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Download What is the evidence of benefits of PSA screening for prostate cancer?
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What is the evidence of benefits of PSA screening for prostate cancer? Outpatient Medicine Objective • Review the evidence concerning the effect of PSA screening on prostate cancer mortality (Question 1 of the USPTF report on prostate cancer screening) RCTs (and quasi-RCTs) of PSA screening • 1988 Quebec Prospective Randomized Controlled Trial • Norkopping, Sweden study • ERSPC • PLCO Observational studies • Canada • Tyrol, Austria • Olmsted County, Minnesota 1988 Quebec Perspective Randomied Controlled Trial • n = 46K men age 45-80 • Randomized to an “invite for screening” group and a control group. • Treatment group received PSA (ULN = 3.0) and DRE. If either abnormal patients received TRUS and sextent Bx 1988 Quebec • Results at 7 year follow up: Compliance in treatment arm: 23% Compliance in control arm: 93% 1988 Quebec • 11 year follow up: no difference according to intention (invitation) to screen. • Among all screened individuals: 19 prostate cancer deaths / 100k • Among non-screened: 53.4 deaths / 100k 11 year follow up of Quebec study 1988 Quebec • Comments: – No comparison between the groups (invited vs. not invited) – No comparison between screened and unscreened groups – Inappropriate analysis of screened vs. unscreened rather than intention to screen Norrkoping Sweden study • n = 9026 men in Norrkoping, Sweden • Patients in the screened group (SG, n = 1494) were given DREs in 1987 and 1990, as well as DRE + PSA in 1993 and 1996. Norrkoping Results • In SG 5.7% of patients were diagnosed with cancer, about ½ on the initial DRE in 1987. 56.5% of these cancers were localized at time of diagnosis. • In the control group (CG), 3.8% were diagnosed with cancer, 27% of which were organ confined. • NO DIFFERENCE IN SURVIVAL at 15 year follow up. • Since PSA was not used until the 6th year of the study, this is not a 15 year follow up for PSA screening Norrkoping • Comments – No reported data comparing baseline characteristics of screened vs control – No reported data on crossover, compliance, etc. European Randomized Study of Screening for Prostate Cancer (ERSPC) • Powered to detect a 25% reduction in prostate cancer mortality through screening. • In 2006 data was assessed and the trial was continued PLCO Trial • N = 76,705 (38,350 screened) • Screened group given annual PSA and DRE • Compliance 89% • 1.4% of men in the initial screening are were diagnosed, the majority with localized • Mortality results pending. Patients enrolled from 1993 through 2001. Population analyses • In several Western countries including the US and Canada (34.1 to 28.3 deaths per 100k), prostate cancer mortality has decreased substantially since the early 1990s, when PSA screening was introduced. • No one knows why this is – PSA screening – New therapies (anti-androgen therapy) – “attribution bias” References • Lin K, Lipsitz R, Miller T, Janakiraman S. Benefits and harms of prostate-specific antigen screening for prostate cancer: an evidence update for the U.S. Preventive Services Task Force. Ann Intern Med. 2008;149:192-199. • Labrie F, Candas B, et al. Screening decreases prostate cancer death: first analysis of the 1988 Quebec prospective randomized controlled trial. Prostate 1999;38:83-91. • Labrie F, Candas B, et al. Screening decreases prostate cancer mortality: 11-year follow-up of the 1988 Quebec prospectve randomized controlled trial. Prostate 2004;59:311-318. • Shroder. Screening for prostate cancer (PC) – an update on recent findings of the European randomized study of screening for prostate cancer (ERSPC). Urologic Oncology: Seminar and Original investigations 2008;26:533-541. • Andriole GL et al. Prostate cancer screening in the prostate, lung, colorectal and ovarian (PLCO) cancer screening trial: findings from the initial screening round of a randomized trial. Journal of the national cancer institute 2005;97:433-438 • Matteo LD, Matteo RD. Does testing for prostate-specific antigen contribute to declining prostate cancer mortality? Eur J Health Econom 2005;6:298-308. • Oberaigner W et al. Reduction of prostate cancer mortality in Tyrol, Austria, after introduction of prostate-specific antigen testing. Am J Epidemiol. 2006;164:376-384. • Bergstralh EJ et al. Population-based case-control study of PSA and DRE screening on prostate cancer mortality. Urology 2007;70:936-941. • Hoffman RM. Screening for prostate cancer. UpToDate 2008. Accessed at www.uptodate.com on 12/6/2008.
