Prostate MRI versus PSA screening for prostate cancer detection (the MVP Study): a randomised clinical trial

Magnetic Resonance Imaging in Prostate Cancer Screening: A Systematic Review and Meta-Analysis

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.

Prostate Cancers in the Prostate-specific Antigen Interval of 1.8-3 ng/ml: Results from the Göteborg-2 Prostate Cancer Screening Trial

BACKGROUND

Magnetic resonance imaging (MRI) and targeted biopsies reduce overdiagnosis of prostate cancer (PC). It is uncertain how this strategy performs for low prostate-specific antigen (PSA) levels.

OBJECTIVE

To investigate the Prostate Imaging Reporting and Data System (PI-RADS) distribution, frequency, and characteristics of screen-detected PC with PSA of 1.8-<3 ng/ml and 3-<10 ng/ml.

DESIGN, SETTING, AND PARTICIPANTS

In the population-based Göteborg-2 screening study, 17974 men choose to participate by having a PSA test (2015-2020). One-third of the participants (n = 6006) were randomized to arm 3, men with a PSA value of ≥1.8 ng/ml were recommended for MRI. Men with positive MRI (PI-RADS 3-5) had four targeted biopsies from each MRI-visible lesion.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Clinically significant PC was defined as Gleason score ≥3 + 4.

RESULTS AND LIMITATIONS

A total of 6006 men were included. The median age was 55.9 yr (interquartile range [IQR] 52.6-59.6). Of them, 4929 (82%) had PSA of <1.8 ng/ml, 670 (11%) had PSA of 1.8-<3 ng/ml (low-PSA group, median PSA 2.1 ng/ml [IQR 1.9-2.5]), and 377 (6.3%) had PSA of 3-<10 ng/ml (high-PSA group, median PSA 3.9 ng/ml [IQR 3.3-5.0]). PI-RADS scores of 3, 4, and 5 were observed in 7.8%, 15%, and 1.0% of men in the low-PSA group, and in 6.9%, 17%, and 5.3% of men in the high-PSA group, respectively. PC was found in 64 men (41%, 95% confidence interval [CI] 0.33-0.49) with positive MRI findings in the low-PSA group, of whom 33 (21%) had Gleason 6 (insignificant PC) and 31 (20%) had Gleason ≥7 (significant PC). In the high-PSA group, PC was detected in 61 men (56%, 95% CI 0.46-0.66), of whom 26 (24%) had Gleason 6 (insignificant PC) and 35 (32%) had Gleason ≥7 (significant PC). Limitations include results from only a single screening round.

CONCLUSIONS

A non-negligible number of men with PSA 1.8-3 ng/ml have clinically significant PC. Whether a delay in the diagnosis of these tumors until they reached PSA ≥3 ng/ml would impair their chance of cure remains to be evaluated.

PATIENT SUMMARY

We studied screening using prostate-specific antigen (PSA) and magnetic resonance imaging in men with PSA 1.8-3 ng/ml. We found a non-negligible number of potentially harmful prostate cancers in these men.

Evolution of European prostate cancer screening protocols and summary of ongoing trials

Population-based organised repeated screening for prostate cancer has been found to reduce disease-specific mortality, but with substantial overdiagnosis leading to overtreatment. Although only very few countries have implemented a screening programme on a national level, individual prostate-specific antigen (PSA) testing is common. This opportunistic testing may have little favourable impact, while stressing the side-effects. The classic early detection protocols as were state-of-the-art in the 1990s applied a PSA and digital rectal examination threshold for sextant systematic prostate biopsy, with a fixed interval for re-testing, and limited indication for expectant management. In the three decades since these trials were started, different important improvements have become available in the cascade of screening, indication for biopsy, and treatment. The main developed aspects include: better identification of individuals at risk (using early/baseline PSA, family history, and/or genetic profile), individualised re-testing interval, optimised and individualised starting and stopping age, with gradual invitation at a fixed age rather than invitation of a wider range of age groups, risk stratification for biopsy (using PSA density, risk calculator, magnetic resonance imaging, serum and urine biomarkers, or combinations/sequences), targeted biopsy, transperineal biopsy approach, active surveillance for low-risk prostate cancer, and improved staging of disease. All these developments are suggested to decrease the side-effects of screening, while at least maintaining the advantages, but Level 1 evidence is lacking. The knowledge gained and new developments on early detection are being tested in different prospective screening trials throughout Europe. In addition, the European Union-funded PRostate cancer Awareness and Initiative for Screening in the European Union (PRAISE-U) project will compare and evaluate different screening pilots throughout Europe. Implementation and sustainability will also be addressed. Modern screening approaches may reduce the burden of the second most frequent cause of cancer-related death in European males, while minimising side-effects. Also, less efficacious opportunistic early detection may be indirectly reduced.

Cancer Detection Rate and Abnormal Interpretation Rate of Prostate MRI Performed for Clinical Suspicion of Prostate Cancer

PURPOSE

To report cancer detection rate (CDR) and abnormal interpretation rate (AIR) in prostate MRI performed for clinical suspicion of prostate cancer (PCa).

