invasive breast cancer for the age group 50-69 years in the AORH-counties in
Norway. The first column shows the incidence rate in the period 1991-5; i.e.
before women were invited to mammography screening. The second column shows
the incidence rate for those not attending screening in the six first year
of the screening program. The two columns to the right show incidence rates
for those attending the second and third screening round (the incidence rate
in the prevalence screening in 1996-97 is not shown). Ductal carcinoma in
situ (DCIS) has not been included in the figure.
If we add the invasive cancer rate and the DCIS rate, then
the combined incidence rate is 400; women who attend screening have doubled
their risk to be diagnosed with breast cancer.