
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D055088:Early Detection of Cancer; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography / Q000009:adverse effects / Q000191:economics; D008403:Mass Screening / Q000009:adverse effects / Q000191:economics / Q000379:methods*; D008875:Middle Aged; D015233:Models, Statistical; D012680:Sensitivity and Specificity; D013997:Time Factors