Illustration of potential use of the new cancer growth model. Age at which screening tumors would have become clinical without screening, by tumor size at the time of screening detection. (a) Screening at 55 years of age. (b) Screening at 65 years of age. (c) Screening at 75 years of age. (d) Screening at 85 years of age. Vertical lines mark the expected time at which 25%, 50% and 75% of the screened women are suspected to have died, based on death rates from Statistics Norway. Panel (c) and (d) are based on the screening test sensitivity and growth estimates from the 60 to 69 years age group.