EAU 2018: Game Changer Prostate Evaluation for Clinically Important Disease: Sampling Using Image-Guidance Or Not? - The PRECISION Study

Copenhagen, Denmark (UroToday.com) The accepted standard of care for men with elevated PSA or a suspicious digital rectal examination (DRE) is to undergo a standard transrectal ultrasonography (TRUS) guided systematic prostate biopsy with 10-12 cores. Unfortunately, the rate of under-detection of high grade prostate cancer (PC), or over-detection of low grade insignificant PC is not meager.[1] Randomized trials (PIVOT and PROTECT) have demonstrated no benefit from treatment in men with clinically insignificant cancers.[2, 3]

Multiparametric MRI (mpMRI) has been used in men with a clinical suspicion of PC. Several studies have been published demonstrating the improving ability of mpMRI to detect and rule out clinically significant PC.[1, 4] It has been suggested that mpMRI could be used as a triage test to avoid biopsy or to be a preliminary step before performing only a targeted prostate biopsy.[1, 5]

In this multicenter, randomized trial (the PRECISION – Prostate Evaluation for Clinically Important Disease: Sampling using image Guidance or Not?) presented at the EAU 2018 and concurrently published at the New England Journal of Medicine, the authors compared MRI targeted biopsy with standard TRUS guided biopsy. This was a prospective trial assessing whether multiparametric MRI, with targeted biopsy in the presence of an abnormal lesion, was non-inferior to standard TRUS–guided biopsy in the detection of clinically significant PC. All participating men had not undergone biopsy of the prostate previously. 

The trial was a non-inferiority trial conducted in 25 centers in 11 countries. All patients had a PSA less than 20 ng/ml, have a DRE that did not suggest extracapsular disease and were medically eligible to undergo a prostate biopsy or MRI. Men who had a positive mpMRI with a PIRADS score of 3,4, or 5 underwent an MRI targeted biopsy with the use of real time ultrasonographic guidance. If the mpMRI was normal, no biopsy was offered. 

Participant-reported questionnaires were used to collect data about intervention-specific side effects immediately and at 30 days after biopsy and after MRI. Health-related quality of life was assessed as well, 24 hours and 30 days after the intervention. The primary outcome was the proportion of men with clinically significant cancer, defined as a single biopsy core indicating disease of Gleason score >=7. Secondary outcomes included the proportion of men with clinically insignificant cancer (Gleason score 6), the proportion of men in the MRI-targeted biopsy group who did not undergo biopsy, and the proportion of men with adverse events after the intervention.

From February 2016 through August 2017, a total of 500 participants underwent randomization with 252 participants being assigned to the MRI-targeted biopsy group and 248 to the standard-biopsy group. Patients in both groups had similar demographic and clinical characteristics. Overall, 71/252 participants (28%) in the MRI-targeted biopsy group had a negative mpMRI precluding them from undergoing a biopsy. Among the participants with a positive result on multiparametric MRI, 29% had a PI-RADS score of 3, 40% had a score of 4, 31% had a score of 5.

Clinically significant cancer was detected in 38% of the MRI-targeted biopsy group, as compared with 26% in the standard-biopsy group (adjusted difference, 12 percentage points; 95% confidence interval [CI], 4 to 20; P = 0.005) (Table 1). The lower boundary of the 95% confidence interval for the difference was greater than −5 percentage points, therefore, mpMRI, with or without targeted biopsy, was deemed to be non-inferior to standard TRUS guided biopsy in the detection of clinically significant PC. Furthermore, the 95% confidence interval demonstrated the superiority of mpMRI, with or without targeted biopsy, over TRUS–guided biopsy. Fewer participants received a diagnosis of clinically insignificant cancer in the mpMRI-targeted biopsy group than in the standard-biopsy group (23 men [9%] vs. 55 [22%]; adjusted difference, −13 percentage points; 95% CI, −19 to −7; P<0.001) (Figure 1). A greater percentage of cores were positive for PC in the MRI-targeted biopsy group (422 of 967 cores [44%]) than in the standard-biopsy group (515 of 2788 [18%]). 

