Lead-time in prostate cancer screening (Finland).
OBJECTIVE
Lead-time in prostate cancer screening was estimated using data from the Finnish randomized, population-based trial.


METHODS
Lead-time was defined as the duration of follow-up needed to accrue the same expected number of incident prostate cancer cases in the absence of screening as detected in the initial screening round. Expected numbers were calculated using an age-cohort model.


RESULTS
Based on findings among 10,000 men screened in 1996-1997 with 292 screen-detected cancers, lead-time was estimated as approximately 5-7 years, depending on the reference rates used. This corresponds to a mean duration of the detectable preclinical phase (DPCP) of 10-14 years, given that the cancers were detected on average at the midpoint of the DPCP.


CONCLUSIONS
The findings suggest that a screening interval substantially longer than the 2 years generally used for mammography screening is unlikely to cause a substantial loss of sensitivity. A long screening interval is further justified in order to diminish the extent of overdiagnosis, until mortality effects can be evaluated.
Auvinen
Anssi
A
University of Tampere, School of Public Health, Finland. anssi.auvinen@uta.fi
Määttänen
Liisa
L
Stenman
Ulf-Håkan
UH
Tammela
Teuvo
T
Rannikko
Sakari
S
Aro
Jussi
J
Juusela
Harri
H
Hakama
Matti
M
D000328:Adult; D017677:Age Distribution; D000368:Aged; D015331:Cohort Studies; D016001:Confidence Intervals; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000592:standards*; D008875:Middle Aged; D015995:Prevalence; D011336:Probability; D011471:Prostatic Neoplasms / Q000517:prevention & control*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013997:Time Factors