Prospective Validation Study of a Novel Integrated Pathway Based on Clinical Features, Magnetic Resonance Imaging Biomarkers, and MicroRNAs for Early Detection of Prostate Cancer

BACKGROUND

Prostate cancer (PCa) is the most diagnosed cancer in men, with an increasing need to integrate noninvasive imaging and circulating microRNAs beyond prostate-specific antigen for screening and early detection.

OBJECTIVE

To validate magnetic resonance imaging (MRI) biomarkers and circulating microRNAs as triage tests for patients directed to prostate biopsy, and to test different diagnostic pathways to compare their performance on patients' outcome, in terms of unnecessary biopsy avoidance.

DESIGN, SETTING, AND PARTICIPANTS

A prospective single-center cohort study, enrolling patients with PCa suspicion who underwent MRI, MRI-directed fusion biopsy (MRDB), and circulating microRNAs, was conducted. A network-based analysis was used to identify MRI biomarkers and microRNA drivers of clinically significant PCa.

INTERVENTION

MRI, MRDB, and blood sampling.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The decision curve analysis was exploited to assess the performance of the proposed diagnostic pathways and to quantify their benefit in terms of biopsy avoidance.

RESULTS AND LIMITATIONS

Overall, 261 men were enrolled and underwent MRDB for PCa detection. A total of 178 patients represented the entire cohort: 55 (30.9%) were negative for PCa, 39 (21.9%) had grade group (GG) 1 PCa, and 84 (47.2%) had GG >1 PCa. The proposed integrated pathway, including clinical data, MRI biomarkers, and microRNAs, provided the best net benefit with a biopsy avoidance rate of about 20% at a low disease probability. The main limitation is the monocentric design in a referral center.

CONCLUSIONS

The integrated pathway represents a validated model that sees MRI biomarkers and microRNAs as a prebiopsy triage of patients at a risk for clinically significant PCa. The proposed pathway showed the highest net benefit in terms of unnecessary biopsy avoidance.

PATIENT SUMMARY

The proposed integrated pathway for early detection of prostate cancer (PCa) allows accurate patient allocation to biopsy and patients' stratification into risk group categories, reducing overdiagnosis and overtreatment of clinically insignificant PCa.

MRI for risk stratification of muscle invasion by upper tract urothelial carcinoma: a feasibility study

BACKGROUND

Magnetic resonance imaging (MRI) is recommended in patients with upper tract urothelial carcinoma (UTUC) only when computed tomography (CT) is contraindicated. However, CT does not allow distinguishing ureter wall layers, making impossible to assess muscle invasion, a factor contributing to differentiate high- from low-risk UTUCs, which require different therapeutic approaches. We investigated the feasibility of MRI assessment of UTUC muscle invasion.

METHODS

From June 2022 to March 2023, we prospectively enrolled patients suspected of UTUC, i.e., with positive urinary tract ultrasound and/or ureteroscopy, or positive urinary cytology and/or hematuria but negative cystoscopy and bladder ultrasound at two Italian centers. They underwent CT followed by MRI (≤ 24 h apart), independently reported by two experienced radiologists, blinded from histopathology results. After imaging confirmation, they all underwent nephroureterectomy and histopathology analysis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the receiver operating characteristic curve (AUC) were calculated.

RESULTS

Thirty-nine lesions were detected in 30 patients on both CT and MRI. Muscle-invasive UTUC prevalence was 81% (21/26) among patients with MRI suspicion and 8% (1/13) among those without MRI suspicion (p < 0.001). Considering the assessment of muscle-layer invasion, the more experienced reader achieved 95% sensitivity (95% confidence interval 82-100), 71% specificity (47-88), 81% PPV (63-93), 92% NPV (70-100), 85% accuracy (67-96), and 0.84 AUC (0.70-0.98). Inter-reader agreement was substantial (κ = 0.73).

CONCLUSIONS

MRI showed a promising diagnostic performance for the assessment of UTUC risk of muscle invasion.

RELEVANCE STATEMENT

Resulting feasible both in technical and clinical terms, MRI could be helpful for upper tract urothelial carcinomas pre-operative risk stratification, to allow a personalized patients' management. These results play in favor of promoting preoperative MRI for UTUC, as already proven for bladder cancer.

