Expected population impacts of discontinued prostate-specific antigen screening

Abstract

Background: Prostate-specific antigen (PSA) screening for prostate cancer has high risks of overdiagnosis, particularly among older men, and reports from screening trials indicate that it saves few lives after 11 to 13 years of follow-up. New clinical guidelines recommend against PSA screening for all men or for men aged >70 years, but, to the authors' knowledge, the expected population effects of these guidelines have not been studied to date.

Methods: Two models of prostate cancer natural history and diagnosis were previously developed using reconstructed PSA screening patterns and prostate cancer incidence in the United States. Assuming a survival benefit of PSA screening consistent with the screening trials, the authors used the models to predict incidence and mortality rates for the period from 2013 through 2025 under continued PSA screening and under discontinued PSA screening for all men or for men aged >70 years.

Results: The models predicted that continuation of recent screening rates will overdiagnose 710,000 to 1,120,000 men (range between models) but will avoid 36,000 to 57,000 cancer deaths over the period 2013 through 2025. Discontinued screening for all men eliminated 100% of overdiagnoses but failed to prevent 100% of avoidable cancer deaths. Continued screening for men aged <70 years eliminated 64% to 66% of overdiagnoses but failed to prevent 36% to 39% of avoidable cancer deaths.

Conclusions: Discontinuing PSA screening for all men may generate many avoidable cancer deaths. Continuing PSA screening for men aged <70 years could prevent greater than one-half of these avoidable cancer deaths while dramatically reducing overdiagnoses compared with continued PSA screening for all ages.

Keywords: mass screening; models; prostate-specific antigen; prostatic neoplasms; statistical; surveillance.

Figure 1

Health state transitions in two models of prostate cancer natural history. Screen-detectable cancers in both models progress from local-regional to distant stage. In the UMICH model, cancer can also progress to distant stage before becoming screen-detectable (horizontal dashed gray arrows). Cancer grade (Gleason score 2–7 or 8–10) is fixed in the FHCRC model but lower grade can progress to higher grade in the UMICH model (vertical dashed gray arrows).

Figure 2

Historical prostate cancer incidence and mortality rates, modeled effects of historical PSA screening, and model predictions under three PSA screening policies: (1) continuation of recent PSA screening patterns (Continued), (2) continuation of recent PSA screening patterns restricted to men under 70 years (Age-restricted), and (3) discontinued PSA screening for all men (Discontinued). Rates are agestandardized per 100,000 men ages 50–84 years.