Overdiagnosis and Overtreatment of Prostate Cancer

Abstract

Context 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. Evidence acquisition 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. Evidence synthesis 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. Patient summary 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.

When no treatment is the best treatment: Active surveillance strategies for low risk prostate cancers

“…In recent decades, this has resulted in a discrepancy between prostate cancer incidence and mortality rates. The value of radical prostatectomy and radiotherapy, previously the gold standard, is now increasingly questioned in the setting of low risk cancer as concerns regarding overdiagnosis and overtreatment continue to grow [5]. This is further complicated by the fact that the impact of PSA screening on overall cancer mortality remains unclear [6,7].…”

Addressing overtreatment following the diagnosis of localized prostate cancer

“…Various strategies have been employed to estimate overdetection with a range varying between 1.7 and 67% [4]. This wide range is because of different elements: population, screening habits in a given setting as well as research methods to determine over-detection.…”

The Risks and Benefits of Current Treatment Options for Prostate Cancer and Future Possibilities in Advanced Imaging and Targeted Therapy: A Review

“…The levels of overdiagnosis and overtreatment are widely variable, with overdiagnosis estimates ranging from 1.7% to 67% of cases detected by PSA screening [10]. Nonetheless, the unspecific nature of PSA screening inhibits physicians from determining which patients will progress to fatal disease [2,7,11].…”