Background: Active surveillance (AS) and watchful waiting (WW) have been proposed as management strategies for low-risk, localized prostate cancer.
Purpose: To systematically review strategies for observational management of prostate cancer (AS or WW), factors affecting their utilization, and comparative effectiveness of observational management versus immediate treatment with curative intent.
Data sources: MEDLINE and Cochrane databases (from inception to August 2011).
Study selection: Screened abstracts and reviewed full-text publications to identify eligible studies.
Data extraction: One reviewer extracted data, and another verified quantitative data. Two independent reviewers rated study quality and strength of evidence for comparative effectiveness.
Data synthesis: Sixteen independent cohorts defined AS, 42 studies evaluated factors that affect the use of observational strategies, and 2 evidence reports and 22 recent studies reported comparisons of WW versus treatment with curative intent. The most common eligibility criteria for AS were tumor stage (all cohorts), Gleason score (12 cohorts), prostate-specific antigen (PSA) concentration (10 cohorts), and number of biopsy cores positive for cancer (8 cohorts). For monitoring, studies used combinations of periodic PSA testing (all cohorts), digital rectal examination (14 cohorts), and rebiopsy (14 cohorts). Predictors of receiving no active treatment included older age, comorbid conditions, lower Gleason score, tumor stage, PSA concentration, and favorable risk group. No published studies compared AS with immediate treatment with curative intent. Watchful waiting was generally less effective than treatment with curative intent; however, applicability to contemporary patients may be limited.
Limitations: Active surveillance and WW often could not be differentiated in the reviewed studies. Published randomized trials have assessed only WW and did not enroll patients diagnosed by PSA screening.
Conclusion: Evidence is insufficient to assess whether AS is an appropriate option for men with localized prostate cancer. A standard definition of AS that clearly distinguishes it from WW is needed to clarify scientific discourse.
Primary funding source: Agency for Healthcare Research and Quality.