Active Surveillance Strategies for Low-Grade Prostate Cancer: Comparative Benefits and Cost-effectiveness.

Area of Science:

• Oncology
• Radiology
• Health Economics

Background:

• Active surveillance (AS) is standard for low-risk prostate cancer (PC), but strategies vary regarding MRI use and biopsy triggers.
• Current AS protocols lack standardization in MRI integration, follow-up frequency, and Prostate Imaging Reporting and Data System (PI-RADS) score thresholds for repeat biopsy.

Purpose of the Study:

• To compare the effectiveness and cost-effectiveness of different AS strategies for low-risk PC, specifically evaluating the impact of incorporating MRI.
• To determine the optimal PI-RADS score threshold for triggering biopsies within an MRI-guided AS protocol.

Main Methods:

• A mathematical model simulated cost-effectiveness of AS strategies for low-risk PC.
• Compared watchful waiting, PSA/biopsy without MRI, and PSA/MRI with varying PI-RADS thresholds (≥3 or ≥4) for biopsy.
• Calculated life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) using microsimulation.

Main Results:

• All MRI-inclusive AS strategies extended QALYs and life-years compared to non-MRI approaches.
• Annual MRI with a PI-RADS score of ≥4 for biopsy yielded similar QALYs but 42% fewer biopsies than other MRI strategies.
• MRI-guided AS with PI-RADS ≥4 was the most cost-effective strategy at a $100,000/QALY threshold (ICER: $67,221/QALY).

Conclusions:

• Active surveillance incorporating annual MRI with biopsy decisions guided by PI-RADS scores (≥4) is cost-effective for low-risk PC.
• This approach reduces the number of biopsies, preserves life expectancy, and maintains quality of life.
• MRI-guided AS with a PI-RADS ≥4 threshold is recommended for men younger than 70 with low-risk prostate cancer.