Health-related quality of life at 24 hours and at 30 days after the intervention did not differ significantly between the groups. Similarly, the intervention was associated with similar results regarding immediate postintervention discomfort and pain in both groups. Complications at 30 days were less frequent in the mpMRI targeted biopsy group than in the standard-biopsy group, including hematuria (30% vs. 63%), hematospermia (32% vs. 60%), pain (13% vs. 23%), rectal bleeding (14% vs. 22%), and erectile dysfunction (11% vs. 16%). A total of 2% of the men in both groups had serious adverse events. 

Quality-control review of mpMRI showed that the percentage of cases that were scored with agreement for concordant biopsy decision by the central radiology team and the site radiologist was 78%. Furthermore, the percentage of cases that were scored with agreement on the Gleason score by the central pathologists and the site pathologist was 88%.

The PRECISION trial showed that mpMRI with or without targeted biopsy, resulted in fewer men undergoing biopsy, more clinically significant cancers being identified, less over-detection of clinically insignificant cancer, and fewer biopsy cores being obtained than did standard TRUS–guided biopsy. A little more than 25% of the men avoided a biopsy altogether, and the 30-day participant-reported side-effect profile appeared to be more favorable in the MRI-targeted biopsy group than in the standard-biopsy group. 

The key strengths of this trial included its size and pragmatism, as the authors did not limit the performance of mpMRI-targeted biopsy to highly experienced operators. Furthermore, most of the participating investigators had modest experience with MRI-targeted biopsy, particularly as compared with standard TRUS–guided biopsy. Furthermore, nonacademic centers took part in the trial as well, and either 1.5-T or 3.0-T MRI machines were permitted. Also, various techniques of MRI-targeted biopsy, with visual registration or software-assisted registration with either transrectal or trans-perineal access routes, were allowed. The major limitations of this study included the central quality-control review of mpMRIs showing moderate agreement (78%) between the site and the central radiologist reading, a small proportion of the pathological

test results were upgraded or downgraded on central pathological review, and there were concerns about the men with negative results on multiparametric MRI who did not undergo biopsy. It has been shown that these men have a low risk of clinically significant cancer.[1] Lastly, it is possible that clinically significant cancers may have been missed by the omission of standard biopsy cores in men in the MRI-targeted biopsy group. 

In summary, this important trial demonstrated that in men with a clinical suspicion of PC, risk assessment with mpMRI before biopsy, and MRI-targeted biopsy in the presence of a suspicious lesion, was superior to the diagnostic pathway of standard TRUS–guided biopsy.

Table 1: Cancer detection among the groups:
PRECISION 1


Figure 1: Percentages of Men with Clinically Significant, Clinically Insignificant, and No Cancer
PRECISION 2


Presented by: Veeru Kasivisvanathan, MD, London, Great Britain

References:

1. Ahmed, H.U., et al., Diagnostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study. Lancet, 2017. 389(10071): p. 815-822.
2. Hamdy, F.C., et al., 10-Year Outcomes after Monitoring, Surgery, or Radiotherapy for Localized Prostate Cancer. New England Journal of Medicine, 2016. 375(15): p. 1415-1424.
3. Wilt, T.J., et al., Follow-up of Prostatectomy versus Observation for Early Prostate Cancer. New England Journal of Medicine, 2017. 377(2): p. 132-142.
4. Weinreb, J.C., et al., PI-RADS Prostate Imaging - Reporting and Data System: 2015, Version 2. Eur Urol, 2016. 69(1): p. 16-40.
5. Rhudd, A., et al., The role of the multiparametric MRI in the diagnosis of prostate cancer in biopsy-naive men. Curr Opin Urol, 2017. 27(5): p. 488-494.

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, twitter: @GoldbergHanan at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark

Read More: 

MRI-Targeted or Standard Biopsy for Prostate-Cancer Diagnosis

Major Study Shows Prostate MRI Reveals More Cancers Which Need Treatment and Reduces Over-diagnosis Compared to Standard Biopsy


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