The University of Wisconsin Breast Cancer Epidemiology Simulation Model: An Update

Abstract

The University of Wisconsin Breast Cancer Epidemiology Simulation Model (UWBCS), also referred to as Model W, is a discrete-event microsimulation model that uses a systems engineering approach to replicate breast cancer epidemiology in the US over time. This population-based model simulates the lifetimes of individual women through 4 main model components: breast cancer natural history, detection, treatment, and mortality. A key feature of the UWBCS is that, in addition to specifying a population distribution in tumor growth rates, the model allows for heterogeneity in tumor behavior, with some tumors having limited malignant potential (i.e., would never become fatal in a woman's lifetime if left untreated) and some tumors being very aggressive based on metastatic spread early in their onset. The model is calibrated to Surveillance, Epidemiology, and End Results (SEER) breast cancer incidence and mortality data from 1975 to 2010, and cross-validated against data from the Wisconsin cancer reporting system. The UWBCS model generates detailed outputs including underlying disease states and observed clinical outcomes by age and calendar year, as well as costs, resource usage, and quality of life associated with screening and treatment. The UWBCS has been recently updated to account for differences in breast cancer detection, treatment, and survival by molecular subtypes (defined by ER/HER2 status), to reflect the recent advances in screening and treatment, and to consider a range of breast cancer risk factors, including breast density, race, body-mass-index, and the use of postmenopausal hormone therapy. Therefore, the model can evaluate novel screening strategies, such as risk-based screening, and can assess breast cancer outcomes by breast cancer molecular subtype. In this article, we describe the most up-to-date version of the UWBCS.

Keywords: breast cancer; incidence; screening; simulation.

Figure 1

Simulation Flowchart of the UWBCS

Figure 2

Translation of Tumor size and Nodal Involvement in the Model to SEER staging

Figure 3. Incidence and Mortality over time compared to SEER

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. (a) Age-Adjusted (30–79 years) Insitu Breast Cancer Incidence (b) Age-Adjusted (30–79 years) Localized Breast Cancer Incidence (c) Age-Adjusted (30–79 years) Regional Breast Cancer Incidence (d) Age-Adjusted (30–79 years) Distant Breast Cancer Incidence (e) Overall Age-Adjusted (30–79 years) Breast Cancer Incidence (f) Age-Adjusted (30–79 years) Breast Cancer Mortality

Figure 3. Incidence and Mortality over time compared to SEER

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. (a) Age-Adjusted (30–79 years) Insitu Breast Cancer Incidence (b) Age-Adjusted (30–79 years) Localized Breast Cancer Incidence (c) Age-Adjusted (30–79 years) Regional Breast Cancer Incidence (d) Age-Adjusted (30–79 years) Distant Breast Cancer Incidence (e) Overall Age-Adjusted (30–79 years) Breast Cancer Incidence (f) Age-Adjusted (30–79 years) Breast Cancer Mortality

Figure 3. Incidence and Mortality over time compared to SEER

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. (a) Age-Adjusted (30–79 years) Insitu Breast Cancer Incidence (b) Age-Adjusted (30–79 years) Localized Breast Cancer Incidence (c) Age-Adjusted (30–79 years) Regional Breast Cancer Incidence (d) Age-Adjusted (30–79 years) Distant Breast Cancer Incidence (e) Overall Age-Adjusted (30–79 years) Breast Cancer Incidence (f) Age-Adjusted (30–79 years) Breast Cancer Mortality

Figure 3. Incidence and Mortality over time compared to SEER

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. (a) Age-Adjusted (30–79 years) Insitu Breast Cancer Incidence (b) Age-Adjusted (30–79 years) Localized Breast Cancer Incidence (c) Age-Adjusted (30–79 years) Regional Breast Cancer Incidence (d) Age-Adjusted (30–79 years) Distant Breast Cancer Incidence (e) Overall Age-Adjusted (30–79 years) Breast Cancer Incidence (f) Age-Adjusted (30–79 years) Breast Cancer Mortality

Figure 3. Incidence and Mortality over time compared to SEER

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. (a) Age-Adjusted (30–79 years) Insitu Breast Cancer Incidence (b) Age-Adjusted (30–79 years) Localized Breast Cancer Incidence (c) Age-Adjusted (30–79 years) Regional Breast Cancer Incidence (d) Age-Adjusted (30–79 years) Distant Breast Cancer Incidence (e) Overall Age-Adjusted (30–79 years) Breast Cancer Incidence (f) Age-Adjusted (30–79 years) Breast Cancer Mortality

