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The PROMIS study: A paired-cohort, blinded confirmatory study evaluating the accuracy of multi-parametric MRI and TRUS biopsy in men with an elevated PSA.
Background: Multi-parametric magnetic resonance imaging (MP-MRI) as a triage test might allow men to avoid unnecessary transrectal ultrasound-guided (TRUS) prostate biopsy since many men with an elevated PSA do not have clinically significant prostate cancer. Methods: PROMIS (ClinicalTrials.gov/NCT01292291) is a prospective, paired-cohort confirmatory study representing level Ib evidence. PROMIS tested MP-MRI and TRUS-biopsy with respect to an accurate reference test, 5mm sampling of the prostate with template prostate mapping biopsy (TPM-biopsy). In 11 UK centres, men with an elevated PSA up to 15ng/ml with no prior biopsy underwent MP-MRI followed by both TRUS-biopsy and TPM-biopsy. The conduct and reporting of each test was performed blind to the other test results. Clinically significant cancer was defined as Gleason ≥4+3 and/or maximum cancer core length ≥6mm. Results: Between May 2012 and December 2015, 576 men underwent all 3 tests. The reference TPM-biopsy detected clinically significant cancer in 230 (40%). For MP-MRI, sensitivity was 93% [95%CI 88-96], specificity 41% [36-46], positive predictive value 51% [46-56] and negative predictive value 89% [83-94]. TRUS-biopsy was significantly less sensitive than MP-MRI; 48% [95%CI 42-55] (p=<0.0001). TRUS-biopsy also had significant worse negative predictive value than MP-MRI: 74% [69-78] vs. 89% [83-94] (p<0.0001). We considered two scenarios compared to the current standard of TRUS-biopsy for all. First, using MP-MRI as a triage test would, at a minimum, avoid a primary biopsy in 158 (27%) men with 14 (2%) fewer cases of clinically significant cancer detected. Second, if biopsy targeted to MP-MRI findings achieves the sensitivity of TPM-biopsy, triage with MP-MRI would again avoid primary biopsy in 158 (27%) but detect 17 (3%) more cases of clinically significant cancer than the standard TRUS-biopsy for all pathway. Conclusions: TRUS-biopsy performs poorly both in detecting and ruling-out clinically significant prostate cancer. MP-MRI as a triage test can identify one quarter of men who might safely avoid unnecessary biopsy, without impairing the detection of clinically significant cancer. Clinical trial information: NCT01292291
Abstracts by Hashim Uddin Ahmed:
Does focal high-intensity focused ultrasound have a role in treating localized prostate cancer in the elderly?Meeting: 2015 Genitourinary Cancers Symposium | Abstract No: 133
Multiparametric magnetic resonance imaging in the diagnosis and characterisation of prostate cancer: The PROMIS study.Meeting: 2012 Genitourinary Cancers Symposium | Abstract No: 62Category: Genitourinary Cancer - Prostate Cancer