Active Surveillance for Intermediate-Risk Prostate Cancer: Systematic Review and Meta-analysis of Current Protocols and Outcomes

Abstract

Introduction: Current guidelines allow active surveillance for intermediate-risk prostate cancer patients but do not provide comprehensive recommendations for selection. We performed a systematic review and meta-analysis of outcomes for active surveillance in intermediate- and low-risk groups.

Methods: We performed a systematic literature search of intermediate-risk localized prostate cancer patients undergoing active surveillance using 3 literature search engines (Medline, Web of Science, and Scopus) over the past 10 years. The primary outcome was the percentage of patients who remain under surveillance. Secondary outcomes included cancer-specific survival, overall survival, and metastasis-free survival. For articles including both low- and intermediate-risk patients undergoing active surveillance, comparisons between the two groups were made.

Results: The proportion of patients who remained on active surveillance was comparable between the low- and intermediate-risk groups after 10 and 15 years' follow-up (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.83-1.14; and OR, 0.86; 95% CI, 0.65-1.13). Cancer-specific survival was worse in the intermediate-risk group after 10 years (OR, 0.47; 95% CI, 0.31-0.69) and 15 years (OR, 0.34; 95% CI, 0.2-0.58). The overall survival rate showed no statistical difference at 5 years' follow-up (OR, 0.84; 95% CI, 0.45-1.57) but was worse in the intermediate-risk group after 10 years (OR, 0.43; 95% CI, 0.35-0.53). Metastases-free survival did not significantly differ after 5 years (OR, 0.55; 95% CI, 0.2-1.53) and was worse in the intermediate-risk group after 10 years (OR, 0.46; 95% CI, 0.28-0.77).

Conclusion: Active surveillance could be offered to patients with intermediate-risk prostate cancer. However, they should be informed of the need for regular monitoring and the possibility of discontinuation as a result of a higher rate of progression. Available data indicate that 5-year survival rates between intermediate- and low-risk patients do not differ; 10-year survival rates are worse. To assess the long-term effectiveness and safety of active surveillance, it is necessary to develop unified algorithms for patient selection and management, and to prospectively conduct studies with long-term surveillance.

Keywords: Activesurveillance; Intermediate-risk; Low-risk; Prostate cancer; Prostatectomy.