Study Tests Office-Based Transperineal Approach to Prostate Biopsies

A multicenter randomized trial compared transperineal prostate biopsy without antibiotic prophylaxis versus transrectal biopsy with targeted prophylaxis, examining infections, prostate cancer detection, pain, and other measures. The findings were presented at the recent Genitourinary Cancers Symposium.

In this exclusive MedPage Today video, investigator Jim C. Hu, MD, of Weill Cornell Medicine/NewYork-Presbyterian Hospital in New York City, shares key findings from the PREVENT trial.

Following is a transcript of his remarks:

I am Jim Hu. I’m the director of the LeFrak Center for Robotic Surgery, as well as the vice chair of clinical research in the Weill Cornell Department of Urology, where I’m also a professor of urology. So it’s a pleasure for me today to discuss our study findings for a randomized control trial, the PREVENT study, where we compared transperineal prostate biopsy without antibiotics to transrectal prostate biopsy with targeted prophylaxis.

And so just as a little bit of background, there’s approximately a million prostate biopsies performed in the United States. There’s probably about two million overall when you take into context Western Europe along with the U.S., and so it’s a very commonly performed procedure. It’s been estimated about one out of three or one out four U.S. men during their lifetimes will have a prostate biopsy. And so of course it’s, I think, very relevant from a broad scale public health perspective.

It’s estimated that about 5% to 7% of men after a transrectal prostate biopsy will experience a serious urinary infection. And so therefore, we set out to see if there’s a newer approach, that is the transperineal approach where the biopsy needle goes through the skin, versus the older approach, the transrectal biopsy where the needle goes through the rectum, whether that newer approach has a lower risk of infection.

I should mention that it’s estimated that the majority of prostate biopsies currently performed in the U.S. are through the transrectal route and approximately 10% maybe through the transperineal route.

And so what we did was we randomized approximately 560 men to transperineal versus transrectal biopsy. This was a 10 center study with other sites such as Johns Hopkins, Northwestern, University of Michigan, Memorial Sloan Kettering, to name a few others. And what we found was that with the transperineal approach, there were zero infections after biopsy, and that’s out of 287 men. And with the transrectal approach with targeted prophylaxis, there were four infections or 1.4% infections, which is again, relatively low compared to the historic estimates of 5% to 7%. And that difference did not reach statistical significance — the P value was 0.059 — but from an antibiotic stewardship perspective, certainly if you don’t have to give antibiotics prior to the biopsy, there are advantages in terms of not potentially increasing antimicrobial resistance.

And in terms of other findings, we found that the transperineal biopsy detection rate for clinically significant prostate cancer was 53%, for transrectal biopsy is 50%, so there was no difference in the effectiveness of the biopsy to diagnose cancer.

And then finally, there was a difference in pain. We found that men answered and rated their pain for the procedure right after the biopsy on a zero to 10 scale, with zero being no pain, 10 being the worst pain in their lives. And the transperineal biopsy was a 3.6 average score, whereas the transrectal biopsy was a 3.0 score. Now, that was statistically significant, but other studies of acute pain have pointed out that a minimally important clinical difference is up to 1.6 on that same scale.

So in summary, we found that the newer approach of transperineal prostate biopsy without antibiotics had zero infections. However, we had underestimated the effect size of the transrectal approach using the historical estimates of 5% to 7%. And as such, our funder or sponsor of the National Cancer Institute is going to let us to continue to enroll patients up to 750 subjects. And so we’ll look forward to presenting the outcomes of that future analysis.

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