RCT: MRI-Guided Biopsy Reduces Overdiagnosis of Clinically Insignificant Prostate Cancer
26 Sep, 2024 | 12:22h | UTCBackground: Overdiagnosis of clinically insignificant prostate cancer is a significant issue in population-based screening programs, primarily when prostate-specific antigen (PSA) testing is followed by systematic biopsy. Magnetic resonance imaging (MRI)-guided biopsies, which avoid systematic biopsies in men with negative MRI results, have shown potential in reducing unnecessary cancer diagnoses. However, long-term data are needed to confirm the safety and efficacy of this approach.
Objective: To evaluate whether MRI-targeted biopsies, when combined with PSA screening, can reduce the detection of clinically insignificant prostate cancer without compromising the identification of clinically significant or advanced disease.
Methods: This population-based, randomized trial in Sweden (GÖTEBORG-2) enrolled 13,153 men aged 50-60 years who underwent PSA screening. Men with PSA levels ≥3 ng/mL were randomized into two groups: (1) MRI-targeted biopsy only in cases with suspicious lesions, or (2) systematic biopsy in all cases with PSA elevation. Screening occurred every 2, 4, or 8 years depending on PSA levels, with follow-up for up to four years. The primary outcome was the detection of clinically insignificant prostate cancer, and secondary outcomes included clinically significant and advanced or high-risk prostate cancer.
Results: After a median follow-up of 3.9 years, the detection of clinically insignificant prostate cancer was significantly lower in the MRI-targeted biopsy group (2.8%) compared to the systematic biopsy group (4.5%), with a relative risk (RR) of 0.43 (95% CI, 0.32-0.57; P < 0.001). The relative risk of detecting clinically significant cancer was 0.84 (95% CI, 0.66-1.07), indicating no significant difference between the two groups. Advanced or high-risk cancers were detected in 15 men in the MRI group and 23 men in the systematic group (RR, 0.65; 95% CI, 0.34-1.24). Severe adverse events occurred in five patients (three in the systematic biopsy group, two in the MRI-targeted biopsy group).
Conclusions: Omitting biopsies in men with negative MRI results substantially reduced the diagnosis of clinically insignificant prostate cancer without increasing the risk of missing clinically significant or advanced cancers. MRI-targeted biopsy strategies can effectively limit overdiagnosis while maintaining safety in screening programs.
Implications for Practice: MRI-targeted biopsies offer a promising strategy to reduce unnecessary cancer diagnoses and avoid overtreatment in prostate cancer screening. Clinicians should consider integrating MRI into prostate cancer screening algorithms, especially in cases with elevated PSA but no MRI-detected lesions. This approach may also decrease biopsy-related complications and patient anxiety.
Study Strengths and Limitations: Strengths of this trial include its population-based design, large sample size, and thorough follow-up. Limitations include its single-center setting in Sweden, which may limit generalizability to more diverse populations, and a modest participation rate of 50%.
Future Research: Further studies should assess the cost-effectiveness of widespread MRI use in prostate cancer screening and explore its utility in diverse populations. Investigations into novel biomarkers that could further refine patient selection for MRI-targeted biopsy are also warranted.