The impact of breast cancer screening on breast cancer registrations in New Zealand.
OBJECTIVE
To investigate the impact of the national breast cancer screening programme, BreastScreen Aotearoa, on breast cancer registrations in New Zealand.


METHODS
Age-specific breast cancer incidence rates for women aged 50-64 years were compared before and after the establishment of BreastScreen Aotearoa. The degree of spread of breast cancers diagnosed at screening was compared with the degree of spread of breast cancers registered before the introduction of population screening in New Zealand.


RESULTS
As expected, there was a marked increase in the age-specific incidence of breast cancer in New Zealand women aged 50-64 years in the first year of screening. There was a shift towards earlier diagnosis in women diagnosed with breast cancer at screening, compared with the diagnosis of breast cancers in women aged 50-64 registered before the introduction of population screening for breast cancer in New Zealand.


CONCLUSIONS
BreastScreen Aotearoa has had the expected impact on breast cancer registration for a screening programme that detects breast cancer early.
Richardson
Ann
A
Department of Public Health and General Practice, Christchurch School of Medicine and Health Sciences, University of Otago, Christchurch, New Zealand. ann.richardson@chmeds.ac.nz
Cox
Brian
B
Brown
Thelma
T
Smale
Paul
P
D017677:Age Distribution; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D015994:Incidence; D008327:Mammography; D008403:Mass Screening; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D009520:New Zealand / Q000453:epidemiology