A stochastic simulation model of U.S. breast cancer mortality trends from 1975 to 2000.
BACKGROUND
We present a simulation model that predicts U.S. breast cancer mortality trends from 1975 to 2000 and quantifies the impact of screening mammography and adjuvant therapy on these trends. This model was developed within the Cancer Intervention and Surveillance Network (CISNET) consortium.


METHODS
A Monte Carlo simulation is developed to generate the life history of individual breast cancer patients by using CISNET base case inputs that describe the secular trend in breast cancer risk, dissemination patterns for screening mammography and adjuvant treatment, and death from causes other than breast cancer. The model generates the patient's age, tumor size and stage at detection, mode of detection, age at death, and cause of death (breast cancer versus other) based in part on assumptions on the natural history of breast cancer. Outcomes from multiple birth cohorts are summarized in terms of breast cancer mortality rates by calendar year.


RESULTS
Predicted breast cancer mortality rates follow the general shape of U.S. breast cancer mortality rates from 1975 to 1995 but level off after 1995 as opposed to following an observed decline. Sensitivity analysis revealed that the impact adjuvant treatment may be underestimated given the lack of data on temporal variation in treatment efficacy.


CONCLUSIONS
We developed a simulation model that uses CISNET base case inputs and closely, but not exactly, reproduces U.S. breast cancer mortality rates. Screening mammography and adjuvant therapy are shown to have both contributed to a decline in U.S. breast cancer mortality.
Plevritis
Sylvia K
SK
Department of Radiology, School of Medicine, Stanford University, Stanford CA 94305, USA. sylvia.plevritis@stanford.edu
Sigal
Bronislava M
BM
Salzman
Peter
P
Rosenberg
Jarrett
J
Glynn
Peter
P
D000367:Age Factors; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D003198:Computer Simulation; D005260:Female; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data; D015233:Models, Statistical; D009010:Monte Carlo Method; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013269:Stochastic Processes; D015996:Survival Rate; D014481:United States / Q000453:epidemiology