Figure 2: Tumor size data from 1995, 6 years after the introduction of screening, representing a maximum of four screening events. Compared with the 1987 controls, there is a significantly smaller proportion of tumors> 20 mm in the 60–70 year age group (p < 0.01); this difference is not significant in the 50–60 year age group. In the age group 60–69 years, the tumor size interval 10–20 mm is still increased but not to a significant extent (p=0.08). The control data are shown for the age group 50–59 years to the left and the age group 60–69 years to the right.