Short summary

This paper presents the results of the PRECISION trial, an international, multicenter, randomized trial comparing standard TRUS biopsy with a diagnostic strategy including mpMRI in patients without prior biopsy.
Men with a negative mpMRI were not biopsied and men with a mpMRI suggestive of prostate cancer underwent a targeted biopsy only (without additional standard biopsy cores).
The mpMRI-targeted biopsy strategy resulted in:
- 28% fewer men needing biopsy (when MRI was negative)
- fewer biopsy cores required (median 4 cores)
- m ore men with clinically significant prostate cancer detected (38% as compared to 26% in the standard TRUS biopsy group)
- 13% fewer men diagnosed with clinically insignificant prostate cancer (9% as compared to 22% in the standard TRUS biopsy group)
- More favourable 30-day patient reported complication profile.

Conclusion

In biopsy naïve men with clinical suspicion of prostate cancer, a diagnostic pathway involving pre-biopsy MRI risk stratification and MRI-targeted biopsy is superior to standard 10-12 core TRUS biopsy.

Multicenter study in 25 centers in 11 countries
500 men with clinical suspicion of prostate cancer underwent randomization, 252 in the mpMRI group, 248 in the standard TRUS biopsy group
Mean age 64y, median PSA 6.7, 15% abnormal DRE, 19% family history
Inclusion criteria: elevated PSA but ≤ 20 ng/ml and digital rectal examination not suggestive for extracapsular disease

This is a large, international, multicenter study with a randomized, prospectively accrued patient cohort.
Key strength is the pragmatism of the study, which makes the results reflective for daily practice:
- The performance of the MRI-targeted biopsy was not limited to highly experienced operators but most of the participating investigators had modest experience
- Nonacademic centers outside the original expert group were also allowed to take part
- 1.5T and 3.0T MRI machines were permitted
- Various techniques of MRI-targeted biopsy were permitted, including visual cognitive targeting and software-assisted registration (MRI-US fusion) with either transrectal or transperineal access routes

A proportion of prostate cancers may be missed in the men with negative MRI who do not undergo biopsy and in the men with MRI-targeted biopsy by omission of the additional standard biopsy cores. mpMRI in this trial showed a sensitivity of 88% (95% CI 84-91%), specificity of 45% (95% CI 39-51%), PPV of 65% (60-69%), and NPV 76% (69-82%) for the detection of clinically significant tumors (defined as any Gleason ≥ 3+4 in at least one core). One on four men with normal mpMRI may thus have an occult Gleason pattern 4 cancer, therefore follow up after a negative mpMRI or negative biopsy is recommended.

Currently most guidelines recommend a mpMRI only in patients with persistently rising PSA despite a previous negative random biopsy. This trial supports the use of mpMRI before first biopsy.
In standard clinical practice MRI-based targeted biopsies are usually supplemented with random cores. This trial suggests that additional random cores may be omitted.

Despite the use of PI-RADSv2 to standardize the mpMRI results in this study, a central quality control review showed only moderate agreement (78%) between the site radiologist and the central radiologist. This highlights that there is still room for improvement of standardized mpMRI reporting to attain better consistency.

I would recommend a mpMRI before biopsy in every man with clinical suspicion of prostate cancer based on PSA kinetics, abnormal digital rectal examination and/or family history. The PRECISION trial confirms that mpMRI improves the efficiency of diagnosing clinically significant prostate cancer when it is used as a triage test to avoid unnecessary biopsy when the MRI is negative or to enable a targeted biopsy when the mpMRI shows suspicious areas.
Close follow up after a negative MRI or a negative biopsy is however important because we have to be aware that a substantial number of prostate cancers, including clinically significant tumors, are missed.