Figure 2.

Summary of data. (a) Distribution of tumor sizes. (b) Observed number of cases at first screening and in the following interval. Tumor measurements from before the official screening program started come from a database at Haukeland Hospital (1985 to 1994). Screening data include only the first appearance of women reporting no earlier screening history, while interval data are based on all available observations. *Cases per 100,000 person-years.