MATERIALS AND METHODS

This retrospective single-institution, three-center study included patients who underwent MRI for clinical suspicion of PCa between 2017 and 2021. Patients with known PCa were excluded. Patient-level Prostate Imaging-Reporting and Data System (PI-RADS) score was extracted from the radiology report. AIR was defined as number of abnormal MRI (PI-RADS score 3-5) / total number of MRIs. CDR was defined as number of clinically significant PCa (csPCa: Gleason score ≥7) detected at abnormal MRI / total number of MRI. AIR, CDR, and CDR adjusted for pathology confirmation rate were calculated for each of three centers and pre-MRI biopsy status (biopsy-naive and previous negative biopsy).

RESULTS

A total of 9,686 examinations (8,643 unique patients) were included. AIR, CDR, and CDR adjusted for pathology confirmation rate were 45.4%, 23.8%, and 27.6% for center I; 47.2%, 20.0%, and 22.8% for center II; and 42.3%, 27.2%, and 30.1% for center III, respectively. Pathology confirmation rate ranged from 81.6% to 88.0% across three centers. AIR and CDR for biopsy-naive patients were 45.5% to 52.6% and 24.2% to 33.5% across three centers, respectively, and those for previous negative biopsy were 27.2% to 39.8% and 11.7% to 14.2% across three centers, respectively.

CONCLUSION

We reported CDR and AIR in prostate MRI for clinical suspicion of PCa. CDR needs to be adjusted for pathology confirmation rate and pre-MRI biopsy status for interfacility comparison.

Key learning on the promise and limitations of MRI in prostate cancer screening

MRI retains its ability to reduce the harm of prostate biopsies by decreasing biopsy rates and the detection of indolent cancers in population-based screening studies aiming to find clinically significant prostate cancers. Limitations of low positive predictive values and high reader variability in diagnostic performance require optimisations in patient selection, imaging protocols, interpretation standards, diagnostic thresholds, and biopsy methods. Improvements in diagnostic accuracy could come about through emerging technologies like risk calculators and polygenic risk scores to select men for MRI. Furthermore, artificial intelligence and workflow optimisations focused on streamlining the diagnostic pathway, quality control, and assurance measures will improve MRI variability. CLINICAL RELEVANCE STATEMENT: MRI significantly reduces harm in prostate cancer screening, lowering unnecessary biopsies and minimizing the overdiagnosis of indolent cancers. MRI maintains the effective detection of high-grade cancers, thus improving the overall benefit-to-harm ratio in population-based screenings with or without using serum prostate-specific antigen (PSA) for patient selection. KEY POINTS: • The use of MRI enables the harm reduction benefits seen in individual early cancer detection to be extended to both risk-stratified and non-stratified prostate cancer screening populations. • MRI limitations include a low positive predictive value and imperfect reader variability, which require standardising interpretations, biopsy methods, and integration into a quality diagnostic pathway. • Current evidence is based on one-time point use of MRI in screening; MRI effectiveness in multiple rounds of screening is not well-documented.

Comparing the Performance of Digital Rectal Examination and Prostate-specific Antigen as a Screening Test for Prostate Cancer: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Although digital rectal examination (DRE) is recommended in combination with prostate-specific antigen (PSA) for detection of prostate cancer (PCa), there are limited data to support its use as a screening/early detection test. Our objective was to assess the diagnostic value of DRE in screening for early detection of PCa.

METHODS

In August 2023, we queried the PubMed, Scopus, and Web of Science databases to identify prospective studies simultaneously investigating the diagnostic performance of DRE and PSA for PCa screening. The primary endpoints were the positive predictive value (PPV) and cancer detection rate (CDR) of DRE. Secondary endpoints included the PPV and CDR of both PSA alone and in combination with DRE. We conducted meta-regression analysis to compare the CDR and PPV of different screening strategies. This meta-analysis is registered on PROSPERO (CRD42023446940).

KEY FINDINGS AND LIMITATIONS

We identified eight studies involving 85 738 participants, of which three were randomized controlled trials and five were prospective diagnostic studies, that reported the PPV and CDR of both DRE and PSA for the same cohort. Our analysis revealed a pooled PPV of 0.21 (95% confidence interval [CI] 0.13-0.33) for DRE, which is similar to the PPV of PSA (0.22, 95% CI 0.15-0.30; p = 0.9), with no benefit from combining DRE and PSA (PPV 0.19, 95% CI 0.13-0.26; p = 0.5). However, the CDR of DRE (0.01, 95% CI: 0.01-0.02) was significantly lower than that of PSA (0.03, 95% CI 0.02-0.03; p < 0.05) and the combination of DRE and PSA (0.03, 95% CI 0.02-0.04; p < 0.05). The screening strategy combining DRE and PSA was not different to that of PSA alone in terms of CDR (p = 0.5) and PPV (p = 0.5).

CONCLUSIONS AND CLINICAL IMPLICATIONS

Our comprehensive review and meta-analysis indicates that both as an independent test and as a supplementary measure to PSA for PCa detection, DRE exhibits a notably low diagnostic value. The collective findings from the included studies suggest that, in the absence of clinical symptoms and signs, DRE could be potentially omitted from PCa screening and early detection strategies.

PATIENT SUMMARY

Our review shows that the screening performance of digital rectal examination for detection of prostate cancer is not particularly impressive, suggesting that it might not be necessary to conduct this examination routinely.

MRI-guided Minimally Invasive Focal Therapies for Prostate Cancer

Two cases involving patients diagnosed with localized prostate cancer and treated with MRI-guided focal therapies are presented. Patient selection procedures, techniques, outcomes, challenges, and future directions of MRI-guided focal therapies, as well as their role in the treatment of low- to intermediate-risk localized prostate cancer, are summarized.