Active surveillance compared with initial treatment for men with low-risk prostate cancer: a decision analysis

Abstract

Context: In the United States, 192,000 men were diagnosed as having prostate cancer in 2009, the majority with low-risk, clinically localized disease. Treatment of these cancers is associated with substantial morbidity. Active surveillance is an alternative to initial treatment, but long-term outcomes and effect on quality of life have not been well characterized.

Objective: To examine the quality-of-life benefits and risks of active surveillance compared with initial treatment for men with low-risk, clinically localized prostate cancer.

Design and setting: Decision analysis using a simulation model was performed: men were treated at diagnosis with brachytherapy, intensity-modulated radiation therapy (IMRT), or radical prostatectomy or followed up by active surveillance (a strategy of close monitoring of newly diagnosed patients with serial prostate-specific antigen measurements, digital rectal examinations, and biopsies, with treatment at disease progression or patient choice). Probabilities and utilities were derived from previous studies and literature review. In the base case, the relative risk of prostate cancer-specific death for initial treatment vs active surveillance was assumed to be 0.83. Men incurred short- and long-term adverse effects of treatment.

Patients: Hypothetical cohorts of 65-year-old men newly diagnosed as having clinically localized, low-risk prostate cancer (prostate-specific antigen level <10 ng/mL, stage ≤T2a disease, and Gleason score ≤6).

Main outcome measure: Quality-adjusted life expectancy (QALE).

Results: Active surveillance was associated with the greatest QALE (11.07 quality-adjusted life-years [QALYs]), followed by brachytherapy (10.57 QALYs), IMRT (10.51 QALYs), and radical prostatectomy (10.23 QALYs). Active surveillance remained associated with the highest QALE even if the relative risk of prostate cancer-specific death for initial treatment vs active surveillance was as low as 0.6. However, the QALE gains and the optimal strategy were highly dependent on individual preferences for living under active surveillance and for having been treated.

Conclusions: Under a wide range of assumptions, for a 65-year-old man, active surveillance is a reasonable approach to low-risk prostate cancer based on QALE compared with initial treatment. However, individual preferences play a central role in the decision whether to treat or to pursue active surveillance.

Figure 1

Threshold Analysis of Utility for Living Under Active Surveillance and for Having Undergone Treatment Without Adverse Effects Line indicates point at which quality-adjusted life expectancy of surveillance is equal to initial treatment. Shading indicates active surveillance favored over initial treatment.

Figure 2

Threshold Analysis of Utility for Being Under Active Surveillance and Probability of PCSD Under Active Surveillance Line indicates point at which quality-adjusted life expectancy of active surveillance is equal to initial treatment. Shading indicates active surveillance favored over initial treatment. PCSD indicates prostate cancer–specific death.