Trends in stage-specific incidence of prostate cancer in Norway, 1980-2010: a population-based study.
To estimate changes in the stage distribution of prostate cancer during the time period where opportunistic prostate-specific antigen (PSA) testing was introduced.



Cancer stage, age, and year of diagnosis were obtained for all men aged >50 years diagnosed with prostate cancer in Norway during the period 1980-2010. Three calendar-time periods (1980-1989, 1990-2000, and 2001-2010) and three age groups (50-65, 66-74, and ≥75 years) were defined. Birth cohorts were categorised into four intervals: ≤1915, 1916-1925, 1926-1940 and ≥1941. We used Poisson regressions to conduct both a time period and cohort-based analysis of trends in the incidence of localised, regional, and distant cancer for each combination of age groups and calendar-time periods or birth cohorts, respectively. Additionally, we explored the effect of cohorts on the stage-specific incidence graphically with a Poisson regression using 5-year age groups, and by estimating cumulative incidence rates for each birth cohort.



The annual incidence of localised cancers among men aged 50-65 and 66-74 years rose from 41.4 and 255.2 per 100 000, respectively, before the introduction of PSA testing to 137.9 and 418.7 in 2001-2010 afterwards, corresponding to 3.3 [95% confidence interval (CI) 3.1-3.5] and 1.6 (95% CI 1.6-1.7) fold increases. The incidence of regional cancers increased by a factor seven among men aged <75 years. The incidence of distant cancers in men aged ≥75 years decreased by 29% (95% CI 25-33%). These findings were confirmed in the cohort-based approach.



Opportunistic PSA testing substantially increased the incidence of localised and regional prostate cancers among men aged 50-74 years, which was not fully compensated by the 30% decrease in incidence of distant prostate cancers in older men.
Department of Public Health, Aarhus University, Aarhus, Denmark. mette.holm.moeller@post.au.dk.
Mette H
MH
Møller
Department of Health Management and Health Economics, Oslo University, Oslo, Norway.
Ivar S
IS
Kristiansen
Department of Urology, Surgical Clinic, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Medicine, University of Bergen, Bergen, Norway.
Christian
C
Beisland
Department of Clinical Medicine, University of Bergen, Bergen, Norway.|Department of Radiology, Haukeland University Hospital, Bergen, Norway.
Jarle
J
Rørvik
Department of Public Health, Aarhus University, Aarhus, Denmark.
Henrik
H
Støvring
D000368:Aged; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009664:Norway / Q000453:epidemiology; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000473:pathology*; D013997:Time Factors
D017430:Prostate-Specific Antigen
early detection of cancer; neoplasm staging; opportunistic screening; over diagnosis; prostate cancer; prostate-specific antigen