Figure 3. Incidence and Mortality over time compared to SEER

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. (a) Age-Adjusted (30–79 years) Insitu Breast Cancer Incidence (b) Age-Adjusted (30–79 years) Localized Breast Cancer Incidence (c) Age-Adjusted (30–79 years) Regional Breast Cancer Incidence (d) Age-Adjusted (30–79 years) Distant Breast Cancer Incidence (e) Overall Age-Adjusted (30–79 years) Breast Cancer Incidence (f) Age-Adjusted (30–79 years) Breast Cancer Mortality

Figure 4. Female Breast Cancer Incidence and Mortality over Time in the UWBCS Compared to the Wisconsin Cancer Reporting System (WCRS) and the SEER Program

UWBCS-best represents the outcomes obtained when the best input vector is used (a) Age-Adjusted (all ages) Breast Cancer Incidence (b) Age-Adjusted (all ages) Breast Cancer Mortality

Figure 4. Female Breast Cancer Incidence and Mortality over Time in the UWBCS Compared to the Wisconsin Cancer Reporting System (WCRS) and the SEER Program

UWBCS-best represents the outcomes obtained when the best input vector is used (a) Age-Adjusted (all ages) Breast Cancer Incidence (b) Age-Adjusted (all ages) Breast Cancer Mortality

Figure 5. Survival after Diagnosis Compared to SEER According to Age, Years of Follow-up and Estrogen Receptor (ER) status (1990–1994)

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. Note that some of the error bars are very narrow therefore are not clearly visible in all of the figures. (a) All cancers (40–49 years) (b) All cancers (50–59 years) (c) All cancers (60–69 years) (d) All cancers (70–84 years) (e) ER- cases (50–59 years) (f) ER- cases (50–59 years)

Figure 5. Survival after Diagnosis Compared to SEER According to Age, Years of Follow-up and Estrogen Receptor (ER) status (1990–1994)

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. Note that some of the error bars are very narrow therefore are not clearly visible in all of the figures. (a) All cancers (40–49 years) (b) All cancers (50–59 years) (c) All cancers (60–69 years) (d) All cancers (70–84 years) (e) ER- cases (50–59 years) (f) ER- cases (50–59 years)

Figure 5. Survival after Diagnosis Compared to SEER According to Age, Years of Follow-up and Estrogen Receptor (ER) status (1990–1994)

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. Note that some of the error bars are very narrow therefore are not clearly visible in all of the figures. (a) All cancers (40–49 years) (b) All cancers (50–59 years) (c) All cancers (60–69 years) (d) All cancers (70–84 years) (e) ER- cases (50–59 years) (f) ER- cases (50–59 years)

Figure 5. Survival after Diagnosis Compared to SEER According to Age, Years of Follow-up and Estrogen Receptor (ER) status (1990–1994)

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. Note that some of the error bars are very narrow therefore are not clearly visible in all of the figures. (a) All cancers (40–49 years) (b) All cancers (50–59 years) (c) All cancers (60–69 years) (d) All cancers (70–84 years) (e) ER- cases (50–59 years) (f) ER- cases (50–59 years)

Figure 5. Survival after Diagnosis Compared to SEER According to Age, Years of Follow-up and Estrogen Receptor (ER) status (1990–1994)

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. Note that some of the error bars are very narrow therefore are not clearly visible in all of the figures. (a) All cancers (40–49 years) (b) All cancers (50–59 years) (c) All cancers (60–69 years) (d) All cancers (70–84 years) (e) ER- cases (50–59 years) (f) ER- cases (50–59 years)

Figure 5. Survival after Diagnosis Compared to SEER According to Age, Years of Follow-up and Estrogen Receptor (ER) status (1990–1994)

UWBCS-best represents the outcomes obtained when the best input vector is used and UWBCS-all represents the outcomes obtained when 310 input vectors that have a score of 9 or less are used. The errors bars around UWBCS-all represent 95% “uncertainty intervals,” which are generated using the 2.5th and 97.5th percentiles’ values among 310 vectors at each annual time point for each model output. Note that some of the error bars are very narrow therefore are not clearly visible in all of the figures. (a) All cancers (40–49 years) (b) All cancers (50–59 years) (c) All cancers (60–69 years) (d) All cancers (70–84 years) (e) ER- cases (50–59 years) (f) ER- cases (50–59 years)