Everyone who wants to go through a prostate biopsy, raise your hand.

What, no takers? Not surprising. Conventional transrectal ultrasound (TRUS) biopsies commonly involve 12-14 needles, and sometimes as many as 24 in a “saturation” biopsy. TRUS biopsies frequently involve pain and risk of infection. There can be side effects like bleeding and even erectile dysfunction.

How to avoid a biopsy

It goes without saying that the obvious way to skip having a biopsy is to not get prostate cancer (PCa), which affects roughly 1 out of every 8 men. “Whew,” you think, “the odds are that I’m one of the 7 men who won’t get it.” The problem is, a million U.S. men annually have biopsies because of high PSA blood test results. And yet, an untold number of them either a) didn’t even have PCa to begin with, or b) they have insignificant PCa. By insignificant, I mean Gleason grade 3+3, or Gleason grade group less than 2.

Did these men really need to go through a TRUS biopsy? Well, yes and no. Yes, men need to know if they have PCa. Yes, they need to know if it’s significant or insignificant, because significant cancer needs to be treated, while insignificant cancer may well qualify for Active Surveillance (AS) as a way to defer treatment. Many men on AS, in fact, end up never getting treatment because insignificant PCa is “associated with scant or no metastatic dissemination.”^[i] In other words, it’s not life-threatening.

However, for well over a third of these men, the answer to the biopsy question is no, they don’t need one. But here’s the catch: If you have a suspicious PSA result and your doctor recommends a prostate needle biopsy, how can you know if you’re one of those fortunate men?

The answer is simple: have an MRI before biopsy. A newly published study presents exciting Phase 3 results of a randomized clinical trial called PRostate Evaluation for Clinically Important Disease: MRI vs. Standard Evaluation Procedures (PRECISE).^[ii] The goal of the study was to determine if the MRI-first strategy coupled with MRI-targeted biopsy if imaging shows Gleason grade group 2 or higher would yield comparable diagnostic results with conventional 12-core TRUS biopsy.

Comparing MRI strategy vs. TRUS bx

For the study, 453 patients with suspicion of PCa were involved. 226 were assigned to the MRI arm, and 227 to the TRUS bx arm. This chart summarizes the findings:

Performance of MRI-guided biopsy for prostate cancer^[iii]

	Systematic TRUS-guided biopsy study arm	MRI-targeted biopsy study arm
Detection of cancers ≥ GG2	67 of 225 patients (29.7%)	79 of 227 patients (34.8%)
Percentage of patients who received biopsies that detected cancers ≥ GG2	33.2%	58.1%
GG1 cancers detected	49 (21.7%)	23 (10.1%)
Mean number of biopsy cores per patient	11.4	6.3
Mean number of positive biopsy cores per patient	4.4	4.4

While the MRI arm had a higher detection rate of Grade group ≥2, it was not statistically significant. This means that the strategy of first having an MRI, and, if indicated, a follow-up targeted biopsy produced positive findings comparable to a randomized, blind 12-needle TRUS biopsy. Technically, this is called “non-inferior” results.

However, here’s where the key differences come in. First, the average number of needles used was 6.3 for the MRI-targeted biopsy vs. 11.4 for the TRUS biopsy. Ouch! Also, the MRI biopsies picked up a far greater percent of significant PCa (58.1%) vs. TRUS biopsy (33.2%). Another way of saying it is, TRUS biopsy missed dangerous PCa more often, while picking up many cancers that would qualify for AS.

Most important in terms of this blog’s topic, MRI reduced the rate of biopsies by nearly 40%! The authors point out, “Eighty-three of 221 men who underwent MRI-TB (37%) had a negative MRI result and avoided biopsy.” Just think about it: their MRI scores showed they did not need biopsy. On the other hand, just over 63% of men in the MRI arm had imagine scores that warranted a biopsy, but their biopsies used far fewer needles than the standard TRUS method.

First author Laurence Klotz, MD, issued this statement: “My colleagues and I are thrilled about these results that show, without a doubt, that imaging and targeted biopsies are the future of prostate cancer diagnosis. We can catch more of the cancers we should be treating, avoid unnecessary treatment at the same time, and improve the quality of life for our patients.”^[iv]

At the Sperling Prostate Center, we’re equally thrilled. The PRECISE results are what we’re all about. We thank Dr. Klotz and his colleagues for their game-changing research.

NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.

References

[i] Garisto JD, Klotz L. Active Surveillance for Prostate Cancer: How to Do It Right. Oncology (Williston Park). 2017 May 15;31(5):333-40, 345.
[ii] Klotz L, Chin J, Black PC, et al. Comparison of Multiparametric Magnetic Resonance Imaging–Targeted Biopsy With Systematic Transrectal Ultrasonography Biopsy for Biopsy-Naive Men at Risk for Prostate Cancer: A Phase 3 Randomized Clinical Trial. JAMA Oncol. Published online February 04, 2021.
[iii] https://www.auntminnie.com/index.aspx?sec=sup&sub=mri&pag=dis&ItemID=131515
[iv] Ibid.