IMPORTANCE: Prostate magnetic resonance imaging (MRI) is increasingly integrated within the prostate cancer (PCa) early detection pathway.
OBJECTIVE: To systematically evaluate the existing evidence regarding screening pathways incorporating MRI with targeted biopsy and assess their diagnostic value compared with prostate-specific antigen (PSA)-based screening with systematic biopsy strategies.
DATA SOURCES: PubMed/MEDLINE, Embase, Cochrane/Central, Scopus, and Web of Science (through May 2023).
STUDY SELECTION: Randomized clinical trials and prospective cohort studies were eligible if they reported data on the diagnostic utility of prostate MRI in the setting of PCa screening.
DATA EXTRACTION: Number of screened individuals, biopsy indications, biopsies performed, clinically significant PCa (csPCa) defined as International Society of Urological Pathology (ISUP) grade 2 or higher, and insignificant (ISUP1) PCas detected were extracted.
MAIN OUTCOMES AND MEASURES: The primary outcome was csPCa detection rate. Secondary outcomes included clinical insignificant PCa detection rate, biopsy indication rates, and the positive predictive value for the detection of csPCa.
DATA SYNTHESIS: The generalized mixed-effect approach with pooled odds ratios (ORs) and random-effect models was used to compare the MRI-based and PSA-only screening strategies. Separate analyses were performed based on the timing of MRI (primary/sequential after a PSA test) and cutoff (Prostate Imaging Reporting and Data System [PI-RADS] score =3 or =4) for biopsy indication.
RESULTS: Data were synthesized from 80?114 men from 12 studies. Compared with standard PSA-based screening, the MRI pathway (sequential screening, PI-RADS score =3 cutoff for biopsy) was associated with higher odds of csPCa when tests results were positive (OR, 4.15; 95% CI, 2.93-5.88; P = .001), decreased odds of biopsies (OR, 0.28; 95% CI, 0.22-0.36; P = .001), and insignificant cancers detected (OR, 0.34; 95% CI, 0.23-0.49; P = .002) without significant differences in the detection of csPCa (OR, 1.02; 95% CI, 0.75-1.37; P = .86). Implementing a PI-RADS score of 4 or greater threshold for biopsy selection was associated with a further reduction in the odds of detecting insignificant PCa (OR, 0.23; 95% CI, 0.05-0.97; P = .048) and biopsies performed (OR, 0.19; 95% CI, 0.09-0.38; P = .01) without differences in csPCa detection (OR, 0.85; 95% CI, 0.49-1.45; P = .22).
CONCLUSION AND RELEVANCE: The results of this systematic review and meta-analysis suggest that integrating MRI in PCa screening pathways is associated with a reduced number of unnecessary biopsies and overdiagnosis of insignificant PCa while maintaining csPCa detection as compared with PSA-only screening.
| Discipline Area | Score |
|---|---|
| Family Medicine (FM)/General Practice (GP) |  |
| General Internal Medicine-Primary Care(US) | |
| Public Health | |
| Oncology - Genitourinary | |
| Surgery - Urology |  |
This is the first meta-analysis of prostatic MRI for detecting prostate cancer via screening. This is complicated by different MRI techniques, PIRADS, PSA cutoffs, and protocols. Where I work as a primary care physician, most urology colleagues are using MRI as a step after PSA screening. This review supports this with reduced unnecessary biopsies and still retaining diagnosis of clinically significant cancers. The big question is: Does this lead to better morbidity and mortality for populations? We don't have that data yet.
This issue comes up very often in primary care. As it stands now, patients with a PSA above the threshold get referred to urology. If there was an accepted way to further refine who should and who should not be referred, that would be a benefit to patients and our consultants.
The results are not surprising to those of us who specialise in prostate cancer, but perhaps useful to have level 1 evidence to support this. MRI-based screening practices are now routine and standard of care at most high-volume tertiary centres.
This meta-analysis provides high-level evidence supporting a combined PSA/MRI screening strategy vs using serum PSA alone. They detected more clinically significant prostate cancers, but in the end other clinically important endpoints such as prostate cancer-specific mortality, OS , and NNT that are linked to the cost of that NNT are needed to robustly recommend this type of practice for entire public health systems. Also, avoiding surgery and radiation treatment in less clinically significant prostate cancer is a meaningful improvement.
Ultimately, the study showed that PSA testing and MRI as first-line screening strategies show no clinically significant difference in detecting clinically significant disease (number needed to screen: 59 for PSA, 63 for MRI). And there is no economic or wider analysis to explore the opportunity costs, etc to change the approach - this focuses only on testing. However, there is useful info for those reviewing literature in screening pathway development to consider if and when different elements can be used in a multi-step screening model.