KEY POINTS

• Muscle invasion is a crucial information for tailored treatments of upper tract urothelial carcinomas. • CT does not distinguish ureter wall layers, making muscle invasion risk assessment not feasible. • MRI was shown to reliably diagnose muscle-layer invasion by upper tract urothelial carcinomas (sensitivity 95%, specificity 71%).

Low cancer yield in PI-RADS 3 upgraded to 4 by dynamic contrast-enhanced MRI: is it time to reconsider scoring categorization?

OBJECTIVES

To evaluate MRI diagnostic performance in detecting clinically significant prostate cancer (csPCa) in peripheral-zone PI-RADS 4 lesions, comparing those with clearly restricted diffusion (DWI-score 4), and those with equivocal diffusion pattern (DWI-score 3) and positive dynamic contrast-enhanced (DCE) MRI.

METHODS

This observational prospective study enrolled 389 men referred to MRI and, if positive (PI-RADS 3 with PSA-density [PSAD] ≥ 0.15 ng/mL/mL, 4 and 5), to MRI-directed biopsy. Lesions with DWI-score 3 and positive DCE were classified as "PI-RADS 3up," instead of PI-RADS 4. Univariable and multivariable analyses were implemented to determine features correlated to csPCa detection.

RESULTS

Prevalence of csPCa was 14.5% and 53.3% in PI-RADS categories 3up and 4, respectively (p < 0.001). MRI showed a sensitivity of 100.0%, specificity 40.9%, PPV 46.5%, NPV 100.0%, and accuracy 60.9% for csPCa detection. Modifying the threshold to consider MRI positive and to indicate biopsy (same as previously described, but PI-RADS 3up only when associated with elevated PSAD), the sensitivity changed to 93.9%, specificity 57.2%, PPV 53.0%, NPV 94.8%, and accuracy 69.7%. Age (p < 0.001), PSAD (p < 0.001), positive DWI (p < 0.001), and PI-RADS score (p = 0.04) resulted in independent predictors of csPCa.

CONCLUSIONS

Most cases of PI-RADS 3up were false-positives, suggesting that upgrading peripheral lesions with DWI-score 3 to PI-RADS 4 because of positive DCE has a detrimental effect on MRI accuracy, decreasing the true prevalence of csPCa in the PI-RADS 4 category. PI-RADS 3up should not be upgraded and directed to biopsy only if associated with increased PSAD.

KEY POINTS

• As per PI-RADS v2.1 recommendations, in case of a peripheral zone lesion with equivocal diffusion-weighted imaging (DWI score 3), but positive dynamic contrast-enhanced (DCE) MRI, the overall PI-RADS score should be upgraded to 4. • The current PI-RADS recommendation of upgrading PI-RADS 3 lesions of the peripheral zone to PI-RADS 4 because of positive DCE decreased clinically significant prostate cancer detection rate in our series. • According to our results, the most accurate threshold for setting indication to prostate biopsy is PI-RADS 3 or PI-RADS 3 with positive DCE both associated with increased PSA density.

Seeing is Believing: State of the Art Imaging of Bladder Cancer

Imaging plays an important role in bladder cancer (BCa) diagnostic work-up. Ultrasound achieves an intermediate sensitivity in detecting urinary tract alterations and is considered a suboptimal imaging technique in diagnosis of BCa. CT urography accurately detects BCa in patients presenting with hematuria Multiparametric MRI achieves a very high rate of BCa detection and helps with accurate staging of patients; however, this modality is still not widely supported by international guidelines. The main applications of MRI are local tumor staging and differentiation between non-muscle-invasive BCa and muscle-invasive BCa. These applications led to development of Vesical Imaging-Reporting and Data System (VI-RADS) scoring system. The VI-RADS scoring system was developed in the setting of post-resection of primary bladder tumor and instillation of intravesical Bacillus Calmette-Guerin therapy; however validation of this system in the post-treatment setting showed promising results. The high risk of BCa recurrence leads to its application in the assessment of response to therapy and for disease surveillance after treatment. MRI is rapidly becoming a leading imaging modality in BCa diagnostic workup, assessment of response to therapies and for longitudinal surveillance, and plays an important role in BCa surgical and radiation therapy treatment planning.