*3.2. Modelling*

For CNBSS1 the model breast cancer predictions are shown in Figure 4 for those in the mammography and usual care arms of the trial as well as for unscreened women. Here, annual screening begins at −4 years and Year 0 represents the point when screening ends. In Figure 5, the excess cancers (difference between MP and UC arms) are shown with separate curves for invasive cancers, all cancers and for DCIS only. Figures 6 and 7 show the corresponding predictions for cancer incidence and excess cancers for the older women in CNBSS2.

**Figure 4.** Predicted cases of breast cancer (OncoSim-Breast model) for women who are unscreened and in the Mammography or Usual Care arms of the CNBSS1 trial.

**Figure 5.** Modeled cumulative excess breast cancer detection in CNBSS1 from OncoSim-Breast. Shaded area represents screening period.

**Figure 6.** Predicted incidence of breast cancer (OncoSim-Breast model) for women who are unscreened and in the Mammography or Physical Examination arms of the CNBSS2 trial.

**Figure 7.** Modeled cumulative excess breast cancer detection in CNBSS2 from OncoSim-Breast.
