 |
Age-specific
incidence of invasive breast cancer in Norway in the period 1971-2001. The
annual increase in the period 1971-1995 was about 0.6%. In 1996 a
mammography screening programme was started in four major counties (Akershus,
Oslo, Rogaland and Hordaland – the AORH-counties) where about 40% of
the population lives. First screening round was in 1996-7; the second
screening round in 1998-9 and the third screening round was in 2000-1.
Compared to the period 1991-5 the breast cancer incidence in the age group
50-69 years was 80% higher during the first (prevalence-) screening.
Compared to the period 1991-5 the breast cancer incidence in the age group
50-69 years in the second and third screening round was increased by 54% and
52% respectively. Note that screening started several years later in the
non-AORH-counties. The increase in breast cancer incidence only occurred
for stage I disease. No decline in the incidence of stage II-IV has been
observed in the Norwegian (or any other) screening programme. |
