Overdiagnosis and overtreatment of prostate cancer.
BACKGROUND
Although prostate cancer (PCa) screening reduces the incidence of advanced disease and mortality, trade-offs include overdiagnosis and resultant overtreatment.


OBJECTIVE
To review primary data on PCa overdiagnosis and overtreatment.


METHODS
Electronic searches were conducted in Cochrane Central Register of Controlled Trials, PubMed, and Embase from inception to July 2013 for original articles on PCa overdiagnosis and overtreatment. Supplemental articles were identified through hand searches.


RESULTS
The lead-time and excess-incidence approaches are the main ways used to estimate overdiagnosis in epidemiological studies, with estimates varying widely. The estimated number of PCa cases needed to be diagnosed to save a life has ranged from 48 down to 5 with increasing follow-up. In clinical studies, generally lower rates of overdiagnosis have been reported based on the frequency of low-grade minimal tumors at radical prostatectomy (1.7-46.8%). Autopsy studies have reported PCa in 18.5-38.5%, although not all are low grade or low volume. Factors influencing overdiagnosis include the study population, screening protocol, and background incidence, limiting generalizability between settings. Reported rates of overtreatment vary widely in the literature, although contemporary international studies suggest increasing use of conservative management.


CONCLUSIONS
Epidemiological, clinical, and autopsy studies have been used to examine PCa overdiagnosis, with estimates ranging widely from 1.7% to 67%. Correspondingly, estimates of overtreatment vary widely based on patient features and may be declining internationally. Careful patient selection for screening and reducing overtreatment are important to preserve the benefits and reduce the downstream harms of prostate-specific antigen testing. Because all of these estimates are extremely population and context specific, this must be considered when using these data to inform policy.


RESULTS
Screening reduces spread and death from prostate cancer (PCa) but overdiagnoses some low-risk tumors that may not have caused harm. Because treatment has potential side effects, it is critical that not all patients with PCa receive aggressive treatment.
Department of Urology, New York University, New York, NY, USA. Electronic address: stacyloeb@gmail.com.
Stacy
S
Loeb
Department of Urology, New York University, New York, NY, USA.
Marc A
MA
Bjurlin
Health Sciences Library, New York University, New York, NY, USA.
Joseph
J
Nicholson
Department of Urology, Tampere University Hospital, Tampere, Finland.
Teuvo L
TL
Tammela
Department of Urology, Vanderbilt University, Nashville, TN, USA.
David F
DF
Penson
Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
H Ballentine
HB
Carter
Department of Urology, University of California, San Francisco, San Francisco, CA, USA.
Peter
P
Carroll
Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
Ruth
R
Etzioni
D014408:Biomarkers, Tumor / Q000097:blood*; D055088:Early Detection of Cancer; D005189:False Positive Reactions; D006801:Humans; D015994:Incidence; D008297:Male; D018579:Patient Selection; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy*; D019564:Unnecessary Procedures
D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen
Overdiagnosis; Overtreatment; Prostate cancer; Prostate-specific antigen; Screening