Study: Transrectal vs transperineal biopsy show similar infection risk

In this video, Jim C. Hu, MD, MPH, shares key findings from the study, “Transperineal Versus Transrectal Magnetic Resonance Imaging–targeted and Systematic Prostate Biopsy to Prevent Infectious Complications: The PREVENT Randomized Trial.” Hu is a professor of urology at Weill Cornell Medicine / NewYork-Presbyterian Hospital in New York, New York.

What were the notable findings from this study?

In a multicenter randomized control trial, which was the first of its kind, I thought it was thought-provoking that there were no infections after a transperineal biopsy in which no antibiotic prophylaxis was given. That was finding number 1. Finding number 2 was that the risk of infection for transrectal biopsy using targeted prophylaxis was only 1.4%. We had a very rigorous definition of infection; that is it had to be a simple UTI, complicated UTI or febrile UTI, and/or sepsis.

The event rate in the transrectal arm being 1.4% is significantly lower than the previous meta-analyses and review articles that I mentioned in which it was estimated to be 5% to 7%. Some of that difference may reflect the fact that there are different biopsy techniques that are being used nationwide. It may reflect the fact that there may be difference in compliance with taking antibiotics prior to the biopsy. I should also note that most transrectal biopsies are not performed with targeted prophylaxis, but rather, they're performed with augmented prophylaxis, where you are choosing 2 agents, for example, and hoping that there's broad coverage of any bacteria, whereas we looked at trying to take empirical lab evidence doing the rectal swab beforehand to identify resistance. That may lead to some of the differences between the lower rates of transrectal infection biopsies in our study vs what has been published previously. Of course, [in] most of those prior studies, the majority of them are all retrospective studies, which also introduces potential recall bias and identifying whether or not something was truly a biopsy-related infection.

The other thing that I'll add is that although impressive that it's 0% in the transperineal arm and 1.4% in the transrectal arm, comparing those 2 rates did not reach statistical significance. In other words, we expected a higher infection rate after transrectal biopsy, however that 1.4% with our current sample size, we weren't powered to detect a significant difference. The p-value was 0.059. So fortunately, the National Cancer Institute has enabled us to continue to enroll approximately 200 more subjects to try to detect whether there's going to be a true difference with larger sample size.

This transcription has been edited for clarity.